Chapter 11 Refraction, Dispersion and Scattering of light

When white light enters a prism, it gets split into its constituent colours. This is due to

• different refractive index for different wavelength of each colour

• each colours has same velocity in the prism.

• prism material have high density.

• Scattering of light

The air layer of atmosphere whose temperature is less then the hot layer behave as optically

• denser medium

• rarer medium

• inactive medium

• either denser or rarer medium

Refraction of light by the earth’s atmosphere due to variation in air density is called

• atmospheric reflection

• atmospheric dispersion

• atmospheric scattering

• atmospheric refraction

The deflection of light by minute particles and molecules of the atmosphere in all direction is called ____________ of light.

• dispersion

• scattering

• interference

• tyndell effect

One cannot see through the fog, because

• refractive index of the fog is very high

• light suffers total reflection at droplets

• fog absorbs light

• light is scattered by the droplets

At noon the sun appears white as

• light is least scattered

• all the colours of the white light are scattered away

• blue colour is scattered the most

• red colour is scattered the most

Twinkling of stars is due to atmospheric

• dispersion of light by water droplets

• refraction of light by different layers of varying refractive indices

• scattering of light by dust particles

• internal reflection of light by clouds.

The clear sky appears blue because

• blue light gets absorbed in the atmosphere.

• ultraviolet radiations are absorbed in the atmosphere.

• violet and blue lights get scattered more than lights of all other colours by the atmosphere.

• light of all other colours is scattered more than the violet and blue colour lights by the atmosphere.

The danger signals installed at the top of tall buildings are red in colour. These can be easily seen from a distance because among all other colours, the red light

• is scattered the most by smoke or fog

• is scattered the least by smoke or fog

• is absorbed the most by smoke or fog

• moves fastest in air

The bluish colour of water in deep sea is due to

• the presence of algae and other plants found in water

• reflection of sky in water

• scattering of light

• absorption of light by the sea