A carrier wave of peak voltage (14, V) is used for transmitt... | Physics | SolveeIt | Solveeit

Today, August 18

Question

A carrier wave of peak voltage $14\, V$ is used for transmitting a message signal. The peak voltage of modulating signal given to achieve a modulation index of $80\%$ will be:

A

$7\, V$

B

$28\, V$

C

$11.2\, V$

D

$22.4\, V$

Answer

$11.2\, V$

Explanation

Solution

Amplitude of carrier wave is $A_{ c }=14\, V$
Index is $\mu=80 \%=0.80$
Amplitude of modulating signal is given by
$\mu=\frac{A_{ m }}{A_{ c }}$
$\Rightarrow A_{ m }=\mu A_{ c }$
$\Rightarrow A_{ m }=0.8 \times 14=11.2\, V$