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Sign convention lens formula and magnification

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Sign convention lens formula and magnification

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v= image distance
u=object distance
f=focus
M=magnification
h=height of image
h'=height of object
Formula for magnification:- M = h'/h
Power of a lens:- P=1/f

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Principal axis and imaginary straight line passing through the centre of curvature of a lens is called its principal axis

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Principal focus several Ray parallel to principal Axis after refracting from the lens converge at a point is called principal axis of a convex lens

Several ray parallel to the principal Axis after refracting from the lens appeared to diverge from a point known as principal focus of a concave lens

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Aperture effective diameter of the circular outline of a spherical lens is called aperture

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Optical centre the central point of a lens is called optical centre

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Centre of curvature a lens has two spherical surfaces each surface form a part of a sphere the centre of the sphere are called centre of curvature

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Concave lens is a diverging lense and thick at edge

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Concave lenses are converging lenses and thick at  middle

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A transparent material bound by two surfaces of which both surfaces a spherical form a lens