Question

A message signal of frequency 10kHz and peak voltage 10 V is used to modulate a carrier of frequency 1 MHz and peak voltage of 20V.Determine

a) Modulation Index

b) the side bands produced

Answer 1

Given
For Message signal'
Frequency, f_m = 10 kHz
Peak voltage, A_m = 10 V

For carrier frequency
Frequency, f_c = 1 MHz = 1000 kHz
Peak voltage, A_c = 20 V

(a) Modulation frequency is given by
$\mu =\frac{A_m}{A_c}=\frac{10}{20}=0.5$
(b) The side bands will be at $(f_c\pm f_m)=(1000\pm 10)kHz=1010kHzand990kHz$