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The half life of a radioactive nucleus is 50 days. The time interval (t2 – t1 ) between the time t2 when 2/3 of it has decayed and the time t1 when 1/3 of it had decayed is :
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- 30 days
- 50 days
- 60 days
- 15 days
Correct Option: B
N1 = N1 e–λt
N1 = | N0 | |
3 |
= N0e- λt2 | ||
3 |
= e- λt2 ....(i) | ||
3 |
N2 = | N0 | |
3 |
N0 = N0e- λt1 | ||
3 |
= e- λt1 | ||
3 |
Dividing equation (i) by equation (ii)
= e- λ(t2 - t1) | ||
2 |
λ(t2 - t1) In 2
t2 - t1 = | = T1/2 = 50 days | |
λ |