Name a prism required for obtaining a spectrum of ultraviolet light.

Give reason for the following: (i) Infrared radiations are used for photography in fog. (ii) Infrared radiations are used for signals during war. (iii) The photographic darkrooms are provided with infrared lamps. (iv) A rock salt prism is used instead of a glass prism to obtain the infrared spectrum. (v) A quartz prism is required for obtaining the spectrum of ultraviolet light. (vi) Ultraviolet bulbs have a quartz envelope instead of glass.

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

The source of ultraviolet light is :

Benzene reacts with excess of chlorine in presence of ultraviolet light to produce

Name the extreme colours in pure spectrum of light.

Name any four regions of electromagnetic spectrum (other than visible light) in increasing order of their wavelength.

Name two sources, each of infrared radiations and ultraviolet radiations.

Charateristic X-rays are not obtained in the spectrum of H-atom bacause-

Statement-1 : When a white light passes through a prism it forms a spectrum of seven colours. Statement-2 : The refractive index for different colour of light is different for the material of prism.

STATEMENT - 1 : The white light incident on a prism, after emerging from the prism will form a spectrum of rays. and STATEMENT - 2 : For different colours, a prism has different refractive indices.