(a) How does the angle of deviation produced by a prism change with increase in the angle of incidence. Draw a curve showing the variation in the angle of deviation with the angle of incidence at a prism surface.
(b) Using the curve in part (a) above, how do you infer that for a given prism, the angle of minimum deviation `delta_("min")` is unique for a given light.

Explanation

Angle of incidence increases there is a decrease in the angle of deviation