Walker, Halliday & Resnick — Electromagnetic Waves: Problem 14

14 Suppose the prism of Fig. 33-34 has apex angle \(\phi = 60.0^\circ\) and index of refraction \(n = 1.56\). (a) What is the smallest angle of incidence \(\theta\) for which a ray can enter the left face of the prism and exit the right face? (b) What angle of incidence \(\theta\) is required for the ray to exit the prism with an identical angle \(\theta\) for its refraction, as it does in Fig. 33-34?