Question

the focal length of a convex lens is 40 cm calculate the power of lens​

Answer 1

Answer:

1/40 is the power of lens

hope it will be right

Answer 2

Answer:

+2.5D

Explanation:

given, focal length 40cm

here focal length is in centimeters so to calculate power of this lens. we should first the focal into meters because our formula uses the focal length in meters

now, 40cm = 40/100m

so,focal length , f =0.4m

power of lens = 1/f (in metres)

p=1/0.4

p= +2.5 dioptres (or+2.5D)