Question : Define the power of lens. What is the meaning of "the power of lens is 1 dioptre" if the power of a lens -2.0D, then what type of lens is that? when an object is kept at infinity from this type of lens, what is the size of the image formed.

Question : Define the power of lens. What is the meaning of "the power

1.	Question : Define the power of lens. What is the meaning of "the power of lens is 1 dioptre" if the power of a lens -2.0D, then what type of lens is that? when an object is kept at infinity from this type of lens, what is the size of the image formed.
Answer» <P> SOLUTION :The ability of a lens to converge or diverge the ray of light after refraction is called power (p) of the lens. It is DEFINED as the reciprocal of the focal length i.e, `P= (1)/(f)`UNIT of power of a lens is diopter. A lens of focal length 100cm has a power of 1 dioptre i,e I dioptre = `1M^(-1)`If the power of a lens is 2 D then the type of lens is concave lens. The size of the image in this lens is highly diminished point sized.