JEE Main 2021 · PhysicsMultiple choiceSingle correctEasyCalculation

JEE Main 25 February 2021, Shift 2, Physics Q16

Question 16 of 90 in this shift, Physics question 16 of 30, Section A.

The wavelength of the photon emitted by a hydrogen atom when an electron makes a transition from n = 2 to n = 1 state is :

(1)121.8 nmOfficial answer
(2)194.8 nm
(3)490.7 nm
(4)913.3 nm

Official answer

Option 1

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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15 Apr 2023, Shift 1 · Q56As per given figure A, B and C are the first, second and third excited energy levels of hydrogen atom respectively. If the ratio of the…MediumNumerical valueHas a figure
25 Jul 2022, Shift 2 · Q50Hydrogen atom from excited state comes to the ground state by emitting a photon of wavelength $\lambda$ . The value of principal quantum…MediumSingle correct
25 Jul 2022, Shift 2 · Q54 $\frac{x}{x+4}$ is the ratio of energies of photons produced due to transition of an electron of hydrogen atom from its (i) third…EasyNumerical value
26 Jul 2022, Shift 1 · Q59In the hydrogen spectrum, $\lambda$ be the wavelength of first transition line of Lyman series. The wavelength difference will be…MediumNumerical value
26 Aug 2021, Shift 1 · Q5A particular hydrogen like ion emits radiation of frequency $2.92\times10^{15}$ Hz when it makes transition from n=3 to n=1. The frequency…EasySingle correct
26 Feb 2021, Shift 1 · Q19If $\lambda_1$ and $\lambda_2$ are the wavelengths of the third member of Lyman and first member of the Paschen series respectively, then…MediumSingle correct

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.