QNEET-2017-Ph-965: NEET 2017 Physics - Class 12 NEET-2017-Ph-965 Solution: A beam of light from a source L is incident normally on a plane …

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 $\frac{y}{x}$ $\frac{x}{2y}$ $\frac{x}{y}$ $\frac{y}{2x}$