A light ray incident at grazing angle on the face AB of a prism ABC, follows the path shown in the figure. Obtain the relation between the angle of prism A and the refractive index µ of its material.

Question

A light ray incident at grazing angle on the face AB of a prism
ABC, follows the path shown in the figure Obtain the relation
between the angle of prism A and the refractive index µ of
its material

Sanjay Singh · Accepted Answer

Dear student
r1+r2=A
1Applying snells law on the front face 1 sini=μ sinr11× sin90=μ sinr1
2and Applying snells law on the rear face μ sinr2=1× sin90
3from eqn 2 and 3  μsinr1=μ sinr2r1=r2putting in eqn 1r1+r1=Ar1=A2putting in eqn 21× 1=μ sinr1 1=μ sinA2μ=1sinA2Regards