Simple Microscope or Magnifying Lens

Magnifying Lens

It consists of a converging lens of small focal length. By keeping the object close to the lens, a virtual, erect and magnified image is obtained as shown

O = optic centre

FO = focal length

AB = object

A¹B¹ = image

Magnifying power is the ratio of the angle subtended by the image and the object on the eye, when both are at the least distance of distinct vision from the eye

For small angles

and image distance v = -D (distance of distant vision)

Note:

As f decreases, m increases.