What is the relation between the radius of curvature $(R)$ and the focal length $(f)$ of a spherical mirror?

Where does an object and its image coincide in a concave mirror?

An object is brought towards a concave mirror. How does the position and size of the image change?

$(a)$ Write one use of a concave mirror as well as a convex mirror.
$(b)$ Draw ray diagrams for the following cases when a ray of light:
$(i)$ passing through the centre of curvature of a concave mirror is incident on it.
$(ii)$ parallel to the principal axis is incident on a convex mirror.
$(iii)$ is incident at the pole of a convex mirror.
$(iv)$ passing through the focus of a concave mirror is incident on it.

$A$ plane mirror produces a magnification of

$A$ plane mirror as well as a convex mirror can produce a real image if the object is virtual. How?