Refraction is the bending of a wave when it enters a medium where its speed is different. We can define it as the change in direction of a wave passing from one medium to another or from a gradual change in the medium.
Laws of refraction state that:
- The incident ray refracted ray, and the normal to the interface of two media at the point of incidence all lie on the same plane.
- The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant. This is also known as Snell’s law of refraction.
sin i/sin r = constant
μ1 sin i = μ2 sin r