JEE Main 2021PhysicsElectromagnetic WavesEasyMCQ

JEE Main 2021 — Electromagnetic Waves Question with Solution

JEE Main 2021 (27 Aug Shift 1)

Question

The electric field in a plane electromagnetic wave is given by, E=50sin500x-10×1010t V m-1. The velocity of an electromagnetic wave in this medium is: (Given c= the speed of light in vacuum).

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Show full solutionCorrect option: D
Correct answer
D23c

Step-by-step explanation

The equation of electric field is given in the question, E=50sin500x-10×1010t V m-1 now compare it the equation of electric field in an electromagnetic wave, E=E0sinkx-ωt V m-1

⇒ω=1010 rad s-1 and, k=50 m-1, so the velocity of electromagnetic waves is, v=ωk=101050=2×108=23c.

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About this question

This is a previous-year question from JEE Main 2021, covering the Electromagnetic Waves 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.