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Question #499Radio Theory and Communication Principles

What device increases the low-power output from a hand-held transceiver?

  1. A voltage divider
  2. An RF power amplifier ✓ Correct answer
  3. An impedance network
  4. A voltage regulator
Explanation: An RF power amplifier increases the low-power RF output of a hand-held transceiver.

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Question #501Radio Theory and Communication Principles

What electrical component is usually composed of a coil of wire?

  1. Switch
  2. Capacitor
  3. Diode
  4. Inductor ✓ Correct answer

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Question #504Radio Theory and Communication Principles

What is the purpose of the squelch control on a transceiver?

  1. To set the highest level of volume desired
  2. To set the transmitter power level
  3. To adjust the automatic gain control
  4. To mute receiver output noise when no signal is being received ✓ Correct answer

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Question #505Radio Theory and Communication Principles

What is the radio horizon?

  1. The distance at which radio signals between two points are effectively blocked by the curvature of the Earth ✓ Correct answer
  2. The distance from the ground to a horizontally mounted antenna
  3. The farthest point you can see when standing at the base of your antenna tower
  4. The shortest distance between two points on the Earth's surface

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Question #506Radio Theory and Communication Principles

What is a good way to guard against electrical shock at your station?

  1. Use three-wire cords and plugs for all AC powered equipment
  2. Connect all AC powered station equipment to a common safety ground
  3. Use a circuit protected by a ground-fault interrupter
  4. All of these choices are correct ✓ Correct answer

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Question #507Radio Theory and Communication Principles

Why must the metal enclosure of every item of station equipment be grounded?

  1. It prevents blowing of fuses in case of an internal short circuit
  2. It prevents signal overload
  3. It ensures that the neutral wire is grounded
  4. It ensures that hazardous voltages cannot appear on the chassis ✓ Correct answer

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Question #512Radio Theory and Communication Principles

What type of bias is required for an LED to emit light?

  1. Reverse bias
  2. Forward bias ✓ Correct answer
  3. Zero bias
  4. Inductive bias

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Question #514Radio Theory and Communication Principles

Which type of modulation is most commonly used for VHF and UHF voice repeaters?

  1. AM
  2. SSB
  3. PSK
  4. FM ✓ Correct answer

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Question #515Radio Theory and Communication Principles

Q factor of a coil is measure of its

  1. Sensitivity
  2. selectivity ✓ Correct answer
  3. Resistivity
  4. conductivity

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Question #516Radio Theory and Communication Principles

How fast does a radio wave travel through free space?

  1. at the speed of light ✓ Correct answer
  2. At the speed of sound
  3. Its speed is inversely proportional to its wavelength
  4. Its speed increases as the frequency increases
Explanation: In free space, radio waves travel at the speed of light (approximately 3 × 10^8 m/s).

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Question #519Radio Theory and Communication Principles

What are the frequency limits of VHF spectrum?

  1. 30 to 300 kHz
  2. 30 to 300MHz ✓ Correct answer
  3. 300 to 3000 kHz
  4. 300 to 3000 MHz.

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Question #520Radio Theory and Communication Principles

What are the frequency of UHF spectrum?

  1. 30 to 300 kHz
  2. 30 to 300MHz
  3. 300 to 3000 kHz
  4. 300 to 3000 MHz. ✓ Correct answer

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Question #521Radio Theory and Communication Principles

What frequency range is referred to as HF?

  1. 3 to 30 MHz ✓ Correct answer
  2. 30 to 300MHz
  3. 300 to 3000 kHz
  4. 300 to 3000 MHz.

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Question #522Radio Theory and Communication Principles

How many milliamperes is 1.5 amperes?

  1. 15 milliamperes
  2. 150 milliamperes
  3. 1500 milliamperes ✓ Correct answer
  4. 15,000 milliamperes

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Question #523Radio Theory and Communication Principles

Which sideband is normally used for 10meter HF, VHF and UHF single-side band communications?

  1. Upper sideband ✓ Correct answer
  2. Lower sideband
  3. Suppressed sideband
  4. Double sideband

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Question #524Radio Theory and Communication Principles

What is the primary advantage of single sideband over FM

  1. SSB signals are easier to tune
  2. SSB signals are less susceptible to interference ✓ Correct answer
  3. SSB signals have narrower bandwidth
  4. All the above options are correct

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Question #526Radio Theory and Communication Principles

What is the electrical term for the electromotive force (EMF) that causes electron flow?

  1. Voltage ✓ Correct answer
  2. Ampere-hours
  3. Capacitance
  4. Inductance

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Question #533Radio Theory and Communication Principles

How many micro-farads are 1,000,000 picofarads?

  1. 0.001 micro farads
  2. one micro farad ✓ Correct answer
  3. 1000 micro farad
  4. 10000 micro farads

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Question #534Radio Theory and Communication Principles

What type of modulation is most commonly used for VHF packet radio transmissions?

  1. FM ✓ Correct answer
  2. SSB
  3. AM
  4. Spread Spectrum

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Question #535Radio Theory and Communication Principles

Which type of voice modulation is most often used for long distance or weak signal contacts on the VHF and UHF hands?

  1. FM
  2. AM
  3. SSB ✓ Correct answer
  4. PM

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