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

Here , `v = 1 MHz , Delta v = 3 kHz = 0.003 MHz`.
Using amplitude modulation , the frequencies of the side band ` = ( v + Delta v) and ( v - Delta v)`
` = ( 1 + 0.003 ) and ( 1 - 0.003) = 1.003 MHz and 0.997 MHz`
Thus option (a) is correct .