A beam of light consisting of red, green and blue colour is incident on a right angled prism. The refractive indices of the material of the prism for the above red, green and blue wavelength are 1.39, 1.44 and 1.47 respectively. The prism will

Separate part of red colour from the green and the blue colour

At face AB, i = 0. So, r = 0, i.e., no bending will take place. So, light beam will be incident on face AC at an angle 45°. The face AC will not transmit the light for which $i>\theta_C$, i.e., $\sin i>\sin \theta_C$

or $\sin 45^{\circ}>(1 / \mu)$ i.e., $\mu>\sqrt{2}(=1.41)$

Now as µ_R < µ while µ_G and µ_B > µ, so red will be transmitted through the face AC while green and blue will be reflected. So, the prism will separate red colour from green and blue.