Question

A beam of light consisting of red, green and blue colours is incident on an isosceles right angled prism as shown in the figure .The refractive indices of the material of the prism for red, green and blue colours are 1.39,1.43 and 1.47 respectively. The prism will

• A. Separate red colour from green and blue colours.
• B. Separate blue colour from red and green colours
• C. Separate green colour from, red and blue colours
• D. Separate all the three colours from one another

Answer 1

The correct option is A

Separate red colour from green and blue colours.

$\mu =\frac{1}{\text{sin}{i}_c}=\frac{1}{\text{sin}{45}^{\circ }}$

$\mu =\sqrt{2}$

Thus only red colour donot suffer total internal reflection.