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194 matching questions

Question #409Radio Theory and Communication Principles

The side-band system adopted for Television transmission

  1. Independent Sideband
  2. vestigial Sideband ✓ Correct answer
  3. Suppressed Sideband.
  4. All the above

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Question #410Radio Theory and Communication Principles

The oscillator that makes a communication receiver capable of receiving morse code is

  1. Voltage Controlled Oscillator
  2. Local Oscillator
  3. Beat Frequency Oscillator ✓ Correct answer
  4. Phase Locked Loop

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Question #414Radio Theory and Communication Principles

Impedance is a combination of:

  1. reactance with reluctance
  2. resistance with conductance ✓ Correct answer
  3. resistance with reactance
  4. reactance with radiation 222.A simple transmitter requires a 50 ohm dummy load. You can fabricate this from:

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Question #415Radio Theory and Communication Principles

The time for one cycle of a 100 Hz signal is:

  1. 1 second
  2. 0.01 second ✓ Correct answer
  3. 0.0001 second
  4. 10 seconds 224.A component is identified as a capacitor if its value is measured in:

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Question #417Radio Theory and Communication Principles

The "S meter" on a receiver:

  1. indicates where the squelch control should be set
  2. indicates the standing wave ratio
  3. indicates the state of the battery voltage
  4. indicates relative incoming signal strengths ✓ Correct answer

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Question #418Radio Theory and Communication Principles

The term "PTT" means:

  1. push to talk ✓ Correct answer
  2. piezoelectric transducer transmitter
  3. phase testing terminal
  4. phased transmission transponder

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Question #419Radio Theory and Communication Principles

The term "ALC" stands for:

  1. audio limiter control
  2. automatic level control ✓ Correct answer
  3. automatic loudness control
  4. automatic listening control

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Question #421Radio Theory and Communication Principles

The frequency stability of a receiver is its ability to:

  1. stay tuned to the desired signal ✓ Correct answer
  2. track the incoming signal as it drifts
  3. provide a frequency standard
  4. provide a digital readout 233.Of two receivers, the one capable of receiving the weakest signal will have:

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Question #422Radio Theory and Communication Principles

The figure in a receiver's specifications which indicates its sensitivity is the:

  1. bandwidth of the IF in kilohertz
  2. audio output in watts
  3. signal plus noise to noise ratio ✓ Correct answer
  4. number of RF amplifiers

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Question #423Radio Theory and Communication Principles

If two receivers are compared, the more sensitive receiver will produce:

  1. more than one signal
  2. less signal and more noise
  3. more signal and less noise ✓ Correct answer
  4. a steady oscillator drift

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Question #424Radio Theory and Communication Principles

The ability of a receiver to separate signals close in frequency is called its:

  1. noise figure
  2. sensitivity
  3. bandwidth
  4. selectivity ✓ Correct answer
Explanation: Selectivity is a receiver’s ability to separate signals close in frequency. The option text was cleaned of OCR spillover.

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Question #425Radio Theory and Communication Principles

The BFO in a superhet receiver operates on a frequency nearest to that of its:

  1. RF amplifier
  2. audio amplifier
  3. local oscillator
  4. IF amplifier ✓ Correct answer
Explanation: The beat-frequency oscillator is used with the receiver’s intermediate-frequency (IF) signal. The option text was cleaned of OCR spillover.

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Question #427Radio Theory and Communication Principles

The mixer stage of a superhet receiver:

  1. produces spurious signals
  2. produces an intermediate frequency signal ✓ Correct answer
  3. acts as a buffer stage
  4. demodulates SSB signals

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Question #428Radio Theory and Communication Principles

The abbreviation AGC means:

  1. attenuating gain capacitor
  2. automatic gain control ✓ Correct answer
  3. anode-grid capacitor
  4. amplified grid conductance 243.Morse code is usually transmitted by radio as:

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Question #429Radio Theory and Communication Principles

The process of modulation allows:

  1. information to be impressed on to a carrier ✓ Correct answer
  2. information to be removed from a carrier
  3. voice and Morse code to be combined
  4. none of these

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Question #431Radio Theory and Communication Principles

Radio wave polarisation is defined by the orientation of the radiated:

  1. magnetic field
  2. electric field ✓ Correct answer
  3. inductive field
  4. capacitive field 248.A half-wave antenna is often called a:

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Question #432Radio Theory and Communication Principles

The correct colour coding for the earth wire in a flexible mains lead is:

  1. Black
  2. violet
  3. Red
  4. Green ✓ Correct answer

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Question #457Radio Theory and Communication Principles

The Abbreviation for ‘ l have nothing for you’

  1. QRU ✓ Correct answer
  2. NIL
  3. QST
  4. None of the above 291.When the Amateur Service is a secondary user of a band and another service is the primary user, this means:

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Question #492Radio Theory and Communication Principles

The UHF range is

  1. 30 to 300 KHz
  2. 300 to 3000 KHz
  3. 3 to 30 GHz
  4. 300 to 3000 MHz ✓ Correct answer
Explanation: UHF is 300–3000 MHz.

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Question #498Radio Theory and Communication Principles

Mutual induction is dependent on

  1. winding ratios
  2. output polarities ✓ Correct answer
  3. DC voltage levels
  4. current changes

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