Question

Snell's law states that

u(constant of refraction) = sini/sinr

If a ray of light is passing through a glass slab through its normal, then sin i = 0 and thus the constant of refraction is not mantained.

But as the definition of snell's law suggests that this law is applicable to light travelling obliquely. If this is so, I have a question:



Refraction occurs due to the change in velocity of light in 2 different mediums. This change in velocity occurs as the atoms in a particular media has a specific frequency and if the light wave has a different frequecy, only then will it let the light pass through. But in this process, the light is refracted at some angle. BUT WHY DOES THIS REFRACTION NOT OCCUR WHEN LIGHT TRAVELS THROUGH THE NORMAL?



(I hope you understand the question. If not, pls tell me where I am not clear, i'll try to explain in a better way)

Answer 1

 "If a ray of light is passing through a glass slab through its normal"

Answer 2

Snell's law states that. u(constant of refraction) = sini/sinr. If a ray of light is passing through a glass slab through its normal, then sin i = 0 and thus the constant of refraction is not mantained. But as the definition of snell's law suggests that this law is applicable to light travelling obliquely.