The angle of deviation decreases with increase in the angle of prism.
(a) How does the angle of deviation produced by a prism change with an 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 δmin is unique for the given light.