Two mirrors $AB$ and $CD$ are arranged along two parallel lines. The maximum number of images of object $O$ that can be seen by any observer is

$A$ man is $180\,cm$ tall and his eyes are $10\,cm$ below the top of his head. In order to see his entire height from toe to head,he uses a plane mirror kept at a distance of $1\,m$ from him. The minimum length of the plane mirror required is.....$cm$.

Two plane mirrors are inclined at $70^{\circ}$. $A$ ray incident on one mirror at an angle $\theta$ with the surface,after reflection,falls on the second mirror and is reflected from there parallel to the first mirror. The value of $\theta$ is ......$^{\circ}$.

$A$ man runs towards a plane mirror at a speed of $15 \, m/s$. The speed of the image relative to the mirror is ...... $m/s$.

To get three images of a single object, the angle between the two plane mirrors should be (in $^{\circ}$)

$A$ plane mirror is approaching you at a speed of $10\,cm/sec$. You can see your image in it. At what speed will your image approach you in $cm/sec$?