Question

AB is an object and PQ is its real, inverted image. The lengths of AB and PQ are equal. This is possible when a lens is present between the object and its image.

1. What kind of lens is used here? Also, state the position of the lens and where it is to be placed.
2. Name a device where this lens action is used.

Answer 1

1. A convex lens is used. For a real, inverted image equal in size to the object, the object must be at 2F on one side of the lens and the image at 2F on the other side. Therefore, the lens is midway between the object and its image.
2. This action is used in a photocopier to form a real image of the same size.