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प्रश्न
With regard to an astronomical telescope of refracting type~ state how you will increase its:
1) magnifying power
2) resolving power
उत्तर
1) Magnifying power can be increased by increasing focal length of objective or by decreasing focal length of the eyepiece.
2) Resolving power can be increased by increasing diameter of the objective lens
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संबंधित प्रश्न
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.
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?
Draw a labelled ray diagram of an image formed by a refracting telescope with the final image formed at infinity. Derive an expression for its magnifying power with the final image at infinity
State the condition under which a large magnification can be achieved in an astronomical telescope.
Write two important limitations of a refracting telescope over a reflecting-type telescope.
A giant refracting telescope at an observatory has an objective lens of focal length 15 m. If an eyepiece lens of focal length 1.0 cm is used, find the angular magnification of the telescope. If this telescope is used to view the moon, what is the diameter of the image of the moon formed by the objective lens? The diameter of the moon is 3.42 × 106 m and the radius of the lunar orbit is 3.8 × 108 m.
An astronomical telescope uses two lenses of powers 10 dioptres and 1 dioptre. If the final image of a distant object is formed at infinity, calculate the length of the telescope
Draw a ray diagram of Astronomical Telescope for the final image formed at infinity
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.
