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Subelement A

General

Section A

SITOR-ARQ is a common mode of data communications in the maritime service. It is a system based on transmission bursts and acknowledgements. What is the baud, and interval between the burst transmissions:

  • Correct Answer
    100 baud, 240 ms interval
  • 50 baud, 1000 �s interval
  • 200 baud, 10 ms interval
  • None of the above

SITOR-ARQ is a common mode of data communications in the maritime service. It is a system based on transmission bursts and acknowledgements. What is the baud, and interval between the burst transmissions:

100 baud, 240 ms interval

For info, see Wavecome site's article on WAVECOM Decoder Online Help 10.2.0 SITOR-ARQ

For data burst calculation, please see CCIR 476-4 / CCIR 625 Mode A (aka SITOR ARQ / AMTOR)

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Weather information is commonly sent by radio in map form by one-way facsimile transmission. Two common parameters which must be set by the receiving station are:

  • Lines-per-inch (LPI), and primary scan direction (PSD)
  • Frequency shift (FS), and phase response pattern (PRP)
  • Black-mode signal (BMS), and frequency jitter tolerance (FJT)
  • Correct Answer
    Index of cooperation (IOC), and revolutions per minute (RPM)

Weather information is commonly sent by radio in map form by one-way facsimile transmission. Two common parameters which must be set by the receiving station are:

Index of cooperation (IOC), and revolutions per minute (RPM)

For radiofax, in radio waves SSB mode, sends by radio weather map pictures and information. To translate the radio waves into pictures, in terms of the number of lines, characters per line between the sending machine and the receiving printer, the numerical data was transmitted, known as the index of cooperation (IOC) must known.

Since the radio fax machines used drum readers, the revolutions per minute (RPM) had to be know.

For more info, please see Wikipedia's article on Radiofax.

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2182 kHz is the international radiotelephone distress frequency. It is also used for a calling channel. The authorized mode of emission is H3E (single-sideband full carrier). A3E (double-sideband full carrier) is only authorized for equipment:

  • Correct Answer
    Solely intended for distress and safety communications
  • Built and sold after the GMDSS implementation date
  • Built and sold before the GMDSS implementation date
  • Solely intended for ship-to-shore public correspondence

2182 kHz is the international radiotelephone distress frequency. It is also used for a calling channel. The authorized mode of emission is H3E (single-sideband full carrier). A3E (double-sideband full carrier) is only authorized for equipment:

Solely intended for distress and safety communications

2182 kHz is Medium Frequency (MF) equivalent of VHF Channel 16. Frequencies in this range typically provide longer range communications.


Code of Federal Regulations, Title 47 Chapter I Subchapter D Part 80 Subpart H Radiotelephony

§ 80.369 Distress, urgency, safety, call and reply frequencies.

47 CFR 80.369(a) In the 1605-3500 kHz band, the frequency 2182 kHz is an international radiotelephony distress, urgency and safety frequency for ship stations, public and private coast stations, and survival craft stations.

It is also used for call and reply by ship stations on a primary basis and by public coast stations on a secondary basis.

The carrier frequency 2191 kHz may be used as a supplementary calling frequency in areas of heavy usage of 2182 kHz .

All stations must use J3E emission when operating on 2182 kHz and 2191 kHz, except that:

47 CFR 80.369(a)(1) H3E emission may be used on 2182 kHz for communications with foreign coast and ship stations; or,

47 CFR 80.369(a)(2) A3E emission may be used on 2182 kHz by portable survival craft stations, or transmitters authorized for use prior to January 1, 1972.

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Ship's power is generated as 3-phase and is ungrounded. On a delta-wound transformer with 120 VAC line-to-line secondary, what is the voltmeter reading from line to ground:

  • Approx 67 volts for a normal balanced system with no faults
  • 0 VAC for a system with that phase faulted to ground
  • 120 VAC when another phase is faulted to ground
  • Correct Answer
    Any of the above

Ship's power is generated as 3-phase and is ungrounded. On a delta-wound transformer with 120 VAC line-to-line secondary, what is the voltmeter reading from line to ground:

Any of the above

  • Approx 67 volts for a normal balanced system with no faults

  • VAC for a system with that phase faulted to ground

  • 120 VAC when another phase is faulted to ground

The 3-phase current has three sine waves. The currents are at different angles, with L1 at +120 degrees, L2 at 0 degrees, and L3 at -120 degrees. This is needed to power large electric motors.

When you measure voltage between L2 and either L1 or L3, you will get 120 VAC (volt alternating current).

If there is a short (fault) or an abnormal sine wave combination, resulting from a sine wave current coming in contact with ground.

When 3 sine waves work symmetrically, in a coordinated sequence, then they are balanced. When not experiencing a short (or ground connection), then volt measurement reflects the difference between volt levels (voltage is an expression of the difference of electron pressure between two connections)

The Delta configuration uses 3 wires for the 3 sine waves, with no 4th wire, which would have been the neutral ground wire.

For info on electric phase power generation and distribution, please see Wikipedia's article on Three-phase electric power

For info on electric short circuit faults, please see Wikipedia's article on Electrical fault

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When passing through areas of static charge, high voltages can accumulate on antennas which are insulated from ground. What protects a connected receiver from damage?

  • Lightning arresters and suppressors
  • Protection diodes on receiver input
  • Capacitive coupling and static dissipative circuits
  • Correct Answer
    Any combination of the above

When passing through areas of static charge, high voltages can accumulate on antennas which are insulated from ground. What protects a connected receiver from damage?

Any combination of the above

  • Lightning arresters and suppressors
  • Protection diodes on receiver input
  • Capacitive coupling and static dissipative circuits

Static charge occurs when there is a difference between negative and positive number of electrons. Electrons flow from negative (toward) to positive (back) connections.

If the flow is interfered with or stopped, then an accumulation of the negative electrons occurs, which is the static electricity (static=> not moving). Thus, electrons can accumulate on antennas, and discharge on the radio receivers.

To prevent sudden electron transfer, like a short spark when you touch something that was rubbed appropriately, items that can absorb the sudden release of electrons protect the radio receiver.

Capacitive coupling is a capacitor that would absorb the release of stored electrons. Diodes control the flow of electrons.

For more info, please see Wikipedia's article on Static Electricity.

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Vertical shipboard antennas for use in the MF band (410-525 kHz) are often fitted with top-hat loading sections. What is the purpose of these structures?

  • Provides aerodynamic compensation for stress during high winds
  • Correct Answer
    Permits a physically short antenna to appear electrically longer
  • Improves the near-field radiated pattern at the expense of the far-field pattern
  • Prevents salt build-up on antennas from shunting RF energy to ground

Vertical shipboard antennas for use in the MF band (410-525 kHz) are often fitted with top-hat loading sections. What is the purpose of these structures?

Permits a physically short antenna to appear electrically longer

The top-hat or T-antenna, is a horizontal wire (akin to the Beverage antenna), suspended between to poles, with a third wire connected at the center of the horizontal wire and connected to the transmitter/receiver, kind of like the dipole antenna.

The receiving waves flow from the horizontal wire to the vertical center wire to the receiver. Transmissions flow from the center wire to the both sides of the horizontal wire.

A vertical wire is connected to the center of the horizontal wires and hangs down close to the ground, connected to the transmitter or receiver.

Combined, the two sections form a ‘T’ shape, hence the name. The transmitter power is applied, or the receiver is connected, between the bottom of the vertical wire and a ground connection.

T-antenna is easily installed ships between masts and vertical center line connected to the trans/receiver. (Even Titanic used this configuration and sended out the distress signal.)

To extend the wavelength of a shorter antenna, it should be mounted as high as possible, as mathematically its height is squared for effective receiving or transmitting.

For more info, please see Wikipedia's article on T-Antenna.

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Modern reserve transmitters are solid-state designs and transmit using only A2 modulation. When measuring transmitter center frequency, what precaution must be taken:

  • Antenna must be grounded to suppress spurious side-lobes
  • Correct Answer
    Modulation must be reduced to zero to eliminate sidebands
  • Voltage to the PA must be kept at half-value
  • Antenna current must be reduced to about 2.5 uA

Modern reserve transmitters are solid-state designs and transmit using only A2 modulation. When measuring transmitter center frequency, what precaution must be taken:

Modulation must be reduced to zero to eliminate sidebands

This modulation can be thought of as the Double Sideband Suppressed Carrier Modulation (DSBSC). Thus, data is sent by modulating the carrier frequency itself. The AM radio can easily pick up these continuous wave propagations.

Because all of the transmitted power (volts x amperes=watts), is concentrated on the carrier frequency, without being dispersed on upper or lower sidebands. Thus, it can carry the signal much farther.

For more info, please see Wikipedia's article on Types of radio emissions and Continuous wave

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Voltage may be expressed by what other expression?

  • Difference of potential
  • IF drop
  • Electromotive force
  • Correct Answer
    All of the above

Voltage may be expressed by what other expression?

All of the above

  • Difference of potential
  • IF drop
  • Electromotive force

Because the difference in the number of electrons between two items, when they are connected there is a waterfall like flow of electrons. The amount of rushing electrons to the low electrons area is called the volt amount.

It can be thought of as the pressure of the flow of electrons due to the difference in potential (amount of electrons).

If you multiply the amount of electrons, or the current (ampers) by the amount of resistance that a medium through which electrons flow (silver, copper, not glass), then you will get the amount of voltage (pressure on the amount of electrons to move).

Voltage as IF drop may refer to the (I) as symbol for current (ampers) and (F) as factor or force. More on Voltage drop on Wikipedia's article Voltage drop

For Voltage info, see Electrical 4 U site article What is Voltage? and Wikipedia's article Voltage

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Amperage may also be known by:

  • Electron flow
  • Electron drift
  • Electric current flow
  • Correct Answer
    All of the above

Amperage may also be known by:

All of the above

  • Electron flow
  • Electron drift
  • Electric current flow

In simplest terms, it is the amount of electrons flowing through the skin of the conduit (gold, silver, iron, copper). Electrons travel on the surface of the conduits. This called the current, and is measured in amperes.

Voltage is what pushes amperes to flow through the conduit which offers some resistance, measured in ohms.

For more info, see Wikipedia's article on Amperes

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Factors which determine the amplitude of the voltage induced in a conductor which is cutting magnetic lines of force:

  • Flux density
  • Velocity that the conductor cuts the magnetic lines of force
  • The angle at which the conductor cuts through the magnetic lines of force
  • Correct Answer
    All of the above

Factors which determine the amplitude of the voltage induced in a conductor which is cutting magnetic lines of force:

All of the above

  • Flux density

  • Velocity that the conductor cuts the magnetic lines of force

  • The angle at which the conductor cuts through the magnetic lines of force

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An electrical potential may be generated by:

  • Varying a magnetic field through a circuit
  • Chemical action
  • Photo-electric action
  • Correct Answer
    All of the above

An electrical potential may be generated by:

All of the above

  • Varying a magnetic field through a circuit
  • Chemical action
  • Photoelectric action

The potential refers to the energy that can be concentrated by various methods.

For more info, please see Wikipedia's article on Electric Potential

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Ohm's law is stated as:

  • E = IR
  • I = E / R
  • R = E / I
  • Correct Answer
    All of the above

Ohm's law is stated as:

All of the above

  • E = IR    Voltage = Current x Resistance
  • I = E / R    Current = Voltage / Resistance
  • R = E / I    Resistance = Voltage / Current

For more info, please see Wikipedia's article on Ohm's law

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The unit of electrical power is:

  • Watt
  • Joule per second
  • Correct Answer
    Both A & B
  • None of the above

The unit of electrical power is:

strong text- Watt

strong text- Joule per second

Electric power is the amount of energy transferred through the conduit, and is measured in watts, which is Joules per second. It can be thought of as the amount of power, which reflects the "work done" per second. The "work done" is also called Joule unit.

For more info, please see Wikipedia's article on Electric power

Also, see article Is one joule per second equivalent to one watt?

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The unit of conductance is:

  • Ohm
  • Correct Answer
    Mho
  • Henry
  • Ampere

The unit of conductance is:

Mho

Conductance is the opposite of resistance. The resistance is measured in Ohms, but conductance is measured in Mho's. The Mho, is the 1/ohm, that is the Mho is the reciprocal of Ohm.

For more info, please see ElectronicNotes' site article Electrical Conductivity: mho, siemens

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The unit of inductance is:

  • Correct Answer
    Henry
  • Joule
  • Coulomb
  • Ohm

The unit of inductance is:

Henry

The inductance is the magnetic field caused by the flow of current, and this field works like resistance to the current flow. The unit of inductance, Henry, refers to Joseph Henry who discovered inductance.

For more info, see Wikipedia's article Inductance Also, see article on Joseph Henry

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The ratio of current through a conductor to the voltage which produces it is:

  • Inductance
  • Correct Answer
    Conductance
  • Resistance
  • None of the above

The ratio of current through a conductor to the voltage which produces it is:

Conductance

It measures how well electricity flows through the skin of the substance such as silver, gold, copper, iron, etc.

For more info, see Electrical4U site, article Conductance: What is it? (Definition, Units & Formula)

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The product of the number of turns and the current in amperes used to describe relative magnitude is:

  • Correct Answer
    Ampere turns
  • Joules per second
  • Push-pull convergence
  • Dissipation collection

The product of the number of turns and the current in amperes used to describe relative magnitude is:

Ampere turns

When you run electric current through wires that were wound in a circular pattern, you get a magnetic field that is strong. In fact, whenever you run current, there is a magnetic field. In the coil, the field is strong because the field goes through the center of the coil.

The more turns in the coil, then there is more magnetic field created.

For more info, see Wikipedia's article Electromagnetic coil
and Tesla Scientific site's Ampere-Turn Calculator

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The property of a conductor or coil which causes a voltage to be developed across its terminals when the number of magnetic lines of force in the circuit or coil is changed is:

  • Capacitance
  • Correct Answer
    Inductance
  • Conductance
  • None of the above

The property of a conductor or coil which causes a voltage to be developed across its terminals when the number of magnetic lines of force in the circuit or coil is changed is:

Inductance

The inductance is the magnetic field caused by the flow of current, and this field works like resistance to the current flow. The unit of inductance, Henry, refers to Joseph Henry who discovered inductance.

For more info, see Wikipedia's article [Inductance][1] Also, see article on [Joseph Henry][2]

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The charge of electricity which passes a given point in one second when a current of one ampere is flowing is:

  • Correct Answer
    Coulomb
  • Joule
  • Watt
  • None of the above

The charge of electricity which passes a given point in one second when a current of one ampere is flowing is:

Coulomb

Coulomb has been adopted as the internationally recognized amount of electric charge, which is the amount of amperes (electrons flowing) per second.

For more info, see Wikipedia's article on Coulomb

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C = capacity in farads. Q = the measure of the quantity of charge of electricity in Coulombs. E = the applied voltage. So Q = CE:

  • Correct Answer
    Determines the quantity of charge in a capacitor
  • Determines the Q of a circuit
  • Both A & B
  • None of the above

C = capacity in farads.
Q = the measure of the quantity of charge of electricity in Coulombs.
E = the applied voltage.
So Q = CE:

Determines the quantity of charge in a capacitor

Coulomb or amount of amperes =
Farads (ability to store electricity) x
Voltage (the amount of difference between two unit's charges or the amount of force pushing of electrons from a unit to another)

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Resistance is:

  • The quantity which determines power loss or dissipation
  • The factor of proportionality between voltage and current
  • Measured in ohms
  • Correct Answer
    All of the above

Resistance is:

All of the above

  • The quantity which determines power loss or dissipation
  • The factor of proportionality between voltage and current
  • Measured in ohms

The amount of resistance (in Ohms) that the electrons (in Amperes) experience when are pushed through a conductor by Voltage pressure.

For more info, see Fluke's site article on What is resistance?
and Wikipedia's article on Electrical resistance and conductance

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The unit of AC impedance in a circuit is:

  • Correct Answer
    Ohm
  • Mho
  • Joule
  • None of the above

The unit of AC impedance in a circuit is:

Ohm

  • The quantity which determines power loss or dissipation
  • The factor of proportionality between voltage and current
  • Measured in ohms

The amount of resistance (in Ohms) that the electrons (in Amperes) experience when are pushed through a conductor by Voltage pressure.

In AC current, the resistance changes the shape of the electrical wave (sinusoidal waveform)

For more details, see Electronic Tutorials' site article AC Resistance and Impedance

For more info, see Fluke's site article on What is resistance?
and Wikipedia's article on Electrical resistance and conductance

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The unit of capacitance is:

  • Farad
  • Microfarad
  • Coulomb
  • Correct Answer
    A & B

The unit of capacitance is:

A & B

  • Farad
  • Microfarad

Ability to store electrons (amperes) in a medium is measured by Farad units. Capacitors are used to store electric charges. Since a unit of Farad has a substantial charge, for smaller charges a microfarad unit is used to measure.

For more info, see Fluke's article on What is capacitance?
and Wikipedia's article on Capacitance

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Decibel is:

  • The unit used to express the ratio between two sound power levels
  • The unit used to express the ratio between two electrical power levels
  • Correct Answer
    Both A & B
  • None of the above

Decibel is:

Both A & B

  • The unit used to express the ratio between two sound power levels

  • The unit used to express the ratio between two electrical power levels

Basically, the amount of push on air, air pressure, is measured in decibels. Decibels increase in logarithmic units, not arithmetical units.

For more info, see Physclips' article on dB: What is a decibel?
and Wikipedia's article on Decibel

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What factors determine the charge stored in a capacitor?

  • Capacitance of the capacitor
  • The applied voltage
  • Correct Answer
    Both A & B
  • None of the above

What factors determine the charge stored in a capacitor?

Both A & B

  • Capacitance of the capacitor
  • The applied voltage

Capacitors store electrical charges when pressure is placed on electrons to move (applied voltage) to a capacitor.

The ability to store electrons (amperes) in a medium is measured by Farad units. Capacitors are used to store electric charges. Since a unit of Farad has a substantial charge, for smaller charges a microfarad unit is used to measure.

For more info, see Fluke's article on What is capacitance?
and Wikipedia's article on Capacitance

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Ohm's law for AC circuits when I = amperes, E = volts, Z = impedance in volts is:

  • I = E/Z
  • E = IZ
  • Z= Z/I
  • Correct Answer
    All of the above

Ohm's law for AC circuits when
I = amperes,
E = volts,
Z = impedance in volts is:

(D). All of the above

  • I = E/Z   Amperes = volts / ohms
  • E = IZ   Volts = amperes x ohms
  • Z= E/I   Ohms = volts / current

It appears that the Z=Z/I in answer C maybe simply misprint

I = E / R  Current =   Voltage / Resistance
E = IR   Voltage =  Current x Resistance
R = E / I  Resistance = Voltage / Current

For more info, please see Wikipedia's article on Ohm's law

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The formula for determining the power in a DC circuit when the voltage and resistance are known is:

  • Correct Answer
    P = ( E squared) R
  • P = EI
  • P = ( I squared) R
  • PF = W/IE

The formula for determining the power in a DC circuit when the voltage and resistance are known is:

(A). P = ( E squared) R

Power is measured in watts, or in units of Joule per second.

Watts = Amperes x Voltage or
Watts = (Amperes)2 x Resistance or
Watts = (Voltage)2 / Resistance

For more info, see Electrical Technology site's article on Power Formulas in DC and AC Single-Phase & Three-Phase Circuits

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The formula for finding power in a DC circuit when current and resistance are known:

  • P = IE
  • Correct Answer
    P = ( I Squared) R
  • PF = W/IE
  • None of the above

The formula for finding power in a DC circuit when current and resistance are known:

(B). P = ( I Squared) R

Power is measured in watts, or in units of Joule per second.

Watts = Amperes x Voltage or
Watts = (Amperes)2 x Resistance or
Watts = (Voltage)2 / Resistance

For more info, see Electrical Technology site's article on Power Formulas in DC and AC Single-Phase & Three-Phase Circuits

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The formula for finding power in a DC circuit when current and voltage are known:

  • Correct Answer
    P = EI
  • P = ( I squared ) R
  • PF = W/IE
  • None of the above

The formula for finding power in a DC circuit when current and voltage are known:

(A). P = EI

Power is measured in watts, or in units of Joule per second.

Watts = Amperes x Voltage or
Watts = (Amperes)2 x Resistance or
Watts = (Voltage)2 / Resistance

For more info, see Electrical Technology site's article on Power Formulas in DC and AC Single-Phase & Three-Phase Circuits

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The prefix " kilo " means:

  • Correct Answer
    To multiply by 1000 whatever quantity follows
  • To divide by 1000 whatever quantity follows
  • To add 1000 to whatever quantity follows
  • None of the above

The prefix " kilo " means:

(A). To multiply by 1000 whatever quantity follows

Kilo means a thousand, or 10 to 3rd power, or 10x10x10

For more info, see Wikipedia's article on Kilo-

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The prefix " micro " means:

  • Correct Answer
    Divide by 1,000,000 whatever quantity follows
  • Multiply by 1,000,000 whatever quantity follows
  • Add 1,000,000 to whatever quantity follows
  • Divide by 1,000 whatever quantity follows

The prefix " micro " means:

(A). Divide by 1,000,000 whatever quantity follows

Micro is a one millionth of a unit, or 10 to minus 6.
To get 10 to minus 6, move the decimal 6 positions from unit 1, or so 0.000 001

10 to minus 1 is 0.1 or deci-
10 to minus 2 is 0.01 or centi-
10 to minus 3 is 0.001 or mili-

For more info, please see Wikipedia's article on Micro-

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The factor by which the product of volts and amperes must be multiplied to obtain true power is:

  • Correct Answer
    Power factor
  • Apparent power
  • Phase angle
  • None of the above

The factor by which the product of volts and amperes must be multiplied to obtain true power is:

(A). Power factor

Power is measured in watts, or in units of Joule per second.

Watts = Amperes x Voltage or
Watts = (Amperes)2 x Resistance or
Watts = (Voltage)2 / Resistance

For more info, see Electrical Technology site's article on Power Formulas in DC and AC Single-Phase & Three-Phase Circuits

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The prefix " meg " means:

  • Correct Answer
    Multiply by 1,000,000 whatever quantity follows
  • Multiply by 100,000 whatever quantity follows
  • Multiply by 1,000 whatever quantity follows
  • Divide by 1,000,000 whatever quantity follows

The prefix " meg " means:

(A). Multiply by 1,000,000 whatever quantity follows

Mega is the unit multiplied by 10 to 6th power. (10)6, which is 10x10x10x10x10x10 = 1,000, 000

For more info, see Wikipedia's article on Mega-

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Factors which influence the resistance of a conductor:

  • Cross-sectional area
  • Length
  • Temperature
  • Correct Answer
    All of the above

Factors which influence the resistance of a conductor:

(D). All of the above

  • Cross-sectional area
  • Length
  • Temperature

The resistance of a conductor is affected by:

  • the amount of cross-section area in inverse proportion
  • the length of a conductor in direct proportion
  • most conductors, not all, increase resistance as the temperature goes up
  • type of conductor material.

For more information, see Engineering Educators site article on Factors Affecting Resistance

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Halving the cross-sectional area of a conductor will:

  • Correct Answer
    Double the resistance
  • Half the resistance
  • Not affect the resistance
  • None of the above

Halving the cross-sectional area of a conductor will:

(A). Double the resistance

The resistance of a conductor is affected by:

  • the amount of cross-section area in inverse proportion
  • the length of a conductor in direct proportion
  • most conductors, not all, increase resistance as the temperature goes up
  • type of conductor material.

For more information, see Engineering Educators site article on Factors Affecting Resistance

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Name four conducting materials in order of their conductivity.

  • Gold, silver, copper, platinum
  • Correct Answer
    Silver, gold, zinc, platinum
  • Silver, copper, zinc, aluminum
  • Aluminum, zinc, copper, platinum

Name four conducting materials in order of their conductivity.

(B). Silver, gold, zinc, platinum

For more information, see Engineering Educators site article on Factors Affecting Resistance the "Figure 41. Resistivity table," for measurements of resistivity.

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Good insulators at radio frequencies are:

  • Pyrex, mica
  • Isolantite, steatite, polyethylene
  • Rubber, porcelain
  • Correct Answer
    A & B

Good insulators at radio frequencies are

(D). A & B

  • Pyrex, mica
  • Isolantite, steatite, polyethylene

What makes a good insulator is not just lack of conductivity, but also the effect of sunlight, especially ultraviolet waves (being highly energetic) they degrade the insulating material.

Well illustrated info on ThoughtCo article 10 Examples of Electrical Conductors and Insulators Things That Don't Conduct Electricity and Things That Do

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A resistance across which a constant voltage is applied is doubled. What power dissipation will result?

  • Correct Answer
    One half
  • One fourth
  • Doubled
  • None of the above

A resistance across which a constant voltage is applied is doubled. What power dissipation will result?

(A). One half

The resistance of a conductor is affected by:

  • the amount of cross-section area in inverse proportion
    So, if you double the resistance, the loss of energy will be the reciprocal, or 1 over double (1/2), or one-half.
  • the length of a conductor in direct proportion
  • most conductors, not all, increase resistance as the temperature goes up
  • type of conductor material.

For more information, see Engineering Educators site article on Factors Affecting Resistance

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The needle of a magnetic compass when placed within a coil carrying an electric current:

  • Will tend to become parallel with the axis of the coil
  • Will point to the north pole end of the coil
  • Will point to the south pole end of the coil
  • Correct Answer
    A & B

The needle of a magnetic compass when placed within a coil carrying an electric current:

(D). A & B

  • Will tend to become parallel with the axis of the coil
  • Will point to the north pole end of the coil

For more details, please see Siyavula Technology-Powered Learning site, article on 10.2 Magnetic field associated with a current

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Electrical resistance is measured with:

  • Correct Answer
    An ohmmeter
  • A wattmeter
  • An Ammeter
  • A voltmeter

Electrical resistance is measured with:

(A). An ohmmeter

The meter measures how much a substance prevents the flow of electrons (current) through its surface skin, known as the electrical resistance, and expressed in ohm units.

For more info, see Elprocus site, for article on What is an Ohmmeter? Circuit Diagram, Types and Applications

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The sum of all voltage drops around a simple DC circuit, including the source, is:

  • Correct Answer
    Zero
  • Insignificant
  • Infinite
  • None of the above

The sum of all voltage drops around a simple DC circuit, including the source, is:

(A). Zero

That is just the definition of changes in voltage in a simple DC circuit. This called the Kirchhoffs' Voltage Law, or the Law of Conservation of Energy.

The law declares that:

"'in any closed loop network, the total voltage around the loop is equal to the sum of all the voltage drops within the same loop.'”

This means that if you sum all the volts in the components, the sum will be zero.

For more info, see Electronics Tutorials site, article on Kirchhoffs Circuit Law

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If a resistance to which a constant voltage is applied is halved, what power dissipation will result?

  • Correct Answer
    Doubled
  • Halved
  • Tripled
  • Same

If a resistance to which a constant voltage is applied is halved, what power dissipation will result?

(A). Doubled

The resistance of a conductor is affected by:

  • the amount of cross-section area in inverse proportion
    So, if you half the resistance, the loss of energy will be the reciprocal, or 1x2 over 1 (2/1), or double.
  • the length of a conductor in direct proportion
  • most conductors, not all, increase resistance as the temperature goes up
  • type of conductor material.

For more information, see Engineering Educators site article on Factors Affecting Resistance

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The diameter of a conductor six inches long is doubled, what will be the effect on the resistance?

  • One-fourth the original value
  • One-half the original value
  • The resistance varies inversely with the cross-sectional area of the conductor
  • Correct Answer
    A & C

The diameter of a conductor six inches long is doubled, what will be the effect on the resistance?

(D). A & C

  • One-fourth the original value

  • The resistance varies inversely with the cross-sectional area of the conductor

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A minute subdivision of matter having the smallest known unit of negative electrical charge is:

  • Correct Answer
    Electron
  • Ion
  • Gilbert
  • Joule

A minute subdivision of matter having the smallest known unit of negative electrical charge is:

(A). Electron

If you have more negative electrons than positive protons, then you have a negative electric charge.

For more info, please see Wikipedia's articles on Electron and Electric charge

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Conductors differ from nonconductors, i.e.:

  • There are a large number of free electrons in a good conductor
  • There is a small number of free electrons in a non-conductor
  • There is an equal amount of free electrons in a good conductor and in a non-conductor
  • Correct Answer
    A & B

Conductors differ from nonconductors, i.e.:

(D). A & B

  • There are a large number of free electrons in a good conductor

  • There is a small number of free electrons in a non-conductors stop the flow of electrons.

Conductors facilitate flow of electrons across their skin surface, while nonconductors do not allow the

Conductance is the opposite of resistance. The resistance is measured in Ohms, but conductance is measured in Mho's. The Mho, is the 1/ohm, that is the Mho is the reciprocal of Ohm.

For more info, please see ElectronicNotes' site article Electrical Conductivity: mho, siemens

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Direction of flow of DC electricity in a conductor can be determined by:

  • A magnetic compass and the left hand rule
  • A magnetic compass and the right hand rule
  • Connecting an ammeter with marked polarities in series with the circuit
  • Correct Answer
    A & C

Direction of flow of DC electricity in a conductor can be determined by:

(D). A & C

  • A magnetic compass and the left hand rule
  • Connecting an ammeter with marked polarities in series with the circuit

Direct Current occurs when electrons flow in a one direction only. Electronic circuits use mostly direct current from a battery or a direct current transformer.

More info on Wikipedia's article on Direct current


The flow of electrons in the same direction (DC current) creates a magnetic field. The magnetic field propagates clockwise around the surface skin of the conductor material. The compass needle will be affected by the magnetic field.

More info on Wikipedia's article on Magnetoresistance


By introducing a magnetic field to a flow of electrons in one direction, there will be created a force that is at 90 degrees (perpendicular) to the magnetic field and the flow of electrons.

On a graph, this force would be on the Y axis, while flow and magnetic force on the X axis. For simplicity, your thumb would be the force, while the index finger would show the magnetic force, while the middle finger would show a flow of electrons.

More info on Wikipedia's article on Magnetoresistance

There are various versions of the interaction of force, magnetic field, and current. Mostly, they are called either a left-hand or right-hand rule. These two are opposite of each other.

The left-hand rule shows the flow of current to produce motion, as in electric motors. The right-hand rule is the opposite, as it creates current, not using it, in generators of electricity.

See detailed explanation on Wikipedia's article Fleming's left-hand rule for motors


In the past, an instrument called "Galvanometer" was used to measure DC current. An improved version which did not require interrupting the electrical circuit is called an "Ammeter" It measures current in amperes.

For more info, please see Wikipedia's article on Ammeter

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The difference between electrical power and electrical energy is:

  • Electrical power is the rate of doing work by electricity
  • Electrical energy is the ability to accomplish work by electricity
  • Correct Answer
    A & B
  • None of the above

The difference between electrical power and electrical energy is:

(C). A & B

  • Electrical power is the rate of doing work by electricity
  • Electrical energy is the ability to accomplish work by electricity

Good simple definitions.

For more info, please see Wikipedia's articles on Electric power
and Electrical energy

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A positive temperature coefficient means:

  • Resistance increases as the temperature increases
  • Resistance decreases as the temperature decreases
  • Correct Answer
    Both A & B
  • None of the above

A positive temperature coefficient means:

(C). Both A & B

  • Resistance increases as the temperature increases
  • Resistance decreases as the temperature decreases

For greater insights, please see Wikipedia's article on Temperature coefficient

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A liquid which is capable of conducting electricity, but undergoes decomposition while doing so is:

  • Correct Answer
    An electrolyte
  • A ferromagnetic material under the influence of a magnetizing force
  • Equal to the ohmic resistance of the circuit
  • None of the above

A liquid which is capable of conducting electricity, but undergoes decomposition while doing so is:

(A). An electrolyte

Liquids with the ability to allow flow of current is called an electrolyte.

For more details, please see Wikipedia's article on Conductivity (electrolytic)

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The effective value of an RF current and the heating value of the current are:

  • Correct Answer
    The same
  • Effective value divided by two equals the heating value
  • Effective value multiplied by two equals the heating value
  • None of the above

The effective value of an RF current and the heating value of the current are:

(A). The same

For greater insights, please see Wikipedia's article on Temperature coefficient

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One horsepower is:

  • 746 Watts
  • Roughly 3/4 kilowatt
  • Corresponds to lifting 550 pounds at the rate of one foot per second
  • Correct Answer
    All of the above

One horsepower is:

(D). All of the above

  • 746 Watts
  • Roughly 3/4 kilowatt
  • Corresponds to lifting 550 pounds at the rate of one foot per second

The horsepower measurement reflects the amount of work done as one unit. There are several different horsepower measurement.

For more info, please see Wikipedia's article on Horsepower

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What factors determine the heat generated in a conductor?

  • It is directly proportional to the resistance
  • It is directly proportional to the square of the current
  • Correct Answer
    Both A & B
  • None of the above

What factors determine the heat generated in a conductor?

(C). Both A & B

Heat generated in a conductor is:

  • directly proportional to the resistance
  • directly proportional to the square of the current

For greater insights, please see Wikipedia's article on Temperature coefficient

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What is the ratio of peak to average value of a sine wave?

  • 1.57 to 1
  • 1 to 0.636
  • 1 to 1
  • Correct Answer
    A & B

What is the ratio of peak to average value of a sine wave?

(D). A & B

  • 1.57 to 1
  • 1 to 0.636

There are a number of formulas for calculating the avg value of sine wave for different waves. The 1.57 refers to the "half wave rectified sine wave." The "full rectified wave" is 0.637.

For more details, see Electrical Technology site, article on RMS Value, Average Value, Peak Value, Peak Factor And Form Factor in AC

and, site All About Circuits article on Measurements of AC Magnitude

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When the current sine wave in a circuit reaches its peak value before the voltage wave:

  • Correct Answer
    It is said to have a leading power factor
  • It is said to have a lagging power factor
  • It is said to be in phase
  • None of the above

When the current sine wave in a circuit reaches its peak value before the voltage wave:

(A). It is said to have a leading power factor

When the electron flow (amperes) is at max before the max in amount of charge (electrons) differential (volts), then we have a leading power factor.

Power is the ability of voltage (push) and amperes (electron flow) to do a unit of work. If you apply root-means-square formula to the amperes and volts, you get "apparent power."

If you imagine that horizontal line is the real power, and at an angle from that line is another line, called apparent power, then the difference between apparent power and real power is the reactive power. (such a fun fact)

If the apparent power line is below the horizontal real power line, then we have the leading power factor If the apparent power line is at an angle above the horizontal real power line, then we have lagging power factor.

"Capacitive loads are leading (current leads voltage), and inductive loads are lagging (current lags voltage)."*

*For more insights, please see Wikipedia's article on Power Factor

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An "harmonic" is:

  • Correct Answer
    A whole multiple of an original frequency
  • The heating value of an RF current
  • The internal impedance of a power source
  • A multiple of the power factor

An "harmonic" is:

(A). A whole multiple of an original frequency

Harmonic is the same note, but some octaves higher. The wave from zero to max back to zero is divided by a number such as 1,2, or 3 or more.

When you divide the wave it occurs at a higher Hz, at a multiple of the initial Hz wave. So, if the initial wave is at 440 Hz, then the second harmonic will be at 880 Hz, and there will be two waves in the time unit of the initial one.

The 3rd harmonic will have three smaller waves in the time unit of the initial wave, and the initial frequency in Hz will be multiplied by 3.

Harmonics are important in music and radio waves. In radio waves, there are circuits to eliminate the harmonics of the frequency desired, to suppress interference.

For more info, please see Wikipedia's article on Harmonic

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Assuming a power source to have a fixed value of internal impedance, maximum power will be transferred to the load when:

  • Correct Answer
    The load impedance equals the internal impedance of the source
  • The load impedance is higher than the source impedance
  • The load impedance is lower than the source impedance
  • None of the above

Assuming a power source to have a fixed value of internal impedance, maximum power will be transferred to the load when:

(A.) The load impedance equals the internal impedance of the source


Impedance is the resistance to alternating current. Impedance is created by the resistance (opposition to flow of electrons, in ohms) and reactance. Reactance includes inductive and capacitive components.
See Wikipedia's article on Electrical Impedance


Impedance matching seeks to maximize the amount of power transferred while minimizing the reflection from the load transferred.

Basically, if the impedance of the input load is the same as the internal impedance of the output (the source), then the maximum amount of power is transferred.
For more info, see Wikipedia's article on Impedance matching

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When two sine waves of the same frequency do not reach their maximum or minimum values simultaneously:

  • A phase difference exists
  • A phase difference does not exist
  • The sign waves are out of phase
  • Correct Answer
    A & C

When two sine waves of the same frequency do NOT reach their maximum or minimum values simultaneously:

(D). A & C

  • A phase difference exists
  • The sign waves are out of phase

Alternating current creates a sine wave as electric motor rotates between north and south magnetic poles in a coil. See Electronic Tutorials Sinusoidal Waveforms article.


