Question

The radiations from a naturally occurring radioactive substance, as seen after deflection by a magnetic field in one direction are:
A. Definitely alpha rays
B. Definitely beta rays
C. Both alpha and beta rays
D. Either alpha or beta rays

Answer 1

Hint: The radiation or ray which is neutral or uncharged has the highest high penetrating power and is not affected by an electrical and magnetic field. This is because the uncharged rays are not affected by the charge of the nucleus of an atom.

Complete Step by Step Solution:
$\alpha $ -rays consist of $\alpha $ particles. The alpha particles are actually helium atoms. Helium atoms have a mass number of $4$ and atomic number of $2$ . Thus an alpha particle is a positively charged particle and bends its path on penetration in presence of magnetic field.

 $\beta $ -rays consist of beta particles. The beta particles are actually high energetic electrons. Beta particles have lower size and higher negative charge than alpha particles. So beta particles bend more than alpha particles in a given magnetic field.

As the alpha and beta particles have opposite charges, they will move in opposite directions from each other under the magnetic field. So, if the radiation from a naturally occurring radioactive substance, as seen after deflection by a magnetic field in one direction, is either alpha or beta ray.
Thus the correct option is D.

Note: The particle or ray which is highly charged and has low mass is highly deflected by a magnet or under magnetic field. Among alpha, beta and gamma particles beta particles have low mass and high negative charge so, it is highly deflected by magnetic fields.