Question

. (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 Smin is unique for the given
light.​

Answer 1

hey for the second part see, if u incident say green and red coloured light rays on a prism with same angle of incidence(i1) they will get refracted by different angles so when they come out they will again get refracted by different angles (i2')and (i2") and as u know the formula for angle of deviation is D=i1 + i2 - A so u will get different deviation angles for different coloured lights.

Answer 2

The answer is here...