A speech signal of 3 kHz is used to modulate a carrier signal of frequency 1 MHz, using amplitude modulation. The frequencies of the side bands will be

Options

A. 1.003 MHz and 0.997 MHz
B. 3001 kHz and 2997 kHz
C. 1003 kHz and 1000 kHz
D. 1 MHz and 0.997 MHz

Answer

A

Explanation

Given, frequency of carrier signal is `omega_c = 1 MHz ` and frequency of speech signal = 3 KHz
`= 3xx10^(-3)` MHz
`= 0.003` MHz
Now, we know that
Frequencies of side bands `= (omega_c pm omega_m)`
`=(1 pm 0.003)`
`= 1.003 MHz and 0.997 MHz`