JEE Main 2020PhysicsAtomic PhysicsEasyMCQ

JEE Main 2020 — Atomic Physics Question with Solution

JEE Main 2020 (09 Jan Shift 2)

Question

The energy required to ionise a hydrogen like ion in its ground state is 9 Rydbergs. What is the wavelength of the radiation emitted when the electron in this ion jumps from the second excited stale to the ground state?

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Show full solutionCorrect option: B
Correct answer
B11.4nm

Step-by-step explanation

hcλ=13.6eVz21n12-1n22
n1=1
n2=3
hcλ=13.6eV32112-132
⇒hcλ=13.6eV989
Wavelength =12408×13.6 nm
λ=11.39 nm 

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About this question

This is a previous-year question from JEE Main 2020, 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.