1.

The half-lives of radioactive sample are 30 years and 60 years for two decay processes. If the sample decays by both the processes simultaneously. The time after which, only one-fourth of the sample will remain isA. (a) 10 yearsB. (b) 20 yearsC. (c) 40 yearsD. (d) 60 years

Answer» Correct Answer - C
`lambda=lambda_1+lambda_2`
`:.` `(1n2)/(T)=(1n2)/(T_1)=(1n2)/(T_1)` (T=Half-life)
or `T=(T_1T_2)/(T_1+T_2)=20y`
`1/4th` sample remains after 2 half-lives or 40 y.


Discussion

No Comment Found

Related InterviewSolutions