JEE Main 2022PhysicsWaves and SoundEasyNumerical

JEE Main 2022 — Waves and Sound Question with Solution

JEE Main 2022 (29 Jul Shift 1)

Question

Two light beams of intensities 4I and 9I interfere on a screen. The phase difference between these beams on the screen at point A is zero and at point B is π. The difference of resultant intensities, at the point A and B, will be _____ I.

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Show full solutionCorrect answer: 24
Correct answer
24

Step-by-step explanation

The resultant intensity is given by Inet =I1+I2+2I1I2cosϕ

Now, for Imax, phase angle is ϕ=0 and for Imin, phase angle is ϕ=π.

Thus, Imax=I1+I22=9I+4I2=25I

And Imin=I1-I22=9I-4I2=I

The difference of resultant intensities is Imax-Imin=25I-I=24I

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About this question

This is a previous-year question from JEE Main 2022, covering the Waves and Sound 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.