Question

The angle of a prism is $ 42^{\circ} $ and refractive index of its material is $ 3/2 $ . Then, angle of minimum deviation for this prism is

• A. $ 63^{\circ} $
• B. $ 42^{\circ} $
• C. $ 28^{\circ} $
• D. $ 21^{\circ} $

Answer 1

Answer: (D)

Angle of minimum deviation
$\delta_{\min }=(\mu-1) A$
$=\left(\frac{3}{2}-1\right) 42^{\circ}$
$=\frac{1}{2} \times 42=21^{\circ}$