Question

If the focal length of a convexlens is 20 cm, its power will be
(a) 2 diopters
(b)3 diopters
(c) Temperature
(d)frequency​

Answer 1

$\mathbb{\pink{ANSWER}}$

Power of lens is defined as the power of convergence or divergence of lens.

Its SI unit is dioptre (D)

GIVEN -

Focal length (f) - 20cm = 0.2m

Power = $\frac{1}{Focal\:Length}$

Note - To apply the formula,the focal length must be in meters.

Using this formula, we get

Power = $\frac{1}{0.2}$

Power = 5D

The power is positive since the focal length is positive

Answer-

5D

Answer 2

hii mate it's power will be 10 dioptre