Radio Receivers problems
- 1. In a radio receiver, if the intermediate frequency is too high
Options- A. Selectivity will be poor
- B. Tracking difficulties will be least
- C. Adjacent channel rejection will improve
- D. All of the above will occur Discuss
Correct Answer: Selectivity will be poor
- 2. A duplexer is a device used to
Options- A. feed more than one receiver from a single antenna
- B. connect two transmitters to the same antenna
- C. connect a receiver and a transmitter to the same antenna
- D. none of these Discuss
Correct Answer: connect a receiver and a transmitter to the same antenna
- 3. The sensitivity curve of a standard receiver is represented by
Options- A. curve A
- B. curve B
- C. curve C
- D. curve D Discuss
Correct Answer: curve C
- 4. In a superheterodyne receiver with an IF of 450 kHz is tuned to a signal at 1200 kHz. The image frequency is
Options- A. 750 kHz
- B. 990 kHz
- C. 1650 kHz
- D. 2100 kHz Discuss
Correct Answer: 2100 kHz
- 5. An unmodulated voltage 10 V effective is applied to a dioxide detector in which load resistance is 4 x 10-5 ohms. A micrometer shows that the rectified DC current in this resistance is 30 A. The input resistance of the detector is
Options- A. 114 kW
- B. 336 kW
- C. 384 kW
- D. 455 kW Discuss
Correct Answer: 336 kW
- 6. RF amplifiers are used in radio receivers for
Options- A. improved image frequency rejection
- B. improved rejection of adjacent unwanted signals
- C. prevention of re-radiation of the local oscillator through the antenna of the receiver
- D. all of the above Discuss
Correct Answer: all of the above
- 7. Which of the following should be used in order to prevent overloading or the last IF amplifier in a receiver?
Options- A. Variable selectivity
- B. Variable sensitivity
- C. Double conversion
- D. Squelch Discuss
Correct Answer: Variable sensitivity
- 8. The output of a diode detector contains
Options- A. D.C. voltage
- B. modulating signal
- C. RF ripple
- D. all of the above Discuss
Correct Answer: all of the above
- 9. A heterodyne frequency changer is called a
Options- A. Modulator
- B. Mixer
- C. Demodulator
- D. Frequency translator Discuss
Correct Answer: Mixer
- 10. Modulated carrier power in FM
Options- A. increases with modulating signal power
- B. decreases with modulating signal power
- C. is independent of the modulating signal power
- D. none Discuss
Correct Answer: is independent of the modulating signal power
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