A point object is placed at 15cm in front of a convex lens of focal length 10cm. Where shall we place a convex mirror of focal length 13cm so that real image and object coincide?
4cm from lens
2cm from lens
3cm from lens
6cm from lens
The correct option is A4cm from lens Using Lens formula 1v−1u=1f;
v=30cm. In order the ray to retrace the path, the ray must be incident normal on the mirror. Hence, distance of mirror from I′ should be equal to R=2f=26cm Distance of mirror from lens should be 30−26=4cm from lens.