Question

A ray of light is incident normally on one of the faces of a prism of apex angle ${30}^{\circ }$ and refractive index $\sqrt{2}$. The angle of deviation of the ray in degree is

• A. 15
• B. 30
• C. 45
• D. 60

Answer 1

The correct option is A 15

$\delta =i_1+i_2-A;A={30}^{\circ }$
$i_1=0$; $\frac{\text{sin}30}{\text{sin}{i}_2}=\frac{1}{\sqrt{2}}$; $i_2={45}^{\circ }$
$\delta ={15}^{\circ }$