(i) A ray PQ of light is incident on the face AB of a glass prism ABC (as shown in the figure) and emerges out of the face AC. Trace the path of the ray. Show that `/_i+/_e=/_A+/_delta` where, `delta` and e denote the angle of deviation and angle of emergence respectively.
Plot a graph showing the variation of the angle of deviation as a function of angle of incidence. State the condition under which `/_delta` is minimum.
(ii) Find out the relation between the refractive index `(mu)` of the glass prism and `/_A` for the case, when the angle of prism (A) is equal to the angle of minimum deviation (`delta_m`). Hence, obtain the value of the refractive index for angle of prism A = 60°.