question_answer

Why is an FM signal less susceptible to noise than an AM signal?             Or Why is an AM signal likely to be more noisy than an FM signal upon transmission through channel?         

Answer:

                In AM, the carrier wave's instantaneous voltage is varied by modulating waves voltage. On transmission, noise signals can also be added and receiver assumes noise a part of the modulating signal. However in FM, the carriers' frequency is changed as per modulating waves instantaneous voltage. This can be done at the mixing / modulating stage and not while signal is transmitting in channel. Hence, noise doesn't affect FM signal.