A plane mirror, reflecting a ray of incident light, is rotated through an angle `theta` about an axis through the point of incidence in the plane of the mirror perpendicular to the plane of incidence, then

Options

A. The reflected ray does not rotate.
B. The reflected ray rotates through an angle `theta.`
C. The reflected ray rotates through an angle `2theta.`
D. None of these

Answer

C

Explanation

From the figure it is clear that
`angle ABC = 2phi + delta = 2 (phi + theta)`
`implies delta = 2 theta`