Nuclear Physics And Radioactivity Question 267
Question: The radioactivity of a certain radioactive element drops to 1/64 of its initial value in 30 seconds. Its half-life is [CPMT 1990, 97]
Options:
A) 2 seconds
B) 4 seconds
C) 5 seconds
D) 6 seconds
Show Answer
Answer:
Correct Answer: C
Solution:
$ N=N_{0}{{( \frac{1}{2} )}^{t/T}}\Rightarrow \frac{N_{0}}{64}=N_{0}{{( \frac{1}{2} )}^{30/T}} $
$ \Rightarrow T=\frac{30}{6}=5\sec $
BETA
