Radio Receivers problems
- 1. It is known that noise phase modulates the FM wave. As the noise side band frequency approaches the carrier frequency, the noise amplitude
Options- A. will increase
- B. will decrease
- C. will remain constant
- D. will reduce to negligible value Discuss
Correct Answer: will decrease
- 2. In superheterodyne receivers, the local oscillator is used to
Options- A. detect the modulating signal
- B. amplify the received modulated carrier
- C. shift the frequency of the received modulated carrier to the IF band Discuss
Correct Answer: shift the frequency of the received modulated carrier to the IF band
- 3. In a radio receiver, the local oscillator is tuned to a frequency
Options- A. lower than the incoming frequency
- B. higher than the incoming frequency
- C. equal to incoming frequency
- D. any of the above Discuss
Correct Answer: higher than the incoming frequency
- 4. The selectivity of a radio receiver is
Options- A. its ability to reject adjacent unwanted signals
- B. its ability to amplify weak signals
- C. the frequency at which it gives maximum amplification to signal.
- D. its ability to suppress noise. Discuss
Correct Answer: its ability to reject adjacent unwanted signals
- 5. Which of the following statement about the amplitude limiter is not valid?
Options- A. Leak type bias must be used
- B. Output must be tuned
- C. The circuit is always biased in class C, by virtue of the leak type bias
- D. When the input increases past the threshold of limiting, the gain decreases to keep the output constant Discuss
Correct Answer: The circuit is always biased in class C, by virtue of the leak type bias
- 6. Which of the following statement about receivers is false?
Options- A. Double conversion is used to improve image rejection
- B. Double conversion is used to improve selectivity
- C. Variable sensitivity is used to improve selectivity
- D. Variable sensitivity is used to eliminate selective fading Discuss
Correct Answer: Variable sensitivity is used to eliminate selective fading
- 7. Neutralization is used in RF amplifiers to
Options- A. stop oscillation
- B. increase bandwidth
- C. improve selectivity
- D. all of the above Discuss
Correct Answer: stop oscillation
- 8. In a superheterodyne receiver
Options- A. the IF stage has better selectivity than RF stage
- B. the RF stage has better selectivity than IF stage
- C. the RF stage has same selectivity than IF stage
- D. none of the above Discuss
Correct Answer: the IF stage has better selectivity than RF stage
- 9. Which of the following cannot be used to demodulate SSB?
Options- A. Complete phase-shift generator
- B. Product detector
- C. Diode balanced modulator
- D. Bipolar transistor balanced modulator Discuss
Correct Answer: Bipolar transistor balanced modulator
- 10. FM amplifier in a superheterodyne receiver
Options- A. increases selectivity
- B. suppresses noise
- C. provides improved tracking
- D. improves the rejection of the image frequency Discuss
Correct Answer: improves the rejection of the image frequency
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