When voltage sine wave leads current (ELI) inductance is the result. When current sine wave leads voltage (ICE), then result is capacitance.
(ELI the ICE man)
E voltage, L inductor, I current;
I current, C capacitor, E voltage


Please see Wikipedia's animated illustration on the relationship of Phases and Sine waves. You can see that when there is no phase difference, the combined sine wave is at maximum.

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Which method may be used to obtain more than one value of voltage from a fixed DC source?

  • Use a resistance type voltage divider
  • Connect voltage regulator tubes of suitable values and tap off the desired output voltage
  • Correct Answer
    Both A & B
  • None of the above

Which method may be used to obtain more than one value of voltage from a fixed DC source?

(C). Both A & B

  • Use a resistance type voltage divider

  • Connect voltage regulator tubes of suitable values and tap off the desired output voltage

For insights regarding DC current, please see IQS Directory site's article on DC Power Supply

For well illustrated practical application of variable DC current, please see How To Get Variable Voltage From a Fixed DC Power Supply

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The conductance (G) of a circuit if 6 A flows when 12 VDC is applied is:

  • Correct Answer
    0.5 mho
  • 1.0 mho
  • 0.25 mho
  • None of the above

The conductance (G) of a circuit if
6 A flows when
12 VDC is applied is:

(A). 0.5 mho

mho is the 1/ohms yielding conductance.

Conductance (G), is 1/R or I/V.

G = 6 A / 12 VDC = 0.5 mho

For more info, please see Wikipedia's article on Electrical resistance and conductance

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Two 10 W, 500 ohm resistors in parallel will dissipate how many watts?

  • Correct Answer
    20 watts
  • 10 watts
  • 30 watts
  • 40 watts

Two (2) 10 W,
500 ohm resistors
in parallel will dissipate how many watts?

(A). 20 watts

Formulas for power dissipation:

Watts = Volts x Amperes or
Watts = Volts(2) / Ohms or
Watts = Amperes(2) x Ohms

Because both resistors in parallel are the same value:
2 quantity (each 500 ohms) x 10 Watts = 20 Watts

For more info, please see All About Circuits site, article Power Calculations Chapter 5 - Series And Parallel Circuits

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A 20 ohm resistor with a current of 0.25 A passing through it will dissipate how many watts?

  • 10 watts
  • 20 watts
  • 0.025 watts
  • Correct Answer
    1.25 watts

A 20 ohm resistor with a current of
0.25 A passing through it
will dissipate how many watts?

(D). 1.25 watts

Watts = Volts x Amperes or
Watts = Volts(2) / Ohms or
Watts = Amperes(2) x Ohms

Watts = 0.25 A (2) x 20 ohms
Watts = 0.0625 A x 20 ohms
Watts = 1.25

For more info, please see All About Circuits site, article Power Calculations Chapter 5 - Series And Parallel Circuits

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If the voltage to a circuit is doubled and the resistance is increased to three times the original value, what will be the final current?

  • 1/3 the original current
  • Correct Answer
    2/3 the original current
  • 3 times the original current
  • None of the above

If the voltage to a circuit is doubled
and the resistance is increased to three times the original value,
what will be the final current?

(B). 2/3 the original current

Voltage x 2 and Resistance * 3 ==> Amperes?

Voltage = Amperes x Ohms
Amperes = Voltage / Ohms
Amperes = 2V/3R which is 2/3 original amperes

For more info, please see Electrical 101 site article on Ohm’s Law

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If a vacuum tube with a filament rating of 0.25 A and 5 V is operated from a 6 volt battery, what value of resistor is necessary?

  • Correct Answer
    4 ohms
  • 5 ohms
  • 10 ohms
  • 2 ohms

If a vacuum tube with a filament rating of
0.25 A and
5 V is operated from a
6 volt battery,
what value of resistor is necessary?

(A). 4 ohms

Ohms = Volts / Amperes
Ohms = 6 volts / 0.25 Amperes = 24
Ohms = 5 volts / 0.25 Amperes = 20
24 ohms - 20 ohms = 4 ohms

For more info, please see All About Circuits site, article Power Calculations Chapter 5 - Series And Parallel Circuits

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The minimum power dissipation rating of a resistor of 20,000 ohms across a potential of 500 V should be:

  • Correct Answer
    25 watts
  • 12.5 watts
  • 15 watts
  • None of the above

The minimum power dissipation rating of a resistor of
20,000 ohms across a potential of
500 V should be:

(A). 25 watts

Watts = Volts(2) / ohms
Watts = 500 ohms (2) / 20,000 = 12.5 watts
12.5 watts x 2 = 25 watts

For more info, please see All About Circuits site, article Power Calculations Chapter 5 - Series And Parallel Circuits

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The total power dissipation capability of two 10 watt, 500 ohm resistors connected in series is:

  • Correct Answer
    20 watts
  • 10 watts
  • 5 watts
  • None of the above

The total power dissipation capability of
two 10 watt,
500 ohm resistors
connected in series is:

(A). 20 watts

Formulas for power dissipation:

Watts = Volts x Amperes or Watts = Volts(2) / Ohms or Watts = Amperes(2) x Ohms

Because both resistors in parallel are the same value: 2 quantity (each 500 ohms) x 10 Watts = 20 Watts

For more info, please see All About Circuits site, article Power Calculations Chapter 5 - Series And Parallel Circuits

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What is the total power dissipation capability of two 10 watt 500 ohm resistors connected in parallel?

  • Correct Answer
    20 watts
  • 40 watts
  • 5 watts
  • None of the above

What is the total power dissipation capability of
two 10 watt
500 ohm resistors
connected in parallel?

(A). 20 watts

Formulas for power dissipation:

Watts = Volts x Amperes or Watts = Volts(2) / Ohms or Watts = Amperes(2) x Ohms

Because both resistors in parallel are the same value: 2 quantity (each 500 ohms) x 10 Watts = 20 Watts

For more info, please see All About Circuits site, article Power Calculations Chapter 5 - Series And Parallel Circuits

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What is the maximum current carrying capacity of a resistor of 5000 ohms, 200 watts?

  • Correct Answer
    0.2 A
  • 1 A
  • 1.2 A
  • None of the above

What is the maximum current carrying capacity of a resistor of
5000 ohms,
200 watts?

(A). 0.2 A

Watts = Volts x Amperes or
Watts = Volts(2) / Ohms or
Watts = Amperes(2) x Ohms

200 watts = 5000 ohms x X(2) Amperes

X(2) = 200 / 5000 = Square Root of 0.04 = 0.2 A

For more info, please see All About Circuits site, article Power Calculations Chapter 5 - Series And Parallel Circuits

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What is the total resistance of a parallel circuit consisting of a 10 ohm branch and a 25 ohm branch?

  • @ ohms
  • 10.3 ohms
  • 7.0 ohms
  • Correct Answer
    7.14 ohms

What is the total resistance of
a parallel circuit consisting of a
10 ohm branch and a
25 ohm branch?

(D). 7.14 ohms

To sum up parallel resistors, you need to take the reciprocal of the resistors.

1/10 + 1/25 = 0.1 + 0.04 = 0.14,
so reciprocal of 1/0.14 =7.14

For more info, please see All About Circuits site, article Parallel Resistance Calculator

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The current through two resistors in series is 3 A. Resistance #1 is 50 ohms, resistance #2 drops 50 V across its terminals. What is the total voltage?

  • Correct Answer
    200 V
  • 220 V
  • 110 V
  • 180 V

The current through two (2) resistors in series is
3 A. Resistance
#1 is 50 ohms, resistance
#2 drops 50 V across its terminals.
What is the total voltage?

(A). 200 V

Voltage = Amperes x Resistance

3 Amperes x 50 Ohms = 150 Volts
since 50 Volts drop is given,
then 150 V + 50 V = 200 V

For more information, please see Sciencing site article on How to Calculate a Voltage Drop Across Resistors

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An 18 ohm and a 15 ohm resistor are connected in parallel; a 36 ohm resistor is connected in series with this combination; a 22 ohm resistor is connected in parallel with this total combination. The total current is 5 A. What current is flowing in the 15 ohm resistor?

  • Correct Answer
    0.908 A
  • 1.000 A
  • 1.908 A
  • 0.809 A

An 18 ohm and a 15 ohm resistor are connected in parallel;
a 36 ohm resistor is connected in series with this combination;
a 22 ohm resistor is connected in parallel with this total combination.
The total current is 5 A.
What current is flowing in the 15 ohm resistor?

(A). 0.908 A

Amperes = Volts / Resistance.

  1. Determine combined resistance, in parallel of 18 and 15 ohms. Use 1/x for addition of parallel resistors.
  2. The series circuit adds 36 ohms. Straight addition.
  3. Determine combined resistance, in parallel of 22 ohms . Again, need to use 1/x to add the previous resistance and the 22 ohms here. This is the total resistance.
  4. The total current is 5 Amperes.

(1) In parallel
1/18 + 1/15 = 15/ 270 + 18 / 270 = 33 / 270 = 0.122 or about 8.18

(2) In series
8.18 + 36 = 36.122 = 44.18 ohms

(3) In parallel
44.18 ohms + 22 ohms = 14.686 ohms

(4) To derive Volts
14.686 ohms x 5 Amperes = 73.43 Volts

Then, you have to work back Amperes to the 15 ohm resistor. Calculate branch currents without voltage

Remember, Amperes flow through series unchanged, but divide in parallel, depending on the resistor.

For more info on parallel and series circuits, see BCampus site article 63 Resistors in Series and Parallel

For more information, please see Sciencing site article on How to Calculate a Voltage Drop Across Resistors

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A circuit passes 3 A. The internal resistance of the source is 2 ohms. The total resistance is 50 ohms. What is the terminal voltage of the source?

  • Correct Answer
    150 V
  • 100 V
  • 110 V
  • 240 V

A circuit passes 3 A.
The internal resistance of the source is 2 ohms.
The total resistance is 50 ohms.
What is the terminal voltage of the source?

(A). 150 V

The formula V=IR can be used.
3Ampers x 50 Ohms = 150 Volts

For more info, see Science by Degrees site's article Why V=IR is not Ohm’s Law, and why that matters

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A relay coil has 500 ohms resistance, and operates on 125 mA. What value of resistance should be connected in series with it to operate from 110 VDC?

  • Correct Answer
    380 ohms
  • 400 ohms
  • 200 ohms
  • None of the above

A relay coil has
500 ohms resistance, and operates on
125 mA. (0.125 A)
What value of resistance should be connected in series with it to operate from 110 VDC?

(A). 380 ohms

For resistance in series circuits, you simply add resistance of each component. See Understanding & Calculating Series Circuits Basic Rules from swtc.edu

V=IR
110 V = (500 ohms + X ohms) * .125 A
(500 ohms + X ohms) = 110 v / .125 A
(500 ohms + X ohms) = 880 ohms
X = 880 ohms - 500 ohms = 380 ohms

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Given: Input power to a receiver is 75 watts. How much power does the receiver consume in 24 hours of continuous operation?

  • 1800 watthours
  • 1.80 kilowatthours
  • Correct Answer
    A & B
  • None of the above

Given: Input power to a receiver is 75 watts. How much power does the receiver consume in 24 hours of continuous operation?

(C). A & B

  • 1800 watt hours
  • 1.80 kilowatt hours

Both answers are the same.
Kilo is 1000, so 1800/1000=1.80

75 Watts x 24 hours = 1,800 Watts

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The total reactance when two capacitances of equal value are connected in series is:

  • The product of the two individual reactances in ohms
  • Correct Answer
    The sum of the two individual reactances in ohms
  • The difference of the two individual reactances in ohms
  • None of the above

The total reactance when two capacitances of equal value are connected in series is:

(B). The sum of the two individual reactances in ohms

For insight, please see Lumen Physics site the article on Resistors in Series and Parallel also Capacitors in Series and Parallel

And, from Electronics Tutorials site the article on Capacitors in Series, and Capacitors in Parallel

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A capacitor's charge is stored:

  • Upon the inner surface of the capacitor plates
  • As an electrostatic field which exists in the space between the plates
  • Correct Answer
    A & B
  • None of the above

A capacitor's charge is stored:

(C). A & B

  • Upon the inner surface of the capacitor plates

  • As an electrostatic field which exists in the space between the plates

For details, please see OPENPRESS.USASK.CA site article on 4.3 Energy Stored in a Capacitor

Also, see Lumen Physics site article on Energy Stored in Capacitors

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The voltage drop across an individual capacitor of a group of capacitors connected in series across an AC source is:

  • Inversely proportional to the ratio of the capacitance of the capacitor being considered
  • Inversely proportional to the total capacitance of the combination
  • Directly proportional to the applied voltage across the series combination
  • Correct Answer
    All of the above

The voltage drop across an individual capacitor of a group of capacitors connected in series across an AC source is:

(D). All of the above

  • Inversely proportional to the ratio of the capacitance of the capacitor being considered

  • Inversely proportional to the total capacitance of the combination

  • Directly proportional to the applied voltage across the series combination

For more info, please see Electronics Tutorials site article Capacitors in Series

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What is the total capacitance of the capacitors of 3, 5, and 7 microfarad connected in series?

  • 14.79 microfarad
  • Correct Answer
    1.479 microfarad
  • 15 microfarad
  • None of the above

What is the total capacitance of the capacitors of 3, 5, and 7 microfarad connected in series?

(B). 1.479 microfarad

1/3 is 0.33333333333
1/5 is 0.2
1/7 is 0.14285714285

The total is 0.67619014285 and the reciprocal 1/67619014285 is 1.479

For more info, see Lumen Physics article on Capacitors in Series and Parallel

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If capacitors of 3, 5, and 7 microfarad are connected in parallel, what is the total capacitance?

  • Correct Answer
    9 microfarad
  • 15 microfarad
  • 10 microfarad
  • 3 microfarad

If capacitors of 3, 5, and 7 microfarad are connected in parallel, what is the total capacitance?

(A). 9 microfarad

The formula calls for simple addition, which comes to 15, and not 9. Seems like an error. Best, just remember that answer. Checked in the FCC Element 6 question pool, and it is 9.

For more info, see Lumen Physics article on Capacitors in Series and Parallel

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How many capacitors of 400 volts and 2 microfarad each would be necessary to obtain a combination rated at 1600 volts and 1.5 microfarad?

  • 10
  • Correct Answer
    12
  • 14
  • 16

How many capacitors of
400 volts and
2 microfarad each would be necessary to obtain a combination rated at
1600 volts and
1.5 microfarad?

(B). 12

Please see Physics Forum site for explanation of the answer.

See DigiKey Electronics for Series and Parallel Capacitor Calculator

See Open Press site for 6.3 Kirchhoff’s Rules

For basic info, see Electronics Tutorials site for Capacitance and Charge

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If a turn in an inductor is shorted:

  • There will be an decrease of induction
  • There will be a decrease of Q
  • There will be overheating with possible burnout
  • Correct Answer
    All of the above

If a turn in an inductor is shorted:

(D). All of the above

There will be:

  • decrease of induction
  • a decrease of Q
  • overheating with possible burnout

The question does not specify whether it is a DC or AC circuit. One property of an inductor is that it resists changes in amperes.

However, the inductance to the flow of amperes is not the same in DC and AC circuits, measured in di/dt, or change in amperes per change in a unit of time. In DC circuits, the coil stores energy, in AC circuits, the coil stores and delivers energy.

Because of the change (decrease in induction), the flowining amperes may overheat the circuit.

Coils do have some resistance, Q, and short may cause a decrease in Q, as it causes some energy loss.


For more info on inductors (chokes), please see Electronic Tutorials site for article on The Inductor

and for even more details, please see Voltech website for the article on Methods for Detection of Shorted Windings

Regarding Q in coils, please see Electronics Notes article on Inductor Q, Quality Factor

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The relationship between the number of turns and the inductance of a coil may be expressed by:

  • Correct Answer
    The inductance varies approximately as the square of the number of turns
  • The inductance varies approximately as the square root of the number of turns
  • Both A & B
  • None of the above

The relationship between the number of turns and the inductance of a coil may be expressed by:

(A). The inductance varies approximately as the square of the number of turns


For more info, please see Quora article on Why is inductance (L) proportional with turns-square (N²)?

and Electronics Tutorial article on Inductance of a Coil

For more info on inductors (chokes), please see Electronic Tutorials site for article on The Inductor

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The formula for determining the resonant frequency of a circuit when the inductance and capacitance are known is:

  • f = 1/(2 pi times the square root of LC)
  • f = 0.159/(the square root of LC)
  • Correct Answer
    Both A & B
  • None of the above

The formula for determining the resonant frequency of a circuit when the inductance and capacitance are known is:

(C). Both A & B

  • f = 1/(2 pi times the square root of LC)

  • f = 0.159/(the square root of LC)

When you graph frequency on X axis, and reactance on Y axis, the inductive reactance is a straight 45 degrees line, but the capacitive reactance curve starts high and decreases as frequency increases.

At the intersection of both, there is the resonant frequency for a specific circuit. It is when the inductive and capacitive reactance are equal. For more info, please see Cadence site, article on What is Resonant Frequency?

Also, for more details see Electronics Tutorials article on Series Resonance Circuit

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The formula for determining the wavelength when the frequency is known is:

  • Wavelength = 300,000/ f kHz
  • Wavelength = 300,000,000/ f Hz
  • Wavelength = 300/ f MHz
  • Correct Answer
    All of the above

The formula for determining the wavelength when the frequency is known is:

(D). All of the above

  • Wavelength = 300,000/ f kHz

  • Wavelength = 300,000,000/ f Hz

  • Wavelength = 300/ f MHz

For graphic explanation, see wikiHow article on How to Calculate Wavelength,
and on Study site, How to Calculate Wavelength, which offers a video and info.

For explanation on metric system of units, kilo, and mega, see Wikipedia's article on Metric prefix

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The wavelength of the period of one complete cycle of a radio wave of 0.000,001 second is:

  • Correct Answer
    300 M
  • 3000 M
  • 30 M
  • 70 cm

The wavelength of the period of one complete cycle of a radio wave of 0.000,001 second is:

(A). 300 M

Since waves travel in vacuum at 300,000 km/second, or 3,000,000 meters per second, multiply by 1,000,000 to get the second, or 300 M (M=1,000,000).

For details, see Socratic Q&A site article on How can I calculate the wavelength of electromagnetic radiation?

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The efficiency of a radio device is:

  • The ratio of the power input to the power output
  • Correct Answer
    The ratio of the useful power output to the power input
  • The ratio of the minimum power output to the maximum power output
  • None of the above

The efficiency of a radio device is:

(B). The ratio of the useful power output to the power input

Generally, efficiency of any system is the cost or amount of what is provided, and the benefits achieved.

For radio, it is the amount of energy as input, and the amount of energy as output, with the difference being radiated during the processing.

For more info, see Socratic Q&A site for How can energy efficiency be calculated?

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What is the total impedance of a parallel capacitor and inductor with equal values of reactance?

  • Infinite total reactance
  • Zero total reactance
  • Parallel impedance is resistive and infinite
  • Correct Answer
    B & C

What is the total impedance of a parallel capacitor and inductor with equal values of reactance?

(D). B & C

  • Zero total reactance
  • Parallel impedance is resistive and infinite

For explanation of impedance and reactance please see Electronics Tutorial site for article on Impedance and Complex Impedance

Also, see EE Power site for article on Impedance and Reactance

Specific explanation here on Electrical Engineering article on Infinite impedance at resonance in parallel LC circuit ? does that mean it is not usable?

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The total inductance of two coils in parallel without any mutual coupling is:

  • Correct Answer
    Equal to the product of the two inductances divided by their sum
  • The sum of the individual inductances
  • Zero
  • None of the above

The total inductance of two coils in parallel without any mutual coupling is:

(A). Equal to the product of the two inductances divided by their sum

If coupling in the circuit of two coils present, then the total amount of inductance will be affected by the total amount of coupling.

For explanation of the formula, please see Electronics Tutorial site, for the article on
Inductors in Parallel,
paragraph on the "Parallel Inductor Equation."

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What is the total reactance of a series AC circuit, with no resistance and equal inductance and capacitive reactances?

  • The two reactances cancel being equal and opposite
  • Net impedance is purely resistive and contains no reactive component
  • The total reactance is zero at the resonant frequency
  • Correct Answer
    All of the above

What is the total reactance of a series AC circuit, with no resistance and equal inductance and capacitive reactances?

(D). All of the above

  • The two reactances cancel being equal and opposite
  • Net impedance is purely resistive and contains no reactive component
  • The total reactance is zero at the resonant frequency

For full explanation, please see Electronics Tutorials article on AC Inductance and Inductive Reactance

Also, a great article on Reactance, Inductive and Capacitive listed on the Lumen Learning site.

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The total inductance of two coils in series without any mutual coupling is:

  • Correct Answer
    The sum of the individual inductances
  • The product of the individual inductances divided by their sum
  • Infinite
  • None of the above

The total inductance of two coils in series without any mutual coupling is:

(A). The sum of the individual inductances

If coupling in the circuit of two coils present, then the total amount of inductance will be affected by the total amount of coupling.

For explanation of the formula, please see Electronics Tutorial site, for the article on
Inductors in Parallel,
paragraph on the "Parallel Inductor Equation."

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One wave-length is:

  • The distance a wave will travel in the time for one cycle
  • Centimeter wavelength = 30,000 / frequency MHz
  • Correct Answer
    A and B
  • Neither A or B

One wave-length is:

(C). A and B

  • The distance a wave will travel in the time for one cycle

  • Centimeter wavelength = 30,000 / frequency MHz

Need to watch out for the units of measure here. We know that light travels at the speed of 300,000,000 meters per second.

The standard formula for wavelength is 300,000,000 meters/second or 300M divided by radio frequency in Hz.

The time unit for the wave is a second. Thus, we state that so many waves occurred in one second.

So, if we use MHz instead of Hz, then we have to adjust the units of speed of light in the formula.

We know that 1 MHz equals to 1,000,000 Hz. And, we know that there are 100 centimeters in a meter.

Then, if we multiply the 300,000,000 meters/second by 100 centimeters/one meter, we get 30,000,000,000 centimeters/second.

To convert Hz to MHz, we must divide by 1,000,000 Hz in 1 MHz, to get 30,000 centimeters per MHz.

Please see NewHams.Info site article on Wavelength. This site is a good resource for various radio topics.

To calculate wavelengths, and try out various units, please see Wavelength Calculator site for Wavelength Calculator

BTW: A great listing of FCC radio frequency allocations is an FCC Online Table Frequency Allocations. Good to print out and keep as reference for when choosing frequencies.

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In an AC circuit, a series inductance acting alone:

  • Correct Answer
    Causes the current to lag the applied voltage by 90 degrees
  • Causes the current to lead the applied voltage by 90 degrees
  • Causes the current to lag the applied voltage by 45 degrees
  • Causes the current to lead the applied voltage by 45 degrees

In an AC circuit, a series inductance acting alone:

(A). Causes the current to lag the applied voltage by 90 degrees

For AC inductance, it is the resistance to the change in current or amperes, expressed in Henry units. When a coil gets alternating current, it produces electrical magnetic frequency, which opposes the change in the current.

Then, volts applied through a sine wave, the volts lead current by 90 degrees, OR the current LAGS voltage by 90 degrees.

For more info, please see Electronics Tutorials site, article on AC Inductance and Inductive Reactance, subsection "Sinusoidal Waveforms for AC Inductance."

Also, see TutorialsPoint site, article on Inductors in AC Circuits.

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Shock excitation into an L-C circuit is the result of:

  • A voltage being momentarily introduced
  • The capacitor may be charged
  • The inductor may have a voltage induced
  • Correct Answer
    All of the above

Shock excitation into an L-C circuit is the result of:

(D). All of the above

  • A voltage being momentarily introduced
  • The capacitor may be charged
  • The inductor may have a voltage induced

To produce vibrations, like resonance, you have to hit it, such as a glass to sound, a guitar string to vibrate, or a bell to sound. In electrical circuits, voltage (a difference between charges in two objects) will cause a spark to jump, or a capacitor, having two plates, maybe shocked when the difference in charges exists between the plates.

For more depth info, please see the Industrial Electronics site, for the article on Guide to Crystal Oscillators -- Review of Oscillation Principles, section 4 Self-Excited L-C Oscillator Characteristics.

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The term cathode ray usually applies to:

  • Correct Answer
    A fairly high velocity electron beam
  • Background noise
  • The logarithm gain of an electron beam
  • None of the above

The term cathode ray usually applies to:

(A). A fairly high velocity electron beam

There are two guns that shoot electron beam at a storage mash. The main beam shoots "fairly high velocity electron beam," to create the picture. The other gun illuminates the mesh by shooting the low velocity electron beam. It does not interfere with the main beam.

For more info, please see Wikipedia's article on Cathode-ray tube

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Shielding an RF inductance:

  • Increases the losses of the inductance
  • Lowers the inductance value and the Q
  • Increases the coil capacity to the shield
  • Correct Answer
    All of the above

Shielding an RF inductance:

(D). All of the above

  • Increases the losses of the inductance
  • Lowers the inductance value and the Q
  • Increases the coil capacity to the shield

When RF inductance occurs, there may be an establishment of undesirable relationship between components. A common method to prevent it is to provide shielding, which could be a physical barrier to RF inductance by absorbing radiation.

For greater insights, please see Passive Components site for article on EMI Suppression Shields: Understanding the Basics.

Also, see GCG Gowanda Components Group practical article on To Shield or Not to Shield - Part 1 It will show up in pdf format.

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The tendency of a tank circuit to keep oscillating for a time after the excitation energy has been removed is:

  • Push-pull effect
  • Correct Answer
    Flywheel effect
  • Polarizing effect
  • Parasitic oscillation

The tendency of a tank circuit to keep oscillating for a time after the excitation energy has been removed is:

(B). Flywheel effect

Tank circuit was so named by radio pioneers, as it reminded them of the behavior of water when pulsing disturbance is introduced.

Now, it is often referred to as the oscillatory circuit, or LC. The letter L represents this tank or resonant circuit, and the letter C stands for a capacitor. The circuit can store energy and release through resonant vibrations.

For more info and great animation, please see Wikipedia's article on LC circuit.

The concept of the "flywheel" is taken from the potter's round stone wheel which he moves with the foot, and when stopped pushing, the wheel has stored energy due to its weight that it keeps rotating.

The continuation of oscillations in LC after input current has been removed, is similarly called the "flywheel effect."

For additional info, please see Wikipedia's article on Flywheel effect

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Power factor is defined as:

  • The ratio between the resistance and the impedance in a circuit
  • The ratio between the true power and the apparent power of a circuit
  • Correct Answer
    Both A&B
  • None of the above

Power factor is defined as:

(C). Both A&B

  • The ratio between the resistance and the impedance in a circuit

  • The ratio between the true power and the apparent power of a circuit

While resistance is used to control the flow of electrons, impedance is a resistance that arises out of the capacitive or inductive reactance. So the ratio between the two is also called the power factor, or how much power actually gets through.

For more info, please see the Linquip Technews article on Difference Between Resistance and Impedance-Resistance vs. Impedance.

Another more practical info site is the Fluke company site article on What is power factor and why is it important?

By measuring the power factor ratio, we can determine how much of available power is actually used. Wikipedia's article called the Power factor describes it as the total available power to the combination of amperes and volts (volt is the difference in charge between two items). That is what is called the difference between the "true power" and the "apparent power."

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High or low frequency oscillations occurring in circuits other than the original tank desired output frequencies are:

  • Harmonics
  • Correct Answer
    Parasitic oscillations
  • Hysteresis
  • Eddy currents

High or low frequency oscillations occurring in circuits other than the original tank desired output frequencies are:

(B). Parasitic oscillations

Oscillations happen when there is a change of states from A to B. It can be a regular unchanging movement which we call the sine wave. Should the movement stop, the item or current moving will find a middle point between the A and B state.

When the vibration is undesirable, such as in currents or radio waves, it is called parasitic. If you ever heard a microphone make a whining sound coming from the amplifier, you hear a mike listening to itself, or parasitic oscillations of sound. In electric systems, the EMI electromagnetic interference is called parasitic oscillation.

For more info, please see Wikipedia's article on Oscillation.

Also, an excellent concept presentation is on the ThoughtCo. website, article Oscillation and Periodic Motion in Physics.

In electric circuits, it happens when there is a connection between the output and input wiring. This is like connecting a fresh water pipe with the sewer pipe in plumbing.

For more info, please see Wikipedia's article on Parasitic oscillation.

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What are effects of parasitic oscillations?

  • Change of bias
  • Reduced efficiency of the amplifier tube
  • Distortion of the modulated wave
  • Correct Answer
    All of the above

What are effects of parasitic oscillations?

(D). All of the above

  • Change of bias
  • Reduced efficiency of the amplifier tube
  • Distortion of the modulated wave

If you ever heard a microphone whine in the amplifier, you heard parasitic oscillation, which is what you don't want in a feedback, or variation in current or voltage.

Whether analog or digital processing, the undesirable feedback can occur. It occurs when part of the output is processed as input.

For more info, please see Wikipedia's article on Parasitic oscillation

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The velocity of propagation of radio frequency waves in free space is:

  • 300,000 meters / second
  • 186,284 miles / second
  • The same as the velocity of light in free space
  • Correct Answer
    All of the above

The velocity of propagation of radio frequency waves in free space is:

(D). All of the above

  • 300,000 meters / second or 3 x 10 (8) m/s
  • 186,284 miles / second
  • The same as the velocity of light in free space

The Speed of Radio Wave == frequency times wavelength.
Thus, since the speed is 300 km per second divided by Frequency in MHz will yield the wavelength.

See EverythingRF site for Wavelength to Frequency Calculator

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To double the resonant frequency of a resonant circuit:

  • Make C one third of its original value
  • Correct Answer
    Make L and C both half their original values
  • Decreasing the value of both L and C in any proportion so that their product will be one-half of the original values
  • None of the above

To double the resonant frequency of a resonant circuit:

(B). Make L and C both half their original values

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How may the Q of a parallel resonant circuit be increased?

  • Increasing coupling to the resonant circuit
  • Using coil and capacitor supports of special low - loss materials
  • Correct Answer
    Both A and B
  • Decreasing coupling to the resonant circuit

How may the Q of a parallel resonant circuit be increased?

(C). Both A and B

  • Increasing coupling to the resonant circuit
  • Using coil and capacitor supports of special low - loss materials

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If L and C in a parallel resonant circuit resonants at 1000 kHz are so varied that their product remains constant, what will be the resulting resonant frequency?

  • 10,000 kHz
  • 100 kHz
  • Correct Answer
    1 MHz
  • None of the above

If L and C in a parallel resonant circuit resonants at 1000 kHz are so varied that their product remains constant, what will be the resulting resonant frequency?

(C). 1 MHz

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What is the resonant frequency of a tuned circuit consisting of a 500 picofarad capacitor, a 150 microfarad tuning coil, and 10 ohms resistance?

  • Correct Answer
    581 kHz
  • 753 kHz
  • 498 kHz
  • None of the above

What is the resonant frequency of a tuned circuit consisting of a 500 picofarad capacitor, a 150 microfarad tuning coil, and 10 ohms resistance?

(A). 581 kHz

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What is voltage regulation as applied to power supplies?

  • Correct Answer
    The ratio of change in voltage between no load and full load to the full-load voltage output
  • The ratio of output to input voltage
  • Voltage output of the power supply under full load
  • The ratio of input to output voltage

What is voltage regulation as applied to power supplies?

(A). The ratio of change in voltage between no load and full load to the full-load voltage output

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An EMF may be generated by sound waves by what principle?

  • Electrostatic
  • Piezo-electric
  • Resistance change
  • Correct Answer
    All of the above

An EMF may be generated by sound waves by what principle?

(D). All of the above

  • Electrostatic
  • Piezo-electric
  • Resistance change

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How can you correct power factor in an electrical circuit?

  • Inductance is used to correct a leading angle
  • Capacitance is used to correct a lagging angle
  • Neither A or B
  • Correct Answer
    Both A and B

How can you correct power factor in an electrical circuit?

(D). Both A and B

  • Inductance is used to correct a leading angle
  • Capacitance is used to correct a lagging angle

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Permeability is:

  • The magnetic field created by a conductor wound on a laminated core and carrying any electric current
  • Correct Answer
    The ratio of magnetic flux density in a substance to the magnetizing force which produces it
  • Polarized molecular alignment in a ferromagnetic material while under the influence of a magnetizing force
  • Both A and C

Permeability is:

(B). The ratio of magnetic flux density in a substance to the magnetizing force which produces it

Basically, how much a given substance can be magnetized.

For more information, please see Wikipedia's article on Permeability (electromagnetism)

And, Electronics Tutorials site for the article The Electromagnet, section Permeability of Electromagnets

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The time in seconds for a capacitor to attain 63.2 % of the applied voltage across its terminals is:

  • Twice the natural period of oscillation of the circuit
  • Varactance
  • Correct Answer
    Time constant
  • Equal to the ohmic resistance of the circuit

The time in seconds for a capacitor to attain 63.2 % of the applied voltage across its terminals is:

(C). Time constant

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What is the reactance of a 2-henry choke at 3000 Hz?

  • 5300 ohms
  • Correct Answer
    37,680 ohms
  • 376,800 ohms
  • 53,000 ohms

What is the reactance of a 2-henry choke at 3000 Hz?

(B). 37,680 ohms

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If there is no resistance in either leg of a circuit with an inductance of 5 henrys in parallel with a capacitance of 1 microfarad, what is the equivalent impedance of the parallel network circuit?

  • Zero
  • Correct Answer
    Infinite
  • Median
  • None of the above

If there is no resistance in either leg of a circuit with an inductance of 5 henrys in parallel with a capacitance of 1 microfarad, what is the equivalent impedance of the parallel network circuit?

B. Infinite

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What is the total impedance of a series AC circuit having a resistance of 6 ohms, an inductive reactance of 17 ohms, and zero capacitive reactance?

  • 15 ohms
  • 27 ohms
  • Correct Answer
    18 ohms
  • 5 ohms

What is the total impedance of a series AC circuit having a resistance of 6 ohms, an inductive reactance of 17 ohms, and zero capacitive reactance?

(C). 18 ohms

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The total impedance of a series AC circuit with an inductive reactance of 24 ohms, a resistance of 16 ohms, and a capacitive reactance of 16 ohms is:

  • 20 ohms
  • Correct Answer
    16 ohms
  • 10 ohms
  • None of the above

The total impedance of a series AC circuit with an inductive reactance of 24 ohms, a resistance of 16 ohms, and a capacitive reactance of 16 ohms is:

(B). 16 ohms

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Essentials for making a good solder connection are:

  • Bright, clean parts
  • Plenty of heat with the minimum amount of solder used
  • Discontinue operating on high power
  • Correct Answer
    None of the above

Essentials for making a good solder connection are:

(D). None of the above

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For protection of personnel handling a transmitter:

  • Correct Answer
    Ground all exposed metal parts
  • Transmitter is equipped to shunt grounded faults
  • Discontinue operating on high power
  • None of the above

For protection of personnel handling a transmitter:

A. Ground all exposed metal parts

This is to avoid human contact with a power cable.

See GT Engineering site for article on EXPOSED CONDUCTIVE PART AND GROUNDING

For overall info on electricity on vessels, see Law Resource site for ABYC E-09: Direct Current (DC) Electrical Systems on Boats 46 CFR 183.340(b)(4)

Also, please see the Code of Federal Regulations, Title 29, Subtitle B, Chapter XVII, Part 1915, for the section 29 CFR 1915.85(a) Vessel radar and communication systems.

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The ratio of peak-to-effective voltage values of a sign wave are:

  • 1.414 to 1
  • 1 to 0.707
  • Correct Answer
    Both A and B
  • Neither A or B

The ratio of peak-to-effective voltage values of a sign wave are:

(C). Both A and B

  • 1.414 to 1
  • 1 to 0.707

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The opposition to the creation of magnetic lines of force in a magnetic circuit is known as:

  • Correct Answer
    Reluctance
  • Hysteresis
  • Permeability
  • Eddy currents

The opposition to the creation of magnetic lines of force in a magnetic circuit is known as:

(A). Reluctance

Basically reluctance is the opposition of magnetic force, just like resistance within an electrical circuit.

For more info, please see Electrical 4 U site for the article on Magnetic Reluctance: What is it? (Formula, Units & Applications)

Also, see Wikipedia's article on Magnetic reluctance

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The ratio of magnetic flux density to the field strength is known as:

  • Residual magnetism
  • Correct Answer
    Permeability
  • Reluctance
  • None of the above

The ratio of magnetic flux density to the field strength is known as:

(B). Permeability

First, magnetic flux density (field intensity) describes how strong the magnetic force is in a material.

For a good detailed description, please see Wikipedia's article on Magnetic flux

Then, permeability is how much magnetization resulted from the application of the magnetic force.

