Q138 / 160 · TS EAMCET 2012 · Physics
The half-life of a radioactive element is $10 \mathrm{~h}$. The fraction of initial radioactivity of the element that will remain after $40 \mathrm{~h}$ is
- A$\frac{1}{2}$
- Correct answerB$\frac{1}{16}$
- C$\frac{1}{8}$
- D$\frac{1}{4}$
Solution
After 4 half-lifes
$\frac{N_0}{2^4}=\frac{N_0}{16}$
Hence, the correct answer is option: 'B'.