Q. Two radioactive samples have decay constant $15x$ and $3x$. If they have the same number of nuclei initially, the ratio of number of nuclei after a time $\frac{1}{6x}$ is
A) $\frac{1}{e}$
B) $\frac{e}{2}$
C) $\frac{1}{e^{4}}$
D) $\frac{1}{e^{2}}$
Explanation
(d) Using
$N = N_{0}e^{- \lambda t} \Rightarrow \frac{N_{1}}{N_{2}} = \frac{1}{e^{2}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.