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194 matching questions

Question #536Radio Theory and Communication Principles

Which of the following types of emission has the narrowest bandwidth?

  1. FM voice
  2. SSB voice
  3. CW ✓ Correct answer
  4. Slow-scan TV

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Question #537Radio Theory and Communication Principles

One GHz is equal to

  1. 1000 kHz
  2. 10 MHz
  3. 100 MHz
  4. 1000 MHz ✓ Correct answer

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Question #539Radio Theory and Communication Principles

What does the abbreviation “LED” stand for?

  1. Low Emission Diode
  2. Light Emitting Diode ✓ Correct answer
  3. Liquid Emission Detector
  4. None of the above

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Question #540Radio Theory and Communication Principles

What does the abbreviation “FET" stand for?

  1. Field Effect Transistor ✓ Correct answer
  2. Fast Electron Transistor
  3. Free Electron Transistor
  4. Field Emission Thickness

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Question #544Radio Theory and Communication Principles

Which instrument would you use to measure electric potential or electromotive force?

  1. An ammeter
  2. A voltmeter ✓ Correct answer
  3. A wave meter
  4. An ohmmeter

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Question #552Radio Theory and Communication Principles

What type of component is often used as an adjustable volume control?

  1. Fixed resistor
  2. Power resistor
  3. Potentiometer ✓ Correct answer
  4. Transformer

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Question #553Radio Theory and Communication Principles

What electrical parameter is controlled by a potentiometer?

  1. Inductance
  2. Resistance ✓ Correct answer
  3. Capacitance
  4. Field strength

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Question #556Radio Theory and Communication Principles

Which of the following is commonly used as a visual indicator?

  1. LED ✓ Correct answer
  2. FET
  3. Zener diode
  4. Bipolar transistor

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Question #559Radio Theory and Communication Principles

What is the function of a product detector?

  1. Detect phase modulated signals
  2. Demodulate FM signals
  3. Detect CW and SSB signals ✓ Correct answer
  4. Modulate speech with RF

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Question #561Radio Theory and Communication Principles

Which term describes the ability of a receiver to discriminate between multiple signals?

  1. Tuning rate
  2. Sensitivity
  3. Selectivity ✓ Correct answer
  4. Noise floor

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Question #562Radio Theory and Communication Principles

Where is an RF pre-amplifier installed?

  1. between the antenna and receiver ✓ Correct answer
  2. At the output of the transmitters power amplifier
  3. Between a transmitter and antenna tuner
  4. At the receiver's audio output

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Question #563Radio Theory and Communication Principles

Why is UHF signals often more effective from inside buildings than VHF signals?

  1. VHF signals lose power faster over distance
  2. the shorter wavelength allows them to more easily penetrate the structure of buildings ✓ Correct answer
  3. This is incorrect; VHF works better than UHF inside buildings
  4. UHF antennas are more efficient than VHF antennas

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Question #566Radio Theory and Communication Principles

What are the two components of a radio wave?

  1. AC and DC
  2. Voltage and current
  3. Electric and magnetic fields ✓ Correct answer
  4. Ionizing and non-ionizing radiation

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Question #567Radio Theory and Communication Principles

What is the function of a mixer in a super-heterodyne receiver?

  1. To reject signals outside of the desired passband
  2. To combine signals from several stations together
  3. To shift the incoming signal with an intermediate frequency ✓ Correct answer
  4. To connect the receiver with an auxiliary device

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Question #571Radio Theory and Communication Principles

An Oscillator is based on

  1. Positive feedback ✓ Correct answer
  2. Negative feedback
  3. No feedback
  4. both a & b

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Question #573Radio Theory and Communication Principles

What does the term “RIT" mean?

  1. Receiver Input Tone
  2. Receiver Incremental Tuning ✓ Correct answer
  3. Rectifier Inverter Test
  4. Remote input Transmitter

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Question #574Radio Theory and Communication Principles

A common use for a permanent magnet is

  1. A computer speaker ✓ Correct answer
  2. An optical mouse
  3. A keyboard
  4. A magnetic loop antenna

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Question #578Radio Theory and Communication Principles

A "linear amplifier" is

  1. an amplifier to remove distortion in signals from the transceiver
  2. an optional amplifier to be switched in when higher power is required ✓ Correct answer
  3. an amplifier with all components arranged in-line
  4. a push-pull amplifier to cancel second harmonic distortion

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Question #580Radio Theory and Communication Principles

Of two receivers, the one capable of receiving the weakest signal will have:

  1. an RF gain control
  2. the least internally-generated noise ✓ Correct answer
  3. the loudest audio output
  4. the greatest tuning range
Explanation: The receiver that can copy the weakest signals has the least internally generated noise (better noise figure).

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Question #581Radio Theory and Communication Principles

A receiver with high selectivity has a

  1. wide bandwidth
  2. wide tuning range
  3. narrow bandwidth ✓ Correct answer
  4. narrow tuning range

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