If two mirrors are placed side-by-side on a wall and one is placed on the ceiling,how many images will be formed?

$A$ prism having an apex angle $4^o$ and refractive index $1.5$ is located in front of a vertical plane mirror as shown in the figure. Through what total angle is the ray deviated after reflection from the mirror (in $^o$)?

An object is placed at a distance of $30\,cm$ from a convex lens of focal length $20\,cm$. On the other side of the lens,a convex mirror is placed such that the image formed by the combination coincides with the object itself. If the distance between the lens and the mirror is $20\,cm$,find the focal length of the convex mirror in $cm$.

In an experiment to determine the focal length of a concave mirror,the object distance is $x$ and the image distance is $y$,both measured from the pole of the mirror. Which of the following graphs correctly represents the relationship between $y$ and $x$?

The flat bottom of a cylindrical tank is silvered and water $(\mu = 4/3)$ is filled in the tank up to a height $h$. $A$ small bird is hovering at a height $3h$ from the bottom of the tank. When a small hole is opened near the bottom of the tank,the water level falls at the rate of $1\, cm/s$. The bird will perceive that its image's velocity is:

$A$ wire is bent in the shape of a right-angled triangle and is placed in front of a concave mirror of focal length $f$,as shown in the figure. Which of the figures shown in the four options qualitatively represent$(s)$ the shape of the image of the bent wire? (These figures are not to scale.)