Find the minimum angle of deviation for a prism with angle A = 60° and $μ$ = 1.5.
Answer & explanation
Correct answer: option 1
Minimum Deviation
The angle of minimum deviation occurs when i = e and $r_1 = r_2$ and is given by:
$μ = \frac{\sin (\frac{A + D_m}{2})}{\sin\frac{A}{2}}$
$⇒ D_m= 2\sin^{−1} (μ\sin \frac{A}{2}) − A$
Substituting $μ = 1.5$ and A = 60°,
$D_m = 2\sin^{−1}(0.75) − 60° = 37°$