Question

The focal lengths of four convex lenses are 20cm, 15cm, 5 cm and
10cm respectively. Which lens has the greatest and smallest power.

Answer 1

Power is inversely proportional to focal distance thus those lens having small focal length will have the highest power..

Power arranged from high to low

5cm, 10cm, 15cm, 20cm

Answer 2

Answer:

si unit of power is dioptre or D

D=1/f

hence more the focal length lesser the power.

hence the one with greatest power is the lens with focal length 5

and the least is the one with focal length 20

pls mark as brainliest answer