A point object is placed from a convex lens of focal length

PHYSICS · Single correct · CBSE · Physics · Ray Optics and Optical Instruments · Ray Optics and Optical Instruments

Problem

A point object is placed

12\,\text{cm}

from a convex lens of focal length

10\,\text{cm}

. On the other side of the lens, a convex mirror is placed

10\,\text{cm}

from the lens such that the image formed by the combination coincides with the object itself. The focal length of the convex mirror is (1)

20\,\text{cm}

(2)

25\,\text{cm}

(3)

15\,\text{cm}

(4)

30\,\text{cm}