Question

108.
The focal length of a convex lenses is 20 cm. Its power is
(A) 20 dioptre
(B) 5 dioptre
(C) 1/5 Dioptre
(D) 1/20 dioptre​

Answer 1

Answer:

Power of lens is reciprocal of focal length

power = 1/20=

B) 5 dioptre