Q. The decay constant of a radioactive element is $1.5 \times 10^{- 9}$ per second. Its mean life in seconds will be
A) $1.5 \times 10^{9}$
B) $4.62 \times 10^{8}$
C) $6.67 \times 10^{8}$
D) $10.35 \times 10^{8}$
Explanation
(c) Mean life $= \frac{1}{\lambda} = 6.67 \times 10^{8}s$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.