When a concave mirror produces a virtual and magnified image of an object,what is the object distance?

An object is placed at a distance of $25 \, cm$ away from a converging mirror of focal length $20 \, cm$. Discuss the effect on the nature and position of the image if the position of the object changes from $25 \, cm$ to $15 \, cm$. Justify your answer without using the mirror formula.

$(a)$ What should be the position of the object,when a concave mirror is to be used $(i)$ as a shaving mirror,and $(ii)$ in torches producing a parallel beam of light? $(b)$ $A$ man standing in front of a mirror finds his image having a very small head and legs of normal size. What type of mirror is used in designing such a mirror?

The rays travelling parallel to the principal axis after reflecting from the concave mirror pass or appear to pass through the focus.

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

$A$ ray of light is incident on a concave mirror after passing through the centre of curvature. What is the angle of incidence (in $°$)?