Question

what do you meant by snell's law in refraction

Answer 1

according to snell's law it states that the The refractive index is from rarer to denser medium or from denser to rarer medium is the sin ratios of angle of incidence & angle of refraction.

i.e. u = refractive index

u = sin(i) / sin(r)

Answer 2

n1 sini =n2sinr .this shows the lights ray enters from first medium to second one