PHYSICS Lecture Notes - Lecture 9: Refraction, Focal Length, Total Internal Reflection
Document Summary
Coming to refraction, it is the bending of light when it enters another medium. For example, if light enters from air to water, it will bend. This happens due to the change in speed of light as it changes medium. Refraction is caused by the change in speed of light. At the boundary of 2 optical media, if there is a sudden change in the speed of light, it will cause the path of light to bend. The incident ray, the refracted ray and the normal lie in the same plane. For two particular media, the raio of sine of incident angle to the sine of refracted angle is a constant. i. e. sin i / sin r = constant. The refractive index of a medium is a ratio between the speed of light in air and the speed of light in a medium. Speed of light in air / speed of light in medium = n.