Radio Receivers(Electrical Engineering ) Questions and Answers

Question 1. A low ratio of the ac to the dc load impedance of a diode detector results in
  1.    Diagonal clipping
  2.    Poor AGC operation
  3.    Negative-peak clipping
  4.    Poor AF response
Explanation:-
Answer: Option C. -> Negative-peak clipping
Question 2. Indicate which of the following statements about the advantages of the phase discriminator over the slope detector is false:
  1.    Much easier alignment
  2.    Better linearity
  3.    Greater limiting
  4.    Fewer tuned circuits
Explanation:-
Answer: Option C. -> Greater limiting
Question 3. If the intermediate frequency is very high (indicate false statement)
  1.    Image frequency rejection is very good
  2.    The local oscillator need not be extremely stable
  3.    The selectivity will be poor
  4.    Tracking will be improved
Explanation:-
Answer: Option D. -> Tracking will be improved
Question 4. One of the following cannot be used to demodulate SSB:
  1.    Product detector
  2.    Diode Balance modulator
  3.    Bipolar transistor balanced modulator
  4.    Complete phase-shift generator
Explanation:-
Answer: Option C. -> Bipolar transistor balanced modulator
Question 5. Indicate which of the following circuits could not demodulate SSB:
  1.    Balance modulator
  2.    Product modulator
  3.    BFO
  4.    Phase discriminator
Explanation:-
Answer: Option D. -> Phase discriminator
Question 6. An AM receiver uses a diode detector for demodulation. This enables it satisfactorily to receive
  1.    Single-sideband, suppressed-carrier
  2.    Single-sideband, reduced-carrier
  3.    ISB
  4.    Single-sideband, full-carrier
Explanation:-
Answer: Option D. -> Single-sideband, full-carrier
Question 7. Indicate the false statement. Noting that no carrier is transmitter with J3E, we see that
  1.    The receiver cannot use a phase comparator for AFC
  2.    Adjacent-channel rejection is more difficult
  3.    Production of AGC is a rather complicated process
  4.    The transmission is not compatible with A3E
Explanation:-
Answer: Option B. -> Adjacent-channel rejection is more difficult
Question 8. In a ratio detector
  1.    the linearity is worse than in phase discriminator
  2.    stabilization against signal strength variations is provided
  3.    the output is twice that obtainable from a similar phase discriminator
  4.    the circuit is the same as in a discriminator, except that the diodes are reversed
Explanation:-
Answer: Option A. -> the linearity is worse than in phase discriminator
Question 9. In a radio receiver with simple AGC
  1.    An increase in signal strength produces more AGC
  2.    The audio stage gain is normally controlled by the AGC
  3.    The faster the AGC time constant the more accurate the output
  4.    The highest AGC voltage is produced
Explanation:-
Answer: Option A. -> An increase in signal strength produces more AGC
Question 10. Three-point tracking is achieved with
  1.    Variable selectivity
  2.    The padder capacitor
  3.    Double spotting
  4.    Double conversion
Explanation:-
Answer: Option B. -> The padder capacitor
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