For a good detailed description, please see Wikipedia's article on Permeability (electromagnetism)

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The magnetic force which remains in a substance after the original magnetizing force has been removed is known as:

  • Reluctance
  • Correct Answer
    Residual magnetism
  • Permeability
  • Hysteresis

The magnetic force which remains in a substance after the original magnetizing force has been removed is known as:

(B). Residual magnetism

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The direction of electron flow through a coil and the manner of winding the turns:

  • Correct Answer
    Influence the direction of magnetic line of force generated by an electromagnet
  • Are determined by the left-hand status rule
  • Are determined by the diameter of the wire and length
  • Both A and C

The direction of electron flow through a coil and the manner of winding the turns:

(A). Influence the direction of magnetic line of force generated by an electromagnet

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Adding an iron core to an air-core inductance:

  • Correct Answer
    Increases the inductance
  • Decreases the inductance
  • Does not affect the inductance
  • Causes parasitic oscillations in the inductor

Adding an iron core to an air-core inductance:

(A). Increases the inductance

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Electromagnets are used in:

  • loudspeakers
  • meters
  • motors
  • Correct Answer
    All of the above

Electromagnets are used in:

(D). All of the above

  • loudspeakers
  • meters
  • motors

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What will be the effect of a small increase in the number of turns upon the field strength of a single layer solenoid?

  • Decrease in field strength if the coil length is increased
  • Unchanged if the spacing is reduced to keep the length constant
  • Correct Answer
    Both A and B
  • None of the above

What will be the effect of a small increase in the number of turns upon the field strength of a single layer solenoid?

(C). Both A and B

  • Decrease in field strength if the coil length is increased

  • Unchanged if the spacing is reduced to keep the length constant

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Can a transformer be used with direct current?

  • In general, no
  • If the DC current is periodically interrupted it would be possible to use an original DC voltage source
  • Correct Answer
    Both A and B
  • None of the above

Can a transformer be used with direct current?

(C). Both A and B

  • In general, no
  • If the DC current is periodically interrupted it would be possible to use an original DC voltage source

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A tube containing either a filament or cathode structure, grid, and a plate is a:

  • Correct Answer
    Triode
  • Tetrode
  • Pentode
  • Diode

A tube containing either a filament or cathode structure, grid, and a plate is a:

(A). Triode

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A tube similar to a triode with the addition of a spirally wound screen grid between the plate and control grid is a:

  • Diode
  • Correct Answer
    Tetrode
  • Pentode
  • Triode

A tube similar to a triode with the addition of a spirally wound screen grid between the plate and control grid is a:

(B). Tetrode

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Theoretical gain of a tube. The ratio of a small change in plate voltage to give a certain small change in plate current to a change in grid which would cause the same current:

  • Correct Answer
    Amplification factor
  • Power factor
  • Maximum inverse plate voltage
  • None of the above

Theoretical gain of a tube. The ratio of a small change in plate voltage to give a certain small change in plate current to a change in grid which would cause the same current:

(A). Amplification factor

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Effectiveness of the grid in causing changes of plate current:

  • Transconductance
  • Mutual conductance
  • Plate resistance
  • Correct Answer
    A & B

Effectiveness of the grid in causing changes of plate current:

(D). A & B

  • Transconductance
  • Mutual conductance

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The maximum negative anode voltage with respect to the cathode. It equals the DC voltage at the input to the plus the peak AC voltage applied during the nonconducting portion of the cycle of operation of the tube:

  • Correct Answer
    Maximum inverse plate voltage
  • Mutual conductance
  • Both A & B
  • None of the above

The maximum negative anode voltage with respect to the cathode. It equals the DC voltage at the input to the plus the peak AC voltage applied during the nonconducting portion of the cycle of operation of the tube:

(A). Maximum inverse plate voltage

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What is the primary purpose of the control grid of the triode?

  • Correct Answer
    To provide a means of obtaining amplification
  • To neutralize RF amplifiers
  • Blocks passage of electrons
  • None of the above

What is the primary purpose of the control grid of the triode?

(A). To provide a means of obtaining amplification

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What is the primary purpose of the screen grid of the tetrode?

  • Reduces the grid to plate capacitance, making it unnecessary to neutralize RF amplifiers except at very high frequencies
  • Makes the plate current substantially independent of plate voltage, permitting much higher values of amplification
  • Correct Answer
    Both A & B
  • None of the above

What is the primary purpose of the screen grid of the tetrode?

(C). Both A & B

  • Reduces the grid to plate capacitance, making it unnecessary to neutralize RF amplifiers except at very high frequencies

  • Makes the plate current substantially independent of plate voltage, permitting much higher values of amplification

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What is the primary purpose of the suppressor grid of a pentode?

  • Correct Answer
    Is highly negative with respect to the plate and returns secondary emission to the plate, increasing the permissible gain and the tube efficiency
  • Reduces interelectrode capacitance between control grid and plate making plate efficiency about 10% greater than a triode
  • Both A & B
  • Neither of the above

What is the primary purpose of the suppressor grid of a pentode?

(A). Is highly negative with respect to the plate and returns secondary emission to the plate, increasing the permissible gain and the tube efficiency

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Thoriated tungsten is usually used to make:

  • Correct Answer
    Filaments
  • Heaters
  • Cathodes
  • None of the above

Thoriated tungsten is usually used to make:

(A). Filaments

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In what types of circuits do beam power vacuum tubes find application?

  • As audio amplifier in the output and power stages of circuits having low to moderately high output ratings
  • As an RF power amplifier
  • Correct Answer
    Both A & B
  • None of the above

In what types of circuits do beam power vacuum tubes find application?

(C). Both A & B

  • As audio amplifier in the output and power stages of circuits having low to moderately high output ratings

  • As an RF power amplifier

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When free electrons in a conductor acquire sufficient energy to leave the conductor and pass into the surrounding space, it is expressed as:

  • Secondary emission
  • Correct Answer
    Electron emission
  • Primary electron release
  • None of the above

When free electrons in a conductor acquire sufficient energy to leave the conductor and pass into the surrounding space, it is expressed as:

(B). Electron emission

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The emission of electrons from a material due to the impact of high-velocity electrons on its surface is:

  • Primary electron emission
  • Correct Answer
    Secondary emission
  • Mimetic emission
  • None of the above

The emission of electrons from a material due to the impact of high-velocity electrons on its surface is:

(B). Secondary emission

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Characteristics of a vacuum tube operating as a class A amplifier:

  • Correct Answer
    Low plate circuit efficiency, about 25%; practically no grid driving power; plate current flowing for 360 degrees of each cycle; practically no distortion of the output waveshape
  • Plate circuit efficiency, about 50-60%; plate current flows slightly more than 180 degrees of each cycle, medium power output
  • High efficiency, up to 80%; plate current drawn in bursts; great distortion of output waveshape
  • None of the above

Characteristics of a vacuum tube operating as a class A amplifier:

(A). Low plate circuit efficiency, about 25%; practically no grid driving power; plate current flowing for 360 degrees of each cycle; practically no distortion of the output waveshape

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Characteristics of a vacuum tube operating as a class B amplifier:

  • Low plate circuit efficiency, about 25%; practically no grid driving power; plate current flowing for 360 degrees of each cycle; practically no distortion of the output waveshape
  • Correct Answer
    Plate circuit efficiency, about 50-60%; plate current flows slightly more than 180 degrees of each cycle, medium power output
  • High efficiency, up to 80%; plate current drawn in bursts; great distortion of output waveshape
  • None of the above

Characteristics of a vacuum tube operating as a class B amplifier:

(B). Plate circuit efficiency, about 50-60%; plate current flows slightly more than 180 degrees of each cycle, medium power output

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Factors which determine bios voltage of a vacuum tube:

  • Class of operation, plate supply voltage, permissible distortion
  • Grid signal magnitude, permissible plate dissipation, desired amplification factor
  • The no-signal plate current desired, the desirability of drawing grid current
  • Correct Answer
    All of the above

Factors which determine bios voltage of a vacuum tube:

(D). All of the above

  • Class of operation, plate supply voltage, permissible distortion

  • Grid signal magnitude, permissible plate dissipation, desired amplification factor

  • The no-signal plate current desired, the desirability of drawing grid current

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In the usual Class A amplifier:

  • Correct Answer
    There is no grid current
  • Plate current flows slightly more than 180 degrees of each cycle
  • Biased to twice
  • None of the above

In the usual Class A amplifier:

(A). There is no grid current

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The DC bias in a Class A amplifier:

  • Correct Answer
    Usually is negative as measured at the grid with respect to cathode
  • Usually is positive as measured at the grid with respect to cathode
  • Cannot be determined
  • None of the above

The DC bias in a Class A amplifier:

(A). Usually is negative as measured at the grid with respect to cathode

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What is the effect of incorrect grid bias in a Class A amplifier?

  • Distortion of the output waveshape
  • Possible excessive plate dissipation if the bias is too low
  • Correct Answer
    Both A & B
  • None of the above

What is the effect of incorrect grid bias in a Class A amplifier?

(C). Both A & B

  • Distortion of the output waveshape

  • Possible excessive plate dissipation if the bias is too low

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The approximate efficiency of a Class A vacuum tube amplifier:

  • Correct Answer
    20%-30%
  • 60%
  • 85%
  • 100%

The approximate efficiency of a Class A vacuum tube amplifier:

(A). 20%-30%

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The approximate efficiency of a Class B vacuum tube amplifier:

  • 20%-30%
  • Correct Answer
    60%
  • 85%
  • 100%

The approximate efficiency of a Class B vacuum tube amplifier:

(B). 60%

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The approximate efficiency of a Class C vacuum tube amplifier:

  • 20%-30%
  • 60%
  • Correct Answer
    85%
  • 100%

The approximate efficiency of a Class C vacuum tube amplifier:

(C). 85%

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A charge due to the accumulation of negative electrons because the plate potential cannot attract all of the electrons leaving the emitter:

  • Getter
  • Correct Answer
    Space charge
  • Plate saturation
  • None of the above

A charge due to the accumulation of negative electrons because the plate potential cannot attract all of the electrons leaving the emitter:

(B). Space charge

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A material flashed by the application of heat after the tube is evacuated that absorbs any gases remaining inside the tube:

  • Space charge
  • Correct Answer
    Getter
  • Collector
  • Emitter

A material flashed by the application of heat after the tube is evacuated that absorbs any gases remaining inside the tube:

(B). Getter

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What types of vacuum tube filaments are reactivated:

  • Barium berylliate
  • Correct Answer
    Thoriated tungsten
  • Nickel
  • Thorium oxide

What types of vacuum tube filaments are reactivated:

(B). Thoriated tungsten

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A tungsten filament is operated at ____ temperature than a thoriated tungsten filament:

  • Correct Answer
    A higher
  • A lower
  • The same
  • Unknown

A tungsten filament is operated at ____ temperature than a thoriated tungsten filament:

(A). A higher

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The presence of gas within a tube is indicated:

  • Correct Answer
    By a blue glow
  • By a red glow
  • By a yellow glow
  • None of the above

The presence of gas within a tube is indicated:

(A). By a blue glow

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The cathode of an indirectly heated type of vacuum tube should be maintained at nearly the same potential as the heater circuit:

  • To reduce hum pickup into the cathode
  • To prevent breakdown of the insulation between the heater and cathode
  • Correct Answer
    A & B
  • None of the above

The cathode of an indirectly heated type of vacuum tube should be maintained at nearly the same potential as the heater circuit:

(C). A & B

  • To reduce hum pickup into the cathode

  • To prevent breakdown of the insulation between the heater and cathode

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Transmitting tube filaments should be maintained at recommended voltages:

  • To realize the greatest life-expectancy
  • If the filament voltage is too low, the emission will be reduced and operation of the circuit may be adversely affected
  • If the voltage is too high, the filament may burn out
  • Correct Answer
    All of the above

Transmitting tube filaments should be maintained at recommended voltages:

(D). All of the above

  • To realize the greatest life-expectancy

  • If the filament voltage is too low, the emission will be reduced and operation of the circuit may be adversely affected

  • If the voltage is too high, the filament may burn out

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Use of an AC filament supply is desirable:

  • Correct Answer
    Mostly for practical reasons. It is easily obtainable
  • Hum may be introduced into the amplifier
  • A & B
  • None of the above

Use of an AC filament supply is desirable:

(A). Mostly for practical reasons. It is easily obtainable

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If a DC filament supply is used, it is advisable to periodically reverse the polarity of the filament potential:

  • Correct Answer
    To lengthen the life of the filament
  • To lengthen the life of the power source
  • Both A & B
  • None of the above

If a DC filament supply is used, it is advisable to periodically reverse the polarity of the filament potential:

(A). To lengthen the life of the filament

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Bias voltage on the grid of an AF amplifier tube:

  • Determines the operating conditions of the tube
  • The correct value is essential for undistorted Class A output
  • In power amplifiers the plate current must be limited to safe value not to exceed the rated plate dissipation of the tube
  • Correct Answer
    All of the above

Bias voltage on the grid of an AF amplifier tube:

  • Determines the operating conditions of the tube

  • The correct value is essential for undistorted Class A output

  • In power amplifiers the plate current must be limited to safe value not to exceed the rated plate dissipation of the tube

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The screen grid in a vacuum tube:

  • Makes it unnecessary to neutralize RF amplifiers except at very high frequencies,
  • Makes it possible to obtain much higher values of amplification than with triodes
  • Correct Answer
    A & B
  • None of the above

The screen grid in a vacuum tube:

(C). A & B

  • Makes it unnecessary to neutralize RF amplifiers except at very high frequencies,

  • Makes it possible to obtain much higher values of amplification than with triodes

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The suppressor grid in a multielement vacuum tube:

  • Is highly negative with respect to the plate
  • Returns secondary electrons to the plate
  • Increases the permissible gain and the efficiency of the tube
  • Correct Answer
    All of the above

The suppressor grid in a multielement vacuum tube:

(D). All of the above

  • Is highly negative with respect to the plate

  • Returns secondary electrons to the plate

  • Increases the permissible gain and the efficiency of the tube

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The gain of a triode audio amplifier is a function of:

  • Tube transconduction
  • Plate load impedance
  • Transformer step-up (if used)
  • Correct Answer
    All of the above

The gain of a triode audio amplifier is a function of:

(D). All of the above

  • Tube transconduction

  • Plate load impedance

  • Transformer step-up (if used)

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"Load" on a vacuum tube commonly refers to:

  • The impedance through which plate current flows to produce a useful output
  • Increases as the load impedance approaches the internal plate impedance in value
  • Correct Answer
    A & B
  • None of the above

"Load" on a vacuum tube commonly refers to:

(C). A & B

  • The impedance through which plate current flows to produce a useful output

  • Increases as the load impedance approaches the internal plate impedance in value

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A case in which the grid is held at an excessively negative value for a period of time thereby cutting off plate current:

  • Correct Answer
    Blocked grid
  • Blocked plate
  • Motorboating
  • Tuned grid

A case in which the grid is held at an excessively negative value for a period of time thereby cutting off plate current:

(A). Blocked grid

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The maximum power that can be safely and continuously dissipated in heat on the plate:

  • Correct Answer
    Maximum plate dissipation
  • Maximum power dissipation
  • Continuous plate dissipation
  • Plate heat dissipation

The maximum power that can be safely and continuously dissipated in heat on the plate:

(A). Maximum plate dissipation

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Occurs when plate current equals electron emission for any given filament or cathode temperature:

  • Correct Answer
    Plate saturation
  • Electron saturation
  • Filament saturation
  • None of the above

Occurs when plate current equals electron emission for any given filament or cathode temperature:

(A). Plate saturation

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The most desirable factor in the choice of a vacuum tube for a voltage amplifier:

  • A low value of transconductance
  • Correct Answer
    A high value of transconductance
  • High output tube capacitance
  • None of the above

The most desirable factor in the choice of a vacuum tube for a voltage amplifier:

(B). A high value of transconductance

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Lack of requirement for neutralizing, except at ultra high frequencies, is an advantage of a tetrode over ____:

  • Correct Answer
    A Triode
  • A Pentode
  • A & B
  • None of the above

Lack of requirement for neutralizing, except at ultra high frequencies, is an advantage of a tetrode over ____:

(A). A Triode

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Characteristics of a vacuum tube operating as a Class C amplifier:

  • Low plate circuit efficiency, about 25%; practically no grid driving power; plate current flowing for 360 degrees of each cycle; practically no distortion of the output waveshape
  • Plate circuit efficiency, about 50-60%; plate current flows slightly more than 180 degrees of each cycle; medium power output
  • Correct Answer
    High plate circuit efficiency, up to 80%; plate current drawn in bursts; great distortion of output waveshape
  • None of the above

Characteristics of a vacuum tube operating as a Class C amplifier:

(C). High plate circuit efficiency, up to 80%; plate current drawn in bursts; great distortion of output waveshape

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Plate current flows for less than 180 degrees (about 120 degrees when the grid bias is about twice cutoff value) in what class amplifier?

  • A
  • B
  • Correct Answer
    C
  • AB

Plate current flows for less than 180 degrees (about 120 degrees when the grid bias is about twice cutoff value) in what class amplifier?

(C). C.

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Tubes operated as Class C amplifiers are not suited for audio-frequency amplifiers:

  • Correct Answer
    Because of excessive distortion
  • Because of current requirement
  • Because of reduced life expectancy of the filament
  • None of the above

Tubes operated as Class C amplifiers are not suited for audio-frequency amplifiers:

(A). Because of excessive distortion

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Low plate current may be caused by:

  • Low filament emission and voltage
  • Excessive bias value, shorted screen by-pass capacitor
  • Open grid circuit, low screen grid supply voltage
  • Correct Answer
    All of the above

Low plate current may be caused by:

(D). All of the above

  • Low filament emission and voltage
  • Excessive bias value, shorted screen bypass capacitor
  • Open grid circuit, low screen grid supply voltage

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A tuned circuit made up of inductance and capacitance is:

  • Correct Answer
    An oscillator
  • A neutralizer
  • Voltage divider
  • None of the above

A tuned circuit made up of inductance and capacitance is:

(A). An oscillator

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Some radio-frequency amplifiers must be neutralized:

  • To maintain linear operation
  • Correct Answer
    To prevent sustained oscillations from occurring in the amplifier
  • Sustain feedback
  • None of the above

Some radio-frequency amplifiers must be neutralized:

(B). To prevent sustained oscillations from occurring in the amplifier

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Cavity resonators are:

  • A form of resonant tank circuit
  • Consist of a hollow metal cylinder bead on all sides
  • Have a very high Q and selectivity
  • Correct Answer
    All of the above

Cavity resonators are:

(D). All of the above

  • A form of resonant tank circuit
  • Consist of a hollow metal cylinder bead on all sides
  • Have a very high Q and selectivity

For more info, please see Cadence article on What is a Cavity Resonator and How is One Used in PCB Design

Also, Wikipedia's article on Resonators

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The diode detector:

  • Is square law on weak signals
  • Is practically linear on strong signals
  • Is square law on strong signals
  • Correct Answer
    A & B

The diode detector:

(D). A & B

  • Is square law on weak signals

  • Is practically linear on strong signals

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The functioning of a grid-leak detector:

  • Depends on the ability of the grid leak and capacitor to follow the average grid current variations which are directly proportioned to the modulation envelope
  • Depends on second harmonic distortion
  • Very sensitive to weak signals
  • Correct Answer
    A & C

The functioning of a grid-leak detector:

(D). A & C

  • Depends on the ability of the grid leak and capacitor to follow the average grid current variations which are directly proportioned to the modulation envelope

  • Very sensitive to weak signals

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Characteristic of a square law type of vacuum tube detector:

  • High sensitivity is provided due to the audio output signal amplitude being proportioned to the square of the radio frequency voltage
  • High percentage of second harmonic distortion
  • Works on weak signals only
  • Correct Answer
    All of the above

Characteristic of a square law type of vacuum tube detector:

(D). All of the above

  • High sensitivity is provided due to the audio output signal amplitude being proportioned to the square of the radio frequency voltage

  • High percentage of second harmonic distortion

  • Works on weak signals only

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A diode detector ordinarily produces ____ overall distortion of the audio output wave than does a triode detector:

  • Correct Answer
    Lower
  • Higher
  • Practically the same
  • Either A or B

A diode detector ordinarily produces ____ overall distortion of the audio output wave than does a triode detector:

(A). Lower

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Operating conditions for determining that a tube is being used as a power detector:

  • Bias at about cutoff
  • High input grid resistance
  • Plate circuit rectification
  • Correct Answer
    All of the above

Operating conditions for determining that a tube is being used as a power detector:

(D). All of the above

  • Bias at about cutoff
  • High input grid resistance
  • Plate circuit rectification

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Why is a center top usually provided for vacuum tube plate and grid return circuits when and AC filament supply is used?

  • Correct Answer
    To prevent hum voltage from modulating the normal signals
  • To allow more filament current
  • A & B
  • None of the above

Why is a center top usually provided for vacuum tube plate and grid return circuits when and AC filament supply is used?

(A). To prevent hum voltage from modulating the normal signals

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How would you determine the cathode-bias resistance necessary to provide correct grid bias for an amplifier?

  • Bias equals the IR drop across the cathode
  • Bias is found by dividing the desired DC bias voltage by the total no-signal cathode current
  • For a tetrode or pentode, the screen current must be added to the plate current
  • Correct Answer
    All of the above

How would you determine the cathode-bias resistance necessary to provide correct grid bias for an amplifier?

(D). All of the above

  • Bias equals the IR drop across the cathode

  • Bias is found by dividing the desired DC bias voltage by the total no-signal cathode current

  • For a tetrode or pentode, the screen current must be added to the plate current

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Given the following vacuum tube constants: Gp = 1000 V, Ip = 150 mA, Ig = 10 mA, Grid leaks = 5000 ohms. What would be the grid bias voltage?

  • Correct Answer
    50 V
  • 100 V
  • 25 V
  • None of the above

Given the following vacuum tube constants:
Gp = 1000 V,
Ip = 150 mA,
Ig = 10 mA,
Grid leaks = 5000 ohms.
What would be the grid bias voltage?

(A). 50 V

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What currents will be indicated by a milliammeter connected between the center top of the filament transformer of a tetrode and negative high voltage?

  • Plate current
  • Screen grid current
  • Correct Answer
    Combined plate and screen grid currents
  • None of the above

What currents will be indicated by a milliammeter connected between the center top of the filament transformer of a tetrode and negative high voltage?

(C). Combined plate and screen grid currents

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A dynatron oscillator is a ____ which depends upon the negative resistance characteristic of a tetrode tube for its operation:

  • Correct Answer
    Tuned circuit operation
  • Diode detector
  • Magnetron oscillator
  • Meystron oscillator

A dynatron oscillator is a ____ which depends upon the negative resistance characteristic of a tetrode tube for its operation:

(A). Tuned circuit operation

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Materials which can be used as crystal detectors:

  • Silicon, galena
  • Carborundum, iron pyrites
  • Silicon, iron pyrites
  • Correct Answer
    All of the above

Materials which can be used as crystal detectors:

(D). All of the above

  • Silicon, galena
  • Carborundum, iron pyrites
  • Silicon, iron pyrites

For more info, please see Electronics Notes site, article on Crystal Detector

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A power detector may be operated:

  • As a square law detector
  • As a linear detector
  • Correct Answer
    As either a square law detector or a linear detector
  • None of the above

A power detector may be operated:

(C). As either a square law detector or a linear detector

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Used to multiply the fundamental frequency by two:

  • Correct Answer
    Frequency doubler
  • Harmonic generator with a suitable resonant circuit
  • A & B
  • None of the above

Used to multiply the fundamental frequency by two:

(A). Frequency doubler

For more info, please see Mini-Circuits site article on Frequency Doublers: Introduction, definition of terms, Q&As

Also, please see Wikipedia's article on Frequency multiplier

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When used as an RF amplifier, a pentode vacuum tube:

  • Usually does not require neutralization
  • Usually requires neutralization
  • May require neutralization at ultra-high frequencies
  • Correct Answer
    A & C

When used as an RF amplifier, a pentode vacuum tube:

(D). A & C

  • Usually does not require neutralization

  • May require neutralization at ultra-high frequencies

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A quartz crystal in a radio transmitter:

  • Is used to provide a high degree of master-oscillator frequency stability
  • May be the sole tuned circuit in the oscillator
  • Correct Answer
    A & B
  • None of the above

A quartz crystal in a radio transmitter:

(C). A & B

  • Is used to provide a high degree of master-oscillator frequency stability

  • May be the sole tuned circuit in the oscillator

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Advantage of crystal control over tuned circuit oscillators:

  • Very high Q
  • Compact size
  • Excellent frequency stability
  • Correct Answer
    All of the above

Advantage of crystal control over tuned circuit oscillators:

(D). All of the above

  • Very high Q
  • Compact size
  • Excellent frequency stability

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If the crystal will undergo very small changes in its operating frequency with relatively large temperature variations:

  • A high-temperature coefficient crystal
  • Correct Answer
    A low-temperature coefficient crystal
  • A constant-temperature coefficient crystal
  • None of the above

If the crystal will undergo very small changes in its operating frequency with relatively large temperature variations:

B. A low-temperature coefficient crystal

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A separate source of power is sometimes desirable for crystal-oscillator units in a transmitter:

  • Correct Answer
    To prevent dynamic instability of the crystal oscillator
  • To prevent thermocoupling of the crystal oscillator
  • To prevent overtuning of the crystal oscillator
  • To cause dynamic instability of the crystal oscillator

A separate source of power is sometimes desirable for crystal-oscillator units in a transmitter:

(A). To prevent dynamic instability of the crystal oscillator

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"The temperature coefficient of an x-cut crystal is negative":

  • The operating frequency of the crystal will decrease as the temperature decreases
  • The operating frequency of the crystal will decrease as the temperature increases
  • The operating frequency of the crystal will increase as the temperature decreases
  • Correct Answer
    B & C

"The temperature coefficient of an x-cut crystal is negative":

(D). B & C

  • The operating frequency of the crystal will decrease as the temperature increases

  • The operating frequency of the crystal will increase as the temperature decreases

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If you apply DC voltage to the opposite plane surfaces of a quartz crystal:

  • The crystal plate will always undergo a physical distortion
  • The crystal might crack under the strain of displacement caused by too much voltage
  • Correct Answer
    A & B
  • None of the above

If you apply DC voltage to the opposite plane surfaces of a quartz crystal:

(C). A & B

  • The crystal plate will always undergo a physical distortion

  • The crystal might crack under the strain of displacement caused by too much voltage

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"The temperature coefficient of a y-cut crystal is positive" means:

  • The operating frequency of the crystal will decrease as the temperature decreases
  • The operating frequency of the crystal will increase as the temperature increases
  • The operating frequency of the crystal will decrease as the temperature increases
  • Correct Answer
    A & B

"The temperature coefficient of a y-cut crystal is positive" means:

(D). A & B

  • The operating frequency of the crystal will decrease as the temperature decreases

  • The operating frequency of the crystal will increase as the temperature increases

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Two dissimilar metals joined together and producing a current between them when the junction is heated is:

  • A point contact type transistor
  • Correct Answer
    A thermocouple
  • A junction contact type transistor
  • A solenoid

Two dissimilar metals joined together and producing a current between them when the junction is heated is:

(B). A thermocouple

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Waveguides:

  • A type of transmission line
  • Hollow rectangular or circular pipe
  • Fine application as transmission lines
  • Correct Answer
    All of the above

Waveguides:

(D). All of the above

  • A type of transmission line
  • Hollow rectangular or circular pipe
  • Fine application as transmission lines

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Transistors may be compared to a conventional triode vacuum tube functionally:

  • Emitter corresponds to the cathode
  • Collector corresponds to the plate
  • Base corresponds to the grid
  • Correct Answer
    All of the above

Transistors may be compared to a conventional triode vacuum tube functionally:

(D). All of the above

  • Emitter corresponds to the cathode
  • Collector corresponds to the plate
  • Base corresponds to the grid

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Types of transistors:

  • Point-contact
  • Junction
  • Correct Answer
    Both A & B
  • NPP

Types of transistors:

(C). Both A & B

  • Point-contact
  • Junction

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When using and storing crystal microphones:

  • They should be protected from shock and vibration
  • They should be protected from humidity
  • They should be protected from high temperatures
  • Correct Answer
    All of the above

When using and storing crystal microphones:

(D). All of the above

They should be protected from:

  • shock and vibration
  • humidity
  • high temperatures

For more info, please see Sweetwater site article on
How to Take Care of Your Microphones

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What effect does a change in the dielectric constant of a capacitor dielectric material have upon the capacitance of a capacitor:

  • Correct Answer
    Capacity varies directly with the dielectric constant
  • Capacity may fluctuate wildly
  • There is no effect upon the capacitance
  • None of the above

What effect does a change in the dielectric constant of a capacitor dielectric material have upon the capacitance of a capacitor:

(A). Capacity varies directly with the dielectric constant

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Increasing the number of plates of a capacitor:

  • Correct Answer
    Will increase the capacitance
  • Will decrease the capacitance
  • Will have no effect on the capacitance
  • Will make the capacitance fluctuate

Increasing the number of plates of a capacitor:

(A). Will increase the capacitance

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If the dielectric constants of a capacitor dielectric material between the capacitor plates were changed from 1 to 1:

  • Correct Answer
    The capacitance would be twice its original value
  • The capacitance would be half its original value
  • The capacitance would decay rapidly
  • None of the above

If the dielectric constants of a capacitor dielectric material between the capacitor plates were changed from 1 to 1:

(A). The capacitance would be twice its original value

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Contacts which slide together on opening and closing:

  • Are butt joined
  • Are known as self-wiping
  • Keep the contacts clean by their action
  • Correct Answer
    B & C

Contacts which slide together on opening and closing:

(D). B & C

  • Are known as self-wiping

  • Keep the contacts clean by their action

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Permanent magnets used in head telephones:

  • Place the diaphragms under tension so that the sensitivity of the telephones will be increased
  • Improve the frequency response
  • Prevents production of second harmonics in the telephones
  • Correct Answer
    All of the above

Permanent magnets used in head telephones:

(D). All of the above

  • Place the diaphragms under tension so that the sensitivity of the telephones will be increased

  • Improve the frequency response

  • Prevents production of second harmonics in the telephones

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Emergency repairs to an inductance coil having burned or charred insulation:

  • Correct Answer
    Are generally impractical, short of rewinding the coil with good wire
  • Are always practical if repaired by coating the bad turns with insulating varnish
  • A & B
  • None of the above

Emergency repairs to an inductance coil having burned or charred insulation:

(A). Are generally impractical, short of rewinding the coil with good wire

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Indications of a defective vacuum tube in a transmitter:

  • Gas blow within the tube, excessive plate color due to overheating
  • No light from the filament, insufficient plate current, reduced output
  • Excessive plate current, possible internal arcing, fluctuating plate or grid current
  • Correct Answer
    All of the above

Indications of a defective vacuum tube in a transmitter:

(D). All of the above

  • Gas blow within the tube, excessive plate color due to overheating

  • No light from the filament, insufficient plate current, reduced output

  • Excessive plate current, possible internal arcing, fluctuating plate or grid current

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The breakdown voltage rating of a capacitor are determined by:

  • The type of dielectric material used
  • The thickness of the dielectric material
  • Correct Answer
    A & B
  • None of the above

The breakdown voltage rating of a capacitor are determined by:

(C). A & B

  • The type of dielectric material used

  • The thickness of the dielectric material

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Crystal surfaces should be free of dirt of grease to operate properly:

  • Do not touch the faces of the crystal with the fingers
  • Clean the faces with soap and water
  • Clean the faces with carbon tetrachloride
  • Correct Answer
    All of the above

Crystal surfaces should be free of dirt of grease to operate properly:

(D). All of the above

  • Do not touch the faces of the crystal with the fingers
  • Clean the faces with soap and water
  • Clean the faces with carbon tetrachloride

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A purplish glow from within a tube indicates:

  • A soft tube
  • A hard tube
  • Air or undesired gases within the tube
  • Correct Answer
    A & C

A purplish glow from within a tube indicates:

(D). A & C

  • A soft tube

  • Air or undesired gases within the tube

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Given a solenoid with a resistance of 5 ohms and 0.34 through the winding when 1108 at 60 Hz is applied. What is the impedance?

  • Correct Answer
    367 ohms
  • 350 ohms
  • 360 ohms
  • None of the above

Given a solenoid with
a resistance of 5 ohms and
0.34 through the winding when 1108
at 60 Hz is applied.
What is the impedance?

(A). 367 ohms

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Use of a low pass filter network:

  • Ripple filter in power supplies, harmonic suppression filters in antenna systems
  • Line noise filters, tone control systems
  • Crossover networks, output filters of detector circuits
  • Correct Answer
    All of the above

Use of a low pass filter network:

(D). All of the above

  • Ripple filter in power supplies, harmonic suppression filters in antenna systems

  • Line noise filters, tone control systems

  • Crossover networks, output filters of detector circuits

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A special type of power supply filter choke whose inductance is inversely proportioned to values of DC within specified limits is:

  • Smoothing choke
  • Correct Answer
    Swinging choke
  • Radio frequency choke
  • Audio frequency choke

A special type of power supply filter choke whose inductance is inversely proportioned to values of DC within specified limits is:

(B). Swinging choke

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The best suited material for use as an antenna strain insulator exposed to the elements:

  • Correct Answer
    Glazed porcelain
  • Glass
  • Graphite composite
  • Rubber

The best suited material for use as an antenna strain insulator exposed to the elements:

(A). Glazed porcelain

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Materials frequently used for relay contacts:

  • Tungsten
  • Silver
  • Gold
  • Correct Answer
    All of the above

Materials frequently used for relay contacts:

(D). All of the above

  • Tungsten
  • Silver
  • Gold

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Why is rosin used as a soldering flux?

  • It is noncorrosive
  • It allows a perfect soldering bond to be made
  • It possesses good insulation qualities
  • Correct Answer
    All of the above

Why is rosin used as a soldering flux?

(D). All of the above

  • It is non corrosive
  • It allows a perfect soldering bond to be made
  • It possesses good insulation qualities

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What substance is the most widely used in crystal oscillators?

  • Correct Answer
    Quartz
  • Galena
  • Silicon
  • Tourmaline

What substance is the most widely used in crystal oscillators?

(A). Quartz

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Why is an oscillator crystal operated at a constant temperature?

  • Just because, stupid!
  • Correct Answer
    To maintain a constant frequency output from the oscillator
  • Constant temperature allows easier frequency change
  • None of the above

Why is an oscillator crystal operated at a constant temperature?

(B). To maintain a constant frequency output from the oscillator

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The advantage of a single-button carbon microphone:

  • High output voltage
  • Sensitivity
  • Low cost
  • Correct Answer
    All of the above

The advantage of a single-button carbon microphone:

(D). All of the above

  • High output voltage
  • Sensitivity
  • Low cost

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A carbon microphone should not be:

  • Jarred while in operation
  • Tapped while in operation
  • Subjected to violent sound intensities
  • Correct Answer
    All of the above

A carbon microphone should not be:

(D). All of the above

  • Jarred while in operation
  • Tapped while in operation
  • Subjected to violent sound intensities

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In connecting head telephones directly in the plate circuit of a vacuum tube one should observe the proper polarity:

  • Correct Answer
    To maintain maximum sensitivity in the headphones
  • So its current flows opposed to the field strength of the permanent magnet
  • A & B
  • None of the above

In connecting head telephones directly in the plate circuit of a vacuum tube one should observe the proper polarity:

(A). To maintain maximum sensitivity in the headphones

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What should the plate current do in the operation of a Class B audio amplifier?

  • Correct Answer
    Fluctuate
  • Remain Steady
  • Increase
  • None of the above

What should the plate current do in the operation of a Class B audio amplifier?

(A). Fluctuate

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What turns ratio does a transformer need to match a source impedance of 500 ohms to a load of 10 ohms?

  • Correct Answer
    7.1 to 1
  • 7 to 1
  • 14 to 1
  • None of the above

What turns ratio does a transformer need to match a source impedance of 500 ohms to a load of 10 ohms?

(A). 7.1 to 1

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What microphones have a high impedance output?

  • Crystal
  • Dynamic
  • Correct Answer
    Any
  • None of the above

What microphones have a high impedance output?

(C). Any

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How may low impedance (75 ohm) head telephones be connected to the output of a vacuum tube?

  • By using an impedance matching transformer in the output stage
  • Connect them as a cathode bias resistor in the output stage
  • Correct Answer
    Either A or B
  • None of the above

How may low impedance (75 ohm) head telephones be connected to the output of a vacuum tube?

(C). Either A or B

  • By using an impedance matching transformer in the output stage

  • Connect them as a cathode bias resistor in the output stage

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Why do headphones usually have high-impedance windings?

  • They can usually be operated without an impedance matching transformer
  • They represent a closer match to the plate load impedance for the tube delivering necessary driving power than low impedance planes
  • Correct Answer
    A & B
  • None of the above

Why do headphones usually have high-impedance windings?

(C). A & B

  • They can usually be operated without an impedance matching transformer

  • They represent a closer match to the plate load impedance for the tube delivering necessary driving power than low impedance planes

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A "choke" coil:

  • Offers a relatively high impedance to AC currents
  • Has a high "Q" (low RF losses)
  • Offers a low resistance to DC currents
  • Correct Answer
    All of the above

A "choke" coil:

(D). All of the above

  • Offers a relatively high impedance to AC currents
  • Has a high "Q" (low RF losses)
  • Offers a low resistance to DC currents

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Why is correct grid bias necessary for audio frequency amplifier?

