### Communication System Question 10

#### Question 10 - 01 February - Shift 2

In an amplitude modulation, a modulating signal having amplitude of $X V$ is superimposed with a carrier signal of amplitude $Y V$ in first case. Then, in second case, the same modulating signal is superimposed with different carrier signal of amplitude $2 Y V$. The ratio of modulation index in the two case respectively will be:

(1) $1: 2$

(2) $1: 1$

(3) $2: 1$

(4) $4: 1$

## Show Answer

#### Answer: (3)

#### Solution:

#### Formula: Modulation Index

Modulating Index

$\mu=\frac{A_m}{A_c}$

$\mu_1=\frac{X}{Y}$

$\mu_2=\frac{X}{2 Y}$

$\frac{\mu_1}{\mu_2}=\frac{2}{1}$