JEE Main 2021 · PhysicsMultiple choiceSingle correctMediumCalculation

JEE Main 26 February 2021, Shift 1, Physics Q19

Question 19 of 90 in this shift, Physics question 19 of 30, Section A.

\lambda_1

and

\lambda_2

are the wavelengths of the third member of Lyman and first member of the Paschen series respectively, then the value of

\lambda_1:\lambda_2

is :

(1) $7:108$
(2) $7:135$ Official answer
(3) $1:3$
(4) $1:9$

Official answer

Option 2

NTA final key.

Chapter: Atoms
Topic: Bohr's Atomic Model
Idea tested: Rydberg Formula and Spectra

Same idea in other shifts

Asked 10× in all

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Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.