We wish to obtain an erect image of an object, using a concave mirror of focal length 15 cm. What should be the range of distance of the object from the mirror? What is the nature of the image? Is the image larger or smaller than the object? Draw a ray diagram to show the image formation in this case.

Explanation

A concave mirror gives an erect, virtual and enlarged image if the object is placed between the pole (P) and principal focus (F).
The given focal length is 15 cm. So, to obtain an erect the object must be placed anywhere in between P and F, that is, between 0 cm and 15 cm. Since all the distances are measured from pole so at pole distance is zero. The image formed will be virtual and magnified.
So, range of distance of object is 0-15 cm.