Explain magnification by a lens with formula.

1. The magnification produced by lens is the ratio of height of the image
(h2) and the height of object (h1).
Magnification = Height of the image/Height of the object
M = h2/h1

2. Magnification produced by a lens is also related to the object distance
(u) and image distance (v).
Magnification = Distance of the image/Distance of the object
M = v/u