JEE Main 2022PhysicsNuclear PhysicsEasyMCQ

JEE Main 2022 — Nuclear Physics Question with Solution

JEE Main 2022 (27 Jul Shift 1)

Question

What is the half-life period of a radioactive material if its activity drops to 116th  of its initial value of 30 years ?

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Show full solutionCorrect option: C
Correct answer
C7.5 years

Step-by-step explanation

Activity of a radioactive material is given by A=A0e-λt, here, λ- is decay constant.

Taking logarithmic function both sides, 

⇒-λt=lnAA0

Using relation between half life and decay constant,

⇒-ln2t12×30=ln116 

 ⇒-ln2t12×30=-4ln2

⇒t12=304=7.5 yrs

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About this question

This is a previous-year question from JEE Main 2022, 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.