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A telescope using an eye piece of focal ...

A telescope using an eye piece of focal length 2 cm has a magnification 20 in normal adjustment. If the telescope is now used to view an object placed at a distance of 2 m from the objective, the new length of the telescope is (assume final image is at infinity).

A

56 cm

B

59 cm

C

52 cm

D

50 cm

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