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If the focal length of a convex lens is 50 cm , which one of the following is its power?

Options

  1. A+2 dioptre
  2. B+0.02 dioptre
  3. C-0.5 dioptre
  4. D+0.5 dioptre

Correct answer

A. +2 dioptre

Step-by-step solution

Power of a lens is always reciprocal to the focal length. So, a convex lens with 50 cm focal length has a power of (1/0.5) Dioptre (D) or 2D. Since, a convex lens is a converging lens, the power of the convex lens is +2 D .

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