JEE Main 2021 · PhysicsMultiple choiceSingle correctEasyApplication

JEE Main 25 July 2021, Shift 1, Physics Q7

Question 7 of 90 in this shift, Physics question 7 of 30, Section A.

A particle of mass 4M at rest disintegrates into two particles of mass M and 3M respectively having non zero velocities. The ratio of de-Broglie wavelength of particle of mass M to that of mass 3M will be :

(1) $1:1$ Official answer
(2) $1:3$
(3) $3:1$
(4) $1:\sqrt{3}$

Official answer

Option 1

NTA final key.

Chapter: Dual Nature of Radiation and Matter
Topic: Matter Waves
Idea tested: Wavelengths in Radioactive Decay

Same topic in other shifts

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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 42 of the 174 JEE Main shifts held from 2017 to 2026.