Question

A modulating signal is a square wave is shown in figure. The carrier wave is given by `C(t) = 2 sin (8 pi t)` volt.
(i) Sketch the amplitude modulated wave form.
(ii) What is the modulating index?

Answer 1

Here, `A_m = 1 V, A_c = 2 V.`
`omega_m = (2pi)/T = (2pi)/1rad s^(-1)`
`= 2pi rad//s`
`omega_c = 8pi rad//s = 4 omega_m`
Superimposition of modulating signal on carrier gives us
the wave form as shown in figure.

(ii) `mu = A_(m)/A_(c) = 1/2 = 0.5` .