Question

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Answer 1

Hey mate
here is your answer

The ability of a lens to converge or diverge a beam of light ray is expressed as the power of lens. The power of a lens is defined as the reciprocal of its focal length. It is represented by the letter P. The SI unit of the power of a lens is dioplre.

OR

Power of lens is the ability of the lens to converge the rays of light falling on it. Definition: The power of a lens is the reciprocal of its focal length in meters. It is represented by the letter P. The power P of a lens of focal length f is given by f = 1/P. The SI unit of power is dioptre .


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Answer 2

Hi

Here devil1407

The ability of lens to converge or diverge light rays depends on its focal length.

The power of a lens is defined as the reciprocal of its focal length.
              P= 1/f

The SI unit of power of lens is 'dioptre'.It is donated by the letter D.1 Dioptre is the power of lens whose focal length is 1 metre.
           1D=1m^-1

Power of a convex lens is positive.......concave lens is negative.....

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