A ray of light passes through an equilateral glass prism such that the angle of incidence is equal to the angle of emergence and each of these angles is equal to 3/4 of angle of prism. Find the angle of deviation.
The angle of deviation δ for a ray of light in a prism is given by
i = Angle of incidence of ray
e = Its angle of emergence
A = Angle of prism
As the prism is equailateral,⇒A=60°