Question

Define power of a lens. A lens X has a focal length 20 cm and lens Y has focal length 40 cm.

which lens would you select to obtain a more convergent beam of light?
(Answer in short 30-40 words)​

Answer 1

Answer:

Power of a lens is the measure of its ability to converge or diverge (as per it's nature) light rays.

also Power of lens P is given by

P=1/f ( where f is the focal length in meters)

also I would select lens X with focal length 20cm.

to obtain more convergence.

the calculation is simple as it's an inverse relation therefore lesser the focal length higher the Power.