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Question: Answered & Verified by Expert
A radioactive material has a half-life of 10 days. What fraction of the material would remain after 30 days?
PhysicsNuclear PhysicsAIIMSAIIMS 2005
Options:
  • A 0.5
  • B 0.25
  • C 0.125
  • D 0.33
Solution:
2463 Upvotes Verified Answer
The correct answer is: 0.125
$T_{1 / 2}=10$ days, $T=30$ days
$$
\begin{aligned}
& T=n \times T_{1 / 2} . \Rightarrow n=\frac{T}{T_{1 / 2}}=\frac{30}{10}=3 \\
& \frac{N}{N_0}=\left(\frac{1}{2}\right)^n=\left(\frac{1}{2}\right)^3=\frac{1}{8}=0.125 .
\end{aligned}
$$

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