Activity of a radioactive substance is $R_1$ at time $t_1$ and $R_2$ at time $t_2(t_2 > t_1).$ Then the ratio $\frac{R_2}{R_1}$ is :
Activity of a radioactive substance is $R_1$ at time $t_1$ and $R_2$ at time $t_2(t_2 > t_1).$ Then the ratio $\frac{R_2}{R_1}$ is :
- A
$\frac{t_2}{t_1}$
- B
${e^{ - \lambda ({t_1} + {t_2})}}$
- C
$e\left( {\frac{{{t_1} - {t_2}}}{\lambda }} \right)$
- D
${e^{ \lambda ({t_1} + {t_2})}}$
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