Question

while passing through a glass prism.how many times a light ray undergo refraction and. what is the direction of refracted ray in each refraction

Answer 1

• light undergoes refraction twice:
first when it enters the prism and second when it leaves the prism.

• in the first case, as glass is an optically denser medium than air, the speed of the light ray decreases and thus the light ray gets refracted towards the normal.

• in the second case air being optically rarer than glass the speed of light increases and the ray gets refracted away from the normal.