Question

Define the power of a lens principle axis. Centre after curvature optic centre principle focus?

Answer 1

3 Converging and diverging lenses. 4Principal axis The straight line that goes through the centre of the lens at right angles to the lens surface. 5 Focal point Rays parallel to theprincipal axis, after being refracted by the lens, will all pass through a point on the principal axis called the focal point.


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Answer 2

The principal focus of a lens is a point on its principal axis wherein the rays of light parallel to it and after passing through it converge (for a convex lens) or appear to diverge (for a concavelens). The principal focus of a lens is denoted by the letter F.