Two plane mirrors are at $45^{\circ}$ to each other. If an object is placed between them,then the number of images will be

$A$ long horizontal mirror is next to a vertical screen (see figure). Parallel light rays are falling on the mirror at an angle $\alpha$ from the vertical. If a vertical object of height $h$ is kept on the mirror at a distance $d$ from the screen,where $d > h \tan \alpha$,the length of the shadow of the object on the screen would be

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

$A$ point source is placed at coordinates $(0,1)$ in the $xy$-plane. $A$ ray of light from the source is reflected on a plane mirror placed along the $X$-axis and perpendicular to the $xy$-plane. The reflected ray passes through the point $(3,3)$. What is the path length of the ray from $(0,1)$ to $(3,3)$?

Which one of the following statements is true?

When an object is placed between two parallel mirrors,the number of images formed is: