Question

An amplitude modulated voltage is expressed as

$e=10(1+0.8\cos 2000\pi t)\cos 3\times {10}^6\pi tvolt$. The bandwidth of modulated signal is :

• A. $1000Hz$
• B. $2000Hz$
• C. $1500Hz$
• D. $2500Hz$

Answer 1

Answer: (B)

$2000Hz$

Amplitude modulated wave is given by :

$e=K(1+A\cos 2\pi f_{m}t\cos 2\pi f_{c}t)$

Bandwidth of modulated signal is given by $W=2f_m$

Comparing with given equation : $f_m=1000Hz$

Bandwidth of modulated signal =$W=2\times 1000=2000Hz$