What is power of a lens Class 10?

Power of a lens is the ability to converge or diverge the ray of light falling on it. Power of a lens is defined as reciprocal of focal length of the lens.

What is unit of power of lens?

A dioptre (British spelling) or diopter (American spelling) is a unit of measurement of the optical power of a lens or curved mirror, which is equal to the reciprocal of the focal length measured in metres. (1 dioptre = 1 m−1.) It is thus a unit of reciprocal length.

How do you find the power of a lens example?

Power of a Lens Formula For example, if the focal length of a lens is 20 cm, converting this to meters, we get 0.2 m To find the power of this lens, take the reciprocal of 0.2, and we get 5. Therefore, the power of this particular lens if 5D.

What is the formula of power of convex lens?

Convex lens power is defined as the ability of the lens to converge the rays of light which fall on it as shown in the below figure. It can mathematically be defined as P = 1f, where f is the focal length. S.I. unit of power is the Diopter.

WHAT IS lens power?

The power of a lens is defined as the reciprocal of the focal length. Lens power is measured in dioptres (D). Diverging (concave ) lenses have negative focal lengths, so they also have negative power values.

Which is the correct formula of power?

P = E/t: This formula is also called the mechanical power equation. Here E stands for energy in joule and t stands for time in seconds. This formula states that the consumption of energy per unit of time is called power.

What is power lens?

The power of a lens is defined as the reciprocal of the focal length. Lens power is measured in dioptres (D). p o w e r o f a l e n s ( D ) = 1 f o c a l l e n g t h ( m ) P = 1 f. Converging (convex ) lenses have positive focal lengths, so they also have positive power values.

What is power of concave lens?

The power of the concave lens is negative. Concave lens surfaces have a virtual radius of curvature, and thus a negative curvature. Optical power is denoted by the same convention signs that are used for focal length.

WHAT IS lens formula and its magnification?

The lens maker’s equation is 1f=1v−1u. The magnification produced by a lens is defined as the ratio of the height of the image to the height of the object. m=hiho. The magnification produced by a lens is defined as the ratio of the image distance to the object distance.