SPHERICAL LENS IMPORTANT FORMULAS - Magnification - Power of lens

First, we should know about the types of lenses there are two types of lenses one is a concave lens another is a convex lens.



The lens is a transparent material bound by two spherical surfaces. The centres of these spheres are called centres of curvature. 

An imaginary straight line passing through centres of curvature is called the principal axis. The central point of a lens is called the optical centre. 
  
Lens formulas

            If we want to measure the distance between an object and an image using a lens we should know about some basic concepts like object distance (u) and image distance (v). One of the important measurements is the focal length (f) because the focal length is used to know about the focus of the lens.


1/v +1/u  = - 1/f

Magnification

           It is the ratio of the image's height to the object's height. 


          Height of the image (v)
m =                                   
          Height of the object (u)

Power of lens

        The power of the lens is defined as the reciprocal of its focal length. 


 P  =  1/f

These are the important formulas to calculate the lens measurements.

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