7. 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 1. When the mirror is rotated through a small angle θ, the spot of the light is found to move through a distance y on the scale. The angle θ is given by ?

6. Match the corresponding entries of column-1 with column-2 (Where m is the magnification produced by the mirror) :

6. Match the corresponding entries of column-1 with column-2 (Where m is the magnification produced by the mirror) :

5. Two plane mirrors are inclined at $70^◦$ . A ray incident on one mirror at angle θ after reflection falls on second mirror and is reflected from there parallel to first mirror. The value of θ is ?

4. A rod of length 10 cm lies along the principal axis of a concave mirror of focal length 10 cm in such a way that its end closer to the pole is 20 cm away from the mirror. The length of the image is ?

3. A person is six feet tall. How tall must a vertical mirror be if he is able to see his entire length ?

2. If two mirrors are kept inclined at $60^◦$ to each other and a body is placed at the middle, then total number of images formed is ?

1. Ray optics is valid, when characteristic dimensions are ?