CUET · PHYSICS · PYQ PAPER 2023
Tritium has a half life of \(12.5\) years against beta decay. What fraction of a sample of pure tritium disintegrates in 25 years ?
- A \(\frac{1}{4}\)
- B \(\frac{2}{3}\)
- C \(\frac{3}{4}\)
- D \(\frac{1}{3}\)
Answer & Solution
Correct Answer
(C) \(\frac{3}{4}\)
Step-by-step Solution
Detailed explanation
\(n = \frac{t}{T_{1/2}}\) \(n = \frac{25}{12.5} = 2\) \(\text{Remaining fraction} = (\frac{1}{2})^n = (\frac{1}{2})^2 = \frac{1}{4}\) \(\text{Disintegrated fraction} = 1 - \frac{1}{4} = \frac{3}{4}\)
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