A concave mirror has a focal length of 25 cm. A person wants to see his face in this mirror, at what distance should the person stand ?

If focal length is 20 cm then what is the radius of curvature of the mirror?

If focal length is 20 cm then what is radius of curvature of mirror ?

We wish to obtain an erect image of an object using a concave mirror of focal length of 15 cm. What should be 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 ?

An object 4 cm in size, is placed at 25 cm in front of a concave mirror of focal length 15 cm. At what distance from the mirror would a screen be placed in order to obtain a sharp image ? Find the nature and size of the image ?