Question

A carrier wave of amplitude A is used to modulate (amplitude) the signal. Modulated signal amplitude swings from 0.1A to 1.9A, calculate modulation index

• A. 1.8
• B. 0.9
• C. 0.5
• D. 0.75

Answer 1

The correct option is B 0.9

We know,

$\text{Modulation Index}\left(\mu \right)=\frac{A_m}{A_c}$

Given,

$A_c+A_m=1.9$

$A_c-A_m=0.1$

Solving,

$A_c=1,A_m=0.9$

$\mu =0.9$

Hence option $\text{B}$ is the correct answer.