  • To minimize distortion
  • To set the operating conditions for determining the class of amplifications
  • So as not to exceed the rated plate dissipation of the tube
  • Correct Answer
    All of the above

Why is correct grid bias necessary for audio frequency amplifier?

(D). All of the above

  • To minimize distortion

  • To set the operating conditions for determining the class of amplifications

  • So as not to exceed the rated plate dissipation of the tube

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When a tube is used as a Class B amplifier what portion of the excitation voltage cycle does plate current flow?

  • Correct Answer
    Slightly more than 180 degrees
  • Slightly less than 180 degrees
  • 360 degrees
  • None of the above

When a tube is used as a Class B amplifier what portion of the excitation voltage cycle does plate current flow?

(A). Slightly more than 180 degrees

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A properly operated Class A audio amplifier:

  • Correct Answer
    Produces no serious modification of the input waveform
  • Serious distortion is present
  • A & B
  • All of the above

A properly operated Class A audio amplifier:

(A). Produces no serious modification of the input waveform

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What is the main advantage obtained by using two triodes in push-pull in a Class a audio frequency amplifier?

  • Increased power output
  • Cancellation of even harmonic distortion in the output
  • Elimination of DC saturation, elimination of cathode by-pass capacitor
  • Correct Answer
    All of the above

What is the main advantage obtained by using two triodes in push-pull in a Class a audio frequency amplifier?

(D). All of the above

  • Increased power output

  • Cancellation of even harmonic distortion in the output

  • Elimination of DC saturation, elimination of cathode by-pass capacitor

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What is the maximum permissible RMS value of audio voltage which can be applied to the grid of a Class A audio amplifier which has a grid bias of 10 V?

  • Correct Answer
    7.07 V
  • 8 V
  • 10 V
  • 14.14 V

What is the maximum permissible RMS value of audio voltage which can be applied to the grid of a Class A audio amplifier which has a grid bias of 10 V?

(A). 7.07 V

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Distortion in a Class A amplifier can be caused by:

  • Insufficient plate and screen potentials, incorrect grid bias defective rube
  • Leaky or shorted input coupling capacitor
  • Excessive anokutyde if grid signal, incorrect value of load impedance
  • Correct Answer
    All of the above

Distortion in a Class A amplifier can be caused by:

(D). All of the above

  • Insufficient plate and screen potentials, incorrect grid bias defective rube

  • Leaky or shorted input coupling capacitor

  • Excessive anokutyde if grid signal, incorrect value of load impedance

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Vacuum tubes operating as Class A amplifiers may be used as:

  • Audio power amplifiers, audio voltage amplifiers, microphones amplifiers, line amplifiers
  • Oscilloscope amplifiers, modulators
  • Phonograph amplifiers
  • Correct Answer
    All of the above

Vacuum tubes operating as Class A amplifiers may be used as:

(D). All of the above

  • Audio power amplifiers, audio voltage amplifiers, microphones amplifiers, line amplifiers
  • Oscilloscope amplifiers, modulators
  • Phonograph amplifiers

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Why is a push-pull audio frequency amplifier preferable to a single-tube stage?

  • Correct Answer
    When compared with a single-tube stage, power output is doubled
  • When compared with a single-tube stage, power output is the same
  • When compared with a single-tube stage, power output is cut in half
  • None of the above

Why is a push-pull audio frequency amplifier preferable to a single-tube stage?

(A). When compared with a single-tube stage, power output is doubled

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What is the DC plate voltage of a resistance-coupled amplifier state with a plate-supply voltage of 260 V, a plate current of 1 mA, and a plate load resistance of 100,000 ohms?

  • Correct Answer
    160 V
  • 100 V
  • 200 V
  • 60 V

What is the DC plate voltage of a resistance-coupled amplifier state with
a plate-supply voltage of 260 V,
a plate current of 1 mA, and
a plate load resistance of 100,000 ohms?

(A). 160 V

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Why is it necessary to use two tubes in a Class B audio amplifier?

  • Correct Answer
    To prevent the excessive distortion which would result from the use of only one tube in Class B
  • To eliminate hum
  • A & B
  • None of the above

Why is it necessary to use two tubes in a Class B audio amplifier?

(A). To prevent the excessive distortion which would result from the use of only one tube in Class B

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If the coupling capacitor leaked in a resistance-coupled audio frequency amplifier:

  • Excessive plate current would result
  • A large value of grid current would result
  • There would be extreme distortion, and very low gain
  • Correct Answer
    All of the above

If the coupling capacitor leaked in a resistance-coupled audio frequency amplifier:

(D). All of the above

  • Excessive plate current would result

  • A large value of grid current would result

  • There would be extreme distortion, and very low gain

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A vacuum tube operated Class C audio amplifier is not feasible, either in single or push-pull:

  • Since the plate current only flows 120 degrees, even in push-pull, only 2/3 of the cycle is reproduced and the resultant distortion would be unacceptable for audio
  • Tank circuits, which replace the missing portions of the cycle, can't be used in an audio amplifier because they only operate on one frequency
  • Correct Answer
    A & B
  • None of the above

A vacuum tube operated Class C audio amplifier is not feasible, either in single or push-pull:

(C). A & B

  • Since the plate current only flows 120 degrees, even in push-pull, only 2/3 of the cycle is reproduced and the resultant distortion would be unacceptable for audio

  • Tank circuits, which replace the missing portions of the cycle, can't be used in an audio amplifier because they only operate on one frequency

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Even harmonics may be reduced in the output of an audio frequency amplifier:

  • By operating the state push-pull
  • In a single tube amplifier, by operating the stage only on the linear part of the tube's characteristic curve
  • Correct Answer
    A & B
  • None of the above

Even harmonics may be reduced in the output of an audio frequency amplifier:

(C). A & B

  • By operating the state push-pull

  • In a single tube amplifier, by operating the stage only on the linear part of the tube's characteristic curve

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The main advantage of a tuned audio frequency amplifier in a receiver used for the reception of CW:

  • Correct Answer
    A reduction in interference from unwanted signals
  • The desired audio beat frequency is attenuates
  • A & B
  • None of the above

The main advantage of a tuned audio frequency amplifier in a receiver used for the reception of CW:

(A). A reduction in interference from unwanted signals

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Decoupling networks in the plate circuit of a multistage audio amplifier:

  • Correct Answer
    Prevents oscillations from occurring in the amplifier
  • Result in oscillations in the amplifier
  • Allow variable oscillations in the amplifier
  • None of the above

Decoupling networks in the plate circuit of a multistage audio amplifier:

(A). Prevents oscillations from occurring in the amplifier

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An audio-transformer is seldom used as the output device in the plate circuit of a tetrode audio-amplifier stage:

  • Correct Answer
    Because an ordinary transformer cannot supply enough impedance to the plate circuit
  • Because an ordinary transformer supplies too much impedance to the plate circuit
  • Because an ordinary transformer would be too costly
  • None of the above

An audio-transformer is seldom used as the output device in the plate circuit of a tetrode audio-amplifier stage:

(A). Because an ordinary transformer cannot supply enough impedance to the plate circuit

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The chief advantage of Class A audio operation is compared to the other classes of audio-frequency amplifiers:

  • Hum currents are in phase
  • Correct Answer
    Low distortion of the output signal
  • Tendency for regeneration is increased
  • Elimination of cathode bypass capacitors

The chief advantage of Class A audio operation is compared to the other classes of audio-frequency amplifiers:

(B). Low distortion of the output signal

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Which is not the principle advantage of transformer coupling compared to resistance coupling in audio-frequency amplifiers?

  • Greater gain per stage
  • Can provide necessary impedance matching
  • A & B
  • Correct Answer
    A transformer is expensive, heavy, and bulky

Which is not the principle advantage of transformer coupling compared to resistance coupling in audio-frequency amplifiers?

(D). A transformer is expensive, heavy, and bulky

Transformers are used to move electricity between coils. It can increase, decrease, or change AC to DC. When electricity moves, it creates magnetic field.

For more info, please see Wikipedia's article on Transformer, and also Inductive coupling.

Also, Elprocus site for article on What is Transformer Coupled Amplifier and Its Working

A comprehensive info on ScienceDirect site article on Coupling Transformer, which includes info on digital audio productions.

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Efficiency of a power transformer is determined by:

  • Eddy current losses
  • Hysteresis losses
  • Copper losses
  • Correct Answer
    All of the above

Efficiency of a power transformer is determined by:

(D). All of the above

  • Eddy current losses
  • Hysteresis losses
  • Copper losses

For detailed info, please see Elprocus site article on What is the Efficiency of Transformer & Its Derivation

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The ratios of primary and secondary currents in a power transformer:

  • Are approximately in inverse ratio to the turns ratio
  • Is to some extent affected by the diameter of the primary and secondary wire
  • The current ratio is in inverse proportion to the voltage ratio
  • Correct Answer
    All of the above

The ratios of primary and secondary currents in a power transformer:

(D). All of the above

  • Are approximately in inverse ratio to the turns ratio
  • Is to some extent affected by the diameter of the primary and secondary wire
  • The current ratio is in inverse proportion to the voltage ratio

For more info, please see Wikipedia's article on Transformer, and also Inductive coupling.

Also, Elprocus site for article on What is Transformer Coupled Amplifier and Its Working

A comprehensive info on ScienceDirect site article on Coupling Transformer, which includes info on digital audio productions.

For detailed info, please see Elprocus site article on What is the Efficiency of Transformer & Its Derivation

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A transformer has a primary voltage of 100, primary turns = 200, and secondary turns = 40. What is the secondary voltage?

  • Correct Answer
    20 V
  • 240 V
  • 140 V
  • 340 V

A transformer has a
primary voltage of 100,
primary turns = 200, and
secondary turns = 40.
What is the secondary voltage?

(A). 20 V

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What factors determine the no-load voltage ratio of a power transformer?

  • Power ratio
  • Correct Answer
    Turns ratio
  • Voltage ratio
  • Power factor

What factors determine the no-load voltage ratio of a power transformer?

(B). Turns ratio.

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The turns ratio of a transformer varies:

  • Correct Answer
    As the square root of the impedance ratio
  • As the square of the impedance ratio
  • As one-half the impedance ratio
  • As twice the impedance ratio

The turns ratio of a transformer varies:

(A). As the square root of the impedance ratio

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Primary cells:

  • Can be recharged
  • Cannot be recharged
  • An attempt to recharge it would not restore the eroded electrode
  • Correct Answer
    B & D

Primary cells:

(D). B & D

THIS IS A MISPRINT: The FCC Pool shows
D
Primary cells:
A..Can be recharged
B..Cannot be recharged
C..An attempt to recharge it would not restore the eroded electrode.
.B & D

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Secondary cells:

  • Can be recharged
  • Cannot be recharged
  • The products of the chemical change are not soluble in the electrolyte
  • Correct Answer
    A & C

Secondary cells:

(D). A & C

  • Can be recharged

  • The products of the chemical change are not soluble in the electrolyte

For more info, see Wikipedia's article
History of the battery, article on
Battery nomenclature, and article
List of battery sizes

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The formation of hydrogen gas around the positive electrode of a primary cell is:

  • Depolarization
  • Correct Answer
    Polarization
  • Manganese dioxide
  • None of the above

The formation of hydrogen gas around the positive electrode of a primary cell is:

(B). Polarization

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A dry cell may be tested:

  • Must be tested under normal load condition
  • May be tested under no load condition
  • May be taken by any conventional voltmeter
  • Correct Answer
    A & C

A dry cell may be tested:

(D). A & C

  • Must be tested under normal load condition

  • May be taken by any conventional voltmeter

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In the usual type dry cell:

  • The negative electrode is made of zinc
  • The positive electrode is made of carbon
  • The negative electrode is made of zinc
  • Correct Answer
    A & B

In the usual type dry cell:

(D). A & B

  • The negative electrode is made of zinc

  • The positive electrode is made of carbon

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"A", "B", and "C" batteries are alike, but specifically constructed for a particular function. Explain:

  • "B" battery is for plate and screen power
  • "C" battery for grid bias voltage
  • "A" battery for filament power
  • Correct Answer
    All of the above

"A", "B", and "C" batteries are alike, but specifically constructed for a particular function. Explain:

(D). All of the above

  • "B" battery is for plate and screen power
  • "C" battery for grid bias voltage
  • "A" battery for filament power

The batteries in "the old days" were categorized by size and type. The A battery was the smallest, then B, C, and D. They were used for portable tube (valve) radios made before transistor radios.

The "A" type battery did power filaments, with a voltage from 1.5 Volts to 9 Volts.

The "B" type battery was used to power portable tube (valve) radios, with a from 22.5 Volts to about 90 Volts. For more info, see Medium site article What Happened to “B” Batteries?

The "C" type battery provided grid bias voltage to the control the grid. Since the tube (valve) grids did not use electric current, the grid bias voltage did not deplete the charge. For more info, please see Wikipedia's article C battery

Also, great overall info is on Wikipedia's article List of battery sizes and Vacuum tube battery

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The condition of a dry "B" battery may be determined:

  • By measuring the voltage under normal load
  • By measuring the voltage under no load
  • A loss of 20 % of the voltage under normal load indicates that the battery should be replaced
  • Correct Answer
    A & C

The condition of a dry "B" battery may be determined:

(D). A & C

  • By measuring the voltage under normal load

  • A loss of 20 % of the voltage under normal load indicates that the battery should be replaced

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Spare "B" batteries should be stored:

  • Correct Answer
    In a dry place
  • In a hot place
  • Anywhere
  • A & C

Spare "B" batteries should be stored:

(A). In a dry place

For more info, please see WikiHow site article on How to Store Batteries

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A means of comparing the weight of a volume of liquid with the same volume of distilled water:

  • Correct Answer
    Specific gravity
  • Specific mass
  • Specific volume
  • None of the above

A means of comparing the weight of a volume of liquid with the same volume of distilled water:

(A). Specific gravity

Specific gravity is the ratio of the substance as compared to the same volume of water. If a substance has a specific density of 5, it means that it is 5 times as dense as the water. A number less than 1 indicates a substance less dense than water.

For more info, please see Wikipedia's article on Relative density

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Edison type batteries:

  • Have plates up nickel
  • Have plates of iron
  • Have plates of compounds of nickel and iron
  • Correct Answer
    All of the above

Edison type batteries:

(D). All of the above

Have plates:

  • up nickel
  • of iron
  • of compounds of nickel and iron

For more info, see Wikipedia's article on Nickel–iron battery

Also, see Iron Edison site article on Nickel Iron (Ni-Fe) Battery

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The electrolyte of a lead-acid storage cell:

  • Concentrated sulfuric acid
  • Dilute sulfuric acid
  • Has a specific gravity about 1.3 fully charged
  • Correct Answer
    B & C

The electrolyte of a lead-acid storage cell:

(D). B & C

  • Dilute sulfuric acid
  • Has a specific gravity about 1.3 fully charged

For more info, see Wikipedia's article on Nickel–iron battery

Also, see Iron Edison site article on Nickel Iron (Ni-Fe) Battery

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The negative plate of a lead-acid storage cell:

  • Correct Answer
    Is composed of pure spongy lead
  • Is composed of lead peroxide
  • Is composed of a compound of pure spongy lead and lead peroxide
  • None of the above

The negative plate of a lead-acid storage cell:

(A). Is composed of pure spongy lead

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The positive plate of a lead-acid storage cell:

  • Is composed of pure spongy lead
  • Correct Answer
    Is composed of lead peroxide
  • Is composed of a compound of pure spongy lead and lead peroxide
  • None of the above

The positive plate of a lead-acid storage cell:

(B). Is composed of lead peroxide

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The chemical composition of the electrolyte in an Edison-type storage cell:

  • Is contained in a nickel-plated sheet steel tank
  • Has a specific gravity of about 1.200
  • Is a 21% solution of potassium and lithium hydroxides in distilled water
  • Correct Answer
    All of the above

The chemical composition of the electrolyte in an Edison-type storage cell:

(D). All of the above

  • Is contained in a nickel-plated sheet steel tank
  • Has a specific gravity of about 1.200
  • Is a 21% solution of potassium and lithium hydroxides in distilled water

For more info, see Wikipedia's article on Nickel–iron battery

Also, see Iron Edison site article on Nickel Iron (Ni-Fe) Battery

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The negative plate of an Edison-type storage cell is:

  • Correct Answer
    Finely powdered pure iron
  • Green oxide of nickel
  • Potassium oxide
  • None of the above

The negative plate of an Edison-type storage cell is:

(A). Finely powdered pure iron

For more info, see Wikipedia's article on Nickel–iron battery

Also, see Iron Edison site article on Nickel Iron (Ni-Fe) Battery

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The positive plate of an Edison-type storage cell is:

  • Finely powdered pure iron
  • Correct Answer
    Green oxide of nickel
  • Lithium oxide
  • None of the above

The positive plate of an Edison-type storage cell is:

(B). Green oxide of nickel

For more info, see Wikipedia's article on Nickel–iron battery

Also, see Iron Edison site article on Nickel Iron (Ni-Fe) Battery

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The average fully-charged voltage of an Edison storage cell is:

  • Correct Answer
    1.2 V
  • 1.5 V
  • 2 V
  • 1 V

The average fully-charged voltage of an Edison storage cell is:

(A). 1.2 V

For more info, see Wikipedia's article on Nickel–iron battery

Also, see Iron Edison site article on Nickel Iron (Ni-Fe) Battery

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Decrease in capacity of an Edison-type storage cell can be caused by:

  • Frequent overheating, and operating conditions over 115 degrees fahrenheit
  • Charging at less than the normal rate
  • Adding impure water to the electrolyte, or a weak or aged electrolyte
  • Correct Answer
    All of the above

Decrease in capacity of an Edison-type storage cell can be caused by:

(D). All of the above

  • Frequent overheating, and operating conditions over 115 degrees fahrenheit

  • Charging at less than the normal rate

  • Adding impure water to the electrolyte, or a weak or aged electrolyte

For more info, see Wikipedia's article on Nickel–iron battery

Also, see Iron Edison site article on Nickel Iron (Ni-Fe) Battery

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The average fully charged voltage of a lead-acid cell is:

  • 1.0 V
  • 1.56 V
  • Correct Answer
    2.06 V
  • 2.5 V

The average fully charged voltage of a lead-acid cell is:

(C). 2.06 V

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To increase the power output of a storage cell:

  • Correct Answer
    Low internal resistance is desirable
  • High internal resistance is desirable
  • Low terminal voltage under load is desirable
  • None of the above

To increase the power output of a storage cell:

(A). Low internal resistance is desirable

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The condition of charge of an Edison cell can be determined:

  • By reading the terminal voltage under load
  • By checking the voltage against a standard discharge curve
  • Correct Answer
    Both A & B
  • Checking the specific gravity

The condition of charge of an Edison cell can be determined:

(C). Both A & B

  • By reading the terminal voltage under load

  • By checking the voltage against a standard discharge curve

For more info, see Wikipedia's article on Nickel–iron battery

Also, see Iron Edison site article on Nickel Iron (Ni-Fe) Battery

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The charge of a lead-acid storage cell:

  • May be determined by hydrometer readings
  • By measuring voltage under a heavy load
  • Correct Answer
    A or B
  • None of the above

The charge of a lead-acid storage cell:

(C). A or B

  • May be determined by hydrometer readings
    OR
  • By measuring voltage under a heavy load

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Sulfation:

  • Reduces terminal voltage
  • Increases internal resistance
  • Reduces power output
  • Correct Answer
    All of the above

Sulfation:

(D). All of the above

  • Reduces terminal voltage
  • Increases internal resistance
  • Reduces power output

The lead plates of batteries allow the accumulation of lead sulfate crystals on the surface of the plates and in surface pores. This is called "sulfation."

If there is a substantial amount of sulfate crystal accumulation, the performance of the battery is degraded.

For more info, see Crown Battery's site article on What is a Sulfated Battery and How to Prevent It

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If the polarity is reversed when charging a storage cell:

  • No damage in a lead-acid cell unless excessive
  • Damage in an Edison-cell
  • No damage in an Edison-cell if temperatures below 115 degrees Fahrenheit
  • Correct Answer
    A & C

If the polarity is reversed when charging a storage cell:

(D). A & C

  • No damage in a lead-acid cell unless excessive

  • No damage in an Edison-cell if temperatures below 115 degrees Fahrenheit

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You may measure the voltage of a battery under heavy load:

  • Correct Answer
    To determine its condition of charge
  • To determine its polarity
  • To determine its age
  • None of the above

You may measure the voltage of a battery under heavy load:

(A). To determine its condition of charge

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If the voltage of some cells in a battery are found to be reversed, what is indicated?

  • Correct Answer
    Polarity was reversed while charging
  • Polarity was doubled while charging
  • Polarity has no influence of charging
  • Polarity was correct while charging

If the voltage of some cells in a battery are found to be reversed, what is indicated?

(A). Polarity was reversed while charging

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Distilled water should be added to a lead-acid storage cell:

  • To keep the electrolyte 1/4 inch above the to of the plates
  • To keep the useful plate area sufficient to maintain the full capacity of the cell
  • None of the above
  • Correct Answer
    A & B

Distilled water should be added to a lead-acid storage cell:

(D). A & B

  • To keep the electrolyte 1/4 inch above the to of the plates -

  • To keep the useful plate area sufficient to maintain the full capacity of the cell

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Local action in a lead-acid storage cell:

  • Causes a slow discharge in the cell
  • Forms a very hard sulfate on the plates
  • May be reduced by trickle charging when the battery is not in actual use
  • Correct Answer
    All of the above

Local action in a lead-acid storage cell:

(D). All of the above

  • Causes a slow discharge in the cell
  • Forms a very hard sulfate on the plates
  • May be reduced by trickle charging when the battery is not in actual use

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To maintain a group of storage cells in good operating condition:

  • Observe correct charge and discharge rates
  • Overcharge about once a month to remove sulfation
  • Keep all terminal corrections clean and tight
  • Correct Answer
    All of the above

To maintain a group of storage cells in good operating condition:

(D). All of the above

  • Observe correct charge and discharge rates
  • Overcharge about once a month to remove sulfation
  • Keep all terminal corrections clean and tight

Battery corrosion can result from:

  • Battery electrolyte leakage due to physical damage.

  • Filling up the battery with too much water.

  • Copper connections may cause copper sulfate to corrode battery terminal stems.

  • When battery is overcharged, it can result in corrosion of terminals. Also, overcharged batteries heat up and physically expand.

  • The useful life of battery expiration

Clean corroded terminal stems with:

  • Baking soda with water
  • Drinking soda, such as colas.
  • Metal whisk brushes

Prevent corrosion by applying:

  • Anti-corrosion spray
  • Grease, such as petroleum jelly, or synthetic
  • Battery-specific grease

For more info, see Carcody site's article on Battery Terminal Corrosion: Why it happens & How to fix it

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What may cause the plates of a lead-acid call to buckle?

  • Excessive sulfation
  • Overheating
  • Overdischarging of the battery
  • Correct Answer
    All of the above

What may cause the plates of a lead-acid call to buckle?

(D). All of the above

  • Excessive sulfation
  • Overheating
  • Over discharging of the battery

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What may cause sulfation of a lead-acid cell?

  • It is a normal process
  • Overdischarging
  • Local action with improper charging
  • Correct Answer
    All of the above

What may cause sulfation of a lead-acid cell?

(D). All of the above

  • It is a normal process
  • Over discharging
  • Local action with improper charging

Battery corrosion can result from:

  • Battery electrolyte leakage due to physical damage.

  • Filling up the battery with too much water.

  • Copper connections may cause copper sulfate to corrode battery terminal stems.

  • When battery is overcharged, it can result in corrosion of terminals. Also, overcharged batteries heat up and physically expand.

  • The useful life of battery expiration

Clean corroded terminal stems with:

  • Baking soda with water
  • Drinking soda, such as colas.
  • Metal whisk brushes

Prevent corrosion by applying:

  • Anti-corrosion spray
  • Grease, such as petroleum jelly, or synthetic
  • Battery-specific grease

For more info, see Carcody site's article on Battery Terminal Corrosion: Why it happens & How to fix it

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What may be used to neutralize an acid electrolyte?

  • Ammonium hydroxide
  • Baking soda
  • Washing soda
  • Correct Answer
    All of the above

What may be used to neutralize an acid electrolyte?

(D). All of the above

  • Ammonium hydroxide
  • Baking soda
  • Washing soda

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To prevent corrosion of battery terminals:

  • Correct Answer
    Occasionally clean and coat them with Vaseline or other suitable lubricants
  • Use only brass terminals
  • Use only stainless steel terminals
  • Keep battery on trickles charge

To prevent corrosion of battery terminals:

(A). Occasionally clean and coat them with Vaseline or other suitable lubricants

Battery corrosion can result from:

  • Battery electrolyte leakage due to physical damage.

  • Filling up the battery with too much water.

  • Copper connections may cause copper sulfate to corrode battery terminal stems.

  • When battery is overcharged, it can result in corrosion of terminals. Also, overcharged batteries heat up and physically expand.

  • The useful life of battery expiration

Clean corroded terminal stems with:

  • Baking soda with water
  • Drinking soda, such as colas.
  • Metal whisk brushes

Prevent corrosion by applying:

  • Anti-corrosion spray
  • Grease, such as petroleum jelly, or synthetic
  • Battery-specific grease

For more info, see Carcody site's article on Battery Terminal Corrosion: Why it happens & How to fix it

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Why should there be ventilation to the room housing a large group of storage cells?

  • To prevent gas accumulation
  • To prevent overheating
  • To prevent the terminals from shorting
  • Correct Answer
    A & B

Why should there be ventilation to the room housing a large group of storage cells?

(D). A & B

  • To prevent gas accumulation
  • To prevent overheating

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Radio equipment on which electrolyte may be used:

  • Electrolyte capacitor
  • Electrolyte rectifier
  • Electrolyte detector
  • Correct Answer
    All of the above

Radio equipment on which electrolyte may be used:

(D). All of the above

Electrolyte:

  • capacitor
  • rectifier
  • detector

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What is the effect of low temperature on the operation of a lead-acid storage battery?

  • Electrolyte may freeze and split the battery if sg too low
  • The capacity is decreased
  • Correct Answer
    A & B
  • None of the above

What is the effect of low temperature on the operation of a lead-acid storage battery?

(C). A & B

  • Electrolyte may freeze and split the battery if sg too low
  • The capacity is decreased

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What form of energy is stored in a lead-acid storage battery?

  • Correct Answer
    Chemical
  • Mechanical
  • Heat
  • Light

What form of energy is stored in a lead-acid storage battery?

(A). Chemical

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How may polarity of a storage battery be determined?

  • Voltmeter
  • Salt water method
  • Correct Answer
    A & B
  • None of the above

How may polarity of a storage battery be determined?

(C). A & B

  • Voltmeter
  • Salt water method

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A battery with a terminal voltage of 12.5 V is to be trickle-charged at a 0.5 A rate. What resistance should be connected in series with the battery to charge from a 110 V line?

  • Correct Answer
    195 ohms
  • 300 ohms
  • 95 ohms
  • None of the above

A battery with a terminal voltage of 12.5 V
is to be trickle-charged at a 0.5 A rate.
What resistance should be connected in series with the battery to charge from a 110 V line?

(A). 195 ohms

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A discharged storage battery of 3 cells has an open circuit voltage of 1.8 V per cell and an internal resistance of 0.1 ohm per cell. What voltage is needed to give an initial charging rate of 10 A?

  • Correct Answer
    8.4 V
  • 10 V
  • 15 V
  • 12.5 V

A discharged storage battery of 3 cells
has an open circuit voltage of 1.8 V per cell and
an internal resistance of 0.1 ohm per cell.

What voltage is needed to give an initial charging rate of 10 A?

(A). 8.4 V

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What capacity in amperes of storage battery is required to operate a 50 W emergency transmitter for 6 hr.? Assume a continuous transmitter load of 70% of the key-locked demand of 40 A, and an emergency light load of 1.5 A.

  • A battery rated greater than 177 amperhours
  • A battery rated at least 177 amperhours
  • Correct Answer
    A & B
  • None of the above

Assume a continuous transmitter load of 70% of the key-locked demand of 40 A,
and an emergency light load of 1.5 A.

What capacity in amperes of storage battery is required to operate a 50 W emergency transmitter for 6 hr.?

(C). A & B

A battery rated:

  • greater than 177 amperhours
  • at least 177 amperhours

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If a receiver storage A battery could not be kept charged, and maintain the required watch period, what should you do?

  • Correct Answer
    Increase the charging rate
  • Get a new battery
  • Discontinue the required watch period
  • B & C

If a receiver storage A battery could not be kept charged, and maintain the required watch period, what should you do?

(A). Increase the charging rate

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Abnormally low input power terminal voltage of a lifeboat radiotelegraph transmitter while in operation could be caused by:

  • Reversed polarity
  • Excessive overload
  • A partially discharged battery
  • Correct Answer
    B & C

Abnormally low input power terminal voltage of a lifeboat radiotelegraph transmitter while in operation could be caused by:

(D). B & C

  • Excessive overload
  • A partially discharged battery

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If a battery has 12.4 V on open circuit and 12.2 V when its charging circuit is closed:

  • Correct Answer
    Could have polarity reversed
  • Could be overloaded
  • A & B
  • None of the above

If a battery has 12.4 V on open circuit
and 12.2 V when its charging circuit is closed:

(A). Could have polarity reversed

When charging, voltage should increase.

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The tops of lead-acid batteries should be kept dry:

  • To prevent slow discharge of the battery
  • To prevent terminal overload
  • To reduce the formation of terminal corrosion
  • Correct Answer
    A & C

The tops of lead-acid batteries should be kept dry:

(D). A & C

  • To prevent slow discharge of the battery

  • To reduce the formation of terminal corrosion

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When lead-acid cells are subject to low temperatures they should:

  • To prevent freezing
  • To provide the maximum capacity
  • Correct Answer
    A & B
  • None of the above

When lead-acid cells are subject to low temperatures they should:

(C). A & B

  • To prevent freezing
  • To provide the maximum capacity

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If an electrolyte in a lead-acid storage cell becomes low due to evaporation:

  • Correct Answer
    The level should be brought to about 1/4 inch above the tops of the plates with pure water
  • The level should be brought to about 1/4 inch above the tops of the plates with tap water
  • The level should be brought to about 1/4 inch above the tops of the plates with salt water
  • None of the above

If an electrolyte in a lead-acid storage cell becomes low due to evaporation:

(A). The level should be brought to about 1/4 inch above the tops of the plates with pure water

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An Edison storage battery should not be charged at less than the manufacturer's specified rate:

  • In order that the capacity of the battery shall be maximum after charge
  • The chemical reactions of the Edison-type cell
  • Correct Answer
    A & B
  • None of the above

An Edison storage battery should not be charged at less than the manufacturer's specified rate:

(C). A & B

  • In order that the capacity of the battery shall be maximum after charge

  • The chemical reactions of the Edison-type cell

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Your emergency battery has a specific gravity reading of 1.120. What should be done?

  • Place the battery on charge at once
  • Bring the electrolyte level to about 1/4 inch above the top of the plates
  • The battery will be fully charged when the specific gravity reads 1.280 to 1.300
  • Correct Answer
    All of the above

Your emergency battery has a specific gravity reading of 1.120. What should be done?

(D). All of the above

  • Place the battery on charge at once

  • Bring the electrolyte level to about 1/4 inch above the top of the plates

  • The battery will be fully charged when the specific gravity reads 1.280 to 1.300

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What care should be taken with selecting water to add to a storage cell?

  • Correct Answer
    It should be chemically pure or distilled
  • It should be only sea water
  • Tap water is as good as any
  • None of the above

What care should be taken with selecting water to add to a storage cell?

(A). It should be chemically pure or distilled

Water is needed along with the electrolyte to take H2O and split into H and 2O when charging a lead battery. During the charging a gas is released which can ignite, so marine batteries need to be vented. Also, water is lost, requiring additional watering of the battery. Water without any other mineral elements is a must. Never use tap water, as the minerals in it will reduce the capacity of the battery and increase charging time.

For detail info, please see Progressive Dynamics, Inc.'s article on Battery Basics

Also, look at West Marine site, article on How to Select a Marine Battery

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If the circuit breakers refuse to stay closed when you place the emergency batteries on charge, what is the trouble?

  • Internally shorted cells
  • Reversed charging polarity
  • Grounded circuit connections
  • Correct Answer
    Any of the above

If the circuit breakers refuse to stay closed when you place the emergency batteries on charge, what is the trouble?

(D). Any of the above

  • Internally shorted cells
  • Reversed charging polarity
  • Grounded circuit connections

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Heat developed within a storage cell under charge or discharge conditions is caused by:

  • I2R losses
  • Energy transfer due to chemical reactions
  • Correct Answer
    A & B
  • None of the above

Heat developed within a storage cell under charge or discharge conditions is caused by:

(C). A & B

  • I2R losses

  • Energy transfer due to chemical reactions

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How would you connect a group of similar cells in a storage battery to obtain the maximum zero resistance current?

  • Correct Answer
    In parallel
  • In series
  • In series/parallel
  • None of the above

How would you connect a group of similar cells in a storage battery to obtain the maximum zero resistance current?

(A). In parallel

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How would you connect a group of similar cells in a storage battery to obtain the maximum no-bond output voltage?

  • In parallel
  • Correct Answer
    In series
  • In series/parallel
  • None of the above

How would you connect a group of similar cells in a storage battery to obtain the maximum no-bond output voltage?

(B). In series

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What current will flow in a 6 V storage battery with an internal resistance of 0.01 ohms, when a 3 W, 6 V lamp is connected?

  • Correct Answer
    0.4995 A
  • 0.4885 A
  • 0.5566 A
  • 0.5795 A

What current will flow in a
6 V storage battery with
an internal resistance of 0.01 ohms,
when a 3 W, 6 V lamp is connected?

A. 0.4995 A

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The charging rate of a storage cell charged from a fixed voltage source decreases as the charging progresses opposition to the charging voltage?

  • Because as cell voltages increase, offering more opposition to the charging voltage
  • When the effective charging potential is reduced, the charging current is decreased
  • Correct Answer
    Both A & B
  • None of the above

The charging rate of a storage cell charged from a fixed voltage source decreases as the charging progresses opposition to the charging voltage?

(C). Both A & B

  • Because as cell voltages increase, offering more opposition to the charging voltage

  • When the effective charging potential is reduced, the charging current is decreased

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The principal function of the filter in a power supply:

  • To remove the variations in amplitude of the rectifier output
  • To provide a relatively unvarying DC voltage for use in the various circuits
  • Correct Answer
    Either A or B
  • None of the above

The principal function of the filter in a power supply:

(C). Either A or B

  • To remove the variations in amplitude of the rectifier output
    OR
  • To provide a relatively unvarying DC voltage for use in the various circuits

The power supply filters even out variations in flow of electrons in Direct Current circuits. There are capacitor filters and choke filters.

For more info, please see All About Circuits site article on An Introduction to Filters

Also, see Learn About Electronics Power Supplies article on Filter Circuits.

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Advantages of capacitor input and choke-input filters when used with rectifiers:

  • Capacitor-input filter provides higher output voltage under reasonably light load conditions
  • Choke-input filter offers better voltage regulations
  • Correct Answer
    A & B
  • None of the above

Advantages of capacitor input and choke-input filters when used with rectifiers:

(C). A & B

  • Capacitor-input filter provides higher output voltage under reasonably light load conditions

  • Choke-input filter offers better voltage regulations

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A high-resistance fixed resistor is shunted across each unit of a high voltage series capacitor bank in the power-supply filter circuit to:

  • Correct Answer
    Insure that the correct voltage appears across each unit
  • Discharge the capacitors
  • Does not insure the correct voltage across each unit
  • None of the above

A high-resistance fixed resistor is shunted across each unit of a high voltage series capacitor bank in the power-supply filter circuit to:

(A). Insure that the correct voltage appears across each unit

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Part of the secondary winding of a transmitters power transformer is accidentally shorted. What should be the immediate effect?

  • Correct Answer
    The current would rise to an excessive value and trip the circuit breaker
  • The short would burn the transformer
  • The current in the secondary winding would decrease
  • None of the above

Part of the secondary winding of a transmitters power transformer is accidentally shorted. What should be the immediate effect?

(A). The current would rise to an excessive value and trip the circuit breaker

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Bleeder resistors are used in power supplies:

  • To improve the output voltage regulation
  • They also discharge the filter capacitor when the power is turned off
  • Correct Answer
    Either A or B
  • None of the above

Bleeder resistors are used in power supplies:

(C). Either A or B

  • To improve the output voltage regulation
    OR
  • They also discharge the filter capacitor when the power is turned

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The ratio of the frequencies of the output and input circuits of a single-phase full-wave rectifier:

  • 1 to 1
  • Correct Answer
    2 to 1
  • 1 to 2
  • None of the above

The ratio of the frequencies of the output and input circuits of a single-phase full-wave rectifier:

(B). 2 to 1

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A capacitor is sometimes placed in series with the primary of a power transformer:

  • Correct Answer
    To improve the power factor
  • To improve output voltage regulation
  • To rectify the primary windings
  • None of the above

A capacitor is sometimes placed in series with the primary of a power transformer:

(A). To improve the power factor

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What is the maximum allowable secondary voltage of a transformer used as a center-tapped full-wave rectifier with tubes having a peak inverse voltage rating of 10,000 V?

