Question

A prism of refractive index $\sqrt{2}$ has refracting angle ${60}^{\circ }$. Angle of minimum deviation is :

• A. ${45}^{\circ }$
• B. ${90}^{\circ }$
• C. ${30}^{\circ }$
• D. None of the above

Answer 1

The correct option is C ${30}^{\circ }$

Given :- $\mu =\sqrt{2}$

A = ${60}^0$

from formula

$\mu =\frac{Sin\left(\frac{A+\delta min}{2}\right)}{Sin\left(A/2\right)}$

$V_2=\frac{Sin\left(\frac{60+\delta min}{2}\right)}{Sin{30}^0}$

$\frac{1}{V_2}=Sin\left(\frac{60+\delta min}{2}\right)$

$\frac{60+\delta min}{2}={45}^0$

$\delta min={30}^0$