Question

A concave mirror of focal length 10cm is placed at a distance of 35cm from a wall. How far from the wall an object be placed so that its image formed by the mirror falls on the wall?

Answer 1

Here, f =-10cm; v =-35 cm (since the image is formed on the wall and distance between the wall and mirror is 35cm). Image is beyond 2f so object has to be in between F and C.

Let the distance of the object from the wall be x.

Therefore, the distance of the object from the wall = 21 cm.