  • Correct Answer
    7070 V
  • 14140 V
  • 10000 V
  • 5000 V

What is the maximum allowable secondary voltage of a transformer used as a center-tapped full-wave rectifier with tubes having a peak inverse voltage rating of 10,000 V?

(A). 7070 V

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If a 60 Hz transformer is connected to a 120 Hz source of the same voltage:

  • The impedance of the transformers would be greater
  • The current would be reduced
  • There would be a decrease in power delivered to the load
  • Correct Answer
    All the above

If a 60 Hz transformer is connected to a 120 Hz source of the same voltage:

(D). All the above

  • The impedance of the transformers would be greater

  • The current would be reduced

  • There would be a decrease in power delivered to the load

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If a 500 Hz transformer is connected to a 60 Hz source of the same voltage:

  • The primary would draw excessive current
  • The transformer would overheat
  • The primary might burn out
  • Correct Answer
    All of the above

If a 500 Hz transformer is connected to a 60 Hz source of the same voltage:

(D). All of the above

  • The primary would draw excessive current

  • The transformer would overheat

  • The primary might burn out

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A 500 Hz AC plate supply, rectified by a full-wave, unfiltered rectifier circuit. What would the emission be?

  • A modulated continuous wave of 500 Hz
  • A modulated continuous wave of 1000 Hz
  • A-2
  • Correct Answer
    All of the above

A 500 Hz AC plate supply, rectified by a full-wave, unfiltered rectifier circuit. What would the emission be?

(D). All of the above

  • A modulated continuous wave of 500 Hz

  • A modulated continuous wave of 1000 Hz

  • A-2

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The purpose of an air gap in a filter choke coil core. Which is the incorrect answer?

  • Correct Answer
    To decrease the effective inductance for the AC component of current by increasing the DC saturation
  • To increase the effective inductance for the AC component of current by decreasing the DC saturation
  • The inductance of the coil in general's decreased
  • All of the above

The purpose of an air gap in a filter choke coil core. Which is the incorrect answer?

(A). To decrease the effective inductance for the AC component of current by increasing the DC saturation

The purpose includes:

  • To increase the effective inductance for the AC component of current by decreasing the DC saturation

  • The inductance of the coil in general's decreased

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Loose laminations in a filter choke:

  • Make it impossible to firmly connect the choke in a circuit
  • A & C
  • Correct Answer
    Cause a buzzing or chattering sound
  • None of the above

Loose laminations in a filter choke:

(C). Cause a buzzing or chattering sound

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Poor regulation in a power supply may be caused by:

  • No bleeder resistance
  • High resistance filter chokes
  • Insufficient filter capacity
  • Correct Answer
    All of the above

Poor regulation in a power supply may be caused by:

(D). All of the above

  • No bleeder resistance

  • High resistance filter chokes

  • Insufficient filter capacity

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Why should the case of a high-voltage transformer be grounded?

  • To protect personnel handling the equipment from shock
  • To prevent high static voltages building up between the case and grounds
  • Correct Answer
    A & B
  • None of the above

Why should the case of a high-voltage transformer be grounded?

(C). A & B

  • To protect personnel handling the equipment from shock

  • To prevent high static voltages building up between the case and grounds

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When connecting electrolytic capacitors in series:

  • Correct Answer
    Observe the polarity marked on the component
  • There is no polarity to observe
  • Connect anode to anode
  • Connect cathode to cathode

When connecting electrolytic capacitors in series:

(A). Observe the polarity marked on the component

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Full wave rectification has ____ than half-wave:

  • Better output voltage regulation
  • Smaller filter components for a given ripple percentage
  • Correct Answer
    A and B
  • None of the above

Full wave rectification has ____ than half-wave:

(C). A and B

  • Better output voltage regulation

  • Smaller filter components for a given ripple percentage

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Voltage regulation is ____ with a high resistance choke:

  • Correct Answer
    Made worse
  • Made better
  • The same
  • None of the above

Voltage regulation is ____ with a high resistance choke:

(A). Made worse

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Electrolyte capacitors are desirable over other types because:

  • A large capacitance may be obtained with small physical dimensions
  • They have a cathode
  • The wet-type electrolytic capacitor is "self-healing"
  • Correct Answer
    A & C

Electrolyte capacitors are desirable over other types because:

(D). A & C

  • A large capacitance may be obtained with small physical dimensions

  • The wet-type electrolytic capacitor is "self-healing"

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The most common values of chokes range from:

  • Correct Answer
    5 H to 30 H
  • 30 H-100 H
  • 1 H to 100 H
  • 100 H to 1000 H

The most common values of chokes range from:

(A). 5 H to 30 H

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The power transformer and rectifier of a radio receiver are designed to supply a plate voltage of 250 V when operating from a 110 V 60 Hz supply, if the transformer is connected to 110 VDC what will happen?

  • The secondary would burn out
  • The primary would overheat and burn out
  • The circuit breaker would open to protect the circuit
  • Correct Answer
    Either A or B

The power transformer and rectifier of a radio receiver are designed to supply a plate
voltage of 250 V
when operating from a
110 V 60 Hz supply,
if the transformer is connected to 110 VDC what will happen?

(D). Either A or B

  • The secondary would burn out

  • The primary would overheat and burn out

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A shunt-wound DC motor:

  • Correct Answer
    Has a practically constant speed under widely varying load conditions
  • Has poor speed regulation under varying load conditions
  • High starting torque
  • None of the above

A shunt-wound DC motor:

(A). Has a practically constant speed under widely varying load conditions

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A series DC motor has:

  • Maximum torque at low speed
  • Quick starting
  • Poor speed regulation under varying loads
  • Correct Answer
    All of the above

A series DC motor has:

(D). All of the above

  • Maximum torque at low speed
  • Quick starting
  • Poor speed regulation under varying loads

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This partially counteracts the line voltage and so limits the armature current in a DC motor:

  • EMF
  • Correct Answer
    Counter EMF
  • Opposition EMF
  • None of the above

This partially counteracts the line voltage and so limits the armature current in a DC motor:

(B). Counter EMF

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A compound-wound DC motor:

  • Has constant speed under changing load conditions
  • Low starting torque
  • High starting torque
  • Correct Answer
    A & B

A compound-wound DC motor:

(D). A & B

  • Has constant speed under changing load conditions
  • Low starting torque
  • High starting torque

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Laminated iron is used in armature and field construction to:

  • Reduce eddy current losses
  • Offer a number of high-resistance paths to Eddy currents
  • Correct Answer
    A or B
  • None of the above

Laminated iron is used in armature and field construction to:

(C). A or B

  • Reduce eddy current losses
    OR
  • Offer a number of high-resistance paths to Eddy currents

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The ____ of a DC motor periodically change the armature coils to maintain one direction of rotation:

  • Field coils
  • Correct Answer
    Connector
  • Brushes
  • Auxiliary speed control

The ____ of a DC motor periodically change the armature coils to maintain one direction of rotation:

(B). Connector

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The speed of a series DC motor may increase and destroy the motor by centrifugal action:

  • Correct Answer
    When operated without a load
  • When operated on AC
  • When operated under varying load
  • None of the above

The speed of a series DC motor may increase and destroy the motor by centrifugal action:

(A). When operated without a load

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When the field of a shunt-wound DC motor opens while the machine is operating under no load:

  • Correct Answer
    The motor would race, and if unchoked, might destroy itself
  • The motor would quit running without damage
  • The motor would burn out the field coils
  • None of the above

When the field of a shunt-wound DC motor opens while the machine is operating under no load:

(A). The motor would race, and if unchoked, might destroy itself

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____ are used in a DC motor to reduce brush sparking without moving the brushes:

  • Interpoles
  • Commutating poles
  • Correct Answer
    Either A or B
  • None of the above

____ are used in a DC motor to reduce brush sparking without moving the brushes:

(C). Either A or B

  • Interpoles are used in a DC motor to reduce brush sparking without moving the brushes

  • Commutating poles are used in a DC motor to reduce brush sparking without moving the brushes

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A short in the armature coils of a DC motor causes:

  • No excessive sparking at the commutator brushes
  • No overheating of the motor
  • Correct Answer
    Reduction of speed under load, and excessive armature current
  • All of the above

A short in the armature coils of a DC motor causes:

(C). Reduction of speed under load, and excessive armature current

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The motor-field rheostat should be ____ when starting a DC motor generator set:

  • Minimum resistance in the armature circuit
  • Correct Answer
    Minimum resistance in the field circuit
  • Maximum resistance in the field circuit
  • None of the above

The motor-field rheostat should be ____ when starting a DC motor generator set:

(B). Minimum resistance in the field circuit

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If a motor generator fails to start when the start button is depressed, the trouble may be:

  • Blown fuse or tripped circuit breaker
  • Open armature or motor-field rheostat
  • Broken connections, defective brushes
  • Correct Answer
    All of the above

If a motor generator fails to start when the start button is depressed, the trouble may be:

(D). All of the above

  • Blown fuse or tripped circuit breaker

  • Open armature or motor-field rheostat

  • Broken connections, defective brushes

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When increased output is desired from a motor-generator, what is the usual procedure?

  • Correct Answer
    Decrease the resistance after rheostat in series with the generator field
  • Increase the resistance of the rheostat in series with the generator field
  • Output cannot be easily increased
  • Shut down the motor-generator and restart under full load

When increased output is desired from a motor-generator, what is the usual procedure?

(A). Decrease the resistance after rheostat in series with the generator field

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A dynamotor is:

  • A combination motor-generator which utilizes a common field winding
  • Usually run by battery power
  • A higher efficiency than a motor-generator
  • Correct Answer
    All of the above

A dynamotor is:

(D). All of the above

  • A combination motor-generator which utilizes a common field winding
  • Usually run by battery power
  • A higher efficiency than a motor-generator

The dynamotor has a single motor and generator coil with a single rotor. It can take input of a voltage that is different than the output voltage, such as DC current of low voltage input and turn it into DC current high voltage.

For more info see Wikipedia's article on Motor–generator and Instructables site's article on Reviving a WW2 Dynamotor, How Tube Radios Went Mobile During the War

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Output voltage of a dynamotor may be regulated:

  • Only by changing the speed of the motor
  • A series resistance in the output line could be used to reduce the available output voltage
  • Correct Answer
    Either A or B
  • None of the above

Output voltage of a dynamotor may be regulated:

(C). Either A or B

  • Only by changing the speed of the motor
    OR
  • A series resistance in the output line could be used to reduce the available output voltage

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What disadvantage is there to a dynamotor?

  • Compactness
  • Operating efficiency
  • It can be operated from batteries
  • Correct Answer
    Its output voltage is dependent on the source voltage stability

What disadvantage is there to a dynamotor?

(D). Its output voltage is dependent on the source voltage stability

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Causes of excessive sparking at the brushes of a DC motor or generator include:

  • Brushes not properly set at neutral point, dirt on commutator, motor overloaded
  • Weak spring tension on brushes, brushes worn, commutator worn eccentric
  • High mica-insulation between bars, commutator bars of uneven height
  • Correct Answer
    All of the above

Causes of excessive sparking at the brushes of a DC motor or generator include:

(D). All of the above

  • Brushes not properly set at neutral point, dirt on commutator, motor overloaded

  • Weak spring tension on brushes, brushes worn, commutator worn eccentric

  • High mica-insulation between bars, commutator bars of uneven height

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By-pass capacitors are often connected across the brushes of a high-voltage DC generator:

  • To regulate the voltage
  • To protect the generator winding from high voltage surges
  • To reduce RF interference
  • Correct Answer
    B & C

By-pass capacitors are often connected across the brushes of a high-voltage DC generator:

(D). B & C

  • To protect the generator winding from high voltage surges
  • To reduce RF interference

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Causes of motor-generator bearing overheating include:

  • Incorrect kind of lubrication, lack of ventilation
  • Constant overload, dirt in bearings
  • Misalignment
  • Correct Answer
    All of the above

Causes of motor-generator bearing overheating include:

(D). All of the above

  • Incorrect kind of lubrication, lack of ventilation
  • Constant overload, dirt in bearings
  • Misalignment

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RF interference may be minimized:

  • By the use of brush by-pass capacitors
  • Low frequency filters
  • Shielding of long connecting leads
  • Correct Answer
    All of the above

RF interference may be minimized:

(D). All of the above

  • By the use of brush by-pass capacitors
  • Low frequency filters
  • Shielding of long connecting leads

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Emery cloth should never be used to clean the commutator of a motor or generator:

  • Correct Answer
    Because it contains particles which may lodge between commutator segments and cause short circuits
  • Because it may polish the commutator too smooth for good brush contact
  • Because it may decrease the insulating quality of its mica between the interpoles
  • None of the above

Emery cloth should never be used to clean the commutator of a motor or generator:

(A). Because it contains particles which may lodge between commutator segments and cause short circuits

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A 3 HP 100 V DC motor is 85% efficient when developing its rated output. What is the current?

  • Correct Answer
    23.93 A
  • 25 A
  • 20 A
  • 8.5 A

A 3 HP 100 V DC motor is
85% efficient when developing its rated output.
What is the current?

(A). 23.93 A

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The speed of a synchronous motor is determined:

  • By the number of pairs of poles
  • By the line frequency
  • By the load
  • Correct Answer
    A & B

The speed of a synchronous motor is determined:

(D). A & B

  • By the number of pairs of poles
  • By the line frequency

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The speed of an induction motor is determined:

  • By the number of pairs of poles
  • By the line frequency
  • By the load
  • Correct Answer
    All of the above

The speed of an induction motor is determined:

(D). All of the above

  • By the number of pairs of poles
  • By the line frequency
  • By the load

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The speed of a DC series motor is determined:

  • Correct Answer
    By the load
  • By the number of pairs of poles
  • By the commutator
  • None of the above

The speed of a DC series motor is determined:

(A). By the load

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What is the line current of a 7 HP motor operating on 120 V at full load, a power factor of 0.8, and 95% efficiency?

  • 56 A
  • Correct Answer
    57.2 A
  • 58 A
  • None of the above

What is the line current of a
7 HP motor operating on
120 V at full load,
a power factor of 0.8, and
95% efficiency?

(B). 57.2 A

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Alternators are usually rated in:

  • Correct Answer
    Volt-amperes output
  • Watts
  • Amperes
  • ***<This answer left blank by the FCC>

Alternators are usually rated in:

(A). Volt-amperes output

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What conditions must be met before two AC generators can be operated in parallel?

  • Output voltages must be equal, frequencies must match
  • Phase rotation, and relative phase positions must match
  • Correct Answer
    A & B
  • None of the above

What conditions must be met before two AC generators can be operated in parallel?

(C). A & B

  • Output voltages must be equal, frequencies must match
  • Phase rotation, and relative phase positions must match

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The voltage of an alternator will:

  • Correct Answer
    Decrease under load
  • Increase under load
  • Load has no effect on voltage
  • None of the above

The voltage of an alternator will:

(A). Decrease under load

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What effect will high coupling between the plate and grid circuits of a quartz-crystal oscillator have?

  • The grid to plate capacitance will be destroyed
  • The oscillation will be higher because of higher Q
  • Correct Answer
    Overheating of the crystal and possible breakage
  • Overmodulation

What effect will high coupling between the plate and grid circuits of a quartz-crystal oscillator have?

(C). Overheating of the crystal and possible breakage

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The operation of a dynatron oscillator depends on what?

  • The positive emission from the anode
  • Correct Answer
    The secondary emission from the anode
  • Cathode being in saturation
  • Positive resistance characteristic of the tetrode tube

The operation of a dynatron oscillator depends on what?

(B). The secondary emission from the anode

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To provide additional feedback voltage in a crystal oscillator what is sometimes needed?

  • Correct Answer
    An additional plate grid feedback capacitor
  • Adding a coupling circuit in series with the plate resistors
  • An astable multivibrator
  • A monostable multivibrator

To provide additional feedback voltage in a crystal oscillator what is sometimes needed?

(A). An additional plate grid feedback capacitor

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What is the primary reason for the use of a crystal controlled oscillator for use as a transmitter?

  • No cross-modulation
  • Increase in gain
  • Correct Answer
    Frequency stability
  • Impedance gain and wider bandpass

What is the primary reason for the use of a crystal controlled oscillator for use as a transmitter?

(C). Frequency stability

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What is are the advantages of self excited oscillator and master-oscillator power-amplifier transmitters?

  • The master-oscillator has fewer parts than the self-excited and is simpler to construct
  • Correct Answer
    The self-excited oscillator transmitter is simpler to construct and has fewer parts than the master-oscillator
  • Either A or B
  • Neither

What is are the advantages of self excited oscillator and master-oscillator power-amplifier transmitters?

(B). The self-excited oscillator transmitter is simpler to construct and has fewer parts than the master-oscillator

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The primary function of the power-amplifier stage of a marine radiotelegraph transmitter is:

  • To transmit messages concerning the safety and health of the ship personnel
  • To transmit messages concerning the weather and safety of upcoming storms
  • Both A and B
  • Correct Answer
    To improve the frequency stability of the oscillator

The primary function of the power-amplifier stage of a marine radiotelegraph transmitter is:

(D). To improve the frequency stability of the oscillator

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The buffer amplifier stage of a transmitter:

  • To hold any discriminator signals until verified by the varactor diode circuits
  • Buffers any signals that may have been imposed upon the carrier signal
  • Correct Answer
    To improve the frequency stability of the oscillator
  • Both A and C

The buffer amplifier stage of a transmitter:

(C). To improve the frequency stability of the oscillator

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Which class of amplifier is used in the final amplifier stage for maximum plate efficiency?

  • Class A
  • Class B
  • Correct Answer
    Class C
  • Filtered Class D

Which class of amplifier is used in the final amplifier stage for maximum plate efficiency?

(C). Class C

Because current passage happens only during active time, otherwise it passes at minimum. This results in minimum loss of electrons (amperes), making it an efficient power use.

For more info, please see Wikipedia's article on Power amplifier classes

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What class of amplifier is used as linear in order not to distort the modulation components?

  • Class A
  • Correct Answer
    Class B
  • Class C
  • None of the above

What class of amplifier is used as linear in order not to distort the modulation components?

(B). Class B

The Class B amplifiers produces output in proportion to the square of the input signal, making it appropriate for linear amplifiers.

For more info, please see Wikipedia's article on Power amplifier classes

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If a class B linear final R-F amplifier were in saturation and no modulation what would happen when modulated?

  • The carrier frequency would override the grid-plate current and the result would be positive shift resulting in amplification
  • The Class B linear amplifier only modulates below cut-off
  • Correct Answer
    A condition of negative carrier shift would be the result
  • Both A and B

If a class B linear final R-F amplifier were in saturation and no modulation what would happen when modulated?

(C). A condition of negative carrier shift would be the result

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A class C amplifier:

  • Has an output for the entire input signal cycle
  • Output is present for less than 180 degrees of the input cycle
  • Bias is set well beyond cutoff
  • Correct Answer
    Both B and C

A class C amplifier:

(D). Both B and C

The two correct answers are these:

  • B) Output is present for less than 180 degrees of the input cycle. A low drive cycle is characteristic of Class C amplifiers. The output element drives for less than 180 degrees of the input cycle, and that attribute causes the distortion for which that Class C amps are known.

  • C) Bias is set well beyond cutoff. The output element (usually a transistor) is biased so that it doesn't conduct for most of the input signal's duration.

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What effect would insufficient radio-frequency excitation have on Class C modulated amplifier output?

  • Correct Answer
    A negative carrier shift
  • A positive carrier shift
  • Both A and B
  • None of the above

What effect would insufficient radio-frequency excitation have on Class C modulated amplifier output?

(A). A negative carrier shift

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The second harmonic of a 380 kHz frequency is:

  • 1520 kHz
  • Correct Answer
    760 kHz
  • 190 kHz
  • 2

The second harmonic of a 380 kHz frequency is:

(B). 760 kHz

The second harmonic is always double the fundamental frequency. In this question, the fundamental frequency is 380 kHz.

Doubling this value yields the correct answer, 760 kHz.

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Two effects of over-excitation of a Class B amplifier grid circuit are:

  • Increased plate efficiency, decreased power output
  • Decreased plate efficiency, excessive grid current
  • Excessive plate current, excessive distortion
  • Correct Answer
    Both B and C

Two effects of over-excitation of a Class B amplifier grid circuit are:

(D). Both B and C

  • Decreased plate efficiency, excessive grid current
  • Excessive plate current, excessive distortion

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Three main factors to consider about grid-leak in a vacuum tube transmitter:

  • The value of grid leak current and grid leak anode to grid
  • The value of grid leak resistance and duration of time the grid current is flowing
  • Internal resistance of the tube between the grid and cathode
  • Correct Answer
    Both B and C

Three main factors to consider about grid-leak in a vacuum tube transmitter:

(D). Both B and C

  • The value of grid leak resistance and duration of time the grid current is flowing

  • Internal resistance of the tube between the grid and cathode

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How can an R-F amplifier stage be neutralized?

  • Correct Answer
    Vary the tuning of the plate tank circuit while observing the amp. meter
  • Vary the tuning of the plate tank circuit while observing the SWR meter
  • Neutralization is done by circuit design either by increasing the input impedance or lowering the inductance value
  • Both A and C are correct

How can an R-F amplifier stage be neutralized?

(A). Vary the tuning of the plate tank circuit while observing the amp. meter

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What is the purpose of a speech amplifier in connection with the modulator of a transmitter?

  • Used to raise the gain of signal after filtering
  • Correct Answer
    To raise the signal-to-noise ratio and the output voltage of microphones
  • To feed the mixer where signal-to-noise ratio is raised
  • To pre-amp the weaker of the two signals received

What is the purpose of a speech amplifier in connection with the modulator of a transmitter?

(B). To raise the signal-to-noise ratio and the output voltage of microphones

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When the first speech-amplifier of a transmitter were overexcited, but the modulation capabilities were not exceeded what would be the effect on the output?

  • The waveform would be sawtooth causing undermodulation
  • The waveform would be square wave creating cross-modulation
  • Correct Answer
    The output would be distorted
  • Both A and C

When the first speech-amplifier of a transmitter were overexcited, but the modulation capabilities were not exceeded what would be the effect on the output?

(C). The output would be distorted

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The bias of a grid-modulated R-F stage is adjusted:

  • Below cut-off frequency
  • At grid saturation
  • At bias
  • Correct Answer
    1 and half to 3 times plate current cutoff value

The bias of a grid-modulated R-F stage is adjusted:

(D). 1 and half to 3 times plate current cutoff value

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Given the following: (1) audio power for 100% modulation equals 50% of DC input power to RF modulated amplifier, (2) load presented to the modulated tube consists of the DC plate impedance of the modulated amplifier, (3) constant grid excitation voltage, very lot distortion, what type of modulation?

  • Grid
  • Correct Answer
    Plate
  • Cathode
  • Anode

Given the following:

(1) audio power for 100% modulation equals 50% of DC input power to RF modulated amplifier,

(2) load presented to the modulated tube consists of the DC plate impedance of the modulated amplifier,

(3) constant grid excitation voltage, very lot distortion,

what type of modulation?

(B). Plate

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Modulation occurring in an RF stage other than the final power amplifier:

  • High level
  • Correct Answer
    Low level
  • Pre-emphasis
  • Plate

Modulation occurring in an RF stage other than the final power amplifier:

(B). Low level

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The efficiency of a grid-bias modulated stage should be:

  • Maximum at complete modulation
  • Minimum at zero modulation
  • Correct Answer
    Either A or B
  • None of the above

The efficiency of a grid-bias modulated stage should be:

(C). Either A or B

  • Maximum at complete modulation
    OR
  • Minimum at zero modulation

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Does grid current flow in a grid-bias modulated stage under modulated conditions?

  • Grid current may exist during the positive porions of the AF cycle
  • Grid current may cause distortion
  • Correct Answer
    A and B
  • None of the above

Does grid current flow in a grid-bias modulated stage under modulated conditions?

(C). A and B

  • Grid current may exist during the positive portions of the AF cycle

  • Grid current may cause distortion

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What might be the cause of a positive shift in carrier amplitude during modulation?

  • Parasitic oscillations, excessive audio drive
  • Incorrect tuning of final amplifier
  • Insufficient RF excitation, incorrect neutralization
  • Correct Answer
    All of the above

What might be the cause of a positive shift in carrier amplitude during modulation?

(D). All of the above

  • Parasitic oscillations, excessive audio drive
  • Incorrect tuning of final amplifier
  • Insufficient RF excitation, incorrect neutralization

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For 100% modulation, DC power input to the modulated RF amplifier should:

  • Be the same as the AC power from the modulation
  • Correct Answer
    Be 1/2 the AC power from the modulation
  • Be 1/4 the AC power from the modulation
  • None of the above

For 100% modulation, DC power input to the modulated RF amplifier should:

(B). Be 1/2 the AC power from the modulation

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When a radiotelephone transmitter is 100% modulated by sinusoidal waveform , how much antenna current will be observed?

  • Correct Answer
    22.5 % increase
  • 22.5 % decrease
  • 12.25% increase
  • No change in antenna current

When a radiotelephone transmitter is 100% modulated by sinusoidal waveform , how much antenna current will be observed?

(A). 22.5 % increase

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What can be done in a Heising modulation system to obtain 100% modulation?

  • Correct Answer
    Use a series resistor between the amplifier and modulator in the DC plate supply
  • Nothing needs to be done
  • Use a series capacitor between amplifier and modulator in the DC grid supply
  • Both A and C

What can be done in a Heising modulation system to obtain 100% modulation?

(A) Use a series resistor between the amplifier and modulator in the DC plate supply

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A plate choke in a Heising modulator:

  • Builds up audio modulating voltages
  • Feeds audio modulating voltages to the plate of the RF modulated amplifier to produce plate modulation
  • Correct Answer
    A and B
  • None of the above

A plate choke in a Heising modulator:

(C). A and B

  • Builds up audio modulating voltages

  • Feeds audio modulating voltages to the plate of the RF modulated amplifier to produce plate modulation

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What value of sinusoidal audio power is required to insure 100% modulation when the DC plate input to a modulated Class C amplifier has an efficiency of 60 % , and is 200 W?

  • Correct Answer
    100 W
  • 50 W
  • 25 W
  • 12 W

What value of sinusoidal audio power is required to insure 100% modulation when the DC plate input to a modulated Class C amplifier has an efficiency of 60 % , and is 200 W?

(A). 100 W

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What would be the antenna current when a transmitter has an antenna current of 8 amp, under A -1, even if it is 100% modulated by sinusoidal modulation?

  • 9.8 amp
  • The antenna current will increase by 22.5%
  • Correct Answer
    Either A or B
  • None of the above

What would be the antenna current when a transmitter has an antenna current of 8 amp, under A -1, even if it is 100% modulated by sinusoidal modulation?

(C). Either A or B

  • 9.8 amp
    OR
  • The antenna current will increase by 22.5%

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If a transmitter is adjusted for maximum power for telegraph, what must be done to be amplitude modulated?

  • The plate voltage must be reduced
  • The plate voltage must be increased
  • Tubes would have to dissipate 1.5 times as much power if the plate voltage were not reduced
  • Correct Answer
    Both A and C

If a transmitter is adjusted for maximum power for telegraph, what must be done to be amplitude modulated?

(D). Both A and C

  • The plate voltage must be reduced

  • Tubes would have to dissipate 1.5 times as much power if the plate voltage were not reduced

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A series-fed plate circuit of a vacuum tube amplifier has a short circuit of the plate bypass capacitor. What happened?

  • It would short out the power supply
  • It would remove the plate voltage
  • It would possibly damage the power supply
  • Correct Answer
    All of the above

A series-fed plate circuit of a vacuum tube amplifier has a short circuit of the plate bypass capacitor. What happened?

(D). All of the above

It would:

  • short out the power supply
  • remove the plate voltage
  • possibly damage the power supply

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A shunt-fed plate circuit of a vacuum tube amplifier has a short circuit of the plate RF choke. What happens?

  • The plate tank circuit would be effectively shorted
  • The DC plate current would increase, possibly to excess
  • No RF output could be expected
  • Correct Answer
    All of the above

A shunt-fed plate circuit of a vacuum tube amplifier has a short circuit of the plate RF choke. What happens?

(D) All of the above

  • The plate tank circuit would be effectively shorted
  • The DC plate current would increase, possibly to excess
  • No RF output could be expected

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The total bandwidth of a transmitter using A-2 emission with a modulating frequency of 800 Hz and a carrier frequency of 500 kHz is:

  • Correct Answer
    1600 Hz
  • 1.6 kHz
  • 800 kHz
  • 1000 kHz

The total bandwidth of a transmitter using
A-2 emission with a modulating frequency of
800 Hz and a carrier frequency of
500 kHz is:

(A). 1600 Hz

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Given a vacuum tube of the following characteristics: plate voltage 1000 V, plate current 127 ma, filament current 5.4 amp, mutual conductance 8000 microvolts, and amplification factor of 25. What is the correct volume of negative grid bias for Class B amplifier?

  • Correct Answer
    40 V
  • 50 V
  • 30 V
  • 60 V

Given a vacuum tube of the following characteristics:
plate voltage 1000 V,
plate current 127 ma,
filament current 5.4 amp,
mutual conductance 8000 microvolts,
and amplification factor of 25.

What is the correct volume of negative grid bias for Class B amplifier?

(A). 40 V

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When the relative amplitudes of the positive and negative modulation peaks are unsymmetrical:

  • Correct Answer
    Carrier shift
  • Frequency shift
  • Amplifier shift
  • None of the above

When the relative amplitudes of the positive and negative modulation peaks are unsymmetrical:

(A). Carrier shift

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What may be used as indicating devices in neutralizing an RF amplifier stage?

  • Neon bulb, sensitive wavemeter
  • A flashlight bulb connected to a small loop of wire, a sensitive thermocoupler either attached to a small loop of wire
  • Amplifier grid current meter, a thermocouple meter connected in series with the plate tank
  • Correct Answer
    All of the above

What may be used as indicating devices in neutralizing an RF amplifier stage?

(D). All of the above

  • Neon bulb, sensitive wavemeter

  • A flashlight bulb connected to a small loop of wire, a sensitive thermocouple either attached to a small loop of wire

  • Amplifier grid current meter, a thermocouple meter connected in series with the plate tank

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Important factors in the operation of the vacuum tube as a frequency doubler are:

  • Plate tank should be tuned to twice the grid circuit frequency
  • The grid bias should be very large, the grid driving voltage must be very large, the plate voltage should be comparatively high
  • The plate tank circuit should have a low C to L ratio
  • Correct Answer
    All of the above

Important factors in the operation of the vacuum tube as a frequency doubler are:

(D). All of the above

  • Plate tank should be tuned to twice the grid circuit frequency

  • The grid bias should be very large, the grid driving voltage must be very large, the plate voltage should be comparatively high

  • The plate tank circuit should have a low C to L ratio

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If a 1500 kHz radio wave is modulated by a 2000 Hz sine wave tone, what frequencies does the modulated wave contain?

  • Correct Answer
    1500 kHz , 1502 kHz , 1498 kHz
  • 1500 MHz , 1502 MHz , 1498 MHz
  • 1500 Hz , 1502 Hz , 1498 Hz
  • None of the above

If a 1500 kHz radio wave is modulated by a 2000 Hz sine wave tone, what frequencies does the modulated wave contain?

(A). 1500 kHz , 1502 kHz , 1498 kHz

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To avoid damage to components what precautions should be observed in tuning a transmitter?

  • Correct Answer
    It should be adjusted at reduced power
  • It should be adjusted under normal power
  • Plate tank circuits are tuned for maximum DC current
  • None of the above

To avoid damage to components what precautions should be observed in tuning a transmitter?

(A). It should be adjusted at reduced power

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A transmitter has a master-oscillator, intermediate amplifier, and final amplifier. In what order should the circuit be adjusted in putting the transmitter in operation?

  • Correct Answer
    Master-oscillator, intermediate amplifier, final amplifier, antenna circuit
  • Antenna circuit, master-oscillator, intermediate amplifier, final amplifier
  • Final amplifier, antenna circuit, master-oscillator, intermediate amplifier
  • Master-oscillator, intermediate amplifier, antenna circuit, final amplifier

A transmitter has a master-oscillator, intermediate amplifier, and final amplifier. In what order should the circuit be adjusted in putting the transmitter in operation?

(A). Master-oscillator,
intermediate amplifier,
final amplifier,
antenna circuit

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Excessive plate current of an RF amplifier may be caused by:

  • Plate-tank circuit off resonance, defective tube
  • Excessive loading of plate tank, insufficient bias, parasitic oscillations
  • Excessive plate and screen voltage, excessive excitation voltage, improper neutralization
  • Correct Answer
    All of the above

Excessive plate current of an RF amplifier may be caused by:

(D). All of the above

  • Plate-tank circuit off resonance, defective tube

  • Excessive loading of plate tank, insufficient bias, parasitic oscillations

  • Excessive plate and screen voltage, excessive excitation voltage, improper neutralization

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The disadvantage of using a self-excited oscillator type of transmitter for shipboard service:

  • Correct Answer
    Frequency instability
  • Parasitic oscillations
  • Violent sound intensities
  • Large capacity

The disadvantage of using a self-excited oscillator type of transmitter for shipboard service:

(A). Frequency instability

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The degree of coupling is varied in a pi-network used to transfer energy from a vacuum tube plate circuit to an antenna:

  • Correct Answer
    By adjusting the series capacitors
  • By adjusting the tank capacitors
  • By changing the plate voltage
  • None of the above

The degree of coupling is varied in a pi-network used to transfer energy from a vacuum tube plate circuit to an antenna:

(A). By adjusting the series capacitors

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In order of selectivity, the best receivers are:

  • Correct Answer
    Superheterodyne, tuned radio frequency, superregenerative
  • Tuned radio-frequency, superheterodyne, superregenerative
  • Superregenerative, tuned radio-frequency, superheterodyne
  • Tuned radio frequency, superregenerative, superheterodyne

In order of selectivity, the best receivers are:

(A). Superheterodyne, tuned radio frequency, superregenerative

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An RF filter in the plate circuit of a tube detector is sometimes necessary to:

  • Correct Answer
    Prevent RF variations from affecting the following audio stages
  • Alter the impedance of the detector load circuit
  • Insert RF variations from affecting the audio stages
  • To prevent RF variations from affecting the following RF stages

An RF filter in the plate circuit of a tube detector is sometimes necessary to:

(A). Prevent RF variations from affecting the following audio stages

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In an RF amplifier with fixed bias, as the plate circuit is varied from below resonance to above resonance, what will the grid current do?

  • Correct Answer
    The grid current will rise slightly at resonance
  • The grid current will dip slightly at resonance
  • The grid current will not vary
  • None of the above

In an RF amplifier with fixed bias, as the plate circuit is varied from below resonance to above resonance, what will the grid current do?

(A). The grid current will rise slightly at resonance

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In a self-biased RF amplifier stage: plate voltage is 1250 V, plate current 150 ma, grid current 15 ma, grid-leak resistance of 4000 ohms, what is the operating grid bias?

  • Correct Answer
    60 V
  • 30 V
  • 90 V
  • 50 V

In a self-biased RF amplifier stage:
plate voltage is 1250 V,
plate current 150 ma,
grid current 15 ma,
grid-leak resistance of 4000 ohms,
what is the operating grid bias?

(A). 60 V

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How would you determine the cathode bias resistance necessary to provide correct grid bias for an amplifier?

  • Correct Answer
    Bias is equal to IR drop across the cathode resistance
  • Measure with a regular multimeter
  • Both A & B
  • None of the above

How would you determine the cathode bias resistance necessary to provide correct grid bias for an amplifier?

(A). Bias is equal to IR drop across the cathode resistance

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What is a method of link coupling between two R-F amplifier stages?

  • Correct Answer
    The coupling together of two circuits which may be separated by a relatively large distance with low-impedance
  • The coupling together of two circuits which may be separated by a relatively short distance
  • Isolating one R-F amplifier stage by using a closed loop coupler
  • Either B or C

What is a method of link coupling between two R-F amplifier stages?

(A). The coupling together of two circuits which may be separated by a relatively large distance with low-impedance

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Which type of amplifier circuit is used in a link coupling R-F?

  • Push-push
  • Correct Answer
    Push-pull
  • Phase splitter
  • FM discriminator

Which type of amplifier circuit is used in a link coupling R-F?

(B). Push-pull

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An advantage of link coupling between RF amplifier stages is:

  • The flexibility of mechanical construction possible
  • Reduction of tube capacitance effects on the L/C ratio of the tank circuits
  • Correct Answer
    Both A and B
  • Neither A or B

An advantage of link coupling between RF amplifier stages is:

(C). Both A and B

  • The flexibility of mechanical construction possible

  • Reduction of tube capacitance effects on the L/C ratio of the tank circuits

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What effect does excessive coupling between the output circuit of an oscillator and an antenna have?

