Question

A carrier wave of peak voltage 12V is used to transmit a messagesignal. What should be the peak voltage of the modulating signal inorder to have a modulation index of 75%?

Answer 1

Given: A carrier wave of peak voltage 12 V and modulation index of the modulating signal 75%.

The modulation index can be given as,

μ= A m A c

Where, Amplitude of modulating wave is A m , Amplitude of carrier wave is A c and the modulating index is m.

By substituting the given values in above equation, we get

75%= A m A c A m = 75 100 ×12 =9 V

Thus, the peak voltage of the modulating signal is 9 V.