10. In carrier system, frequency fogging is used to :
(a) Reduce noise
(b) Reduce cross talk
(c) Converse frequencies
(d) Reduce distortion
11. In a FM signal, the power …… as the modulation index increases.
(a) Increases
(b) Decreases
(c) Remains constant
(d) None of these
12. If signal band limited to fm is sampled at a rate less than 2 fm., the reconstructed signal will :
(a) Be smaller in amplitude
(b) Have higher frequencies suppressed
(c) Be distorted
(d) All the above
13. De-emphasis circuit is used :
(a) Before detection
(b) After detection
(c) Before modulation
(d) After modulation
14. Pre-emphasis is used to amplify …………… frequencies.
(a) Low
(b) High
(c) Both a and b
(d) None of the above
15. Pre-emphasis circuit is used :
(a) Before detection
(b) After detection
(c) Before modulation
(d) After modulation
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