A ray of light is incident normally on one face of a right angled isosceles prism. It then grazes the hypotenuse. The refractive index of the material of the prism is

• A

  $1.33$
• Correct answer
  B

  $1.414$
• C

  $1.5$
• D

  $1.732$

Solution

Refractive index, $\mu=\frac{1}{\sin C}$, where $C$ is the critical angle

Here, $$ \begin{aligned} &C=45^{\circ} \\ &\mu=\frac{1}{\sin 45^{\circ}} \text { or } \mu=\sqrt{2} \\ &\mu=1.414 \end{aligned} $$

Hence, the correct answer is option: 'B'.