Question

please solve this question

Answer 1

A..The student is suffering from Myopia..

Causes are.. Elongation of eye ball.. Decrease in focal length of eye lens.. Ciliary muscles are unable to adjust the eye lens..

Correction..Using a concave lens before the eye..( Spectacles )

B..The twinkling of a star is due to atmospheric refraction of starlight..

The starlight, on entering the earth’s atmosphere, undergoes refraction continuously before it reaches the earth..
The atmospheric refraction occurs in a medium of gradually changing refractive index..

Hope it helps..;)