Q : Why is a AM signal likely to be more noisy than a FM signal on transmission through a channel ?
Solution : In case of AM , the instantaneous voltage of carrier waves is varied by the modulating wave voltage . So , during the transmission , noise signals can also be added and receiver assumes noise a part of the modulating signal .
In case of FM , the frequency of carrier waves is changed as the change in the instantaneous voltage of modulating waves . This can be done by mixing and not while the signal is transmitting in channel . So , noise does not affect FM signal .