An isosceles glass prism with small refractive angles a is placed in a parallel beam of rays incident normally on its base (Fig. 132). Refractive index of glass n = 1.57, base size 2a = 5 cm. Find the value of the refractive angle a if a dark stripe 2d = 1 cm wide is formed in the middle of the screen located at a distance L = 100 cm from the prism.

Detailed solution. Format gif