The Focal Length of a Lens of Power +4 D will be
The Focal length of a lens of power +4D will be +0.25 meter.
Definition of Focus lens:-
Focal length is the distance between the center of a concave lens or a concave mirror and the focal point of the lens or mirror. The focal length is always positive.
Power of lens = +4D
Focal length =?
Formula of focal length—
Focal length = 1 / power of lens.
Focal length = ¼
= +0.25 meter.
Hence, the focal length of a lens of power +4D will be +0.25 meter.