Nuclear Physics And Radioactivity Question 366
Question: Half-life of a substance is 10 years. In what time, it becomes $ \frac{1}{4} $ th part of the initial amount [AIEEE 2002]
Options:
A) 5 years
B) 10 years
C) 20 years
D) None of these
Show Answer
Answer:
Correct Answer: C
Solution:
$ N=N_{0}{{e}^{-t/{T_{1/2}}}}\Rightarrow \frac{1}{4}={{e}^{-t/10}} $
$ \Rightarrow {{( \frac{1}{2} )}^{2}}=\frac{1}{{{e}^{t/10}}}\Rightarrow t=20\ years $
BETA
