JEE Main 2018PhysicsNuclear PhysicsEasyMCQ

JEE Main 2018 — Nuclear Physics Question with Solution

JEE Main 2018 (16 Apr Online)

Question

At some instant, a radioactive sample S1 having an activity 5 μCi has twice the number of nuclei as another sample S2 which has an activity of 10 μCi . The ratio of half lives of S1 and S2 is

Choose an option

Show full solutionCorrect option: A
Correct answer
A 4:1

Step-by-step explanation

Given: N 1 =2. N 2

Now, activity A1=λ1N1=5μCi  .....(1)

and A2=λ2N2=10μCi  .....(2)

Dividing ( 1 ) ( 2 ) we get

λ 1 λ 2 . N 1 N 2 = 5 10

⇒ t 2 t 1 .2= 1 2 ⇒ t 1 t 2 = 4 1

Practice this on the real CBT interface

Solve this JEE Main question (and the rest of the Nuclear Physics chapter) on PrepSharp's TCS iON-style CBT player — with timer, bookmarks and session analytics.

Solve interactively →

About this question

This is a previous-year question from JEE Main 2018, 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.