Question

In the following  fig. shows a radioactive source S in a thick lead container. The radiations pass through an electric field between the plates P and Q. Complete the diagram to show the paths of α , β and γ radiations.

Why is the source S placed in a thick lead container?

Answer 1

(i) Alpha particles are heavy in mass and are positively charged so they are deflected less and are deflected towards - charged plate.
(ii) Beta particles are negIigible in mass so they are highly deflected by electric field anc they are negatively charge particle so they are deflected towards positive charged plate.
(iii) Gamm a radiations have no mass and no charge so they are not deflected by electric field.
Source S is placed in thick lead container because it is radioactive substance and radiates. Thick walls of lead absorb a II the radiation except radiation going straight outside towards opened end. Thus, thick walIs help to reduce leakage of radiations outside.