An experiment with a convex lens gives the graph shown between 1/v and 1/u. What is the power of the lens used? Image
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An experiment with a convex lens gives the graph shown between 1/v and 1/u. What is the power of the lens used? Image

G1 Physics · Accepted Answer

For a convex lens, 1/f = 1/u + 1/v (using magnitudes). A straight-line plot of 1/v versus 1/u has intercept 1/f. Reading the intercept from the source graph gives f = 0.05 m, hence power P = 1/f = 20 D. Correct answer: D.