Question

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

• A. ${30}^o$
• B. $4^o$
• C. $3^o$
• D. ${1.5}^0$

Answer 1

The correct option is D ${1.5}^0$

$n=\sin \left[\left(D+a\right)/2\right]/\sin \left(a/2\right)$

$=\sin \left[\left(60+40\right)/2\right]/\sin \left(60/2\right)$

$=\sin 50/\sin 30$

$=1.532$

Hence,

option $\left(D\right)$ is correct answer.