Nuclear Physics And Radioactivity Question 339
Question: A radioactive sample has half-life of 5 years. Probability of decay in 10 years will be [RPET 2000]
Options:
A) 100%
B) 75%
C) 50%
D) 25%
Show Answer
Answer:
Correct Answer: B
Solution:
Number of half lives $ n=\frac{10}{5}=2, $ now $ \frac{N}{N_{0}}={{( \frac{1}{2} )}^{2}}=\frac{1}{4} $ Fraction decayed $ =1-\frac{N}{N_{0}}=1-\frac{1}{4}=\frac{3}{4} $
Þ In percentage $ =\frac{3}{4}\times 100=75% $
BETA
