Refraction of light at plane surfaces

The process of changing speed at

The process of changing speed at an interface when light travels from one medium to another, resulting in a change in direction (bending) of the light

The ratio of speed of light

The ratio of speed of light in vacuum (c) to speed of light in a medium (v). Absolute refractive index n = c/v. It indicates how much light slows down

The fundamental law governing refraction

The fundamental law governing refraction: n₁ sin i = n₂ sin r, where n₁ and n₂ are refractive indices of first and second media, i is angle of inciden

Critical angle C is the angle

Critical angle C is the angle of incidence (in denser medium) at which refracted ray grazes the interface (r = 90°). For angles greater than C, total

When light passes through a parallel

When light passes through a parallel-sided glass slab, it undergoes refraction at both surfaces. The emergent ray is parallel to incident ray but late