A signal of 5 kHz frequency is amplitude modulated on a carrier wave of frequency 3 MHz. The frequency of the resultant signal are:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 3000 kHz, 3005 kHz and 2995 kHz
When a signal of frequency $f_s=5kHz$ is amplitude modulated on a carrier wave of frequency $f_c=3MHz$, the resultant AM signal contains three frequencies -
Carrier frequency $(f_c)=3MHz=3000kHz$
Upper side band frequency = $f_c+f_s=3005kHz$
Lower side band frequency = $f_c-f_s=2995kHz$