A beam of light is incident on a glass plate at an angle of incidence 600. The reflected ray is polarised. What is the angle of refraction when the angle of incidence is 450

when reflected  light is completely polarised angle of incident must be Brewster angle and  at Brewster angle   μ=tan 600=3 when angle of incidence is 450  sin450= 3sin r     then sinr=1213=16