JEE Main 2018PhysicsAtomic PhysicsMediumMCQ

JEE Main 2018 — Atomic Physics Question with Solution

JEE Main 2018 (16 Apr Online)

Question

Both the nucleus and the atom of some element are in their respective first excited states. They get de-excited by emitting photons of wavelengths λN, λA respectively. The ratio λNλA is closest to:

Choose an option

Show full solutionCorrect option: B
Correct answer
B10-6 

Step-by-step explanation

λNλa= EaEN, where Ea and EN are energies of photons from atom and nucleus respectively. EN is of the order of MeV and Ea in few eV. So, λNλa=10-6.

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 2018, 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.