MHT CET · Physics · Nuclear Physics
A radioactive element having half-life 30 min . is undergoing beta decay. The fraction of radioactive element remains undecayed after 90 min . will be
- A \(\frac{1}{2}\)
- B \(\frac{1}{4}\)
- C \(\frac{1}{8}\)
- D \(\frac{1}{16}\)
Answer & Solution
Correct Answer
(C) \(\frac{1}{8}\)
Step-by-step Solution
Detailed explanation
\(n = \frac{t}{T_{1/2}} = \frac{90 \text{ min}}{30 \text{ min}} = 3\) Fraction remaining \( = (\frac{1}{2})^n = (\frac{1}{2})^3 = \frac{1}{8}\)
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