Where does Snell's law of refraction fail?

Snell's law states that, 1. The incident ray, the refracted ray and the normal to the interface seperating two media lie in the same plane. 2. read more

Snell's Law of Refraction fail when light incidents on the surface of separation of the 2 media normally or through the normal. It is because when light incidents through the normal, the angle of incidence is equal to zero. read more

snell's law of refraction fails in 2 situations: (I)when TIR(total internal reflection) takes place at an angle greater than the critical angle. (II)when light is incident normally on a surface, as i =0,r =0 thus not applicable. read more

The law of refraction is also known as Snell's Law, named for Willobrord Snell, who discovered the law in 1621. Snell's Law Like with reflection, refraction also involves the angles that the incident ray and the refracted ray make with the normal to the surface at the point of refraction. read more