Question

A signal wave of frequency 12 KHz is modulated with a carrier wave of frequency 2.51 MHz. The upper and lower side band frequency are respectively. 

(A) 2512 Hz and 2508 KHz 

(B) 2522 KHz and 2488 KHz 

(C) 2502 KHz and 2498 KHz 

(D) 2522 KHz and 2498 KHz

Answer 1

The correct option is (D) 2522 KHz and 2498 KHz.

Explanation:

f_c = 2.51 MHz = 2510 KHz 

f_m = 12 KHz 

upper side band at f_c + f_m = 2510 + 12 = 2522 KHz 

lower side band at f_c – f_m = 2510 – 12 = 2498 KHz