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Light Reflection and Refraction
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17/08/2021 3:53 pm
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Calculate the focal length of a convex lens which produces a virtual image at a distance of 50 cm of an object placed 20 cm in front of it.
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17/08/2021 3:56 pm
v = -50 cm (virtual image)
u = -20 cm
\(\frac{1}{v}\) - \(\frac{1}{u}\) = \(\frac{1}{f}\)
\(\frac{1}{-50}\) - \(\frac{1}{-20}\) = \(\frac{1}{f}\)
\(\frac{-2 + 5}{100}\) = \(\frac{1}{f}\)
\(\frac{3}{100}\) = \(\frac{1}{f}\)
f = 33.3 cm