JEE Main 2019PhysicsNuclear PhysicsMediumMCQ

JEE Main 2019 — Nuclear Physics Question with Solution

JEE Main 2019 (10 Jan Shift 1)

Question

Using a nuclear counter the count rate of emitted particles from a radioactive source is measured. At t=0 it was 1600 counts per second and t=8 seconds it was 100 counts per second. The count rate observed, as counts per second, at t=6 seconds is close to:

Choose an option

Show full solutionCorrect option: B
Correct answer
B200

Step-by-step explanation

After 8 seconds count rate changes from A1=1600 per second to A2=100 per second.

A 2 = A 1 16 = A 1 2 4

∴8s in 4 half life

⇒1 half life =2 s

t=6s is 3 half life.

∴ Count rate after 3 second

A=A123=16008=200

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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.