An audio signal $V_{m}=20 \sin 2 \pi(1500 t)$ amplitude modulates a carrier $V_{c}=80 \sin 2 \pi(100,000 t)$. The value of percent modulation is ______.

JEE Main · 2021 · 24 Feb 2021 · Shift 1 · Semiconductors

An audio signal

V_{m} = 20 sin 2 π (1500 t)

amplitude modulates a carrier

V_{c} = 80 sin 2 π (100, 000 t)

. The value of percent modulation is ______.

Answer: 25

The modulation index (or percent modulation) is given by:

μ = \frac{A _{m}}{A _{c}} \times 100%

where

A_{m}

is the amplitude of the modulating signal and

A_{c}

is the amplitude of the carrier.

From the given signals:

μ = \frac{20}{80} \times 100% = 25%

Answer: 25

JEE Main · 2021 · 24 Feb 2021 · Shift 1 · Integer answer