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What is the focal length of a convex lens in water if its focal length in air is 20 cm? (Given: Refractive index of air-water = 1.33, refractive index for air-glass = 1.5.)

Options

  1. A24.0 cm
  2. B22.0 cm
  3. C78.2 cm
  4. D19.4 cm

Correct answer

C. 78.2 cm

Step-by-step solution

Correct Option is : (C) 78.2 cm

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