JEE Main 2021PhysicsRay OpticsHardNumerical

JEE Main 2021 — Ray Optics Question with Solution

JEE Main 2021 (16 Mar Shift 2)

Question

A deviation of 2° is produced in the yellow ray when prism of crown and flint glass are achromatically combined. Taking dispersive powers of crown and flint glass are 0.02 and 0.03 respectively and refractive index for yellow light for these glasses are 1.5 and 1.6 respectively. The refracting angles for crown glass prism will be ________° (in degree)

(Round off to the Nearest Integer)

Enter your answer

Show full solutionCorrect answer: 12
Correct answer
12

Step-by-step explanation

ω1=0.02;μ1=1.5; ω2=0.03;μ2=1.6

Achromatic combination

∴ θnet=0

θ1-θ2=0

θ1=θ2

ω1δ1=ω2δ2

and δnet=δ1-δ2=2°

δ1-ω1δ1ω2=2°

δ11-ω1ω2=2°

δ11-23=2°

δ1=6°

δ1=μ1-1A1

6°=1.5-1A1

A1=12°

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About this question

This is a previous-year question from JEE Main 2021, 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.