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Question
The carrier wave is given by
C(t) = 2sin(8πt) volt.
The modulating signal is a square wave as shown. Find modulation index.
Solution
Modulation index (μ) is the ratio of the amplitude of the modulating signal to the amplitude of the carrier wave.
The generalised equation of a carrier wave is given below:
c(t) =Acsinωct
The generalised equation of a modulating wave is given below:
cm(t)=Acsinωct+μAcsinωmtsinωct
Here, μ is defined as `A_m/A_c`
On comparing this with the equations of carrier wave and modulating wave, we get:
Amplitude of modulating signal, Am=1 V
Amplitude of carrier wave, Ac=2 V
`:.mu=A_m/A_c=1/2=0.5`
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