If decay or disintegration constant of a radioactive substance is β , then its half life and mean l

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13.Nuclei

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If the decay or disintegration constant of a radioactive substance is $\beta $, then its half life and mean life are respectively

$(log_e \,2 =ln\, 2)$

A

$\frac{{1}}{{\lambda}} $ and $\frac{{{{\log }_e}\,2}}{\lambda }$

B

$\frac{{{{\log }_e}\,2}}{\lambda }$ and $\frac{{1}}{{\lambda}} $

C

$\lambda \;{\log _e}\,2$ and $\frac{{1}}{{\lambda}} $

D

$\frac{\lambda }{{{{\log }_e}\,2}}$ and $\frac{{1}}{{\lambda}} $

(IIT-1989)

Solution

(b) For radioactive decay, half-life $=\frac{\log _{e} 2}{\lambda}$ and average-life $=\frac{1}{\lambda}$

Standard 12

Physics

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