Question

A ray of monochromatic light is incident on one refracting face of a prism of angle 75

Answer 1

Explanation:

According to Snell’s law,

Here, i and r are the incident and refracted angle respectively and μ is their corresponding refractive medium index.

At critical incident angle, i = 90°

So,

As the refractive index of the prism is given as

Thus c = 45°

The angle of the prism is 75°

We know that Angle of prism (A) = angle of refraction of first face (r) + angle of refraction or critical angle of second face (c)

Angle of refraction of first face,

Thus by applying the snell’s law again,

Where,

r = 30°

Thus, the angle of incidence is 45°