Question

$\frac{1}{16}$ part of a radioactive material is left after one hour. It's half life is ?

• A. 45 min
• B. 30 min
• C. 20 min
• D. 15 min

Answer 1

The correct option is D 15 min

Using relation $N=N_0(1/2{)}^n$ and putting $N=\frac{N_0}{16}$(given in the question)

Thus we get $n=4$

But $n=\frac{Time}{t_{1/2}}$ so half life $t_{1/2}=Time/n=\frac{60min}{4}=15min$

Option D is correct.