For refractin of light through a prism

Options

A. For every angle of deviation there are two angle of incidence.
B. The light travelling inside an equilateral prism is necessarily parallel to the base when prism is set for minimum deviation.
C. There are two angels of incidence for maximum deviation.
D. Angle of the minimum deviation will increase if refractive index of prism is increased keeping the outside medium unchanged if`mu_(P)gtmu_(S)`

Answer

B,C,D

Explanation

[B] at minimum deviation `r_(1)=r_(2)=A//2` so ,ray passes parallel to base through prism.
(C)
(D) `delta=(mu-1)A`