Halliday, Resnick & Walker — Electromagnetic Waves: Problem 26

26 Dispersion in a window pane. In Fig. 33-41, a beam of white light is incident at angle \(\theta = 40^\circ\) on a common window pane (shown in cross section). For the pane’s type of glass, the index of refraction for visible light ranges from 1.524 at the blue end of the spectrum to 1.509 at the red end. The two sides of the pane are parallel. What is the angular spread of the colors in the beam (a) when the light enters the pane and (b) when it emerges from the opposite side? (Hint: When you look at an object through a window pane, are the colors in the light from the object dispersed as shown in, say, Fig. 33-20?)