SSC MTS EXAM

Detailed explanation-1: -Light refracts whenever it travels at an angle into a substance with a different refractive index (optical density). This change of direction is caused by a change in speed. For example, when light travels from air into water, it slows down, causing it to continue to travel at a different angle or direction.

Detailed explanation-2: -A denser medium provides more matter from which the light can scatter, so light will travel more slowly in a dense medium. A slower speed means a higher index of refraction, so n2 > n1, as indicated in the image on the left.