Question

The most penetrating radiation out of the following is :

• A. gamma-rays
• B. alpha particles
• C. beta-rays
• D. X-rays

Answer 1

Answer: (A)

Key Idea: Penetrating power is maximum for which wavelength is minimum. The penetrating power of radiation is directly proportional to the energy of its photon. Energy of photon $=\frac{hc}{\lambda }\propto \frac{1}{\lambda }$ $\therefore$ Penetrating power $\propto \frac{1}{\lambda }$ Since, $\lambda$ is minimum for $\gamma -rays$ , so, penetrating power is maximum for $\gamma -rays$ .