JEE Mains · Physics · STD 12 - 13. Nuclei
Calculate the time (in \(minutes\)) interval between \(33 \,\%\) decay and \(67\, \%\) decay if half-life of a substance is \(20\, minutes.\)
- A \(60\)
- B \(20\)
- C \(40\)
- D \(13\)
Answer & Solution
Correct Answer
(B) \(20\)
Step-by-step Solution
Detailed explanation
\(N _{1}= N _{0} e ^{-\lambda t_{1}}\) \(\frac{ N _{1}}{ N _{0}}= e ^{-\lambda t _{1}}\) \(0.67= e ^{-\lambda t _{1}}\) \(\ln (0.67)=-\lambda t _{1}\) \(N _{2}= N _{0} e ^{-\lambda t _{2}}\) \(\frac{ N _{2}}{ N _{0}}= e ^{-\lambda t _{2}}\) \(0.33= e ^{-\lambda t _{2}}\)…
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