question_answer

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

B)  1.414

C)  1.5

D)  1.732

Correct Answer: B

Solution :

Refractive index, \[\mu =\frac{1}{\sin C}\]where C is the critical angle.   Here,          \[C=45{}^\circ \]        (as shown) \[\therefore \] \[\mu =\frac{1}{\sin {{45}^{o}}}\]or\[\mu =\sqrt{2}\]or\[\mu =1.414\]