Question

Given figure shows amplitude modulated wave. By how much percentage is wave modulated?

• A. 80%
• B. 50%
• C. 40%
• D. 30%

Answer 1

The correct option is C 40%

Modulation index is $\mu =\frac{A_m}{A_c}$, where $A_c=50$ and $A_m=20$

So $\mu =\frac{20}{50}=\frac{2}{5}$

and $\%$ modulation is $=\frac{2}{5}\times 100\%=40\%$