Question

what is snell 's law​

Answer 1

The interpretation of Snell's law is that, light tends to travel through the path through which it takes the shortest time.

Answer 2

Snell's law is defined as "The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant, for the light of a given colour and for the given pair of media".

i.e..:

sini/sinr=constant