JEE Main 2022 · PhysicsNumerical answerNumerical valueMediumCalculation

JEE Main 29 July 2022, Shift 2, Physics Q59

Question 59 of 90 in this shift, Physics question 29 of 30, Section B.

Two radioactive materials A and B have decay constants

25\lambda

and

16\lambda

respectively. If initially they have the same number of nuclei, then the ratio of the number of nuclei of B to that of A will be "e" after a time

\frac{1}{a\lambda}

. The value of a is ______.

Official answer

NTA final key.

Chapter: Nuclei
Topic: Radioactive Decay
Idea tested: Statistical Decay Law

Same idea in other shifts

Asked 5× in all

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