JEE Main 2019PhysicsNuclear PhysicsMediumMCQ

JEE Main 2019 — Nuclear Physics Question with Solution

JEE Main 2019 (09 Jan Shift 1)

Question

A Sample of radioactive material A, that has an activity of 10 m Ci 1 Ci=3.7×1010 decays s-1, has twice the number of nuclei as another sample of a different radioactive material B which has an activity of 20 m Ci. The correct choices for half-lives of A and B would then be, respectively:

Choose an option

Show full solutionCorrect option: D
Correct answer
D20 days and 5 days

Step-by-step explanation

Activity A=λN
10=λANA
20=λBNB
12=λAλB2
λAλB=14 ⇒TATB=41

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About this question

This is a previous-year question from JEE Main 2019, covering the Nuclear 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.