Question

Define power of lens. a lens x has focal length 20 cm and lensy has focal length 40 cm. which lens would you select to obtain a more convergent beam of light

Answer 1

Power =the ability of the lens to converge or diverge any beam of light coming from a source of light. convex lens constitue +ve power and and concave lens constitute -ve power. we would prefer convex lens as its converges the light.

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