Question

A ray of light passing from air through an equilateral glass prism undergoes minimum deviation when the angle of incidence is $3/4$ of the angle of prism. Calculate the aped of light in the prism.

Answer 1

Angle of prism'A =60

$i=\frac{3\ast A}{4}$

=$\frac{3\ast 60}{4}$ =45

For minimum deviation $i_1=i_2=i$ and $r_1=r_2=\frac{A}{2}=30$

Refractive index of prism, n = $\frac{sin\left(45\right)}{sin\left(30\right)}$

=1.414

Speed of light in prism, $v=\frac{c}{n}$ = $2.13\ast {10}^{8}m/s$