Magnification-Formula

Description:

Whenever we observe an image of an object after refraction by a lens, there can be a change in the size of object i.e. image formed can have a larger size or smaller size than the actual size of the object. This phenomenon of change in the image size is known as magnification.

Magnification is given by −

Magnification = Size of image/Size of object

i.e.

m = -h_i/h₀

From figure −

In similar ΔABO and ΔA′B′O

A′B/A′B′ = B′O/OB

Putting values −

-h_i/h₀ = +v/-u

∴ m = - v/u

Where,

m = Magnification.

v = Image distance.

u = Object distance.

Negative sign indicates that the image is inverted.