Question

In the diagram a narrow beam of white light is incident on a right angled isosceles prism. The critical angle of the material of prism for yellow colour of white light is 45°. Complete the diagram to show the path of blue, yellow and red colours of white light till they emerge out of the prism.

Answer 1

 The completed diagram is shown below:

The critical angle for yellow light is given to be 45°. Since μ_blue > μ_yellow and μ_red < μ_yellow so the critical angle for blue light will be less than 45° and for red light will be more than 45°.