Question

Figure shows a mixture of blue, green and red coloured rays incident normally on a right angled prism. The critical angles of the material of the prism for red, green and blue are ${46}^o$, ${44}^o$ and ${43}^o$ respectively. The arrangement will separate :

• A. Red colour from blue and green
• B. Blue colour from red and green
• C. Green colour from red and blue
• D. All the three colours

Answer 1

The correct option is A Red colour from blue and green

All three rays will hit the prism side at ${45}^o$, so incident angle is ${45}^o$, Only red will go through the internal reflection and other two ray will pass, So this arrangement will separate red colour from blue and green