question_answer

An amplitude modulated signal is given by.

Here t is in seconds. The side band frequencies [JEE Main 11-Jan-2019 Morning]

(in kHz) are, [Given ]

A) 178.5 and 171.5

B) 89.25 and 85.75

C) 1785 and 1715

D) 892.5 and 857.5

Correct Answer: B

Solution :

[b] The equation for a amplitude modulated wave is

Comparing it with given equation,

So, the side band frequency,