Physics · 2021
JEE Main · 26 February 2021, Shift 2 · Q1
A radioactive sample is undergoing α decay. At any time t_1, its activity is A and another time t_2, the activity is A/5. What is the average life…
A radioactive sample is undergoing $\displaystyle \alpha$ decay. At any time $\displaystyle \mathrm{t}_1$, its activity is A and another time $\displaystyle \mathrm{t}_2$, the activity is $\displaystyle \frac{\mathrm{A}}{5}$. What is the average life time for the sample ?
Official answer
(3)
$\displaystyle \frac{\mathrm{t}_2-\mathrm{t}_1}{\ln 5}$
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JEE Main 2021 Physics question, with the answer from NTA’s final answer key. Where our answers come from.