$A$ convex mirror of radius of curvature $30 \,cm$ forms an image that is half the size of the object. The object distance is: (in $\,cm$)

$A$ small rod of length $2 \, mm$ lies along the principal axis at a distance of $30 \, cm$ from a concave mirror of focal length $20 \, cm$. The axial length of the image of the rod is.....$mm$.

An object $5 \ cm$ tall is placed $1 \ m$ from a concave spherical mirror which has a radius of curvature of $20 \ cm$. The size of the image is $...... \ cm$.

$A$ square object of area $100\,cm^2$ is placed perpendicular to the principal axis of a concave mirror. If the lateral magnification of the mirror,for the above object position,is $0.4$,then the area of the image will be......$cm^2$.

What is the maximum distance at which an image can be formed by a convex mirror of focal length $10 \ cm$?

In the case of a spherical mirror,if the object distance $(u)$ and image distance $(v)$ are measured from the pole,then the graph plotted between $(1/u)$ and $(1/v)$ will be: