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refraction is an effect of a wave when it enters a medium where its speed is different.The refraction of light when it passes from a fast medium to a slow medium affect the light ray . The amount of bending depends on the indices of refraction of the two media and is described quantitatively by Snell's law.
where θ 1 and θ 2 are the angles between the normal (to the interface) and the incident and refracted waves, respectively. This phenomenon is also associated with a changing speed of light as seen from the definition of index of refraction provided above which implies:
where v1 and v2 are the wave velocities through the respective media. Various consequences of Snell's Law include the fact that for light rays travelling from a material with a high index of refraction to a material with a low index of refraction, it is possible for the interaction with the interface to result in zero transmission.
Index of refraction
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Reflection is the abrupt change in the direction of propagation of a wave that strikes the boundary between two different media. At least some part of the incoming wave remains in the same medium.
Curved Mirror
the curved mirrors are partial spherical surfaces. The line of symmetry of the curved mirror is called as the principal axis of the mirror. The radius of the sphere is called the radius of curvatureand half radius of curvature of the mirror is called thefocal length of the mirror. The focal length is also defined as the distance from the mirror along the principal axis to the point called focus of the mirror.
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