The laws of reflection hold good for

Define the principal focus of a concave mirror.

What do you understand by the terms
$(i)$ Real image?
$(ii)$ Virtual image?

Where should an object be placed in front of a concave mirror to obtain a real and diminished image?

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.

When an object is placed between the principal focus $(F)$ and the pole $(P)$ of a concave mirror,what kind of image is formed?