$A$ mirror is placed at a distance of $60 \ m$ from the base of a tower. The angle between the top of the tower and the top of its image is $90^o$. Find the height of the tower in $m$.

Two plane mirrors $M_1$ and $M_2$ have a length of $20 \, m$ each and are $10 \, cm$ apart. $A$ ray of light is incident on one end of mirror $M_2$ at an angle of $53^{\circ}$. The number of reflections the light undergoes before reaching the other end is

To get three images of a single object, one should have two plane mirrors at an angle of $...^\circ$.

$A$ ray of light travelling in the direction $\frac{1}{2}(\hat{i}+\sqrt{3} \hat{j})$ is incident on a plane mirror. After reflection,it travels along the direction $\frac{1}{2}(\hat{i}-\sqrt{3} \hat{j})$. The angle of incidence is: (in $^{\circ}$)

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

The light rays from an object have been reflected towards an observer from a standard flat mirror. The image observed by the observer is: