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Find the focal lengths of a lens of power -2.0 D, What type of lens is this? |
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Answer» Given, Power = -2.0 The given lens is concave (power of concave lens is -ve) P = \(\frac{1}{f(in\,metre)}\) -2.0 = \(\frac{1}{f}\) ∴ f = \(\frac{1}{-2}m\) = -50 cm ∴ the focal length is = -50 cm. |
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