# A report onWavelength, Light and Refractive index                                             In optics, the refractive index ( refraction index) of an optical medium is a dimensionless number that gives the indication of the light bending ability of that medium.

- Refractive index

Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 terahertz, between the infrared (with longer wavelengths) and the ultraviolet (with shorter wavelengths).

- Light

The refractive index can be seen as the factor by which the speed and the wavelength of the radiation are reduced with respect to their vacuum values: the speed of light in a medium is v = c/n, and similarly the wavelength in that medium is λ = λ0/n, where λ0 is the wavelength of that light in vacuum.

- Refractive index

Examples of waves are sound waves, light, water waves and periodic electrical signals in a conductor.

- Wavelength

For electromagnetic waves the speed in a medium is governed by its refractive index according to

- Wavelength

where θ1 is the angle between the ray and the surface normal in the first medium, θ2 is the angle between the ray and the surface normal in the second medium and n1 and n2 are the indices of refraction, n = 1 in a vacuum and n > 1 in a transparent substance.

- Light ## 1 related topic with Alpha ## Refraction

Redirection of a wave as it passes from one medium to another.

Redirection of a wave as it passes from one medium to another.                Refraction of light is the most commonly observed phenomenon, but other waves such as sound waves and water waves also experience refraction.

For light, refraction follows Snell's law, which states that, for a given pair of media, the ratio of the sines of the angle of incidence θ1 and angle of refraction θ2 is equal to the ratio of phase velocities (v1 / v2) in the two media, or equivalently, to the refractive indices (n2 / n1) of the two media.

The refractive index of materials varies with the wavelength of light, and thus the angle of the refraction also varies correspondingly.