Write the lens formula explaining the meaning of the symbols used.

Lens formula,

$\dfrac{1}{v} – \dfrac{1}{u} = \dfrac{1}{f}$

where, 'u' is the distance of the object from the optical centre of the lens, 'v' is the distance of the image from the optical centre while 'f' is the focal length, the distance between the optical centre and the focus of the lens.