Question

(i) Name the radiation which can be detected by (a) a thermopile (b) a solution of silver chloride.

(ii) Name two sources, each of infrared radiations and ultraviolet radiations.

(iii) Name the material of prism required for obtaining the spectrum of (a) ultraviolet light, (b) infrared radiations

Answer 1

(i) (a) Infrared radiations can be detected by thermopile.
(b) Ultraviolet radiations can be detected by silver chloride because in their presence silver chloride becomes dark.

(ii) All red hot bodies such as a heated iron ball, flame, fire, etc. are the sources of infrared radiations.
The electric arc and sparks give ultraviolet radiations.

(iii) (a) A quartz prism is required for obtaining the spectrum of ultraviolet light.
(b) Infrared radiations is obtained by passing radiations through a rock salt prism.