Define power of a lens and write the $SI$ unit of power.
(N/A) The power of a lens is defined as the reciprocal of its focal length in meters. It is a measure of the degree of convergence or divergence of light rays falling on the lens.
Mathematically,$P = \frac{1}{f(m)}$,where $P$ is the power of the lens and $f$ is the focal length in meters.
The $SI$ unit of power of a lens is the Dioptre $(D)$,where $1 \ D = 1 \ m^{-1}$.
Mathematically,$P = \frac{1}{f(m)}$,where $P$ is the power of the lens and $f$ is the focal length in meters.
The $SI$ unit of power of a lens is the Dioptre $(D)$,where $1 \ D = 1 \ m^{-1}$.
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