Question

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

• 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 1

Answer: (A)

1.003 MHz and 0.997 MHz

Answer 2

: Here , $\upsilon_{c} = 1MHz,\upsilon_{m} = 3kHz = 0.003MHz$

The frequencies of the side bands

$= (\upsilon_{c} + \upsilon_{m})and(\upsilon_{c} - \upsilon_{m})$

$= (1 + 0.003)and(1 - 0.003)$

$= 1.003MHzand0.997MHz$