(a) If the image formed by a mirror for all positions of the object placed in front of it is always diminished, erect and virtual, state the type of the mirror and also draw a ray diagram to justify your answer. Write one use such mirrors are put to and why?
(b) Define the radius of curvature of spherical mirrors. Find the nature and focal length of a spherical mirror whose radius of curvature is +24 cm.

Explanation

(a) This mirror is Convex mirror.

Such mirrors are used as rear view mirror in automobiles, as convex mirror gives erect, and wider range of view of objects coming behind the automobile.
(b) Radius of curvature of a mirror is the distance between 'P' point (pole) and 'C' point (centre of curvature) of a spherical mirror.
`f=(r)/(2) " So, " f=(24)/(2)`
`therefore f= +12` cm and this mirror is a convex mirror.