Question

 Calculate the minimum deviation produced by a 60° glass prism if the refractive index of the glass is

    1.50. What is the angle of incidence at which minimum deviation occurs?

Answer 1

Answer

Angle of incidence is given by using snell law

$I=\sin^{-1}({\mu sin R})$

$=\sin^{-1}({1.5sin 60°})$

=49°

Now minimum deviation

$\delta_m=2I-A \\=2\times49°-60°\\=38°$