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Solution for A modulating signal is a square wave. Sketch the amplitude modulated waveform - CBSE (Science) Class 12 - Physics

Question

A modulating signal is a square wave, as shown

The carrier wave is given by  c(t) = 2 sin (8pit) "volts"

(i) Sketch the amplitude modulated waveform

(ii) What is the modulation index?

Solution

It can be observed from the given modulating signal that the amplitude of the modulating signal, Am = 1 V

It is given that the carrier wave c (t) = 2 sin (8πt)

∴Amplitude of the carrier wave, Ac = 2 V

Time period of the modulating signal Tm = 1 s

The angular frequency of the modulating signal is calculated as:

omega_m = 2pi/T_m

= 2pi "rad" s^(-1)  ... (1)

The angular frequency of the carrier signal is calculated as:

omega_c = 8pi "rad" s^(-1)  ... (ii)

From equations (i) and (ii), we get:

mega_c = 4omega_m

The amplitude modulated waveform of the modulating signal is shown in the following figure.

(ii)Modulation index, m = A_m/A_c = 1/2 = 0.5

Is there an error in this question or solution?

APPEARS IN

NCERT Physics Textbook for Class 12 Part 2 (with solutions)
Chapter 15: Communication Systems
Q: 6 | Page no. 530

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Solution for question: A modulating signal is a square wave. Sketch the amplitude modulated waveform concept: Amplitude Modulation. For the course CBSE (Science)
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