Q. Keeping a fixed incident ray of light, if a plane mirror is rotated with an angle of 20°, the reflected ray will turn by which among the following values?
Answer: 40°
Notes: Before the mirror has rotated, the angle of incidence is taken ? as is the angle of reflection. If the mirror is rotated through an angle f the normal is rotated by an angle f and thus the angle of incidence increases to ? +f. Therefore, the angle of reflection must also increase by f to ?+f The difference between the final angle of reflection and the initial angle of reflection and is 2f.

This Question is Also Available in:

हिन्दी

This question is part of 40000+ General Studies MCQ Series Course on GKToday Android app.

Question Number: 37 in Physics GK 19 - Light and Human Eye in above course in App.