A carrier wave is used to transmit a message signal. If the peak voltage of modulating signal and carrier signal are increased by 1 % and 3 % respectively, the modulation index is changed by

Step-by-step solution

Modulation index, m = Peak   value   of   modulating   signal E m Peak   value   of   carrier   signal E c When modulating signal is increased by 1 % , then, E m ' = 1 + 0 . 01 E m = 1 . 01 E m And when carrier signal in increased by 3 % , then, E c ' = 1 + 0 . 03 E c = 1 . 03 E c Now, the new modulation index is m ' = 1 . 01 E m 1 . 03 E c = 0 . 98 m Thus, the modulation index changes by - 2 % .