Chapter 10. Light-Reflection and Refraction
Refraction of light:
When a ray of light enters from one transparent medium to another transparent medium it changes its direction or it bends. This bending of light path is called refraction of light.
The refraction of light only takes place through transparent materials like glass, air and water etc.
There are two situation of this bending.
(i) When a ray of light enters from rarer medium to denser medium it bends towards the normal.
(ii) When a ray of light enters from denser medium to rarer medium it bends away from normal.
Cause of the refraction of light: The refraction of light occurs due to changing in speed of light it enter on transparent medium to another.
The Law of refraction:
The following are the laws of refraction of light:
(i) The incident ray, the refracted ray and the normal to the interface of two transparent media at the point of incidence, all lie in the same plane.
(ii) The ratio of sine of angle of incidence to the sine of angle of refraction is a constant, for the light of a given colour and for the given pair of media. This law is also known as Snell’s law of refraction.
Snell's Law: The ratio of sine of angle of incidence to the sine of angle of refraction is a constant, for the light of a given colour and for the given pair of media. This law is also known as Snell’s law of refraction.
Denser Medium: The medium which has greater refractive index is called dender medium. The particles of this medium is denser.
Rarer Medium: The medium which has smaller refractive index is called rarer medium.