A body is located on a wall. Its image of equal size is to be obtained on a parallel wall with the help of a convex leng. The lens is placed at a distance d ahead of second wall, then the required focal length will be:

A bulb is located on a wll.Its image of equal size is to be obtained on a parallel wall with the help of a convex lens .The lens is placed at a distance d ahead of second wall.Then the required focal length will be

An object is there on a wall. Now by help of convex lens, an image of object is obtained of same size as of object on the opposite parallel wall. If the lens is at distance d from second wall, then what should be the focal length of lens ?

An object is placed at a distance f in front of a concave lens of focal length f. Locate its image.

An object is placed at a distance f in front of a concave lens of focal length f. Locate its image.

If in a convex lens object and its image distances are each equal to d, the focal length of the lens is

The image of a small electric bulb fixed on the wall of a room is to be obtained on the opposite wall 3m away by means of a large convex lens. What is the maximum posible focal length of the lens required for the purpose ?

In order to obtain a real image twice the size of the with a convex lens of focal length 15 cm, the object distance should be:

The image of a small electric bulb fixed on the wall of a room is to be obtained on the opposite wall 3m away by means of a large convex lens. What is the maximum possible focal length of the lens required for the purpose?

The image of a small electric bulb fixed on the wall of a room is to be obtained on the opposite wall 3m away by means of a large convex lens. What is the maximum possible focal length of the lens required for the purpose?