Question

Give reason for the following:

a) A pencil dipped in water appears bent at the surface of the water.

b) Stars appear to be slightly higher in the sky than they actually are.​

Answer 1

Answer:

1) The pencil appears to be bent due to refraction of light. This occurs when the speed of light changes when it travels from one medium to another

2)Starts seem higher in the sky than they actually are due to atmospheric refraction as the light travels in different layers of atmosphere

Answer 2

Explanation:

a) The pencil appears to be bent when it is kept in a glass tumbler with water due to refraction of light. The refraction of light occurs when the speed of light changes when it travels from one medium to another.

b) Due to atmospheric refraction, the stars seem to be higher in the sky than the actual. Due to continuous refraction Light from a star is refracted as it leaves space and enters the earth's atmosphere. Air higher up in the sky is rarer but that nearer the earth's surface is denser. When the light from a star comes down, the dense air bends the light more.

Due to continuous refraction of star's light, the star appears to be at a higher position and our eye will see the star at that position from where light enters it in the straight line direction.