A conversing beam of rays is incident on a diverging lens. Having passed though the lens the rays intersect at a point 15 ~cm from the lens on the opposite side. If the lens is removed the point where the rays meets will move 5 ~cm closer t

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A conversing beam of rays is incident on a diverging lens. Having passed though the lens the rays intersect at a point 15 ~cm from the lens on the opposite side. If the lens is removed the point where the rays meets will move 5 ~cm closer to the lens. The focal length of the lens is

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Correct answer: C. -30 ~cm

Given u=10 ~cm , y=15 ~cm aligned & 1 f = 1 y - 1 u & 1 f = 1 15 - 1 10 & 1 f = 10-15 150 & 1 f = -5 150 & f=-30 ~cm aligned

A conversing beam of rays is incident on a diverging lens. Having passed though the lens the rays intersect at a point 15 ~cm from the lens on the opposite side. If the lens is removed the point where the rays meets will move 5 ~cm closer to the lens. The focal length of the lens is

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