A beam of light from a source L is incident normally on a plane mirror fixed at a certain distance x from the source. The beam is reflected back as a spot on a scale placed just above the source L, when the mirror is rotated through a small angle theta the spot of the light is found to move through a distance y on the scale. The angle theta is given by:

A beam of light from a source L is incident normally on a plane mirror

1.	A beam of light from a source L is incident normally on a plane mirror fixed at a certain distance x from the source. The beam is reflected back as a spot on a scale placed just above the source L, when the mirror is rotated through a small angle theta the spot of the light is found to move through a distance y on the scale. The angle theta is given by:
Answer» `X/y` `x/(2X)` `y/x` `x/(2Y)` ANSWER :B