Question

If the angle of a prism is ${60}^o$ and angle of minimum deviation is ${40}^o$, then the angle of refractive in the prism will be

• A. ${30}^o$
• B. ${45}^o$
• C. ${50}^o$
• D. ${20}^o$

Answer 1

The correct option is A ${30}^o$

The angle of prism

$n=\frac{\sin (\Delta +a)/2}{sina/2}$

$n=\frac{\sin ({60}^0+40)/2}{\sin 60/2}$

$=\frac{\sin {50}^0}{\sin {30}^0}=\frac{0.766}{0.5}=1.532$