Question

The radioactivity of an element becomes $\frac{1}{64}$th of its original value in 60 seconds. Then the half life period of element is

• A. 5 secs
• B. 10 secs
• C. 20 secs
• D. 30 secs

Answer 1

The correct option is B 10 secs

$2^n=64\Rightarrow n=6$
$\therefore T_{\frac{1}{2}}=\frac{60}{6}=10s$