Question

What is a power of a lens in ray optics and optical instruments?writes it's S.I unit.

Answer 1

power of lens is the reciprocal of focal length.

1/f is formula of focal length.

S.I unit of power is diopter...

Answer 2

Power P of a lens is defined to be the inverse of its focal length, P=1f P = 1 f . A lens that causes the light rays to bend away from its axis is called a diverging lens. Ray tracing is the technique of graphically determining the paths that light rays take.