Question

The diagram shows a radioactive source S placed in a thick lead walled container. The radiations given out are allowed to pass through a magnetic field. The magnetic field (shown as x) acts perpendicular to the plane of paper inwards. Arrows show the paths of the radiations A, B and C. Name the radiations labelled A, B and C.

Answer 1

For alpha particles the direction of deflection which can be determined by Fleming’s left hand rule demonstrates that they must be positively charged

they will deflect towards left side. So, B represents $\alpha$ particles

$\beta$ particles will be opposite of $\alpha$ particles. So, C represents $\beta$ particles.

$\gamma$ rays are unaffected by a magnetic field. So, A represents $\gamma$ rays.