Question

What is power of the lens?

Answer 1

the reciprocal of focal lenght of the lens is known as power of lens

Answer 2

Answer:

→It is defined as the reciprocal of focal length in diameter.

→ The degree of convergence or divergence of light rays is expressed in terms of power.

$\\ \large{ \boxed{ \sf{ \blue{power \: (p) = 1/v - 1/u = 1/f \: }}}}$

→ SI unit of power = dioptre = D.

→ 1 D = 1 $\sf{m}^{-1}$.

→ 1 dioptre is the power of the lens whose focal length is one metre.

→ Power of convex lens is positive.

→ Power of concave lens is negative.

→ Power $\propto$ 1/(focal length or thickness).

→ Power of a lens combination ( P ) = $\sf{P}_{1}+{P}_{2}+{P}_{3}.......$