The focal length of a convex lens is 25 cm. Express its power with sign. - Noon Academy

The focal length of a convex lens is 25 cm. Express its power with sign.

Class 10 | ICSE | Physics | Refraction through a Lens | Selina

The focal length of a convex lens is 25 cm. Express its power with sign.

Solution:

According to the question,

Focal length is f = +25 cm = +0.25 m

We know that the expression of power of a lens is –

P = 1 / f

Substituting value of focal length, we get => P = 1 / +0.25

Therefore, P = +4.0 D

i

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