Question

. A narrow beam of light is incident on the surface of a plane mirror. The initial angle between the
incident ray and reflected ray is 2α. If the mirror is turned around point A by the angle Θ what is
the change of the angle between two rays?

Answer 1

$\huge{\underline{\underline{\boxed{\sf{\blue{αɳรᏇɛƦ \: ࿐}}}}}}$

Consider a plane-mirror and a fixed incident ray of light reflecting from the surface at an angle . Before the mirror has rotated, the angle of incidence is is the angle of reflection. If the mirror is rotated through an angle the normal is rotated by an angle and thus the angle of incidence increases to +. Therefore, the angle of reflection must also increase by tow The difference between the final angle of reflection and the initial angle of reflection and is 2θ.