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An astronomical telescope has objective and eyepiece of focal lengths 40 cm and 4 cm respectively. To view an object 200 cm away from the objective, at what distance the lenses must be separated (in cm )?

Correct answer

54

Step-by-step solution

1 V - 1 - 200 = 1 40 1 V = 5 5 1 40 - 1 200 = 5 200 - 1 200 1 V = 4 200 = 1 50 V = 50 ∴ d = 50 + 4 = 54 c m

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