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JEE Main202120 Jul 2021Morning ShiftPhysicsRay OpticsActual

An object viewed from a near point distance of 25 cm , using a microscopic lens with magnification 6 , gives an unresolved image. A resolved image is observed at infinite distance with a total magnification double the earlier using an eyepiece along with the given lens and a tube of length 0 . 6 m , if the focal length of the eyepiece is equal to ____ cm .

Correct answer

0

Step-by-step solution

For simple microscope, m = 1 + D f 0 6 = 1 + D f 0 5 = 25 f 0 f 0 = 5   cm For compound microscope, m = ℓ · D f 0 · f e 12 = 60 × 25 5 · f e f e = 25   cm

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