Question

power of lend is -40cm.Then what is the focal length????☺️☺️​

Answer 1

Answer:

power of lens = 1/focal length

-40 = 1/f

focal length = 1/-40

F = -40 cm

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Answer 2

Answer:

The power of the lens, P=1/f

Focal length of concave lens, f= ?

-40= 1/f

Then the focal length, P= 0.025 m

The diopter is the unit of measure for the refractive power of a lens. The power of a lens is defined as the reciprocal of its focal length in metres, or P=f1, where P is the power in dioptres and f is the focal length in metres.