  • The effect of cross-modulation of nearby frequencies
  • Instability of the oscillator and feedback op-amp
  • Correct Answer
    The oscillator will be very unstable
  • Frequency discrimination will be unstable

What effect does excessive coupling between the output circuit of an oscillator and an antenna have?

(C). The oscillator will be very unstable

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How is power output of a transmitter adjusted?

  • It should radiate the minimum power necessary to insure reliable communications
  • It may be controlled by varying the plate supply
  • Correct Answer
    Both A and B
  • None of the above

How is power output of a transmitter adjusted?

(C). Both A and B

  • It should radiate the minimum power necessary to insure reliable communications

  • It may be controlled by varying the plate supply

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When is a transmitter tuned to reduced power?

  • Correct Answer
    The receiver is initially reduced because the receiver is very sensitive
  • The receiver is non adjustable in almost all applications
  • The receiver has a pre-stage amplifier that self-adjusts
  • In the doubler stages

When is a transmitter tuned to reduced power?

(A). The receiver is initially reduced because the receiver is very sensitive

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What is meant by split tuning?

  • An effect resulting from excessive coupling between two tuned circuits which are at the same frequency
  • Also known as double hump
  • Also known as critical coupling
  • Correct Answer
    Both A and B

What is meant by split tuning?

(D). Both A and B

  • An effect resulting from excessive coupling between two tuned circuits which are at the same frequency

  • Also known as double hump

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What is a self rectified circuit?

  • Provides a tone frequency for F3F emissions
  • An op-amp circuit that provides a feed-back to the input
  • Correct Answer
    Provides a tone frequency for A-2 emissions
  • A self oscillating frequency discriminator circuit

What is a self rectified circuit?

(C). Provides a tone frequency for A-2 emissions

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What would be the dB change in field intensity at a given distance if the power is doubled?

  • Correct Answer
    3 dB
  • 6 dB
  • 2 dB
  • 10 dB

What would be the dB change in field intensity at a given distance if the power is doubled?

(A). 3 dB

To calculate dB change in field intensity, please see this simple and useful online calculator on A.H. Systems site Field Strength Calculation

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Keying can be accomplished at various points in a radiotelegraph transmitter. Some are:

  • At the primary of power transformer, at filament centertap, at screen grid circuit
  • At the control grid circuit, at the DC supply
  • Correct Answer
    A or B
  • None of the above

Keying can be accomplished at various points in a radiotelegraph transmitter. Some are:

(C). A or B

  • At the primary of power transformer, at filament center tap, at screen grid circuit
    OR
  • At the control grid circuit, at the DC supply

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What is the term used when the receiving operator may interrupt the transmitting operator at any point during transmission?

  • Modulation compandering
  • Interruption shift keying
  • Correct Answer
    Break-in operation
  • Transmission shift keying

What is the term used when the receiving operator may interrupt the transmitting operator at any point during transmission?

(C). Break-in operation

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Which of the following best explains frequency-shift keying?

  • The shifting of frequencies by modulating the carrier antenna
  • Changing the frequency of the input when the key is depressed
  • Correct Answer
    Changing the frequency of the output when the key is depressed
  • None of the above

Which of the following best explains frequency-shift keying?

(C). Changing the frequency of the output when the key is depressed

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What is one of the advantages frequency-shift keying has over "on-off" keying?

  • Increase of transmitter bandwidth
  • Decrease of signal-to-noise ratio
  • Correct Answer
    Increase of signal-to-noise ratio
  • Both A and C

What is one of the advantages frequency-shift keying has over "on-off" keying?

(C). Increase of signal-to-noise ratio

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Code speed or number of words per minute transmitted have what effect if any on the bandwidth of emission of a radiotelegraph transmitter?

  • Correct Answer
    It does have an effect. Bandwidth increases as the code speed is increased
  • No effect. Bandwidth decreases as the code speed is increased
  • Signal strength increases as the speed increases
  • Both A & C

Code speed or number of words per minute transmitted have what effect if any on the bandwidth of emission of a radiotelegraph transmitter?

(A). It does have an effect. Bandwidth increases as the code speed is increased

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Keying a simple-oscillator type of emergency transmitter may be accomplished by:

  • Correct Answer
    Inserting the key in series with the primary of the high voltage plate transformer
  • Inserting the key in parallel with the primary of the high voltage plate transformer
  • Inserting the key in series with the final output to the antenna
  • None of the above

Keying a simple-oscillator type of emergency transmitter may be accomplished by:

(A). Inserting the key in series with the primary of the high voltage plate transformer

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The plate current of the final RF amplifier in a transmitter increases and radiation decreases, if the antenna circuit is in good order, what could be the cause?

  • Neutralization may have been upset
  • The plate circuit may have been detuned, bias may have been lost
  • Grid excitation may have decreased, there may be a faulty tube, or there may be parasitic oscillations
  • Correct Answer
    All of the above

The plate current of the final RF amplifier in a transmitter increases and radiation decreases, if the antenna circuit is in good order, what could be the cause?

(D). All of the above

  • Neutralization may have been upset

  • The plate circuit may have been detuned, bias may have been lost

  • Grid excitation may have decreased, there may be a faulty tube, or there may be parasitic oscillations

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When hoisting a shipboard antenna, to avoid damage to the wire and insulators:

  • Avoid bending the wire
  • Avoid smashing the insulators against metal objects
  • Correct Answer
    A and B
  • None of the above

When hoisting a shipboard antenna, to avoid damage to the wire and insulators:

(C). A and B

  • Avoid bending the wire

  • Avoid smashing the insulators against metal objects

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If a field strength is 100 microvolts per meter at 100 miles, what is the field strength at 200 miles?

  • Correct Answer
    50 microvolts
  • 10 microvolts
  • 200 microvolts
  • 150 microvolts

If a field strength is
100 microvolts per meter at
100 miles, what is the field strength at
200 miles?

(A). 50 microvolts

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Field intensity is:

  • Correct Answer
    Directly proportional to the antenna current
  • Inversely proportional to the antenna current
  • Directly proportional to the square of the antenna current
  • Directly proportional to the square root of the antenna current

Field intensity is:

(A). Directly proportional to the antenna current

The electric field is like a magnetic cloud, and field intensity is a measure of the strength of the electrostatic force. If you ever got a spark after rubbing something, you've measured the field intensity of the electrostatic force.

For more info, please see OX Science site article on What is difference between electric field and electric field intensity?

To calculate field intensity, please see this simple and useful online calculator on A.H. Systems site Field Strength Calculation

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What point on a shipboard antenna system displays the maximum potential?

  • Correct Answer
    The end of the antenna furthest from the transmission line connections
  • The end of the antenna closest to the transmission line connections
  • Near the center of the antenna
  • None of the above

What point on a shipboard antenna system displays the maximum potential?

(A) The end of the antenna furthest from the transmission line connections

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A defective vacuum tube in a transmitter may be indicated by:

  • Gas glow within the tube
  • No light from the filament
  • Reduced output
  • Correct Answer
    All of the above

A defective vacuum tube in a transmitter may be indicated by:

(D). All of the above

  • Gas glow within the tube
  • No light from the filament
  • Reduced output

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A master-oscillator power-amplifier transmitter has been operating normally. The antenna ammeter suddenly reads zero. All filaments are burning and plate and grid meters read normal currents and voltages. What happened?

  • A shorted antenna ammeter
  • An open connection in the remote reading meter
  • Correct Answer
    Both a and b
  • None of the above
  • A master-oscillator power-amplifier transmitter has been operating normally.

  • The antenna ammeter suddenly reads zero.

  • All filaments are burning and plate and grid meters read normal currents and voltages.

What happened?

(C). Both a and b

  • A shorted antenna ammeter
  • An open connection in the remote reading meter

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Effects of dirty or salt-encrusted insulation are:

  • Erratic readings of antenna current
  • Increased corona discharge
  • Decreased radiation power
  • Correct Answer
    All of the above

Effects of dirty or salt-encrusted insulation are:

(D). All of the above

  • Erratic readings of antenna current
  • Increased corona discharge
  • Decreased radiation power

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To reduce the sparking at the contacts of a key used in a radiotelegraph transmitter:

  • Correct Answer
    Connect a suitable key-click filter across the key
  • Connect a suitable key-click filter in series with the key
  • Connect a suitable high-pass filter across the key
  • Increase the contact space of the key

To reduce the sparking at the contacts of a key used in a radiotelegraph transmitter:

(A). Connect a suitable key-click filter across the key

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In a self excited oscillator, a swinging antenna:

  • Correct Answer
    Will cause serious frequency instability
  • Will cause no noticeable frequency instability
  • May cause minor frequency instability
  • None of the above

In a self excited oscillator, a swinging antenna:

(A). Will cause serious frequency instability

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What may be observed as the antenna circuit is brought into resonance about the plate current of the final amplifier?

  • Correct Answer
    It will increase
  • It will decrease
  • It will remain constant
  • None of the above

What may be observed

  • as the antenna circuit is brought into resonance about the plate

{about the} current of the final amplifier?

(A). It will increase

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Instruments used to indicate various DC currents and voltages in a transmitter may be protected against damage to stray RF by:

  • Insufficient grid blocking bias is applied to the grid when the key is open
  • Shorted bias resistor
  • Shorted key-click filter
  • Correct Answer
    All of the above

Instruments used to indicate various DC currents and voltages in a transmitter may be protected against damage to stray RF by:

(D). All of the above

  • Insufficient grid blocking bias is applied to the grid when the key is open
  • Shorted bias resistor
  • Shorted key-click filter

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In a radiotelegraph transmitter with a DC generator plate voltage source, an AC generator filament supply, and grid-bias keying, what could be wrong when the emission continues with the key contacts open?

  • Insufficient grid blocking bias is applied to the grid when the key is open
  • Shorted bias resistor
  • Shorted key-click filter
  • Correct Answer
    All of the above

In a radiotelegraph transmitter

  • with a DC generator plate voltage source,
  • an AC generator filament supply, and
  • grid-bias keying,

what could be wrong when the emission continues with the key contacts open?

(D). All of the above

  • Insufficient grid blocking bias is applied to the grid when the key is open
  • Shorted bias resistor
  • Shorted key-click filter

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A station has an assigned frequency of 8000 kHz and a frequency tolerance of plus or minus 0.04%. The oscillator operates at 1/8th of the input. What is the maximum permitted deviation of the oscillation frequency in Hz, which will not exceed the tolerance?

  • Correct Answer
    Plus or minus 400 Hz
  • Plus or minus 320 Hz
  • Plus or minus 800 Hz
  • Plus or minus 640 Hz

A station has an assigned frequency of 8000 kHz and
a frequency tolerance of plus or minus 0.04%.

The oscillator operates at 1/8th of the input.

What is the maximum permitted deviation of the oscillation frequency in Hz,
which will not exceed the tolerance?

(A). Plus or minus 400 Hz

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A transmitter operating on 5000 kHz uses a 1000 kHz crystal with a tempered coefficient of - 4 Hz/MHz/0 degrees centigrade. What is the change in the output frequency of the transmitter if the temperature increases 6 degrees centigrade?

  • Correct Answer
    499.88 kHz
  • 5000.12 kHz
  • 4120.0 kHz
  • 5120.0 kHz

A transmitter operating on 5000 kHz
uses a 1000 kHz crystal
with a tempered coefficient of - 4 Hz/MHz/0 degrees
centigrade.

What is the change in the output frequency of the transmitter
if the temperature increases 6 degrees centigrade?

(A). 499.88 kHz

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The correct formula for determining the surge impedance of a quarter wavelength matching line is:

  • Impedance total equal 0.25 over 1 squared
  • Impedance total equal impedance of the antenna times impedance of the line squared over 1 times C.14
  • Correct Answer
    Impedance zero equal impedance of antenna times impedance of the line squared
  • None of the above

The correct formula for determining the surge impedance of a quarter wavelength matching line is:

(C). Impedance zero equal impedance of antenna times impedance of the line squared

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What are the three factors to consider when figuring the surge impedance of a non-resonant transmission line?

  • Correct Answer
    Diameter of the conductor, space between conductors, dielectric constant of insulating material
  • Voltage on RF line, diameter of conductors, space between dielectric
  • Diameter of shielding, space between dielectric constant, insulating shield around the conductor
  • None of the above

What are the three factors to consider when figuring the surge impedance of a non-resonant transmission line?

(A). Diameter of the conductor,
space between conductors,
dielectric constant of insulating material

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If the output frequency after passing through three doubler stages is 16,800 kHz, give the crystal frequency of a transmitter:

  • 2160 kHz
  • 2 GHz
  • Correct Answer
    2110 kHz
  • 2 kHz

If the output frequency after passing through three doubler stages is 16,800 kHz, give the crystal frequency of a transmitter:

(C). 2110 kHz

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Adding an inductor in series with an antenna will have what effect on the resonant frequency?

  • Correct Answer
    Decrease
  • Increase
  • Neutralization
  • Equalization

Adding an inductor in series with an antenna will have what effect on the resonant frequency?

(A). Decrease

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Adding a capacitor in series with an antenna will have what effect on resonant frequency?

  • Decrease
  • Correct Answer
    Increase
  • Neutralization
  • Equalization

Adding a capacitor in series with an antenna will have what effect on resonant frequency?

(B). Increase

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The radiated wavelength of a Hertzian antenna is:

  • 1/2 the physical length of the modulated coaxial
  • 1/4 the physical length of the modulated RF line
  • 1/2 the physical length of the antenna
  • Correct Answer
    Approximately twice the physical length of the antenna

The radiated wavelength of a Hertzian antenna is:

(D). Approximately twice the physical length of the antenna

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To operate on a lower resonant frequency on an available Marconi antenna which would be the correct procedure?

  • Add a capacitor in series with the antenna
  • Correct Answer
    Add an inductor in series with the antenna
  • Add a screen grid bypass capacitor parallel to the antenna trap
  • Add an RF choke across the feed line to ground

To operate on a lower resonant frequency on an available Marconi antenna which would be the correct procedure?

(B). Add an inductor in series with the antenna

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By reducing the physical length of a Hertzian antenna what are the results?

  • The resonant frequency will be reduced
  • The signal on a nearby frequency will be saturated upon modulation
  • The antenna trap is reduced causing cross modulation
  • Correct Answer
    The resonant frequency will increase

By reducing the physical length of a Hertzian antenna what are the results?

(D). The resonant frequency will increase

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Which antenna system has the ability to discriminate between various directions of receiving or transmitting?

  • 1/4 stub bi-directional
  • Multi-band Marconi 1/2 wave
  • 1/2 wavelength Yagi perpendicular polarized antenna
  • Correct Answer
    Single element vertical antenna

Which antenna system has the ability to discriminate between various directions of receiving or transmitting?

(D). Single element vertical antenna

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Given the current and resistance of the base of a Marconi antenna, what would be the formula for determining the power?

  • P = watts x amps
  • Correct Answer
    P = amps. squared x resistance
  • P = current x resistance
  • None of the above

Given the current and resistance of the base of a Marconi antenna, what would be the formula for determining the power?

(B). P = amps. squared x resistance

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A vertical loop antenna has a:

  • Omni-directional pattern which is maximum in the directions of the plane of the loop, and minimum in the directions broadside to the loop
  • Non-directional with regard to compass points
  • Has minimum radiation or reception in the direction of the ends of the antenna
  • Correct Answer
    Has a bi-directional pattern which is maximum in the direction of the plane of the loop, and minimum in the directions broadside to the loop

A vertical loop antenna has a:

(D). Has a bi-directional pattern which is maximum in the direction of the plane of the loop, and minimum in the directions broadside to the loop

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What modulation is contained in static and lightning radio waves?

  • All odd harmonic frequencies
  • All even harmonic frequencies
  • Correct Answer
    Amplitude modulation
  • Frequency modulation

What modulation is contained in static and lightning radio waves?

(C). Amplitude modulation

For insights, please see Wikipedia's article on Electromagnetic interference and Radio noise

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The difference between a Hertz and Marconi antenna is:

  • Correct Answer
    The physical length
  • The positioning of the capacitor feed traps
  • The grounding of RF shielding
  • None of the above

The difference between a Hertz and Marconi antenna is:

(A). The physical length

The length of a Hertz antenna is about a half of the frequency most suitable for transmission. The Hertz antenna is a dipole, half-length.

The Marconi antenna is a vertical antenna found in portable transmitters, with about quarter frequency length.

For more info, please see Evangelos Kranakis, School of Computer Science, Carleton University, Ottawa pdf presentation Antennae Basics page 6.

Also, see IEEExplore site pdf paper entitled Hertz and Marconi: A Comparison Between The Apparatus of Their Landmark Experiments

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What is meant by the term polarization of a radio wave?

  • Electromagnetic waves penetrate conductors because of eddy currents
  • Electromagnetically charged waves cross the zero axis in perpendicular patterns causing polarization to appear
  • Correct Answer
    The polarization of a radio wave is determined by the direction of the electromagnetic wave plane
  • The polarization of a radio wave is determined by the direction of the magnetic wave plane

What is meant by the term polarization of a radio wave?

(C). The polarization of a radio wave is determined by the direction of the electromagnetic wave plane

For more info, please see Wikipedia's article on Polarization (waves)

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What are the lowest frequencies used in radio communication today?

  • SSB voice
  • Double-sideband FM voice
  • Correct Answer
    15 kHz
  • 1 kHz to 5 kHz

What are the lowest frequencies used in radio communication today?

(C). 15 kHz

For more info, please see Wikipedia's article on
Low frequency and on Radio spectrum

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Radio frequencies that are useful for long distance communications requiring continuous operation:

  • Correct Answer
    Low frequency
  • High frequency
  • Very high frequency
  • Ultra high frequency

Radio frequencies that are useful for long distance communications requiring continuous operation:

(A). Low frequency

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Communication at frequencies in the order of 15 kHz are usually accomplished by ground waves, and require generation of ____ power outputs for reliable and continuous operation:

  • High power
  • Low power
  • Correct Answer
    Extremely high power
  • Extremely low power

Communication at frequencies in the order of 15 kHz are usually accomplished by ground waves, and require generation of ____ power outputs for reliable and continuous operation:

(C). Extremely high power

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Frequencies with substantially line propagations:

  • VHF, UHF, microwave
  • About 50-30,000 MHz
  • Correct Answer
    A & B
  • None of the above

Frequencies with substantially line propagations:

(C). A & B

  • VHF, UHF, microwave
  • About 50-30,000 MHz

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On an average yearly basis the received Trans-Atlantic signals increased in strength in proportion to the degree of ____. Made on the basis of the 11 year cycle:

  • Correct Answer
    Sun spot activity
  • Aurora borealis
  • Extratropical Advection
  • Perigean tide

On an average yearly basis the received Transatlantic signals increased in strength in proportion to the degree of ____.

Made on the basis of the 11 year cycle:

(A). Sun spot activity

For more info, please see NOAA'S Space Weather Prediction Center's article on Sunspots/Solar Cycle. and the article on Sun and Sun Spots

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Harmonic radiation is:

  • Radiation occurring on frequencies that are whole multiples of the original frequency
  • Is always higher than the fundamental frequency
  • Reduced by proper tuning of the transmitter
  • Correct Answer
    All of the above

Harmonic radiation is:

(D). All of the above

  • Radiation occurring on frequencies that are whole multiples of the original frequency

  • Is always higher than the fundamental frequency

  • Reduced by proper tuning of the transmitter

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Harmonic radiation from a transmitter may cause interference:

  • Where the fundamental signal cannot be heard because of "skip"
  • In other shipboard equipment
  • Correct Answer
    A & B
  • None of the above

Harmonic radiation from a transmitter may cause interference:

(C). A & B

  • Where the fundamental signal cannot be heard because of "skip"
  • In other shipboard equipment

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Why suppress RF harmonics in the output of a transmitter?

  • To prevent interference from occurring with other radio services
  • To restrict the bandwidth of the particular station to the legal limits
  • Correct Answer
    Both A & B
  • None of the above

Why suppress RF harmonics in the output of a transmitter?

(C). Both A & B

  • To prevent interference from occurring with other radio services

  • To restrict the bandwidth of the particular station to the legal limits

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A wavetrap in a receiver:

  • Correct Answer
    Prevents the effects of any undesired output of the receiver
  • Generates desired frequencies in the output of the receiver
  • A & B
  • None of the above

A wave trap in a receiver:

(A). Prevents the effects of any undesired output of the receiver

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The follow devices that could be used to indicate oscillation in a crystal oscillator are:

  • Plate DC milliammeter, grid DC ammeter, neon bulb
  • Thermogalvanometer, wavemeter
  • Flashlight bulb on a loop of wire, heterodyne type frequency meter
  • Correct Answer
    All of the above

The follow devices that could be used to indicate oscillation in a crystal oscillator are:

(D). All of the above

  • Plate DC milliammeter, grid DC ammeter, neon bulb
  • Thermo-galvanometer, wavemeter
  • Flashlight bulb on a loop of wire, heterodyne type frequency meter

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An artificial antenna sometimes used in testing a transmitter:

  • Dummy antenna
  • Dummy load
  • Prevents undesired radiation
  • Correct Answer
    All of the above

An artificial antenna sometimes used in testing a transmitter:

(D). All of the above

  • Dummy antenna
  • Dummy load
  • Prevents undesired radiation

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The system producing A-2 emission by a "chopper" may be thought of:

  • As a double-keying system
  • The automatic "chopper" turns the transmitter on and off at a rapid rate
  • The other key is a normal hand operated key
  • Correct Answer
    All of the above

The system producing A-2 emission by a "chopper" may be thought of:

(D). All of the above

  • As a double-keying system
  • The automatic "chopper" turns the transmitter on and off at a rapid rate
  • The other key is a normal hand operated key

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Advantages of high-frequency radio communication:

  • Correct Answer
    The upper frequencies are substantially free of atmospheric interference, small antennas permit efficient mobile operation
  • Man-made noises are no problem, reflections may easily occur from buildings and other objects
  • A & B
  • None of the above

Advantages of high-frequency radio communication:

(A). The upper frequencies are substantially free of atmospheric interference, small antennas permit efficient mobile operation

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Transmitters that employ variometers rather than variable capacitors as tuning elements do so because of:

  • The size of required variable capacitors in the medium frequency band
  • There is no such thing as a variometer!
  • Variometers can be relatively compact
  • Correct Answer
    A & C

Transmitters that employ variometers rather than variable capacitors as tuning elements do so because of:

(D). A & C

  • The size of required variable capacitors in the medium frequency band
  • Variometers can be relatively compact

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The relationship between the antenna current and radiated power of an antenna:

  • P=I2 X R
  • Correct Answer
    P=I2 X radiated resistance
  • No relationship exists
  • P=E x I

The relationship between the antenna current and radiated power of an antenna:

(B). P=I2 X radiated resistance

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Iron compound cylinders found in inductances:

  • Increase Q
  • Increase selectivity
  • Increase gain
  • Correct Answer
    All of the above

Iron compound cylinders found in inductances:

(D). All of the above

Increase:

  • Q
  • selectivity
  • gain

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Modulation of an RF carrier produces in the plate circuit of the last radio stage of the system:

  • Correct Answer
    High-level modulation
  • Low-level modulation
  • Medium-level modulation
  • None of the above

Modulation of an RF carrier produces in the plate circuit of the last radio stage of the system:

(A). High-level modulation

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Basically, am FM receiver is a conventional superheterodyne but differs in:

  • The method of detection
  • The reduction of sensitivity to amplitude modulation
  • De-emphasis
  • Correct Answer
    All of the above

Basically, am FM receiver is a conventional superheterodyne but differs in:

(D). All of the above

  • The method of detection
  • The reduction of sensitivity to amplitude modulation
  • De-emphasis

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A form of regenerative receiver in which the detector breaks into and out of oscillation at a rate above audibility:

  • Correct Answer
    Superregenerative receiver
  • Superheterodyne receiver
  • Discriminator receiver
  • Detuned radio frequency receiver

A form of regenerative receiver in which the detector breaks into and out of oscillation at a rate above audibility:

(A). Superregenerative receiver

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A tuned RF amplifier stage ahead of the mixer stage in a superheterodyne receiver:

  • Improves receiver sensitivity, improves image rejection
  • Improves selectivity, improves stability
  • Improves signal-to-noise ratio, reduced interference
  • Correct Answer
    All of the above

A tuned RF amplifier stage ahead of the mixer stage in a superheterodyne receiver:

(D). All of the above

Improves:

  • receiver sensitivity,
  • image rejection
  • selectivity, improves stability
  • signal-to-noise ratio, reduced interference

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What is the "mixer" tube in the superheterodyne receiver?

  • Correct Answer
    The first detector
  • The second detector
  • The beat frequency oscillator
  • None of the above

What is the "mixer" tube in the superheterodyne receiver?

(A). The first detector

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An incoming signal causing image interference is ____ the IF above or below the frequency to which the receiver is tuned:

  • Correct Answer
    Twice
  • Three times
  • Half of
  • Three quarters of

An incoming signal causing image interference is ____ the IF above or below the frequency to which the receiver is tuned:

(A). Twice

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A superheterodyne receiver is adjusted to 2738 kHz. The IF is 475 kHz. What is the grid circuit of the second detector tuned to?

  • Correct Answer
    475 kHz
  • 950 kHz
  • 2263 kHz
  • 3213 kHz

A superheterodyne receiver is adjusted to 2738 kHz.
The IF is 475 kHz.
What is the grid circuit of the second detector tuned to?

(A). 475 kHz

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A superheterodyne receiver may not successfully be used for reception of frequencies very near the IF frequency:

  • Correct Answer
    Because those near frequencies would pass directly through the IF amplifier and not be greatly affected by the tuning of the RF or oscillator stages
  • Because those near frequencies would not pass directly through the IF amplifier
  • Because those near frequencies would be greatly affected by the tuning of the RF or oscillator stages
  • None of the above

A superheterodyne receiver may not successfully be used for reception of frequencies very near the IF frequency:

(A). Because those near frequencies would pass directly through the IF amplifier and not be greatly affected by the tuning of the RF or oscillator stages

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Some superheterodyne receives employ a crystal-controlled oscillator:

  • Correct Answer
    To insure maximum stability of operation
  • To reduce noise generated by a conventional oscillator
  • Because it require no shielding
  • To control feedback

Some superheterodyne receives employ a crystal-controlled oscillator:

(A). To insure maximum stability of operation

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To obtain maximum response to weak CW signals with a superheterodyne receiver:

  • RF gain control should be fully advanced
  • BFO control varied to obtain the clearest tone
  • AVC advanced to the best volume
  • Correct Answer
    All of the above

To obtain maximum response to weak CW signals with a superheterodyne receiver:

(D). All of the above

  • RF gain control should be fully advanced
  • BFO control varied to obtain the clearest tone
  • AVC advanced to the best volume

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Most receiver hiss is due to:

  • Correct Answer
    Noise generated in the first detector
  • Noise generated in the first AF amplifier
  • Faulty regeneration control
  • None of the above

Most receiver hiss is due to:

(A). Noise generated in the first detector

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High IF frequencies in a superheterodyne receiver:

  • Correct Answer
    Reduce image frequency response
  • Increases image frequency response
  • Places the image frequency as close as possible to the normal received frequency
  • None of the above

High IF frequencies in a superheterodyne receiver:

(A). Reduce image frequency response

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What is the IF of a superheterodyne receiver receiving on 1000 kHz and the mixing oscillator is tuned to 1500 kHz?

  • Correct Answer
    500 kHz
  • 2500 kHz
  • 2000 kHz
  • None of the above

What is the IF of a superheterodyne receiver receiving on 1000 kHz and the mixing oscillator is tuned to 1500 kHz?

(A). 500 kHz

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Image response may be minimized in a superheterodyne receiver:

  • By using one or more tuned RF stages ahead of the mixer
  • By choosing a suitable IF (such that the image frequency will fall within the receiver's operating range)
  • By choosing a suitable IF (such that the image frequency will fall outside of the receiver's operating range)
  • Correct Answer
    A & C

Image response may be minimized in a superheterodyne receiver:

(D). A & C

  • By using one or more tuned RF stages ahead of the mixer

  • By choosing a suitable IF (such that the image frequency will fall outside of the receiver's operating range)

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In a tuned RF receiver the heterodyne method, over the autodyne reception, has:

  • Great sensitivity
  • More stable operation of the circuit
  • Wider control of the beat-frequency
  • Correct Answer
    All of the above

In a tuned RF receiver the heterodyne method, over the autodyne reception, has:

(D). All of the above

  • Great sensitivity
  • More stable operation of the circuit
  • Wider control of the beat-frequency

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A regenerative receiver's operation is:

  • An incoming RF carrier is coupled into the tuned-grid circuit and applied to the grid
  • It is then amplified in the usual manner. A controllable portion of the plate signal is coupled back into the grid circuit
  • The coupled back signal is in phase with the original signal thus amplifying it and providing a greater output signal in the plate circuit
  • Correct Answer
    All of the above

A regenerative receiver's operation is:

(D). All of the above

  • An incoming RF carrier is coupled into the tuned-grid circuit and applied to the grid

  • It is then amplified in the usual manner. A controllable portion of the plate signal is coupled back into the grid circuit

  • The coupled back signal is in phase with the original signal thus amplifying it and providing a greater output signal in the plate circuit

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Advantages of a stage of RF amplification are:

  • Improved sensitivity, improved signal-to-noise ratio
  • Improved selectivity, improved signal-to-noise ratio
  • Improved signal-to-noise ratio, more efficient and more stable operation of the detector
  • Correct Answer
    All of the above

Advantages of a stage of RF amplification are:

(D). All of the above

Improved:

  • sensitivity,
  • signal-to-noise ratio
  • selectivity,
  • more efficient and more stable operation of the detector

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Disadvantages of a stage of RF amplification are:

  • A power audio amplifier would be needed to operate a loudspeaker
  • An RF amplifier requires additional tuned circuits and tuning elements
  • Shielding will probably be necessary
  • Correct Answer
    All of the above

Disadvantages of a stage of RF amplification are:

(D). All of the above

  • A power audio amplifier would be needed to operate a loudspeaker
  • An RF amplifier requires additional tuned circuits and tuning elements
  • Shielding will probably be necessary

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The sensitivity of a 3 circuit receiver is controlled by:

  • Correct Answer
    The setting of the regeneration control
  • The setting of the audio frequency control
  • The setting of the radio frequency control
  • The setting of the beat frequency oscillator

The sensitivity of a 3 circuit receiver is controlled by:

(A). The setting of the regeneration control

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A regenerative, oscillating-detector receives directly coupled to an antenna:

  • Correct Answer
    May radiate energy that can beat with other carrier frequencies and cause heterodyning interference in a number of receivers
  • Cannot radiate energy
  • Radiates extremely high energy
  • None of the above

A regenerative, oscillating-detector receives directly coupled to an antenna:

(A). May radiate energy that can beat with other carrier frequencies and cause heterodyning interference in a number of receivers

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Low sensitivity of a 3 circuit regenerative receiver might be caused by:

  • Faulty tube
  • Out of phase feedback
  • Insufficient feedback
  • Correct Answer
    All of the above

Low sensitivity of a 3 circuit regenerative receiver might be caused by:

(D). All of the above

  • Faulty tube

  • Out of phase feedback

  • Insufficient feedback

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Some components of a three-circuit regenerative circuit tested in troubleshooting:

  • All tubes, power supply voltage, continuity of coils
  • Proper contacting of each position of tapped switches, pigtail connections, shorted variable capacitor
  • Grid leak for open circuit, grid capacitor for short, audio transformer for continuity, jacks & cords, antenna and ground connections
  • Correct Answer
    All of the above

Some components of a three-circuit regenerative circuit tested in troubleshooting:

(D). All of the above

  • All tubes, power supply voltage, continuity of coils

  • Proper contacting of each position of tapped switches, pigtail connections, shorted variable capacitor

  • Grid leak for open circuit, grid capacitor for short, audio transformer for continuity, jacks & cords, antenna and ground connections

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Noisy operation of a regenerative, 3-circuit receiver with two stages of AF amplification may be caused by:

  • Defective tubes, poor connections
  • Defective audio transformers
  • Defective grid resistance of grid-capacitor, or defective elements in the power supply
  • Correct Answer
    All of the above

Noisy operation of a regenerative, 3-circuit receiver with two stages of AF amplification may be caused by:

(D). All of the above

  • Defective tubes, poor connections
  • Defective audio transformers
  • Defective grid resistance of grid-capacitor, or defective elements in the power supply

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How could you test a regenerative receiver to determine if the detector is oscillating?

  • Touch a finger on grounded wire to the grid circuit. You will hear a "plop" if the circuit was oscillating
  • Vary the regeneration control to its maximum limits. You will hear a "plop" as the circuit goes in and out of oscillation
  • Correct Answer
    Either A or B
  • None of the above

How could you test a regenerative receiver to determine if the detector is oscillating?

(C). Either A or B

  • Touch a finger on grounded wire to the grid circuit. You will hear a "plop" if the circuit was oscillating
    OR
  • Vary the regeneration control to its maximum limits. You will hear a "plop" as the circuit goes in and out of oscillation

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How would you adjust a regenerative receiver without RF amplifier stages to receive radiotelegraph signals through interference?

  • Correct Answer
    Provide the maximum selectivity and gain at the incoming signal frequency
  • Increase the degree of coupling between the antenna and grid coils
  • Provide the minimum possible regeneration
  • None of the above

How would you adjust a regenerative receiver without RF amplifier stages to receive radiotelegraph signals through interference?

(A). Provide the maximum selectivity and gain at the incoming signal frequency

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How would you reduce or eliminate broadcast signal interference of reception on 500 kHz?

  • Use a regenerative receiver without RF amplifier stages
  • Correct Answer
    Use a suitable wavetrap resonated to reject the undesired signals
  • Use a crystal detector receiver tuned to the exact frequency
  • None of the above

How would you reduce or eliminate broadcast signal interference of reception on 500 kHz?

(B). Use a suitable wave trap resonated to reject the undesired signals

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To adjust a regenerative receiver for maximum sensitivity:

  • The station is tuned in with the receiver in the oscillating condition
  • Slowly back the regeneration control off until the receiver just breaks out of oscillation and is also below the fringe howl point
  • Correct Answer
    First A then B
  • First B then A

To adjust a regenerative receiver for maximum sensitivity:

(C). First A then B

FIRST

  • The station is tuned in with the receiver in the oscillating condition

SECOND

  • Slowly back the regeneration control off until the receiver just breaks out of oscillation and is also below the fringe howl point

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What type of radio receiver do not respond to static interference?

  • AM receivers are less responsive
  • FM receivers have better sensitivity to such interference
  • Both AM & FM
  • Correct Answer
    B & C

What type of radio receiver do not respond to static interference?

(D). B & C

  • FM receivers have better sensitivity to such interference
  • Both AM & FM

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Audio howl may be caused by:

  • A "fringe" setting of the regeneration control
  • A defective tube
  • An open grid resistor
  • Correct Answer
    All of the above

Audio howl may be caused by:

(D). All of the above

  • A "fringe" setting of the regeneration control
  • A defective tube
  • An open grid resistor

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If signals are heard with headphones in the detector plate circuit of a receiver, but none are heard with headphones in the first AF stage plate circuit, what might be the cause?

  • Open winding of the coupling transformer
  • Defective coupling capacitor, improper operating potentials
  • Defective tube
  • Correct Answer
    All of the above

If signals are heard with headphones in the detector plate circuit of a receiver, but none are heard with headphones in the first AF stage plate circuit, what might be the cause?

