Linear Magnification of Spherical Mirror

Linear magnification is ratio of the size of the image to the size of the object.

We know,

Concave Mirror

For Real Image

using sign convention

A^lB^l = -h₂ ; AB = +h₁

PB^l = -V, PB = - u

For Virtual Image

A^lB^l = +h₂ ; AB = h₁

PB^l = +V ; PB = -u

Convex Mirror

A^lB^l = +h_{2 ;} AB = +h₁

PB^l = +v ; PB = -u

Note:

If m>1, image is enlarged.

If m <1, image is diminished.

If m is +ve , image is erect and virtual.

If m is -ve, image is inverted and real.

Other formulae for magnification

or