A beam of light consisting of red, green and blue colurs is incident on a right angled prism as shown in figure. The refractive indices of the maaterial of the prism for above red, green and blue wavelengths are 1.39, 1.44 and 1.47, respectivley .

Explanation

The colours for which `i gt theta_C ` , will get total int-ernal reflection `i gt theta_C or sin i gt sin theta_C `
`or sin 45^@ gt (1)/( mu ) (or) (1)/(sqrt2) gt (1)/(mu)`
of for which `mu gt sqrt(2) or mu gt 1.414 `
Hence, the rays for which `mu gt 1.414` will get TIR.
For green and blue `mu gt 1.414, `so they will suffer TIR on face AC only red comes out from this face.