Question

The power of convex lens is 0.5 D . Hence, its focal length is ----------​

Answer 1

Given:

Power of lens = 0.5D

To Find:

Focal length of the convex lens.

Solution:

$\sf{P=}{\dfrac{1}{f}}$

$\sf{0.5=}{\dfrac{1}{f}}$

$\sf{f=}{\dfrac{1}{0.5}}$

$\sf{f=2m}$

$\sf{or, 200cm}$

Answer 2

Answer:

We know that, The power of convex lens is positive. The power of the lens is reciprocal of the focal length of the lens. Hence, The focal length of the lens is 20 cm.