State the laws of refraction

Explanation

The incident ray , the refracted ray of light and normal to the refracting surface all lie in the same plane .
Second law of Refraction
(i) The ratio of the sine of the angle of incidense and sine of the angle of refraction is equal to the ratio of refractive indices of the two media . This law is also known as Snell .s law
`(sini)/(sinr)=(mu_(2))/(mu_(1))`
(ii) Refractive index gives us an idea of how fast or how slow light travels in a medium. The ratio of speed of light in vacuum to the speed of light in a medium is defined as refractive index `mu` of that medium.
(iii) The speed of light in a medium is low if the refractive index of the medium is high and vice versa.
(iv) When light travels from a denser medium into a rarer medium , the refracted ray is bent away from the normal drawn to the interface.
(v) When light travels from a rarer medium into a denser medium , the refracted ray is bent towards the normal drawn to the interface.