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Question #401Radio Theory and Communication Principles

The output signal of a detector in a communication receiver is in

  1. Audio Frequency range ✓ Correct answer
  2. Radio frequency range
  3. Intermediate Frequency range
  4. All the above

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Question #402Radio Theory and Communication Principles

In a Radio receiver, the sensitivity is governed by

  1. RF ✓ Correct answer
  2. Detector
  3. AF
  4. None of the above

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Question #403Radio Theory and Communication Principles

The noise in a Radio receiver can be expressed as

  1. S/N ratio ✓ Correct answer
  2. N/S ratio
  3. Level of reference signal
  4. None of above

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Question #404Antennas and Radio Wave Propagation

The most suitable antenna for receiving VHF range is

  1. Dipole
  2. Log periodic
  3. Yagi ✓ Correct answer
  4. None of the above 208.Which of the following instruments can be used to determine if an antenna is resonant at the designed frequency?

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Question #405Basic Electricity and Electronics

The 'RMS value' of a sine-wave signal is:

  1. half the peak voltage
  2. 1.414 times the peak voltage
  3. the peak-to-peak voltage
  4. 0.707 times the peak voltage ✓ Correct answer
Explanation: For a sinusoidal signal, Vrms = Vpeak/√2 ≈ 0.707 Vpeak. The option text was cleaned of OCR spillover.

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Question #406Basic Electricity and Electronics

The colour bands of a 4.7KOhm 5% resistor are

  1. Yellow, Violet, Orange and Gold
  2. Yellow, Violet, Red and Gold ✓ Correct answer
  3. Yellow, Violet, Orange and Silver
  4. Yellow, Violet, Red and Silver

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Question #407Radio Theory and Communication Principles

The layer that reflects higher frequencies in HF range during the day time is

  1. F1 layer
  2. F2 layer ✓ Correct answer
  3. E layer
  4. D layer

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Question #408Basic Electricity and Electronics

The power conversion efficiency of a Full-wave rectifier is

  1. 40.6%
  2. 51.2%
  3. 100%
  4. 81.2% ✓ Correct answer

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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 #411Basic Electricity and Electronics

The following material is considered to be a semiconductor:

  1. copper
  2. sulphur
  3. silicon ✓ Correct answer
  4. tantalum

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Question #412Basic Electricity and Electronics

The Transformers are rated in

  1. Watts
  2. Volts
  3. Amperes
  4. Volt-Amperes ✓ Correct answer
Explanation: Transformer ratings are expressed in volt-amperes (VA), not watts alone. The option text was cleaned of OCR spillover.

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Question #413Basic Electricity and Electronics

In an n-type semiconductor, the current carriers are:

  1. holes
  2. electrons ✓ Correct answer
  3. positive ions
  4. photons

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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 #416Basic Electricity and Electronics

Two basic types of bipolar transistors are:

  1. p-channel and n-channel types
  2. NPN and PNP types ✓ Correct answer
  3. diode and triode types
  4. Varicap and Zener types 226.A "linear amplifier" is:

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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 #420Basic Electricity and Electronics

The AGC circuit is to:

  1. expand the audio gain
  2. limit the extent of amplitude generation
  3. minimize the adjustments needed to the receiver gain control knobs ✓ Correct answer
  4. amplitude limits the crystal oscillator output

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