An object $O$ is placed between two parallel plane mirrors $M_1$ and $M_2$. The distance of the object from $M_1$ is $6\,cm$ and from $M_2$ is $15\,cm$. The position of the $4^{th}$ image formed by mirror $M_1$ is:

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

$A$ man of height $170 \, cm$ wants to see his complete image in a plane mirror (while standing). His eyes are at a height of $160 \, cm$ from the ground. Which of the following statements are correct?
$(a)$ Minimum length of mirror is $80 \, cm$
$(b)$ Minimum length of mirror is $85 \, cm$
$(c)$ Bottom of the mirror should be at a height $80 \, cm$
$(d)$ Bottom of the mirror should be at a height $85 \, cm$

An object is fixed at the bottom of a vessel and water is filled in the vessel up to a height of $10 \,cm$. $A$ plane mirror is placed at a height of $7 \,cm$ from the surface of water in such a way that its reflecting surface faces the water. The distance of the image from the mirror is (Refractive index of water,$n=1.33$). (in $\,cm$)

Ray $1$ is parallel to the horizontal mirror. Ray $2$ is parallel to the other mirror. Then the angle between the two mirrors is .......... $^o$.

Two plane mirrors are placed parallel to each other at a distance $L$ apart. $A$ point object $O$ is placed between them,at a distance $L/3$ from one mirror. Both mirrors form multiple images. The distance between any two images cannot be: