Nuclear Physics And Radioactivity Question 298
Question: After two hours, one- sixteenth of the starting amount of a certain radioactive isotope remained undecayed. The half-life of the isotope is [Bihar MEE 1995; Manipal MEE 1995; EAMCET 1994 MP PMT 1997; DPMT 2002; AFMC 2000, 05]
Options:
A) 15 minutes
B) 30 minutes
C) 45 minutes
D) 1 hour
Show Answer
Answer:
Correct Answer: B
Solution:
$ \frac{N}{N_{0}}={{( \frac{1}{2} )}^{t/T}} $
$ \Rightarrow ( \frac{1}{16} )={{( \frac{1}{2} )}^{2/T}}\Rightarrow {{( \frac{1}{2} )}^{4}}={{( \frac{1}{2} )}^{2/T}} $
$ \Rightarrow T=0.5\ hour $ = 30 minutes.
BETA
