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In the figure shown, find the relative s...

In the figure shown, find the relative speed of a approach/ separation of the two final images formed after the light rays pass through the lens, at the moment when u = 30 cm . The speed of object = 4 cm/s . The two lens halves are placed symmetrically w.r.t. the moving object

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The correct Answer is:
`((8)/(5)) cm//s`
`(I)/(0) = m = (v)/(u) = (f)/(f+u) , "rel" (2dI)/(dt) = [-(f_(0))/((f+u)^(2)) (du)/(dt)] xx 2`
=`(-40 xx(1)/(2))/(10 xx 10) xx 4 xx 2 = (-8)/(5)"cm"//"sec"`
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ALLEN -GEOMETRICAL OPTICS-EXERCISE-04[B]
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