JEE Main 2019PhysicsElectromagnetic WavesMediumMCQ

JEE Main 2019 — Electromagnetic Waves Question with Solution

JEE Main 2019 (12 Apr Shift 1)

Question

An electromagnetic wave is represented by the electric filed E→=E0n^sin⁡ωt+6y-8z. Taking unit vectors in x,y and z directions to be i^,j^,k^,  the directions of propogations s^, is:

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Show full solutionCorrect option: B
Correct answer
Bs^=-3i^+4j^5

Step-by-step explanation

The standard equation of electromagnetic wave E→=E0n^sinωt-kx^

here x^ represents the direction of propagation wave.

On comparing the given equation with the standard equation, the direction of propagation is along line -6y+8z . Thus, unit vector along the direction of propagation is,
s^=-6j^+8k^10=-35j^+45k^

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About this question

This is a previous-year question from JEE Main 2019, 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.