Frequency Domain Description MCQ’s

This set of Analog Communication Multiple Choice Questions & Answers (MCQs) focuses on “Frequency Domain Description”.

1. Frequency components of an AM wave are?
a) Carrier frequency (ωc) with amplitude A
b) Lower side band (ωc + ωm) having amplitude mA2
c) Upper side band (ωc – ωm) having amplitude mA2
d) Carrier frequency (ωc/2) with amplitude A

2. In amplitude modulation frequency and phase of carrier ________
a) varies simultaneously
b) varies alternately
c) initially varies but become same after sometime
d) remains constant

3. What is Amplitude Modulation?
a) Change in amplitude of carrier according to modulating signal amplitude
b) Change in frequency of carrier according to modulating signal amplitude
c) Change in amplitude of carrier according to modulating signal frequency
d) Change in amplitude of modulating signal according to carrier signal amplitude

4. Envelope of AM wave has the same shape as the message of baseband signal.
a) True
b) False

5. Why the Synchronous detection of AM signals is considered as a disadvantage?
a) Needs additional system for synchronization of carrier
b) Receiver is available at cheap prices
c) Needs less number of system as estimated for generation of carrier
d) Receiver is not complex

6. Square Law modulators ________
a) used for amplitude modulation
b) have non linear current-voltage characteristics
c) have non linear current-voltage characteristics as well as used for Amplitude Modulation
d) used for frequency modulation

7. When aliasing takes place?
a) Sampling signals less than Nyquist Rate
b) Sampling signals more than Nyquist Rate
c) Sampling signals equal to Nyquist Rate
d) Sampling signals at a rate which is twice of Nyquist Rate

8. Which devices did we use for AM Demodulation?
a) Envelope detector and Square law demodulator
b) PLL detector and Foster-Seeley discriminator
c) Ratio detector and Slope detector
d) Only quadrature detector

9. What do you understand by low level AM?
a) Output power is low
b) Modulation is done at high power of carrier and modulating signal
c) Collector Modulation Method is low level AM
d) Output power is high

10. What do you understand by high level AM?
a) Output power is low
b) Modulation is done at high power of carrier and modulating signal
c) No need to boost the carrier and modulating signal
d) Modulation is done at low power of carrier and modulating signal