Question

The minimum value of the refractive index for a ${90}^{\circ }-{45}^{\circ }-{45}^{\circ }$ prism that is used to deviate a beam by ${90}^{\circ }$ by the phenomenon of total internal reflection is ________.

• A. $2$
• B. $1$
• C. $\sqrt{2}$
• D. $0$

Answer 1

The correct option is C $\sqrt{2}$