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AP EAMCET20227 Jul 2022Evening ShiftPhysicsRay OpticsActual

An optician prescribes a corrective lens of power +2 D , then the focal length of the required convex lens is

Options

  1. A10 ~cm
  2. B50 ~cm
  3. C10 ~m
  4. D50 ~m

Correct answer

B. 50 ~cm

Step-by-step solution

Power of a lens in diopters, P= 100 f f= Focal length of lens in cm . here, P=+20 D so, 2= 100 f( ~cm ) f( ~cm )= 100 2 =50 Focal length of lens =50 ~cm .

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