A diminished real image is obtained when the object is placed between centre of curvature and focus of a concave mirror.

Define the principal focus of a concave mirror.

What is centre of curvature of a spherical mirror?

A virtual, erect and enlarged image is formed by a concave mirror, if the object is placed between the principal focus and centre of curvature of the mirror.

Give the relation between focal length and radius of curvature of a spherical mirror.

How would you determine the focal length and radius of curvature of a concave mirror?

If an object is placed at the focus of a concave mirror, where is the image formed?