JEE Main 2021PhysicsCommunication SystemEasyNumerical

JEE Main 2021 — Communication System Question with Solution

JEE Main 2021 (26 Aug Shift 1)

Question

An amplitude-modulated wave is represented by, Cm(t)=10(1+0.2cos12560t)sin111×104t V. The modulating frequency in kHz will be

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Show full solutionCorrect answer: 2
Correct answer
2

Step-by-step explanation

The function of the amplitude-modulated wave is represented by, Cm=AC1+AmACsin2πfmt, now compare it from the given equation, 
Cm(t)=10(1+0.2cos12560t)sin111×104t V

⇒2πfm=12560 s-1⇒fm=2000 Hz=2 kHz.

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About this question

This is a previous-year question from JEE Main 2021, covering the Communication System chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.