JEE Main 2021PhysicsAtomic PhysicsMediumNumerical

JEE Main 2021 — Atomic Physics Question with Solution

JEE Main 2021 (16 Mar Shift 1)

Question

The first three spectral lines of H-atom in the Balmer series are given λ1,λ2,λ3 considering the Bohr atomic model, the wave lengths of first and third spectral lines λ1λ3 are related by a factor of approximately x ×10-1. The value of x, to the nearest integer, is ________.

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Show full solutionCorrect answer: 15
Correct answer
15

Step-by-step explanation

1λ1=Rz2122-132

1λ1=Rz2536   ...(i)

For 3rd line

1λ3=Rz2122-152

1λ3=Rz221100   ...(ii)

(ii)+(i)

λ1λ3=21100×365=1.512=15.12×10-1

x≈15

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About this question

This is a previous-year question from JEE Main 2021, covering the Atomic Physics 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.