Light shows staged with lasers use moving mirrors to swing beams and create colorful effects. The light ray reflected from a mirror changes direction by θ when the mirror is rotated by an angle θ.
Light shows staged with lasers use moving mirrors to swing beams and create colorful effects. The light ray reflected from a mirror changes direction by θ when the mirror is rotated by an angle θ.
The correct option is B False
In the 1st figure, let us suppose that a light ray is incident at an angle α to a mirror. As per the law of reflection, the reflected ray makes an angle α with the normal OX.
In the 2nd figure, the mirror is tilted at an angle θ. As the mirror is tilted, the normal will also tilt by the same angle (blue line).The same incident light ray now makes an angle θ+α with the new normal . As per the law of reflection, the new reflected ray OY (indicated by a green line) makes an angle θ+α with the new normal (blue line). From the figure , we can observe that the new reflected ray (green line) makes an angle 2θ+α with the normal OX.
Hence, the change of angle is 2θ.
False
In the 1st figure, let us suppose that a light ray is incident at an angle α to a mirror. As per the law of reflection, the reflected ray makes an angle α with the normal OX.
In the 2nd figure, the mirror is tilted at an angle θ. As the mirror is tilted, the normal will also tilt by the same angle (blue line).The same incident light ray now makes an angle θ+α with the new normal . As per the law of reflection, the new reflected ray OY (indicated by a green line) makes an angle θ+α with the new normal (blue line). From the figure , we can observe that the new reflected ray (green line) makes an angle 2θ+α with the normal OX.
Hence, the change of angle is 2θ.
