Frequency Modulation MCQ Questions and Answers for Practice

1. Frequency deviation in Frequency Modulation is

1. Change in carrier frequency to the frequency above and below the centre frequency
2. Formation of side bands
3. The variation of the instantaneous carrier frequency in proportion to the modulating signal
4. All of the above

2. In Frequency Modulation

1. Amplitude of the carrier remains same
2. Frequency of the carrier varies in accordance with the modulating signal
3. The number of side bands are infinite
4. All of the above

3. Phase-locked loop can be used as

1. FM demodulator
2. AM demodulator
3. FM receiver
4. AM receiver

4. The amount of frequency deviation in FM signal depends on

1. Amplitude of the modulating signal
2. Carrier frequency
3. Modulating frequency
4. Transmitter amplifier

5. The modulation index of FM is given by

1. = frequency deviation/ modulating frequency
2. = modulating frequency /frequency deviation
3. = modulating frequency/ carrier frequency
4. = carrier frequency / modulating frequency

6. VCO is used to generate

1. Direct FM
2. Indirect FM
3. SSB-SC
4. DSB-SC

7. What is the effect on the deviation d of an FM signal when it is passed through a mixer?

1. Doubles
2. Reduces
3. Becomes half
4. Remains unchanged

8. The bandwidth in ........ depends on the number of significant sidebands.

1. FCM
2. QAM
3. Delta Modulation
4. Frequency Modulation

9. Armstrong method is used for the generation of

1. Direct FM
2. Indirect FM
3. SSB-SC
4. DSB-SC

10. FM is disadvantageous over AM signal because

1. much wider channel bandwidth is required
2. FM systems are more complex and costlier
3. Adjacent channel interference is more
4. Both a and b