Test: The Human Eye & the Colorful World - 1 - Class 10 MCQ

Scattering of light occurs when light deflects in all directions due to interactions with tiny particles and molecules in the atmosphere.

• It is responsible for the blue colour of the sky.
• This phenomenon occurs because shorter wavelengths of light (like blue) are scattered more than longer wavelengths (like red).
• Scattering is crucial in understanding various atmospheric and optical phenomena.

Answer: b) Diagram (iv)

Why:
• At the first face (air → glass), the ray bends towards the normal, i.e., towards the base of the prism.
• At the second face (glass → air), it bends away from the normal, but the overall deviation is still towards the base.
• Hence inside the prism the ray is inclined towards the base and the emergent ray is deviated towards the base — exactly as in (i).

Why others are wrong:
(ii) emergent ray deviates towards the apex;
(iii) shows no deviation;
(iv) inside ray goes towards the apex.

Stars appear to twinkle due to atmospheric refraction. This phenomenon occurs because:

• The Earth's atmosphere is composed of layers with varying densities.
• These layers cause the starlight to bend as it passes through.
• The bending of light makes stars seem to shift and flicker.

When white light passes through a glass prism, the violet coloured ray undergoes maximum deviation. The red coloured ray undergoes minimum deviation.

Eye lens is convex, in nature. So, image formed by it on the retina is real and inverted.

Atmospheric refraction is the bending of light as it passes through the Earth's atmosphere. This phenomenon occurs due to changes in air density.

• Light travels through air of varying densities, causing it to bend.
• This bending makes celestial objects appear higher than their actual position.
• Common examples include the apparent position of the sun during sunrise and sunset.

When light travels from a rarer medium (like air) to a denser medium (like glass), its speed decreases because the denser medium has a higher optical density. As a result, the light ray bends towards the normal at the point of incidence due to refraction. This behavior is described by Snell's law, which relates the angles of incidence and refraction to the refractive indices of the two media.

Dispersion takes place because refractive index of the material of prisra is different for different wavelength.

Phenomena of refraction, dispersion and internal reflection are involved in the formation of rainbow.

 Splitting of white light into its constituent seven colours, while passing through a prism, is on account of dispersion of fight.