Question

A ray of light travelling in air enters obliquely into water. does the light ray towards the normal or away from the normal? why?

Answer 1

The light rays goes away from the normal because the light ray is going from optical denser to optical rarer medium. Because water is a denser medium.

Answer 2

When a ray of light enters from air to water the ray will bend towards the normal as it enters an optically rarer to an optically denser medium. Here, rarer medium is air and denser medium is water. Rarer mediums have faster speed of light in them than the speed of light in denser mediums. So, when the ray of light enters from air to water the speed decreases comparatively and the ray thus deviates more when it passes obliquely and that too towards the normal.