Question

Ans The question from the figure ?

Answer 1

twinkling of stars
due to atmospheric refraction the stars can twinkle

Answer 2

This daigram is shown twinkling effect of starts

The stars seem to be higher in the sky than they actually are due to atmospheric refraction.

As the light rays from a star pass through the different layers of atmosphere (density of layers increasing downwards), they suffer atmospheric refraction from a rarer to a denser medium. So they bend towards the naormal at each layer. Due to continuous refraction, the light from the star appears to come from a point which is actually higher than the star.