(D). All of the above

  • Open winding of the coupling transformer
  • Defective coupling capacitor, improper operating potentials
  • Defective tube

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In the case of an open secondary winding in a coupling transformer causing no signal in the first AF stage, satisfactory repair could be made by:

  • Replacing the transformer
  • Disconnecting the secondary winding and changing the coupling system to impedance coupling with a grid resistor and coupling capacitor
  • Correct Answer
    A & B
  • None of the above

In the case of an open secondary winding in a coupling transformer causing no signal in the first AF stage, satisfactory repair could be made by:

(C). A & B

  • Replacing the transformer

  • Disconnecting the secondary winding and changing the coupling system to impedance coupling with a grid resistor and coupling capacitor

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An oscillator in a receiver operating on a frequency near the IF of the receiver:

  • Correct Answer
    Beats with the IF in the second detector to produce an audible note
  • May cause audio howl in the receiver
  • Increases sensitivity
  • May cause noisy operation of the receiver

An oscillator in a receiver operating on a frequency near the IF of the receiver:

(A). Beats with the IF in the second detector to produce an audible note

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Generally used to prevent any undesired frequencies from appearing in the output of a receiver:

  • Correct Answer
    Wave trap
  • Wave guide
  • Ripple filter
  • Tarody screen

Generally used to prevent any undesired frequencies from appearing in the output of a receiver:

(A). Wave trap

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By-pass capacitors across the cathode-bias resistors of an RF amplifier:

  • Prevent variations of bias during excitation of the amplifier
  • Results in better gain of the amplifier stage
  • Correct Answer
    A & B
  • None of the above

By-pass capacitors across the cathode-bias resistors of an RF amplifier:

(C). A & B

  • Prevent variations of bias during excitation of the amplifier
  • Results in better gain of the amplifier stage

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In general, shielding between RF amplifier stages:

  • Prevents electromagnetic coupling
  • Prevents electrostatic coupling
  • Improves the overall stability of a receiver
  • Correct Answer
    All of the above

In general, shielding between RF amplifier stages:

(D). All of the above

  • Prevents electromagnetic coupling
  • Prevents electrostatic coupling
  • Improves the overall stability of a receiver

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Minimizes transfer of harmonic frequencies between two inductively coupled circuits:

  • ***<This answer left blank by the FCC>
  • Induces magnetic shielding between two coils
  • Transfers energy between two coils
  • Correct Answer
    None of the above

Minimizes transfer of harmonic frequencies between two inductively coupled circuits:

(D). None of the above

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An auxiliary receiving antenna on a ship with a radio direction finder:

  • Is mainly a spare antenna
  • Correct Answer
    Enables the radio operator to maintain watch on 500 kHz whether or not the direction finder is in use
  • Enables the radio operator to use the direction finder whether or not the communications receiver is in use
  • None of the above

An auxiliary receiving antenna on a ship with a radio direction finder:

(B). Enables the radio operator to maintain watch on 500 kHz whether or not the direction finder is in use

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Feeding back into the control grids of the IF and RF amplifiers a negative DC bias which is proportioned to the average magnitude of the received carrier wave accomplished:

  • Rhymed effect
  • Correct Answer
    Automatic volume control
  • Neutralization
  • Refraction

Feeding back into the control grids of the IF and RF amplifiers a negative DC bias which is proportioned to the average magnitude of the received carrier wave accomplished:

(B). Automatic volume control

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The center-tap connection in a filament supply transformer:

  • Prevents hum voltages from modulating the normal signal
  • The voltage change on one side of the filament will be effectively cancelled out by an equal and opposite voltage change at the other side of the filament, yielding no hum
  • Correct Answer
    A & B
  • None of the above

The center-tap connection in a filament supply transformer:

(C). A & B

  • Prevents hum voltages from modulating the normal signal

  • The voltage change on one side of the filament will be effectively cancelled out by an equal and opposite voltage change at the other side of the filament, yielding no hum

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A shorted grid capacitor in a three-circuit regenerative receiver would:

  • Render the receiver mostly or completely inoperative
  • Have no noticeable effect
  • Some forms of plate detection might occur but with considerably reduced sensitivity and volume
  • Correct Answer
    A & C

A shorted grid capacitor in a three-circuit regenerative receiver would:

(D). A & C

  • Render the receiver mostly or completely inoperative

  • Some forms of plate detection might occur but with considerably reduced sensitivity and volume

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The first detector in a superheterodyne receiver:

  • Acts as a mixer, providing the action which produces the desired intermediate frequency
  • The first detector must be operated on the non linear portion of its characteristic to provide the proper action
  • Correct Answer
    A & B
  • None of the above

The first detector in a superheterodyne receiver:

(C). A & B

  • Acts as a mixer, providing the action which produces the desired intermediate frequency

  • The first detector must be operated on the non linear portion of its characteristic to provide the proper action

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The advantage of using iron cores of special construction in RF transformers and inductance?

  • Increase of Q and gain of circuits using such cores
  • Increase of selectivity and gain of circuits using such cores
  • Increase of Q and selectivity
  • Correct Answer
    All of the above

The advantage of using iron cores of special construction in RF transformers and inductance?

(D). All of the above

  • Increase of Q and gain of circuits using such cores
  • Increase of selectivity and gain of circuits using such cores
  • Increase of Q and selectivity

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The auto alarm receiver is tuned to ____ but is able to respond to signals from ____ to ____ (+/- 12.5 kHz)

  • Correct Answer
    500 kHz, 487.5 kHz, 512.5 kHz
  • 500 kHz, 485.0 kHz, 515 kHz
  • 500 kHz, 490.00 kHz, 510 kHz
  • 500 kHz, 470.00 kHz, 530 kHz

The auto alarm receiver is tuned to ____ but is able to respond to signals from ____ to ____ (+/- 12.5 kHz)

(A). 500 kHz, 487.5 kHz, 512.5 kHz

The auto alarm receiver is tuned to 500 kHz
but is able to respond to signals
from 487.5 kHz, to 512.5 kHz (+/- 12.5 kHz)

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The auto-alarm signal is:

  • Correct Answer
    Four consecutive dashes from C.5 to D.5 seconds, separated by spaces ranging from 0.1 to 0.5 seconds. The combination may not exceed 5 seconds
  • Three consecutive dashes from D.5 to 5.5 seconds, separated by spaces ranging from 0.5 to A.0 seconds
  • Five consecutive dashes from B.5-3.5 seconds, separated by spaces ranging from 0.01 to 0.25 seconds. The combination may not exceed 5 seconds
  • None of the above

The auto-alarm signal is:

(A). 4 consecutive dashes from C.5 to D.5 seconds,
separated by spaces ranging from 0.1 to 0.5 seconds.
The combination may not exceed 5 seconds

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The determining factor of the setting of the sensitivity control of an auto-alarm receiver:

  • Prevailing static at a given time
  • Radio interference at a given time
  • Signal strength
  • Correct Answer
    A & B

The determining factor of the setting of the sensitivity control of an auto-alarm receiver:

(D). A & B

  • Prevailing static at a given time

  • Radio interference at a given time

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With an auto alarm that uses a square-law detector and a mechanical selector what causes the bell to ring?

  • Receipt of the true auto-alarm signal, low battery voltage
  • Filament circuit open, the 24 V circuit to receiver open
  • Battery charger fuse blown, motor stopped or running
  • Correct Answer
    All of the above

With an auto alarm that uses a square-law detector and a mechanical selector what causes the bell to ring?

(D). All of the above

  • Receipt of the true auto-alarm signal, low battery voltage

  • Filament circuit open, the 24 V circuit to receiver open

  • Battery charger fuse blown, motor stopped or running

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Intermittent ringing of the bells of an auto alarm with a linear detector and an electronic selector could be caused by:

  • An intermittent vacuum tube filament
  • Fluctuating line voltage
  • Faulty contacts or relay adjustment of warning relay receiver
  • Correct Answer
    All of the above

Intermittent ringing of the bells of an auto alarm with a linear detector and an electronic selector could be caused by:

(D). All of the above

  • An intermittent vacuum tube filament

  • Fluctuating line voltage

  • Faulty contacts or relay adjustment of warning relay receiver

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An open filament on an auto-alarm with a linear detector and an electronic selector will:

  • De-energize the restore relay K-105
  • K105 applies voltage to K-100, time delay relay
  • K106 causes the bell to ring after about 2 minutes
  • Correct Answer
    All of the above

An open filament on an auto-alarm with a linear detector and an electronic selector will:

(D). All of the above

  • De-energize the restore relay K-105
  • K105 applies voltage to K-100, time delay relay
  • K106 causes the bell to ring after about 2 minutes

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The auto-alarm bell rings and the release button stops it:

  • There could be reception of a true alarm signal
  • There could be reception of a false alarm signal
  • Correct Answer
    A or B
  • Neither A or B

The auto-alarm bell rings and the release button stops it:

(C). A or B

  • There could be reception of a true alarm signal
    OR
  • There could be reception of a false alarm signal

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If the auto-alarm bell rings and the release button doesn't stop it:

  • Bell relay K-107 could be stuck, or there could be an open filament
  • The alarm bell relay circuit ground could be bad
  • There could be failure or low line voltage
  • Correct Answer
    All of the above

If the auto-alarm bell rings and the release button doesn't stop it:

(D). All of the above

  • Bell relay K-107 could be stuck, or there could be an open filament
  • The alarm bell relay circuit ground could be bad
  • There could be failure or low line voltage

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If the vacuum tube heater in an approved auto-alarm system burns out:

  • Correct Answer
    A pair of contacts close and energize the bell relay
  • A pair on contacts open and energize the ball relay
  • A pair of contacts close and de-energize the bell relay
  • A pair of contacts open and deenergize the bell relay

If the vacuum tube heater in an approved auto-alarm system burns out:

(A). A pair of contacts close and energize the bell relay

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Unused portions of inductances in receivers are ____ to reduce any losses that might occur in these unused windings:

  • Correct Answer
    Shorted
  • Removed from the circuit
  • Insulated
  • Straightened out

Unused portions of inductances in receivers are ____ to reduce any losses that might occur in these unused windings:

(A). Shorted

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Harmonic radiation by a transmitter may be prevented:

  • By using a suitable crystal filter
  • By using a Faraday shield between the final amplifier and antenna circuit
  • By using suitable tuned filters in the transmission line system
  • Correct Answer
    B & C

Harmonic radiation by a transmitter may be prevented:

(D). B & C

  • By using a Faraday shield between the final amplifier and antenna circuit

  • By using suitable tuned filters in the transmission line system

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The keying circuit of the ships transmitter is disconnected:

  • Correct Answer
    When the auto-alarm antenna switch is placed in the auto-alarm operating position
  • When the auto-alarm antenna switch is placed in the auto-alarm off position
  • Manually as desired
  • None of the above

The keying circuit of the ships transmitter is disconnected:

(A). When the auto-alarm antenna switch is placed in the auto-alarm operating position

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Normal undistorted modulation is indicated by:

  • Correct Answer
    An increase in antenna current without carrier shift
  • A decrease in antenna current without carrier shift
  • An increase in antenna current with carrier shift
  • A decrease in antenna current with carrier shift

Normal undistorted modulation is indicated by:

(A). An increase in antenna current without carrier shift

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If a vacuum tube in the only RF stages of your receiver burned out, make a temporary repair by:

  • Remove its tube and connect a small (about 0.001 microfarad) capacitor between the control grid and plate connections
  • Connect the antenna to the control grid of the stage following the one which was burned out
  • Correct Answer
    Either A or B
  • A & B

If a vacuum tube in the only RF stages of your receiver burned out, make a temporary repair by:

(C). Either A or B

  • Remove its tube and connect a small (about 0.001 microfarad) capacitor between the control grid and plate connections
    OR
  • Connect the antenna to the control grid of the stage following the one which was burned out

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A ____ provides a very high degree of selectivity in a receiver:

  • Correct Answer
    Crystal filter
  • Low pass filter
  • Bleeder resistor
  • By-pass capacitor

A ____ provides a very high degree of selectivity in a receiver:

(A). Crystal filter

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The D'Arsonval type meter consists of:

  • A permanent magnet, a movable coil with pointer attached rotating in jewel bearing
  • A movable coil with pointer attached rotating in jewel bearings, and two spiral springs (one on each side of the removable coil)
  • Correct Answer
    A & B
  • None of the above

The D'Arsonval type meter consists of:

(C). A & B

  • A permanent magnet, a movable coil with pointer attached rotating in jewel bearing

  • A movable coil with pointer attached rotating in jewel bearings, and two spiral springs (one on each side of the removable coil)

For more info, see Wikipedia's article on Galvanometer

Also, see a DOE site's pdf paper on Test Instruments & Measuring Devices, page 1. D'Arsonval Movement

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What is the purpose of multiplier resistance used with a voltmeter?

  • Multiplier resistance is not used with a voltmeter
  • Correct Answer
    To increase the voltage indicating range of the voltmeter
  • To decrease the voltage indicating range of the voltmeter
  • None of the above

What is the purpose of multiplier resistance used with a voltmeter?

(B). To increase the voltage indicating range of the voltmeter

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What is the purpose of a shunt as used with an ammeter?

  • To permit a decrease in the indicating range of the meter
  • Correct Answer
    To permit an increase in the indicating range of the meter which is almost inversely proportional to the resistance of the shunt
  • A shunt should not be used with a ammeter
  • None of the above

What is the purpose of a shunt as used with an ammeter?

(B). To permit an increase in the indicating range of the meter which is almost inversely proportional to the resistance of the shunt

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What is indicated if a voltmeter connected between the negative side of a ship's DC line and ground reads the full line voltage?

  • It indicates that the voltmeter leads are reversed
  • This indicates that the positive side of the line, rather then the negative side is grounded
  • The generator terminals should be reversed
  • Correct Answer
    Both B & C are correct

What is indicated if a voltmeter connected between the negative side of a ship's DC line and ground reads the full line voltage?

(D). Both B & C are correct

  • This indicates that the positive side of the line, rather then the negative side is grounded

  • The generator terminals should be reversed

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Why are copper oxide rectifiers, associated with DC voltmeters to measure AC, unsuitable for the measurement of voltages at radio frequencies?

  • Because of the relatively low shunt capacitance of the copper oxide rectifier
  • The AC & DC voltages will read low
  • Correct Answer
    Because of the relatively large shunt capacitance of the copper oxide rectifier
  • All of the above

Why are copper oxide rectifiers, associated with DC voltmeters to measure AC, unsuitable for the measurement of voltages at radio frequencies?

(C). Because of the relatively large shunt capacitance of the copper oxide rectifier

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How may the power in a AC circuit be determined?

  • The power in an AC circuit may be determined by a wattmeter
  • By multiplying the product of the circuit voltage and current by the power factor
  • Correct Answer
    Both answers A & B
  • None of the above

How may the power in a AC circuit be determined?

(C). Both answers A & B

  • The power in an AC circuit may be determined by a wattmeter

  • By multiplying the product of the circuit voltage and current by the power factor

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The product of the readings of an AC voltmeter and ammeter in an AC circuit is called what?

  • Reverse power
  • Correct Answer
    Apparent power
  • Current power
  • None of the above

The product of the readings of an AC voltmeter and ammeter in an AC circuit is called what?

(B). Apparent power

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Does an AC ammeter indicate peak, average, or effective values of current?

  • The conventional AC ammeter is calibrated to indicate effective (TRM) values of current
  • Correct Answer
    The conventional AC ammeter is calibrated to indicate effective (RMS) values of current
  • An AC ammeter indicates peak values of current
  • An AC ammeter indicates average values of current

Does an AC ammeter indicate peak, average, or effective values of current?

(B). The conventional AC ammeter is calibrated to indicate effective (RMS) values of current

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What types of meters may be used to measure RF currents?

  • The hot wire ammeter
  • The thermocouple ammeter
  • Correct Answer
    Both A & B
  • None of the above

What types of meters may be used to measure RF currents?

(C). Both A & B

  • The hot wire ammeter

  • The thermocouple ammeter

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How may the range of a thermocouple ammeter be increased?

  • By using a current transformer
  • By using a capacitor shunt
  • Correct Answer
    Both A & B
  • By using a resistor shunt

How may the range of a thermocouple ammeter be increased?

(C). Both A & B

  • By using a current transformer

  • By using a capacitor shunt

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By what factor must the voltage of an ac circuit, as indicated on the scale of an AC voltmeter, be multiplied to obtain the average voltage value?

  • Correct Answer
    By the factor of 0.9
  • By the factor of 9.0
  • By the factor of A.0
  • By the factor of B.0

By what factor must the voltage of an ac circuit, as indicated on the scale of an AC voltmeter, be multiplied to obtain the average voltage value?

(A). By the factor of 0.9

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By what factor must the voltage of an AC circuit, as indicated on the scale of an AC voltmeter, be multiplied to obtain the peak value?

  • The multiplying factor is .414
  • Correct Answer
    The multiplying factor is A.414
  • The multiplying factor is A.114
  • The multiplying factor is A.141

By what factor must the voltage of an AC circuit, as indicated on the scale of an AC voltmeter, be multiplied to obtain the peak value?

(B). The multiplying factor is A.414

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What is the meaning of "zero beat" as used in connection with frequency measuring equipment?

  • Correct Answer
    Zero beat occurs when two frequencies are being mixed together and have no difference frequency between them
  • To achieve this the frequencies must be suppressed
  • The transmitter must be nulled
  • None of the above

What is the meaning of "zero beat" as used in connection with frequency measuring equipment?

(A). Zero beat occurs when two frequencies are being mixed together and have no difference frequency between them

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What is the directional reception pattern of a loop antenna?

  • A vertical loop antenna has a bidirectional pattern which is maximum in the directions in the plane of the loop, and minimum in the directions broadside to the loop
  • A horizontal loop antenna is nondirectional along the plane of the loop. It has minimum radiation or reception vertically
  • A horizontal loop antenna is directional along the plane of the loop antenna
  • Correct Answer
    Both A & B

What is the directional reception pattern of a loop antenna?

(D). Both A & B

  • A vertical loop antenna has a bidirectional pattern which is maximum in the directions in the plane of the loop, and minimum in the directions broadside to the loop

  • A horizontal loop antenna is nondirectional along the plane of the loop. It has minimum radiation or reception vertically

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What is the reception pattern of a vertical antenna?

  • Correct Answer
    It has minimum radiation or reception vertically
  • A vertical Jackson antenna has a pattern which is nondirectional with regard to all compass points
  • It has maximum radiation or reception vertically
  • None of the above

What is the reception pattern of a vertical antenna?

(A). It has minimum radiation or reception vertically

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What is the principal function of a vertical sense antenna associated with a unilateral radio direction finder?

  • Correct Answer
    To determine from which direction the signal is coming
  • A vertical sense antenna is not associated with a radio direction finder
  • Unilateral radio direction finders are associated with loop antennas
  • None of the above

What is the principal function of a vertical sense antenna associated with a unilateral radio direction finder?

(A). To determine from which direction the signal is coming

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What figure represents the reception pattern of a properly adjusted unilateral radio direction finder?

  • A cardioid
  • A figure eight
  • A heart shaped figure
  • Correct Answer
    Both A & C

What figure represents the reception pattern of a properly adjusted unilateral radio direction finder?

(D). Both A & C

  • A cardioid
  • A heart shaped figure

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From how many simultaneous directions is a direction finder capable of receiving signals if adjusted to take unilateral bearings through 360 degrees?

  • From 360 degrees
  • From 180 degrees
  • Correct Answer
    From all but one direction
  • None of the above

From how many simultaneous directions is a direction finder capable of receiving signals if adjusted to take unilateral bearings through 360 degrees?

(C). From all but one direction

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How is the unilateral effect obtained in a direction finder?

  • With a balancing capacitor
  • With a compensator
  • With insulating material
  • Correct Answer
    None of the above

How is the unilateral effect obtained in a direction finder?

(D). None of the above

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What is the function of the balancing capacitor in a direction finder?

  • To maximize "antenna effect" and so obtain a sharper null point indication of direction
  • To reduce the noise factor in the first IF
  • Correct Answer
    To minimize "antenna effect" and so obtain a sharper null point indication of direction
  • None of the above

What is the function of the balancing capacitor in a direction finder?

(C). To minimize "antenna effect" and so obtain a sharper null point indication of direction

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What is indicated by the bearing obtained from the use of a bilateral radio direction finder?

  • A line of direction which passes through two stations
  • Correct Answer
    A line of direction which passes through the originating station
  • A line of direction can read in either direction
  • None of the above

What is indicated by the bearing obtained from the use of a bilateral radio direction finder?

(B). A line of direction which passes through the originating station

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On shipboard what factors may effect the accuracy of a direction finder after it has been properly installed, calibrated?

  • A received wave which has been bent by night effect
  • By any changing of the position of nearby metallic objects
  • Correct Answer
    Both A & B
  • None of the above

On shipboard what factors may effect the accuracy of a direction finder after it has been properly installed, calibrated?

(C). Both A & B

  • A received wave which has been bent by night effect
  • By any changing of the position of nearby metallic objects

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What is indicated by the bearing obtained from the use of a unilateral radio direction finder?

  • The direction of another station
  • Correct Answer
    The sense of direction of the originating station
  • All bearings are from
  • None of the above

What is indicated by the bearing obtained from the use of a unilateral radio direction finder?

(B). The sense of direction of the originating station

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Within what frequency band limits do all United States marine radio beacon stations operate?

  • From 280 to 385 kHz
  • From 162 to 385 kHz
  • Correct Answer
    From 285 to 315 kHz
  • From 300 to 465 kHz

Within what frequency band limits do all United States marine radio beacon stations operate?

(C). From 285 to 315 kHz

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In what part of the RF spectrum do marine radar systems operate?

  • In the order of 10,000 MHz or 3000 MHz
  • Wavelength of 3 cm or 10 cm
  • Correct Answer
    Both A & B
  • None of the above

In what part of the RF spectrum do marine radar systems operate?

(C). Both A & B

  • In the order of 10,000 MHz or 3000 MHz

  • Wavelength of 3 cm or 10 cm

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Approximately at what speed does the antenna of a navigational radar rotate?

  • At speeds ranging from about 6 to 19 RPM
  • Correct Answer
    At speeds ranging from about 6 to 15 RPM
  • At speeds ranging from about 15 to 30 RPM
  • At speeds ranging from about 20 to 40 RPM

Approximately at what speed does the antenna of a navigational radar rotate?

(B). At speeds ranging from about 6 to 15 RPM

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How should a radar set be adjusted by the operator to reduce "sea return"?

  • Rotate the antenna for a deep null
  • Reduce the gain control
  • Correct Answer
    The operator should manually adjust the "suppressor" control or sensitivity time control, STC
  • None of the above

How should a radar set be adjusted by the operator to reduce "sea return"?

(C). The operator should manually adjust the "suppressor" control or sensitivity time control, STC

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In determining a "fix" position by a marine LORAN system, what is the minimum number of land transmitters involved?

  • A master & a slave station
  • 1 slave station
  • 2 slave stations & 1 master station
  • Correct Answer
    Four, or two pairs of "master and "slave" stations

In determining a "fix" position by a marine LORAN system, what is the minimum number of land transmitters involved?

(D). Four, or two pairs of "master and "slave" stations

For more LORAN info, please see Wikipedia's article on the LORAN and the Loran-C

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What is the relationship between a master and a slave station in reference to LORAN navigation systems?

  • Correct Answer
    A master station originates the RF pulse which then travels in all directions and is intercepted by the slave station
  • The slave station originates the RF pulse
  • There must be at least two slave stations
  • All of the above

What is the relationship between a master and a slave station in reference to LORAN navigation systems?

(A). A master station originates the RF pulse which then travels in all directions and is intercepted by the slave station

For more LORAN info, please see Wikipedia's article on the LORAN and the Loran-C

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How can the operator of a LORAN receiver on shipboard identify the transmitting stations that are being received?

  • By their pulse recurrence rate
  • By reference to their frequency of transmission
  • None of the above
  • Correct Answer
    Both A & B

How can the operator of a LORAN receiver on shipboard identify the transmitting stations that are being received?

(D). Both A & B

  • By their pulse recurrence rate

  • By reference to their frequency of transmission

For more LORAN info, please see Wikipedia's article on the LORAN and the Loran-C

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During daytime hours, approximately what is the maximum distance in nautical miles from LORAN transmitting stations from which LORAN lines of position can be determined?

  • Correct Answer
    About 700 miles
  • During nighttime hours, the maximum distance is increased to about 1800 miles by the use of sky waves
  • About 1000 miles
  • About 1500 miles

During daytime hours, approximately what is the maximum distance in nautical miles from LORAN transmitting stations from which LORAN lines of position can be determined?

(A). About 700 miles

For more LORAN info, please see Wikipedia's article on the LORAN and the Loran-C

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What is the purpose of blinking in a loran navigational system?

  • Correct Answer
    To warn the receiving operator that difficulty exists at the transmitting stations?
  • To warn the operator that the system is in use
  • The loran system needs to be aligned
  • None of the above

What is the purpose of blinking in a LORAN navigation system?

(A). To warn the receiving operator that difficulty exists at the transmitting stations?

For more LORAN info, please see Wikipedia's article on the LORAN and the Loran-C

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What precautions should an operator or serviceman observe when working with cathode-ray tubes?

  • The tube must not strike against any hard surface
  • The tube might implode
  • Safety goggles and gloves should be worn when handling cathode-ray tubes
  • Correct Answer
    All of the above

What precautions should an operator or serviceman observe when working with cathode-ray tubes?

(D). All of the above

  • The tube must not strike against any hard surface
  • The tube might implode
  • Safety goggles and gloves should be worn when handling cathode-ray tubes

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If the velocity of a radio wave is 186,000 statute miles per second, how many nautical miles does a radar pulse travel in one microsecond?

  • Correct Answer
    0.1614 nautical miles
  • 11614 nautical miles
  • 0.2014 nautical miles
  • 2200 nautical miles

If the velocity of a radio wave is 186,000 statute miles per second, how many nautical miles does a radar pulse travel in one microsecond?

(A). 0.1614 nautical miles

For millisecond, multiply by 1,000.
For microsecond, multiply by 1,000,000.

The 1 nautical mile is 1.15078 statute miles.
Thus, 0.868976 nautical mile is 1 statute mile.

Thus, 186,000 statute miles per second is 161.629.581 nautical miles.
So, 161,629.581 / 1,000, 000 = 0.161629581
The difference with the answer must be a rounding difference.

Check out on Google calculator

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In all cases other than those in which the transmitter output must be maintained at a fixed value, what amount of power should be employed for routine communications?

  • The maximum amount of power to maintain communications
  • The transmitter must be maintained at a fixed value
  • Correct Answer
    The minimum amount of power necessary to ensure reliable communications
  • None of the above

In all cases other than those in which the transmitter output must be maintained at a fixed value, what amount of power should be employed for routine communications?

(C). The minimum amount of power necessary to ensure reliable communications

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What is the definition of a "station open to public service"?

  • A station which handles public correspondence
  • Paid or toll messages
  • Radiotelephone facilities for the general public at prescribed rates
  • Correct Answer
    All of the above

What is the definition of a "station open to public service"?

(D). All of the above

  • A station which handles public correspondence
  • Paid or toll messages
  • Radiotelephone facilities for the general public at prescribed rates

For detailed information and regulations, please see Code of Federal Regulations, Title 47 Chapter I Subchapter D
PART 80 - STATIONS IN THE MARITIME SERVICES, especially related to question here is the
Subpart C Operating Procedures - Land Stations

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In the transmission of the international Morse code, what are the relative time lengths of dashes, dots?

  • Dashes are about four times as long as dots
  • Dots are about half the length of dashes
  • Correct Answer
    Dashes are about three times as long as dots
  • None of the above

In the transmission of the international Morse code, what are the relative time lengths of dashes, dots?

(C). Dashes are about three times as long as dots

For info, see Morse Code World site, article on Morse Code Timing

For overall info, see Wikipedia's article on Morse Code.

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Why is the clock on a compulsorily equipped ship radiotelegraph station required to have a sweep second hand?

  • To be able to accurately time the spaces and dashes of the auto-alarm system
  • To accurately time the silent periods
  • Correct Answer
    Both A & B
  • None of the above

Why is the clock on a compulsorily equipped ship radiotelegraph station required to have a sweep second hand?

(C). Both A & B

  • To be able to accurately time the spaces and dashes of the auto-alarm system

  • To accurately time the silent periods

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Between what points on a ship, compulsorily equipped with a radiotelegraph installation, is a reliable intercommunication system required?

  • Between the forward bridge and the radio room
  • Between the radio room and engineering
  • Correct Answer
    Between the radio room and the navigation bridge
  • None of the above

Between what points on a ship, compulsorily equipped with a radiotelegraph installation, is a reliable intercommunication system required?

(C). Between the radio room and the navigation bridge

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Are there any age requirements that a person must meet before he can be issued a radiotelegraph operator license?

  • At least 18 years of age for a second class license
  • Correct Answer
    At least 21 years of age for a first class license
  • Persons under 21 now holding a radiotelegraph first class license may renew same without regard to age requirement
  • All of the above

Are there any age requirements that a person must meet before he can be issued a radiotelegraph operator license?

(B). At least 21 years of age for a first class license

The age requirement was part of the First Class T1 license, BUT the license itself is no longer issued.

Per FCC, Commercial Radio Operator Types of Licenses To qualify, you must:

  • be a legal resident of (or otherwise eligible for employment in) the United States; and
  • be able to receive and transmit spoken messages in English; and
  • pass a written and/or telegraphy examination(s) as required by the Rules.
  • be at least 21 years old; and
  • have one year of experience in sending and receiving public correspondence by radiotelegraph at a public coast station, a ship station, or both.

As of May 20, 2013, the Commission no longer accepts applications for new T1 licenses, and T1 licenses for which renewal applications are filed are renewed as T licenses.

CURRENT Radiotelegraph Operator License (T) requirements consist of:

  • be a legal resident of (or otherwise eligible for employment in) the United States; and
  • be able to receive and transmit spoken messages in English; and
  • pass a written and/or telegraphy examination(s) as required by the Rules.

Additional information can be found at Code of Federal Regulations, Title 47 Chapter I Subchapter A Part 13 - COMMERCIAL RADIO OPERATORS

§ 13.9 Eligibility and application for new license or endorsement.

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Upon compulsorily equipped vessels which are required to have an accurate clock in the radio room, how frequently must this clock be adjusted and be compared with standard time?

  • Every three hours
  • Ever four hours
  • Every six hours
  • Correct Answer
    At least once every 24 hours

Upon compulsorily equipped vessels which are required to have an accurate clock in the radio room, how frequently must this clock be adjusted and be compared with standard time?

(D). At least once every 24 hours

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How frequently must an entry be made in a ship radiotelegraph log while a radio watch is being maintained?

  • At least every 15 minutes
  • This is in addition to the entries referring to silent periods
  • At least every 30 minutes
  • Correct Answer
    Both A & B

How frequently must an entry be made in a ship radiotelegraph log while a radio watch is being maintained?

(D). Both A & B

  • At least every 15 minutes

  • This is in addition to the entries referring to silent periods

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At what time(s) are routine transmissions forbidden in the bands of 480 to 515 kHz?

  • Routine transmissions are forbidden in 480 to 515 kHz
  • 480 to 515 kHz are out of the marine radio band
  • Correct Answer
    Routine transmissions are forbidden during the international silent period
  • None of the above

At what time(s) are routine transmissions forbidden in the bands of 480 to 515 kHz?

(C). Routine transmissions are forbidden during the international silent period

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What time system shell be used in making log entries with respect to the observance of the international silent period?

  • Zulu time according to the twelve hour system
  • Correct Answer
    Greenwich Mean Time according to the 24 hour system
  • Zulu time according to the 12 hour time
  • None of the above

What time system shell be used in making log entries with respect to the observance of the international silent period?

(B). Greenwich Mean Time according to the 24 hour system

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What is the international radiotelegraph distress frequency for stations in the mobile service?

  • 300 kHz
  • 400 kHz
  • Correct Answer
    500 kHz
  • 600 kHz

What is the international radiotelegraph distress frequency for stations in the mobile service?

(C). 500 kHz

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Describe how a distress call should be made:

  • The distress call should be made three times
  • SOS should be called twice
  • Correct Answer
    The distress call shall include the distress signal transmitted three times, the word DE, and the call signal of the mobile station in distress transmitted three times
  • None of the above

Describe how a distress call should be made:

(C). The distress call shall include the distress signal transmitted three times, the word DE, and the call signal of the mobile station in distress transmitted three times

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What transmission should precede the transmission of the distress call?

  • Correct Answer
    The distress call, when sent in radiotelegraph on 500 kHz shall as a general rule, be immediately preceded by the auto-alarm signal
  • SOS should be sent three times
  • The words "MAY DAY" should be sent three times
  • None of the above

What transmission should precede the transmission of the distress call?

(A). The distress call, when sent in radiotelegraph on 500 kHz shall as a general rule, be immediately preceded by the auto-alarm signal

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What stations shall be in control of distress traffic?

  • Control of the distress traffic shall be with the station first hearing the call
  • The control of the distress traffic rests with the mobile station in distress
  • With the mobile station which sends the distress call in the event that the station in distress is not able to transmit it
  • Correct Answer
    Both B & C

What stations shall be in control of distress traffic?

(D). Both B & C

  • The control of the distress traffic rests with the mobile station in distress

  • With the mobile station which sends the distress call in the event that the station in distress is not able to transmit it

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During what periods must a distress message be repeated following the initial transmission?

  • Correct Answer
    Until an answer is received, especially during the silent periods
  • Must repeated every 15 minutes
  • Must be repeated every 5 minutes
  • Must be repeated every 3 minutes

During what periods must a distress message be repeated following the initial transmission?

(A). Until an answer is received, especially during the silent periods

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For how long must mobile stations listen after hearing an urgency signal?

  • Correct Answer
    For at least 5 minutes
  • For at least 30 minutes
  • For at least 3 minutes
  • None of the above

For how long must mobile stations listen after hearing an urgency signal?

(A). For at least 5 minutes

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When the auto-alarm bell rings, what should the operator do?

  • Proceed immediately to the radio room and press the reset button
  • If the bell stops, the operator should listen for further signals
  • Correct Answer
    Both A & B
  • None of the above

When the auto-alarm bell rings, what should the operator do?

(C). Both A & B

  • Proceed immediately to the radio room and press the reset button

  • If the bell stops, the operator should listen for further signals

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What space of time should elapse between the transmission of the international auto-alarm signal and the distress call?

  • Correct Answer
    2 minutes
  • 4 minutes
  • 5 minutes
  • 10 minutes

What space of time should elapse between the transmission of the international auto-alarm signal and the distress call?

(A). 2 minutes

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While a vessel is at sea, how frequently must the auto-alarm be tested?

  • At least once ever 6 hours
  • At least once ever 12 hours
  • Correct Answer
    At least once ever 24 hours
  • None of the above

While a vessel is at sea, how frequently must the auto-alarm be tested?

(C). At least once ever 24 hours

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Upon hearing an SOS, what should an operator do?

  • Should repeat the SOS to all traffic
  • Correct Answer
    Immediately cease all transmissions capable of interfering with the distress traffic
  • Contact the vessel in distress
  • None of the above

Upon hearing an SOS, what should an operator do?

(B). Immediately cease all transmissions capable of interfering with the distress traffic

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What is the purpose of an auto-alarm signal keying device on a compulsorily equipped ship?

  • To automatically produce Morse code
  • To automatically send an SOS signal
  • Correct Answer
    To automatically produce the correct auto-alarm signal
  • None of the above

What is the purpose of an auto-alarm signal keying device on a compulsorily equipped ship?

(C). To automatically produce the correct auto-alarm signal

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On a United States vessel equipped with an approved auto-alarm, where is the control button which silences the warning bells located?

  • On the navigation bridge
  • In main engineering control
  • Correct Answer
    In the main radiotelegraph operating room
  • None of the above

On a United States vessel equipped with an approved auto-alarm, where is the control button which silences the warning bells located?

(C). In the main radiotelegraph operating room

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With what type(s) of emission and upon what frequency should a transmitter be adjusted to transmit a distress call?

  • The distress wave of 600 kHz and type C emission
  • The distress wave of 400 kHz and type C emission
  • Correct Answer
    The international distress wave of 500 kHz / type A-2 OR B emission
  • None of the above

With what type(s) of emission and upon what frequency should a transmitter be adjusted to transmit a distress call?

(C). The international distress wave of 500 kHz / type A-2 OR B emission

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If you receive a distress call signed by a call signal composed of five letters, could you determine the type of craft which transmitted the signal?

  • Five letter call signals are assigned to aircraft stations
  • Three letter call signals are assigned to land stations
  • Four letter call signals are assigned to ship stations
  • Correct Answer
    All of the above

If you receive a distress call signed by a call signal composed of five letters, could you determine the type of craft which transmitted the signal?

(D). All of the above

Call signals assigned have letters:

  • Three (3) for land stations
  • Four (4) for ship stations
  • Five (5) for aircraft stations

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While the vessel is in the open sea, how frequently must the specific gravity of the emergency battery be taken?

  • Every 12 hours
  • Correct Answer
    Once daily
  • Every 48 hours
  • Once every week

While the vessel is in the open sea, how frequently must the specific gravity of the emergency battery be taken?

(B). Once daily

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How frequently must the quantity of fuel in the supply tank for use with an oil or gas driven emergency generator be checked while the vessel is in the open sea?

  • Once a week
  • Every 12 hours
  • Every 48 hours
  • Correct Answer
    Once daily

How frequently must the quantity of fuel in the supply tank for use with an oil or gas driven emergency generator be checked while the vessel is in the open sea?

(D). Once daily

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While a vessel is in port, how frequently should the emergency equipment be tested?

  • Once a day
  • Once a week
  • Once a month
  • Correct Answer
    Only when the vessel is ready to leave port

While a vessel is in port, how frequently should the emergency equipment be tested?

(D). Only when the vessel is ready to leave port

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You intercept "CQ CQ WSV TFC"; what does this mean?

  • General call to all stations
  • Call letter of a coastal station
  • Traffic
  • Correct Answer
    All of the above

You intercept "CQ CQ WSV TFC"; what does this mean?

(D). All of the above

  • General call to all stations
  • Call letter of a coastal station
  • Traffic

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Explain the use and meaning of the following indicator or prefix "RP" on radiotelegrams:

  • Please reply
  • Repeat following parts of message
  • Correct Answer
    "Reply paid"
  • None of the above

Explain the use and meaning of the following indicator or prefix "RP" on radio telegrams:

(C). "Reply paid"

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Upon what band, in addition to the 350 to 515 kHz band must a main receiver on a United States ship be capable of operation?

