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प्रश्न
You are given three lenses of power 0.5 D, 4 D, and 10 D to design a telescope.
1) Which lenses should be used as objective and eyepiece? Justify your answer.
2) Why is the aperture of the objective preferred to be large?
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उत्तर
(1) The lens with the smallest power or largest focal length should be used as the objective i.e lens with power 0.5 D.
The lens with the largest power or smallest focal length should be used as the eye-piece i.e. lens with power 10 D.
(2) The aperture is preferred to be large so that the telescope can collect as much as light coming from the distant object as possible.
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संबंधित प्रश्न
Draw a schematic ray diagram of a reflecting telescope showing how rays coming from a distant object are received at the eyepiece.
Why should the objective of a telescope have large focal length and large aperture? Justify your answer.
Write two important advantages of reflecting telescope over a refracting telescope.
Describe briefly the two main limitations and explain how far these can be minimized in a reflecting telescope ?
"A telescope resolves whereas a microscope magnifies." Justify this statement ?
Define magnifying power of a telescope. Write its expression.
Draw a labelled ray diagram showing the formation of an image by a refracting telescope when the final image lies at infinity.
Draw a ray diagram of astronomical telescope for the final image formed at infinity.
Draw a ray diagram for the formation of image of an object by an astronomical telescope, in normal adjustment. Obtain the expression for its magnifying power.
Assertion: An astronomical telescope has an objective lens having large focal length.
Reason: Magnifying power of an astronomical telescope varies directly with focal length of the objective lens.
