Prove that i = e, If the angle of incidence and angle of emergence subtended by a light ray falling on a surface of glass slab are i and e respectively. How much angular deviation is suffered by the incident ray.

Prove that i = e, If the angle of incidence and angle of emergence sub

1.	Prove that i = e, If the angle of incidence and angle of emergence subtended by a light ray falling on a surface of glass slab are i and e respectively. How much angular deviation is suffered by the incident ray.
Answer» Solution :In the FOLLOWING FIGURE, `SR \|\| PQ` and NM is the REFRACTED ray. HENCE, `r = i_(1)`. Now, `._(g)n_(a) = sin i//sin r ` and `._(a) n_(g) = sin i_(1)//sin e ` Also `._(g)n_(a) = ( 1)/(._(a)n_(g))` `:. ( sin i)/(sinr ) = ( sin e )/(sin i_(1))` As ` r = i_(1)` , it follows that `sin i = sin e ` `:. i = e `