Question

A lens has power 4d find the focal length that lens

Answer 1

$answer=>$

The focal length of the lens is 25 cm.

Explanation------------>>>>>>>>>>

Given that,

Power of the lens P = 4 D

power =100/focal length(in cm)

4D=100/ focal length (in cm)

focal leghth (in cm)=100÷4=25 cm

Answer 2

Answer:

p=1/f

4=1/f

4f=1

f=1/4=0.25