  • 600 TO 700 kHz
  • 1000 TO 1200 kHz
  • Correct Answer
    100 TO 200 kHz
  • 516 TO 615 kHz

Upon what band, in addition to the 350 to 515 kHz band must a main receiver on a United States ship be capable of operation?

(C). 100 TO 200 kHz

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After a distress call has been transmitted, every distress-traffic radiotelegram shall contain what symbol in the preamble?

  • SOS followed by the call signal
  • Correct Answer
    The distress signal preceding the call and repeated at the beginning of the preamble
  • All of the above
  • None of the above

After a distress call has been transmitted, every distress-traffic radiotelegram shall contain what symbol in the preamble?

(B). The distress signal preceding the call and repeated at the beginning of the preamble

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For how long a period of continuous operation should the emergency power supply of a compulsorily equipped ship station be capable of energizing the emergency radiotelegraph installation?

  • Correct Answer
    At least 6 consecutive hours
  • At least 12 hours
  • At least 24 consecutive hours
  • At least 48 consecutive hours

For how long a period of continuous operation should the emergency power supply of a compulsorily equipped ship station be capable of energizing the emergency radiotelegraph installation?

(A). At least 6 consecutive hours

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What is the principal port of the United States, on the Pacific coast, at which navigation lines terminate?

  • Los Angeles
  • Correct Answer
    San Francisco
  • San Diego
  • None of the above

What is the principal port of the United States, on the Pacific coast, at which navigation lines terminate?

(B). San Francisco

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In what city is the major telecommunication center of the United States located?

  • Houston
  • Correct Answer
    New York City
  • Washington
  • Chicago

In what city is the major telecommunication center of the United States located?

(B). New York City

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Under what condition may an eligible person hold a radiotelegraph operator's license and a Marine Radio Operator permit?

  • When the planned telegraphy operation will occur aboard ship in international waters and another vessel is licensed for operation on the inland waterways
  • When the commercial radio operator is legally eligible for both foreign and domestic employment
  • Correct Answer
    No person may hold any class of radiotelegraph operator's certificate and a Marine Radio Operator Permit
  • Commercial radiotelegraphers are required to also hold a Marine Radio Operator Permit when the operation occurs on vessels of less than 1600 gross tons

Under what condition may an eligible person hold a radiotelegraph operator's license and a Marine Radio Operator permit?

(C). No person may hold any class of radiotelegraph operator's certificate and a Marine Radio Operator Permit

Code of Federal Regulations, Title 47 Chapter I Subchapter A
Part 13 - COMMERCIAL RADIO OPERATORS

§ 13.11 Holding more than one commercial radio operator license.

47 CFR 13.11(a) An eligible person may hold more than one commercial operator license.

  • 47 CFR 13.11(a)(1) No person may hold two or more unexpired radiotelegraph operator's certificates at the same time;

  • 47 CFR 13.11(a)(2) No person may hold any class of radiotelegraph operator's certificate and a Marine Radio Operator Permit;

  • 47 CFR 13.11(a)(3) No person may hold any class of radiotelegraph operator's certificate and a Restricted Radiotelephone Operator Permit.

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How does a First Class Radiotelegraph Operator renew an unexpired license?

  • Renewal document indicating license serial number must be forwarded to the FCC during the last 90 days of the license term
  • Application is made to the nearest Commercial Operator Licensing Examination Manager (COLEM) during the final six months of the license term
  • Correct Answer
    By submitting Form 756, current license copy, and appropriate fee to the FCC during the last year of the five year license term
  • A current Radio telegraphy Proficiency Testimonial (RPT) obtained from the ship's master must be attached to the renewal application Form 739

How does a First Class Radiotelegraph Operator renew an unexpired license?

(C). By submitting Form 756, current license copy, and appropriate fee to the FCC during the last year of the five year license term

This license has been stopped from renewals on May 20, 2013.

Code of Federal Regulations, Title 47 Chapter I Subchapter A Part 13 - COMMERCIAL RADIO OPERATORS

§ 13.15 License term.

First Class Radiotelegraph Operator's Certificates, Second Class Radiotelegraph Operator's Certificates, and Third Class Radiotelegraph Operator's Certificates are normally valid for a term of five years from the date of issuance.

All other commercial radio operator licenses are normally valid for the lifetime of the holder.

§ 13.7 Classification of operator licenses and endorsements.

47 CFR 13.7(b)(1) First Class Radiotelegraph Operator's Certificate. Beginning May 20, 2013, no applications for new First Class Radiotelegraph Operator's Certificates will be accepted for filing.

§ 13.13 Application for a renewed or modified license.

47 CFR 13.13(b)... Beginning May 20, 2013, no applications for new First, Second, or Third Class Radiotelegraph Operator's Certificates will be accepted for filing.

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How does an eligible Second Class Radiotelegraph Operator upgrade his license to First Class?

  • Correct Answer
    By submitting the necessary Proof-of-Passing Certificates (PPC) from a COLEM along with the required fee and Form 756 to the FCC
  • By fulfilling the Six Months Service Endorsement requirement
  • By presenting a one year radiotelegraph experience certification to a commercial radio operator examination manager
  • By complying with the ITU Provision "D" concerning telegraphy operation in the Maritime Service

How does an eligible Second Class Radiotelegraph Operator upgrade his license to First Class?

(A). By submitting the necessary Proof-of-Passing Certificates (PPC) from a COLEM along with the required fee and Form 756 to the FCC

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What is the license term of the First Class Radiotelegraph Operator License?

  • The license is valid for the lifetime of the holder
  • A license is valid for a period of ten years form the DOI (date of issuance)
  • The five year term license is renewable by retaking updated exam Elements 1 and 3 during the last 90 days before expiration
  • Correct Answer
    The license term is five years and may be renewed indefinitely without retesting

What is the license term of the First Class Radiotelegraph Operator License?

(D). The license term is five years and may be renewed indefinitely without retesting


Per FCC site on Obtaining a License

Term of Licenses: The following licenses are issued for the holder's lifetime:

Restricted Radiotelephone Operator Permit
Restricted Radiotelephone Operator Permit-Limited Use Marine Radio Operator Permit
General Radiotelephone Operator License
GMDSS Radio Operator's License
Restricted GMDSS Radio Operator's License
GMDSS Radio Maintainer's License
GMDSS Radio Operator/Maintainer License
Radiotelegraph Operator License


Code of Federal Regulations, Title 47 Chapter I Subchapter A Part 13 - COMMERCIAL RADIO OPERATORS

§ 13.15 License term.

First Class Radiotelegraph Operator's Certificates, Second Class Radiotelegraph Operator's Certificates, and Third Class Radiotelegraph Operator's Certificates are normally valid for a term of five years from the date of issuance.

All other commercial radio operator licenses are normally valid for the lifetime of the holder.

§ 13.7 Classification of operator licenses and endorsements.

[47 CFR 13.7(b)(1)][8] First Class Radiotelegraph Operator's Certificate. Beginning May 20, 2013, no applications for new First Class Radiotelegraph Operator's Certificates will be accepted for filing.


Per FCC Commercial Radio Operator Types of Licenses page

Currently, there is only Radiotelegraph Operator License (T).

Must Pass: Written Element(s) 1 & 6 (this exam) Telegraphy Element(s) 1 & 2

Element 1 -16 code groups per minute.
Element 2 - 20 words per minute.


Per FCC Commercial Radio Operator Types of Licenses page
As of May 20, 2013, the Commission no longer accepts applications for new T1, T2, or T3 licenses, and T1 licenses for which renewal applications are filed are renewed as T licenses. T1 is the First Class, T2 is the Second Class, and T3 is the Third Class.

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What is a requirement of every commercial operator on duty and in charge of a transmitting system?

  • A copy of the Proof-of-Passing Certificate (PPC) must be on display at the transmitter location
  • Correct Answer
    The original license or a photocopy must be posted or in the operator's personal possession and available for inspection
  • The FCC Form 756 certifying the operator's qualifications must be readily available at the transmitting system site
  • A copy of the operator's license must be supplied to the radio station's supervisor as evidence of technical qualification

What is a requirement of every commercial operator on duty and in charge of a transmitting system?

(B). The original license or a photocopy must be posted or in the operator's personal possession and available for inspection.

Code of Federal Regulations, Title 47 Chapter I Subchapter A Part 13 General
§ 13.19 Operator's responsibility.

47 CFR 13.19(c) When the operator is on duty and in charge of transmitting systems, or performing service, maintenance or inspection functions, the license or permit document, or a photocopy thereof, or a copy of the application and PPC(s) received by the FCC, must be posted or in the operator's personal possession, and available for inspection upon request by a FCC representative.

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What is the experience requirement of a First Class Radiotelegrapher?

  • The applicant must have been employed as a radio operator on board a United States ship for at least six months
  • The operator must have held a Second Class Radiotelegraph Operator's Certificate for at least six months
  • Correct Answer
    The applicant must have a background of sending or receiving radiotelegraph messages for one year
  • Both A & B

What is the experience requirement of a First Class Radiotelegrapher?

(C). The applicant must have a background of sending or receiving radiotelegraph messages for one year

Code of Federal Regulations, Title 47 Chapter I Subchapter A Part 13 - COMMERCIAL RADIO OPERATORS

§ 13.7 Classification of operator licenses and endorsements.

47 CFR 13.7(b)(1) First Class Radiotelegraph Operator's Certificate. Beginning May 20, 2013, no applications for new First Class Radiotelegraph Operator's Certificates will be accepted for filing.


§ 13.201 Qualifying for a commercial operator license or endorsement.

47 CFR 13.201(b)(1) Radiotelegraph Operator License.


§ 13.203 Examination elements.

47 CFR 13.203(b) A telegraphy examination (telegraphy Elements) must prove that the examinee has the ability to send correctly by hand and to receive correctly by ear texts in the international Morse code at not less than the prescribed speed, using all the letters of the alphabet, numerals 0-9, period, comma, question mark, slant mark, and prosigns AR, BT, and SK.

47 CFR 13.203(b)(1) Telegraphy Element 1: 16 code groups per minute.
47 CFR 13.203(b)(2) Telegraphy Element 2: 20 words per minute.


Per FCC Commercial Radio Operator Types of Licenses page

Currently, there is only Radiotelegraph Operator License (T).

Must Pass: Written Element(s) 1 & 6 (this exam) Telegraphy Element(s) 1 & 2

Element 1 -16 code groups per minute.
Element 2 - 20 words per minute.


Per FCC Commercial Radio Operator Types of Licenses page
As of May 20, 2013, the Commission no longer accepts applications for new T1, T2, or T3 licenses, and T1 licenses for which renewal applications are filed are renewed as T licenses. T1 is the First Class, T2 is the Second Class, and T3 is the Third Class.

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What examination requirements are necessary to obtain a Second Class Radiotelegraph Operator's Certificate?

  • Written Element 1 (radio law), Element 3 (electronic fundamentals), Element 5 (radiotelegraph operations) and sending/receiving 16/20 words per minute
  • Telegraphy Element 1 (sending/receiving 16 code groups per minute) and Telegraphy Element 2 (16 code groups and 20 words per minute text.)
  • Correct Answer
    Successful completion of written test Elements 1, 5 and 6 on basic radio law and operating practices plus telegraphy Elements 1 and 2
  • Successful completion of written test Elements 1, 3, 5 and 6 on basic radio law and operating practices plus telegraphy Elements 1 and B

What examination requirements are necessary to obtain a Second Class Radiotelegraph Operator's Certificate?

(C) Successful completion of written test Elements 1, 5 and 6 on basic radio law and operating practices plus telegraphy Elements 1 and 2

Code of Federal Regulations, Title 47 Chapter I Subchapter A Part 13 - COMMERCIAL RADIO OPERATORS

§ 13.7 Classification of operator licenses and endorsements.

47 CFR 13.7(b)(2) Second Class Radiotelegraph Operator's Certificate. Beginning May 20, 2013, no applications for new Second Class Radiotelegraph Operator's Certificates will be accepted for filing.


§ 13.201 Qualifying for a commercial operator license or endorsement.

47 CFR 13.201(b)(1) Radiotelegraph Operator License.


§ 13.203 Examination elements.

47 CFR 13.203(b) A telegraphy examination (telegraphy Elements) must prove that the examinee has the ability to send correctly by hand and to receive correctly by ear texts in the international Morse code at not less than the prescribed speed, using all the letters of the alphabet, numerals 0-9, period, comma, question mark, slant mark, and prosigns AR, BT, and SK.

47 CFR 13.203(b)(1) Telegraphy Element 1: 16 code groups per minute.
47 CFR 13.203(b)(2) Telegraphy Element 2: 20 words per minute.


Per FCC Commercial Radio Operator Types of Licenses page

Currently, there is only Radiotelegraph Operator License (T).

Must Pass: Written Element(s) 1 & 6 (this exam) Telegraphy Element(s) 1 & 2

Element 1 -16 code groups per minute.
Element 2 - 20 words per minute.


Per FCC Commercial Radio Operator Types of Licenses page
As of May 20, 2013, the Commission no longer accepts applications for new T1, T2, or T3 licenses, and T1 licenses for which renewal applications are filed are renewed as T licenses. T1 is the First Class, T2 is the Second Class, and T3 is the Third Class.

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How does an applicant qualify for a Third Class Radiotelegraph Operator's Certificate?

  • Correct Answer
    By passing the appropriate written examinations and receiving by ear code groups and plain text for a period of one minute without error at the appropriate speed
  • Applicant must send and receive radiotelegraphy at the prescribed speed and be at least 21 years old
  • By the successful completion of radiotelegraphy Elements 1 and 2 plus written examinations on radio law, telegraphy practices and transmitter maintenance
  • By passing a written examination on radio law, electronic fundamentals and radiotelegraph practices plus a telegraphy receiving examination

How does an applicant qualify for a Third Class Radiotelegraph Operator's Certificate?

(A). By passing the appropriate written examinations and receiving by ear code groups and plain text for a period of one minute without error at the appropriate speed

Code of Federal Regulations, Title 47 Chapter I Subchapter A Part 13 - COMMERCIAL RADIO OPERATORS

§ 13.7 Classification of operator licenses and endorsements.

47 CFR 13.7(b)(3) Third Class Radiotelegraph Operator's Certificate (radiotelegraph operator's special certificate). Beginning May 20, 2013, no applications for new Third Class Radiotelegraph Operator's Certificates will be accepted for filing.


§ 13.201 Qualifying for a commercial operator license or endorsement.

47 CFR 13.201(b)(1) Radiotelegraph Operator License.


§ 13.203 Examination elements.

47 CFR 13.203(b) A telegraphy examination (telegraphy Elements) must prove that the examinee has the ability to send correctly by hand and to receive correctly by ear texts in the international Morse code at not less than the prescribed speed, using all the letters of the alphabet, numerals 0-9, period, comma, question mark, slant mark, and prosigns AR, BT, and SK.

47 CFR 13.203(b)(1) Telegraphy Element 1: 16 code groups per minute.
47 CFR 13.203(b)(2) Telegraphy Element 2: 20 words per minute.


Per FCC Commercial Radio Operator Types of Licenses page

Currently, there is only Radiotelegraph Operator License (T).

Must Pass: Written Element(s) 1 & 6 (this exam) Telegraphy Element(s) 1 & 2

Element 1 -16 code groups per minute.
Element 2 - 20 words per minute.


Per FCC Commercial Radio Operator Types of Licenses page
As of May 20, 2013, the Commission no longer accepts applications for new T1, T2, or T3 licenses, and T1 licenses for which renewal applications are filed are renewed as T licenses. T1 is the First Class, T2 is the Second Class, and T3 is the Third Class.

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What examination credit is accorded Amateur Extra Class operators?

  • 20 code groups and 25 text words per minute
  • Amateur radio operators are not eligible for commercial radio operator examination credit
  • Correct Answer
    Commercial radio operator telegraphy Elements 1 and 2
  • Written Element 1, basic radio law and operating practices

What examination credit is accorded Amateur Extra Class operators?

(C). Commercial radio operator telegraphy Elements 1 and 2

Code of Federal Regulations, Title 47 Chapter I Subchapter A Part 13 - COMMERCIAL RADIO OPERATORS

§ 13.9 Eligibility and application for new license or endorsement.

47 CFR 13.9(d)(2) An expired or unexpired FCC-issued Amateur Extra Class operator license grant granted before April 15, 2000: Telegraphy Elements 1 and 2;

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What must every examination for the code portion of a radiotelegraph license contain?

  • Applicants for Commercial Radiotelegraph licenses must be examined using a message format that they are likely to receive aboard ship
  • Both a telegraphy sending and a receiving distress signals
  • The proper transmission of radiotelegraph distress signals
  • Correct Answer
    All alphabet letters, all numerals, period, comma, question mark, slant mark and prosigns AR, BT, and SK

What must every examination for the code portion of a radiotelegraph license contain?

(D). All alphabet letters, all numerals, period, comma, question mark, slant mark and prosigns AR, BT, and SK.

§ 13.207 Preparing an examination.

47 CFR 13.207(c) A telegraphy examination must consist of a plain language text or code group message sent in the international Morse code at no less than the prescribed speed for a minimum of five ? (see below)minutes.

The message must contain each required telegraphy character at least once. No message known to the examinee may be administered in a telegraphy examination.

Each five letters of the alphabet must be counted as one word or one code group. Each numeral, punctuation mark, and prosign must be counted as two letters of the alphabet.

The COLEM may obtain the telegraphy message from a supplier or other COLEM.


Per FCC Commercial Radio Operator Types of Licenses page

Telegraphy exams may consist of both transmitting and receiving tests or just a receiving test.

Although the FCC rules provide that passing a telegraphy receiving examination is adequate proof of an examinee's ability to both send and receive telegraphy, a COLEM may nonetheless include a sending segment in a telegraphy examination.

Examinees must copy by ear and, if subject to a sending test, send by hand plain text and code groups in the international Morse code using all the letters of the alphabet, numerals 0-9, period, comma, question mark, slant mark, and prosigns AR, BT, and SK.

Examinees must copy and send at the required speeds for one continuous minute without making any errors.

Each test lasts approximately five minutes.

The failing of any code test automatically terminates the examination. Code speeds are computed using five letters per word or code group. Punctuation symbols and numbers count as two letters each.

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What answer format is accepted on commercial radiotelegraph license contain?

  • The examiner may use any answer format which ascertains that the examinee can comprehend the message transmitted
  • Any of the following: one minute solid copy, answering seven out of ten question, fill-in-the-blank, or multiple choice questions
  • Correct Answer
    Examinees are required to receive international Morse code messages by ear for a period of one minute without error
  • Examinees must obtain a passing mark of 75% or higher on questions concerning the transmitted telegraphy message

What answer format is accepted on commercial radiotelegraph license contain?

(C). Examinees are required to receive international Morse code messages by ear for a period of one minute without error

§ 13.207 Preparing an examination.

47 CFR 13.207(c) A telegraphy examination must consist of a plain language text or code group message sent in the international Morse code at no less than the prescribed speed for a minimum of five ? (see below)minutes.

The message must contain each required telegraphy character at least once. No message known to the examinee may be administered in a telegraphy examination.

Each five letters of the alphabet must be counted as one word or one code group. Each numeral, punctuation mark, and prosign must be counted as two letters of the alphabet.

The COLEM may obtain the telegraphy message from a supplier or other COLEM.


Per FCC Commercial Radio Operator Types of Licenses page

Telegraphy exams may consist of both transmitting and receiving tests or just a receiving test.

Although the FCC rules provide that passing a telegraphy receiving examination is adequate proof of an examinee's ability to both send and receive telegraphy, a COLEM may nonetheless include a sending segment in a telegraphy examination.

Examinees must copy by ear and, if subject to a sending test, send by hand plain text and code groups in the international Morse code using all the letters of the alphabet, numerals 0-9, period, comma, question mark, slant mark, and prosigns AR, BT, and SK.

Examinees must copy and send at the required speeds for one continuous minute without making any errors.

Each test lasts approximately five minutes.

The failing of any code test automatically terminates the examination. Code speeds are computed using five letters per word or code group. Punctuation symbols and numbers count as two letters each.

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What is a requirement of all transmitting apparatus used aboard United States vessels?

  • Equipment must be approved by the U.S. Coast Guard for maritime mobile use
  • Certification is required by the International Maritime Organization (IMO)
  • Correct Answer
    Only equipment that has been type accepted by the FCC for Part 80 operations is authorized
  • Programming of all maritime channels must be performed by a licensed Marine Radio Operator

What is a requirement of all transmitting apparatus used aboard United States vessels?

(C). Only equipment that has been type accepted by the FCC for Part 80 operations is authorized

Code of Federal Regulations Title 47 Chapter I Subchapter D Part 80 Subpart E
§ 80.203 Authorization of transmitters for licensing.

47 CFR 80.203(a) Each transmitter authorized in a station in the maritime services after September 30, 1986, except as indicated in paragraphs (g), (h) and (i) of this section, must be certified by the Commission for part 80 operations.

See FCC presentation on Part 80 - VHF Transceivers VHF Transceivers and Marine Radars and Marine Radars

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What happens to a lower grade of Commercial Radiotelegraph License when a licensee qualifies for a higher grade?

  • The lower grade is allowed to expire and may not be renewed
  • The Second or Third Class Radiotelegraph license is modified to a higher class
  • Correct Answer
    The lower grade is canceled. Only one unexpired radiotelegraph operator's certificate may be held at the same time
  • Licensees are permitted to hold any number of radiotelegraph operator certificates at the same time

What happens to a lower grade of Commercial Radiotelegraph License when a licensee qualifies for a higher grade?

(A). The lower grade is canceled. Only one unexpired radiotelegraph operator's certificate may be held at the same time

Code of Federal Regulations, Title 47 Chapter I Subchapter A Part 13 - COMMERCIAL RADIO OPERATORS

§ 13.11 Holding more than one commercial radio operator license.

47 CFR 13.11(a) An eligible person may hold more than one commercial operator license.

  • 47 CFR 13.11(a)(1) No person may hold two or more unexpired radiotelegraph operator's certificates at the same time;

  • 47 CFR 13.11(a)(2) No person may hold any class of radiotelegraph operator's certificate and a Marine Radio Operator Permit;

  • 47 CFR 13.11(a)(3) No person may hold any class of radiotelegraph operator's certificate and a Restricted Radiotelephone Operator Permit.


§ 13.7 Classification of operator licenses and endorsements.

47 CFR 13.7(b)(1) First Class Radiotelegraph Operator's Certificate. Beginning May 20, 2013, no applications for new First Class Radiotelegraph Operator's Certificates will be accepted for filing.

47 CFR 13.7(b)(2) Second Class Radiotelegraph Operator's Certificate. Beginning May 20, 2013, no applications for new Second Class Radiotelegraph Operator's Certificates will be accepted for filing.

47 CFR 13.7(b)(3) Third Class Radiotelegraph Operator's Certificate (radiotelegraph operator's special certificate). Beginning May 20, 2013, no applications for new Third Class Radiotelegraph Operator's Certificates will be accepted for filing.


§ 13.201 Qualifying for a commercial operator license or endorsement.

47 CFR 13.201(b)(1) Radiotelegraph Operator License.


§ 13.203 Examination elements.

47 CFR 13.203(b) A telegraphy examination (telegraphy Elements) must prove that the examinee has the ability to send correctly by hand and to receive correctly by ear texts in the international Morse code at not less than the prescribed speed, using all the letters of the alphabet, numerals 0-9, period, comma, question mark, slant mark, and prosigns AR, BT, and SK.

47 CFR 13.203(b)(1) Telegraphy Element 1: 16 code groups per minute.
47 CFR 13.203(b)(2) Telegraphy Element 2: 20 words per minute.


Per FCC Commercial Radio Operator Types of Licenses page

Currently, there is only Radiotelegraph Operator License (T).

Must Pass: Written Element(s) 1 & 6 (this exam) Telegraphy Element(s) 1 & 2

Element 1 -16 code groups per minute.
Element 2 - 20 words per minute.


Per FCC Commercial Radio Operator Types of Licenses page
As of May 20, 2013, the Commission no longer accepts applications for new T1, T2, or T3 licenses, and T1 licenses for which renewal applications are filed are renewed as T licenses. T1 is the First Class, T2 is the Second Class, and T3 is the Third Class.

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What is an operating control requirement of a ship station using telegraphy?

  • Correct Answer
    The ship station must be capable of automatically changing from telegraphy transmission to telegraph reception
  • A ship station control operator must stand watch on emergency channels at all times
  • Only a licensed First Class Radiotelegraph Operator may operate a ship station
  • The ship station must be capable of changing from one radio channel to another within five seconds

What is an operating control requirement of a ship station using telegraphy?

(A) The ship station must be capable of automatically changing from telegraphy transmission to telegraph reception

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How does a radiotelegraph operator transmit a routine call to another station?

  • The letters "CQ" are followed by the call sign of the station called and the call sign of the originating station
  • Correct Answer
    The station is called not more than twice, followed by the word "DE" and the call sign of the calling station not more than twice
  • The originating station must obtain permission from the nearest public coast station
  • Routine calls are initiated by using the appropriate service abbreviation

How does a radiotelegraph operator transmit a routine call to another station?

(B). The station is called not more than twice, followed by the word "DE" and the call sign of the calling station not more than twice

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What is the proper procedure to conduct a radiotelegraph equipment test?

  • By transmitting "EI" on the test frequency as a warning that a test transmission is about to be made
  • Correct Answer
    Sending a series of "VVV" followed by the call sign of the testing station at about 10 words-per-minute
  • The test transmission may not proceed until all stations on frequency have signalled their consent
  • The nearest public or private coast station must be notified of an impending test

What is the proper procedure to conduct a radiotelegraph equipment test?

(B). Sending a series of "VVV" followed by the call sign of the testing station at about 10 words-per-minute

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How often must a radiotelegraph station transmit its call sign when a transmission is maintained for more than 20 minutes in the band 405-525 kHz?

  • Correct Answer
    At 20 minute intervals
  • At least every 10 minutes
  • At 15 minute intervals unless public correspondence is in progress
  • At the beginning and end of each communication with any other station

How often must a radiotelegraph station transmit its call sign when a transmission is maintained for more than 20 minutes in the band 405-525 kHz?

(A). At 20 minute intervals

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When may a public coast station authorized to use high frequency narrow-band direct-printing (NB-DP) establish contact with a ship station using telegraphy?

  • Never. Contact may only be established using NB-DP circuits
  • When the ship is in excess of 300 gross tons
  • Correct Answer
    When the radio station license reflects authority for this type of operation and harmful interference is avoided
  • When it is known that the vessel does not have a selective ringing or calling device

When may a public coast station authorized to use high frequency narrow-band direct-printing (NB-DP) establish contact with a ship station using telegraphy?

(C). When the radio station license reflects authority for this type of operation and harmful interference is avoided

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Which operator is authorized to make equipment adjustments at maritime radio stations which may affect transmitter operation?

  • The holder of a marine radio operator permit or higher class license
  • The holder of a restricted radiotelephone operator permit when the radiated power is less than 100 watts
  • Correct Answer
    Only the holders of a first or second class radiotelegraph of the general radiotelephone operator's license
  • The holder of a GMDSS radio operator or higher class radiotelephone license

Which operator is authorized to make equipment adjustments at maritime radio stations which may affect transmitter operation?

(C). Only the holders of a first or second class radiotelegraph of the general radiotelephone operator's license

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Who may install, maintain or adjust radiotelephone transmitters which radiate less than 50 watts carrier power?

  • Correct Answer
    Anyone under the immediate supervision and responsibility of a person holding a first of second class radiotelegraph or general radiotelephone operator license
  • Only a properly licensed radiotelephone operator
  • Any holder of a marine radio operator permit or higher
  • Only persons holding an operator certificate containing a ship radar endorsement

Who may install, maintain or adjust radiotelephone transmitters which radiate less than 50 watts carrier power?

(A). Anyone under the immediate supervision and responsibility of a person holding a first of second class radiotelegraph or general radiotelephone operator license

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Who may program authorized frequency channels into a transmitter or transceiver used in the maritime service?

  • Any person who has the authorization of the station licensee or ship's master
  • A licensed marine radio operator or higher
  • A person holding a restricted radiotelephone operator permit or higher
  • Correct Answer
    Only persons holding a first or second class radiotelegraph operator's certificate or a general radiotelephone operator's license

Who may program authorized frequency channels into a transmitter or transceiver used in the maritime service?

(D). Only persons holding a first or second class radiotelegraph operator's certificate or a general radiotelephone operator's license

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What is the maximum authorized bandwidth of a high frequency radiotelegraphy signal, emission A1A, in the maritime service?

  • Correct Answer
    0.4 kHz
  • 0.2 kHz
  • Minimum necessary to complete necessary communications
  • 1 kHz

What is the maximum authorized bandwidth of a high frequency radiotelegraphy signal, emission A1A, in the maritime service?

(A). 0.4 kHz

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What is the maximum transmitter power that a ship station may radiate using radiotelegraphy emissions on frequencies below 27500 kHz?

  • 400 W
  • 2 kW, unless a passenger ship 5000 gross tons and over
  • Correct Answer
    3 kW
  • 1 kW

What is the maximum transmitter power that a ship station may radiate using radiotelegraphy emissions on frequencies below 27500 kHz?

(C). 3 kW

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Where must ship station logs be kept during a voyage?

  • They must be secured in the vessel's strongbox for safekeeping
  • In the personal custody of the licensed commercial radio operator
  • Correct Answer
    At the principal radiotelephone operating position or radiotelegraph operating room
  • All logs are turned over to the ship's master when the radio operator goes off duty

Where must ship station logs be kept during a voyage?

(C). At the principal radiotelephone operating position or radiotelegraph operating room

§ 80.409 Station logs.

47 CFR 80.409(b) Availability and retention. Station logs must be made available to authorized Commission employees upon request and retained as follows:

47 CFR 80.409(b)(3) Ship radiotelegraph logs must be kept in the principal radiotelegraph operating room during the voyage.

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How often must compulsory radiotelegraph installations on passenger vessels be inspected?

  • When the vessel is placed in service and every 2 years thereafter
  • At least every 3 years when the ship is within 75 miles of an FCC field office
  • The ship's master is responsible for completion of the Annual Equipment Verification Report
  • Correct Answer
    Equipment inspections are required at least once every 12 months

How often must compulsory radiotelegraph installations on passenger vessels be inspected?

(D). Equipment inspections are required at least once every 12 months

Code of Federal Regulations, Title 47 Chapter I Subchapter D Part 80 Subpart Q - Compulsory Radiotelegraph Installations

§ 80.802 Inspection of station.

(a) Every ship of the United States subject to Part II of Title III of the Communications Act or the radio provisions of the Safety Convention must have the required equipment inspected at least once every 12 months.

If the ship is in compliance with the requirements of the Safety Convention, a Safety Certificate will be issued; if in compliance with the Communications Act, the license will be endorsed accordingly.

  • (1) The effective date of ship safety certificates is the date the station is found to be in compliance or not later than one business day later.

  • (2) At inspection, the minimum field strength capability of the main installation and reserve installation when connected to the main antenna may be shown by the licensee by one of the following methods:

    • (i) Producing a record of communications on 500 kHz over a minimum distance of 370 kilometers (200 nautical miles) for the main installation and 185 kilometers (100 nautical miles) for the reserve installation which demonstrates the transmission and reception of clearly perceptible signals from ship to ship by day and under normal conditions and circumstances,

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What is the antenna requirement aboard a survival craft equipped with a non-portable radiotelegraph installation?

  • The minimum lifeboat antenna requirement is an HF half-wave dipole capable of efficiently tuning distress frequencies
  • Correct Answer
    The antenna must be single wire inverted L type of maximum practicable length and height above the waterline
  • The antenna must be tested at least once during each voyage and a minimum of once a week on longer voyages
  • The antenna must be located a minimum of 8 meters above the waterline to insure the safety of passengers

What is the antenna requirement aboard a survival craft equipped with a non-portable radiotelegraph installation?

(B). The antenna must be single wire inverted L type of maximum practicable length and height above the waterline

If you invert letter "L" it will have a horizontal wire, suspended between two highest points on a survival craft.

From one end of the wire, there is another wire that is vertical and connects to the transreceiver.

The horizontal wire should be suspended at least 3 feet or about 1 meter from water (being the ground here), so that it can propagate and receive radio wave signals better.


For additional information, please see, Code of Federal Regulations, Title 47 Chapter I Subchapter D Part 80 Subpart W - Equipment Requirements for Ship Stations, especially § 80.1095 Survival craft equipment.

For inverted L info, please see QSOshack.com multi-band inverted L antenna.

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What document is issued after a radio station inspection aboard a large ship that is not a passenger vessel?

  • Great Lakes Radio Agreement surety authorization
  • International Maritime Organization safety permit
  • Correct Answer
    Cargo ship safety radiotelegraphy or radiotelephony certificate
  • Safety Convention radio certification

What document is issued after a radio station inspection aboard a large ship that is not a passenger vessel?

(C). Cargo ship safety radiotelegraphy or radiotelephony certificate

Code of Federal Regulations, Title 46 Chapter I Subchapter D
PART 31 - INSPECTION AND CERTIFICATION

§ 31.40-15 Cargo Ship Safety Radio Certificate - T/ALL.

Every tankship equipped with a radio installation on an international voyage must have a Cargo Ship Safety Radio Certificate. Each radio installation must meet the requirements of the Federal Communication Commission and the International Convention for Safety of Life at Sea.

§ 31.40-40 Duration of Convention certificates - T/ALL.

46 CFR 31.40 40(a) The following certificates are valid for a period of not more than 60 months.

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What is the minimum radio operator license requirement of a chief radio officer on U.S. passenger ships?

  • First or Second Class Radiotelegraph Operator Certificate with six month endorsement
  • Correct Answer
    First Class Radiotelegraph Operator Certificate
  • General Radiotelephone Operator License
  • Marine Radio Operator Permit

What is the minimum radio operator license requirement of a chief radio officer on U.S. passenger ships?

(B). First Class Radiotelegraph Operator Certificate

Although this is the answer they want, per FCC

"As of May 20, 2013, the Commission no longer accepts applications for new T1 licenses, and T1 licenses for which renewal applications are filed are renewed as T licenses."

HOWEVER, there is the "Radiotelegraph Operator License (T)" Per FCC,

"The T authorizes the holder to operate, repair, and maintain ship stations, and to repair and maintain coast radiotelegraph stations in the maritime services. It also confers all of the operating authority of a T2."

For more info, see FCC's Commercial Radio Operator Types of Licenses

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What is the order of priority of radiotelegraph communications in the maritime services?

  • Alarm, radio-direction finding, and health and welfare communications
  • Navigation hazards, meteorological warnings, priority traffic
  • Correct Answer
    Distress calls, and signals, followed by communications preceded by urgency and safety signals
  • Government precedence, messages concerning safety of life and protection of property and traffic concerning grave imminent danger

What is the order of priority of radiotelegraph communications in the maritime services?

(C). Distress calls, and signals, followed by communications preceded by urgency and safety signals

Code of Federal Regulations, Title 47 Chapter I Subchapter D Part 80 Subpart
C - Operating Requirements and Procedures

§ 80.91 - Order of priority of communications.

47 CFR 80.91(a) All stations in the maritime mobile service and the maritime mobile-satellite service shall be capable of offering four levels of priority in the following order:

  • (1) Distress calls, distress messages, and distress traffic.
  • (2) Urgency communications.
  • (3) Safety communications.
  • (4) Other communications.

47 CFR 80.91(b) In a fully automated system, where it is impracticable to offer all four levels of priority, category 1 shall receive priority until such time as intergovernmental agreements remove exemptions granted for such systems from offering the complete order of priority.

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What should a station operator do before making a transmission?

  • Check transmitting equipment to be certain it is properly calibrated
  • Correct Answer
    Except for the transmission of distress calls, determine that the frequency is not in use by monitoring the frequency before transmitting
  • Ask if the frequency is in use
  • Transmit a general notification that the operator wishes to utilize the channel

What should a station operator do before making a transmission?

(B). Except for the transmission of distress calls, determine that the frequency is not in use by monitoring the frequency before transmitting

The accepted practice in radio communications is to listen before initiating a communication. This prevents jumping on top of someone's continuing radio message.

Code of Federal Regulations, Title 47 Chapter I Subchapter D Part 80 Subpart
C Operating Procedures - General

§ 80.92 Prevention of interference.

47 CFR 80.92(a) The station operator must determine that the frequency is not in use by monitoring the frequency before transmitting, except for transmission of signals of distress.

47 CFR 80.92(b) When a radiocommunication causes interference to a communication which is already in progress, the interfering station must cease transmitting at the request of either party to the existing communication. As between non distress traffic seeking to commence use of a frequency, the priority is established under § 80.91.

47 CFR 80.92(c) Except in cases of distress, communications between ship stations or between ship and aircraft stations must not interfere with public coast stations.

The ship or aircraft stations which cause interference must stop transmitting or change frequency upon the first request of the affected coast station.

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