JEE Main 2023PhysicsRay OpticsEasyNumerical

JEE Main 2023 — Ray Optics Question with Solution

JEE Main 2023 (11 Apr Shift 1)

Question

The radius of curvature of each surface of a convex lens having refractive index 1.8 is 20 cm. The lens is now immersed in a liquid of refractive index 1.5. The ratio of power of lens in air to its power in the liquid will be x: 1. The value of x is

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Show full solutionCorrect answer: 4
Correct answer
4

Step-by-step explanation

The power of a lens is given by 

P1=1f

Using Lens Maker's formula,

P1=(1.8−1)1R1−1R2 and 

P2=1fimmersed =1.81.5−11R1−1R2

Hence, the ratio is,

P1P2=(1.8−1)1.81.5−1=0.8×1.50.3=4

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About this question

This is a previous-year question from JEE Main 2023, covering the Ray 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.