Question

The power of lens is +4D.what kind of lens and what is its focal length???

Answer 1

Answer:

Convex lens

P =

$\frac{1}{f}$

$4 = \frac{1}{f}$

$f = \frac{1}{4}$

As we know, Focal lengths are in centimetres meters

f = 1/4

f = 0.25 metres

focal length = 0.25 * 100 = 25 cm

Answer 2

Explanation:

Convex lens

P=1/f

4=1/f

f=1/4