JEE Main 2020PhysicsAtomic PhysicsEasyMCQ

JEE Main 2020 — Atomic Physics Question with Solution

JEE Main 2020 (07 Jan Shift 1)

Question

The time period of revolution of electron in its ground state orbit in a hydrogen atom is 1.6×10-16s. The frequency of revolution of the electron in its first excited state (in s-1 ) is:

Choose an option

Show full solutionCorrect option: B
Correct answer
B7.8×1014

Step-by-step explanation

T∝rv∝n2z×nz∝n3z2
T1T2=n13n23=18
T2=8T1

now,
f2=1T2 
f2=112.8×10-16≈7.8×1014

Practice this on the real CBT interface

Solve this JEE Main question (and the rest of the Atomic Physics chapter) on PrepSharp's TCS iON-style CBT player — with timer, bookmarks and session analytics.

Solve interactively →

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.