A carrier wave of peak voltage 24 V is used to transmit a message signal. What should be the peak Voltage of the modulating signal in order to have a modulation index of 70%?

16.8V

The correct answer is Option (1) → 16.8V

The modulation index (m) for amplitude modulation (AM) is given by -

$m=\frac{V_m}{V_c}$

where,

$V_m$ = Peak voltage of modulating signal

$V_c$ = Peak voltage of carrier signal

$V_m=24V$ [given]

$m=70\%=0.70$ [given]

$V_m=m.V_c$

$=(0.70×24)V$

$=16.8V$