Question

Define one dioptre of power of a lens

Answer 1

1 dioptre is SI unit of the power of a lenswhose focal length is 1 metre. ... Simply, when focal length ' f ' is expressed in metres, then, power is expressed indioptres.

Answer 2

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

OR

Power of a lens is said to be 1 dioptre when its focal length is 1 metre.

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