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The focal length of a concave lens is 0·5 m. The power of the lens is

Options

  1. A+0·5 D
  2. B−0·5 D
  3. C+2·0 D
  4. D−2·0 D

Correct answer

D. −2·0 D

Step-by-step solution

The focal length of a concave lens is taken as negative. f = -0 5 m The power of a lens is given by P = 1 f P = 1 -0 5 = -2 0 D Answer: −2·0 D

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