Question

What is the power in diopters of converging lens of focal length 0.5m, 2m, 0.5cm

Answer 1

$D=\frac 1F,$

$D_1=\frac{1}{0.5}=2~dpt,$

$D_2=\frac{1}{2}=0.5~dpt,$

$D_3=\frac{1}{0.05}=20~dpt.$