A radioactive sample at any instant has its disintegration rate 5000 disintegration per minute. Afte

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13.Nuclei

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A radioactive sample at any instant has its disintegration rate $5000$ disintegration per minute. After $5$ minutes, the rate is $1250$ disintegrations per minute. Then, the decay constant (per minute) is

A

$0.8 \, ln\, 2$

B

$0.4 \, ln\, 2$

C

$0.2 \, ln\, 2$

D

$0.1 \, ln\, 2$

(AIEEE-2003)

Solution

(b)$\lambda = \frac{{{{\log }_e}\frac{{{A_1}}}{{{A_2}}}}}{t}$

$= \frac{{{{\log }_e}\frac{{5000}}{{1250}}}}{5} = 0.4 \, ln\, 2$

Standard 12

Physics

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