Question

The twinkling of stars is due to atmospheric

• A. dispersion of light by water droplets
• B. refraction of light by different layers of varying refractive indices
• C. scattering of light by dust particles
• D. internal reflection of light by clouds

Answer 1

The correct option is B

refraction of light by different layers of varying refractive indices

The explanation for the correct option:

In the case of option B,

1. Atmospheric refraction is the refraction of light by the Earth's atmosphere.
2. Atmospheric refraction is caused by the bending of light rays as they pass through the different optical densities of the earth's atmosphere.
3. The refraction of light by various layers of different refractive indices is the explanation for the twinkling of stars.
4. When we see a star from the surface, it does not always twinkle. It always emits light, but our surroundings cause it to appear as a twinkle. Our atmosphere is divided into layers by refractive indexes.

The explanation for the incorrect options:

1. In the case of option A, when light strikes a water droplet, it is refracted at the air-water interface and enters the droplet, where it is dispersed into the seven colors.
2. In the case of option C, when light passes from one medium to another, such as air or a glass of water, a portion of the light is absorbed by medium particles, followed by subsequent radiation in a specific direction. This phenomenon is known as light scattering.
3. In the case of option D, total internal reflection, in physics, is the complete reflection of a ray of light within a medium such as water or glass from the surrounding surfaces back into the medium.

Hence, option(B) is correct.