Q. The penetrating powers of $\alpha,\beta\ and\ \gamma$ radiations, in decreasing order are
A) $\gamma,\ \alpha,\beta$
B) $\gamma,\beta,\ \alpha$
C) $\alpha,\beta,\gamma$
D) $\beta,\gamma,\alpha$
Explanation
(b) Penetrating power varies inversely as mass of penetrating radiation. Therefore, $\gamma$ radiations have maximum penetrating power and $\alpha$-particles have minimum penetrating power.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.