Question

If the refracting angle of a prism is ${60}^{\circ }$ and minimum deviation is ${30}^{\circ }$, the angle of incidence is

• A. ${30}^{\circ }$
• B. ${45}^{\circ }$
• C. ${60}^{\circ }$
• D. ${90}^{\circ }$

Answer 1

The correct option is B

${45}^{\circ }$

$i=\frac{{\delta }_{\text{m}}+A}{2}=\frac{{30}^{\circ }+{60}^{\circ }}{2}={45}^{\circ }$