When a mirror is rotated by an angle of 6, the reflected ray will rotate by
Reviewed by Dalvoy
UPSC Civil Services preparation
- A0°
- B? /2
- C?Correct
- D2?
Explanation
The correct answer is C.
According to the laws of reflection, the angle of incidence equals the angle of reflection. When a plane mirror is rotated by an angle theta, the normal to the mirror also shifts by the same angle theta.
Because both the incident angle and the reflected angle change relative to the new normal, the total change in the path of the reflected ray is doubled. Therefore, if a mirror rotates by an angle theta, the reflected ray rotates by an angle of 2 theta. Since the question states the mirror is rotated by an angle theta, the reflected ray rotates by 2 theta, which corresponds to option C.
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