Question

A carrier wave of peak voltage $12\,V$ is used to transmit a message signal. The peak voltage of the modulating signal in order to have a modulation index of $75\%$ $3\,N$ volt then $N$ is?

Answer 1

Modulation index $=\frac{75}{100}=\frac{A_{m}}{A_{c}}$
$\Rightarrow A_{m}=\frac{75}{100}\times A_{c}=\frac{75}{100}\times 12=9$ volt