JEE Main 2025PhysicsWave OpticsHuygens Principle And Interference Of LighteasyMCQ

JEE Main 2025 — Wave Optics Question with Solution

From: JEE Main 2025 (Online) 22nd January Morning Shift

Question

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion-(A) : If Young's double slit experiment is performed in an optically denser medium than air, then the consecutive fringes come closer.

Reason-(R) : The speed of light reduces in an optically denser medium than air while its frequency does not change.

In the light of the above statements, choose the most appropriate answer from the options given below :

Choose an option

Show full solutionCorrect option: C
Correct answer
CBoth (A) and (R) are true and (R) is the correct explanation of (A)

Step-by-step explanation

We know, in YDSE,

(fringe width)

In denser medium,

fringes come closer.

Also,

speed of light reduces.

frequency remains same,

(as )

Hence, option C is correct.

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About this question

This is a previous-year question from JEE Main 2025, covering the Wave Optics 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.