Nuclear Physics And Radioactivity Question 354
Question: If a radioactive substance reduces to $ \frac{1}{16} $ of its original mass in 40 days, what is its half-life [DCE 2001; AIIMS 2003]
Options:
A) 10 days
B) 20 days
C) 40 days
D) None of these
Show Answer
Answer:
Correct Answer: A
Solution:
$ \frac{N}{N_{0}}={{( \frac{1}{2} )}^{n}} $
Þ $ \frac{1}{16}={{( \frac{1}{2} )}^{4}}={{( \frac{1}{2} )}^{n}} $
Þ n = 4. Also $ n=\frac{t}{{T_{1/2}}} $
Þ $ {T_{1/2}}=\frac{40}{4}=10,days $
BETA
