JEE Main 2022 · 27 Jul · Shift 1 · Physics Q48

PhysicsSingle correct+4 / -1Question 48 of 90

What is the half-life period of a radioactive material if its activity drops to 1/16 $^{\text{th}}$ of its initial value in 30 years?

9.5 years

8.5 years

7.5 years

10.5 years

Answer and worked solution

Official answer: C

$\frac1{16}=\left(\frac12\right)^4$ : four half lives in 30 years, so 7.5 years.

(C)

Topics:Radioactive decay

JEE Main 2022 · 27 Jul · Shift 1, Physics question 48