Question

A lens has focal length 50 cm.find its power

Answer 1

Answer:

2 D

Explanation:

We know that,

Power of lens P =1/f  (in m)

                           =100/f    (in cm)

Given,

Focal length of the lens=50 cm

=>      100/f=P    (in cm)

=>  100/50=P

=>   2=P

=>Since power of lens is measured in Dioptre (D)

=>Power of lens =2 D

of focal length 50 cm