JEE Mains · Physics · STD 12 - Nuclei
- JEE Mains 2021
- Medium
- MCQ
For a certain radioactive process the graph between \(In\, {R}\) and \({t}\,({sec})\) is obtained as shown in the figure. Then the value of half life for the unknown radioactive material is approximately \(....\,{sec}.\)

Pick an option to check your answer.
Answer & Solution
Correct Answer
(B) \(4.62\)
Step-by-step Solution
Detailed explanation
\({R}=R_{o} e^{-\lambda t}\)
\(\ell n R=\ell n R_{o}-\lambda t\)
\(-\lambda\) is slope of straight line
\(\lambda=\frac{3}{20}\)
\(t_{1 / 2}=\frac{\ell n 2}{\lambda}=4.62\)
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