InterviewSolution
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InterviewSolution
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A sample of radioactive material decays simultaneouly by two processes A and B with half-lives `(1)/(2)` and `(1)/(4)h`, respectively. For the first half hour it decays with the process A, next one hour with the proecess B, and for further half an hour with both A and B. If, origianlly, there were `N_0` nuceli, find the number of nuclei after 2 h of such decay.A. `N_0/(2)^(8)`B. `N_0/(2)^(4)`C. `N_0/(2)^(6)`D. `N_0/(2)^(5)` |
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Answer» Correct Answer - a After First half hours, `N=N_(0)(1)/(2)` For`t=(1)/(2)h" to "t=1(1)/(2),1h` = four half-lives Hence, `N=(N_(0)(1)/(2))[(1)/(2)]^(2)=N_(0)((1)/(2))^(5)` For `t=(1)/(2)" to "t=2h` `[" for both" `A` and `B`, `(1)/(t_(1//2))=(1)/(t_(1//2)) + (1)/(t_(1)//4)=2 +4 =6 rArr t_(1//2) =(1)/(6)]` `(1)/(2) h=` half -lives `:. N=[(N_(0)(1)/(2))^(5)](1)/(2^(3))=N_(0)(1)/(2^(8))`. |
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