Question 80: Ray Optics

Question

The refractive index of a prism with apex angle $A$ is $\cot A / 2$. The angle of minimum deviation is :

Accepted Answer

$\begin{aligned}
& \mu=\frac{\sin \left(\frac{A+\delta m}{2}ight)}{\sin \frac{A}{2}} \
& \frac{\cos \frac{A}{2}}{\sin \frac{A}{2}}=\frac{\sin \left(\frac{A+\delta m}{2}ight)}{\sin \frac{A}{2}} \
& \sin \left(\frac{\pi}{2}-\frac{A}{2}ight)=\sin \left(\frac{A+\delta_m}{2}ight) \
& \frac{\pi}{2}-\frac{A}{2}=\frac{A}{2}+\frac{\delta m}{2} \
& \delta_m=\pi-2 A
\end{aligned}$

Answer

$\delta_m=180^{\circ}-3 \mathrm{~A}$

Answer

$\delta_m=180^{\circ}-4 A$

Answer

$\delta_m=180^{\circ}-2 A$

Answer

$\delta_m=180^{\circ}-A$

Ray Optics

The refractive index of a prism with apex angle A is \cot A / 2. The angle of minimum deviation is :

Choose the correct answer: