What should be the angle between the reflecting surfaces of two plane mirrors in order for every incident beam to be parallel to its reflected beam?
A) 0°
B) 30°
C) 45°
D) 60°
E) 90°

Question

Quizplus · Accepted Answer

When the angle between the reflecting surfaces of two plane mirrors is 90°, the incident beam will be perpendicular to the first mirror and will reflect at a 90° angle to the second mirror. Since the incident angle and reflection angle are equal, the reflected beam will be perpendicular to the second mirror and parallel to the initial incident beam. This will hold true for any incident angle on the first mirror, ensuring that every incident beam is parallel to its reflected beam. Therefore, the correct answer is E).

What Should Be the Angle Between the Reflecting Surfaces of Two