Q. The half life of a radioactive element which has only $\frac{1}{32}$ of its original mass left after a lapse of 60 days is
A) 12 days
B) 32 days
C) 60 days
D) 64 days
Explanation
(a) $\frac{N_{0}}{32} = N_{0}\left( \frac{1}{2} \right)^{60/T} \Rightarrow 5 = \frac{60}{T} \Rightarrow T = 12days$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.