Question

The time of decay for the nuclear reaction is given by $t=5t_{1/2}$. The relation between mean life $\tau$ and time of decay '$t$' is given by:

• A. $2\tau \ln 2$
• B. $5\tau \ln 2$
• C. $2{\tau }^4\ln 2$
• D. $\frac{1}{{\tau }^4}\ln 2$

Answer 1

The correct option is B $5\tau \ln 2$

Mean life($\tau$)=$\frac{1}{\lambda }$

$t=5t_{1/2}$

$t=5\times \frac{\ln 2}{\lambda }$

$t=5\tau \ln 2$

Hence, option $B$ is correct.