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प्रश्न
Give two reasons to explain why a reflecting telescope is preferred over a refracting telescope.
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उत्तर
The reflecting telescopes are preferred over the refracting type because of the following reasons:
- There is no chromatic aberration in the case of reflecting telescopes, as the objective is a mirror.
- Spherical aberration is reduced in the case of reflecting telescopes by using a mirror objective in the form of a paraboloid.
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संबंधित प्रश्न
An object is kept on the principal axis of a concave mirror of focal length 10 cm. at a distance of 15
cm from its pole. The image formed by the mirror is:
(a) Virtual and magnified
(b) Virtual and diminished
(c) Real and magnified
(d) Real and diminished
Define the term 'limit of resolution'?
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For paraxial rays, show that the focal length of a spherical mirror is one-half of its radius of curvature.
A point object is placed at a distance of 20 cm from a thin plano-convex lens of focal length 15 cm, if the plane surface is silvered. The image will form at:
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When a clock is viewed in a mirror, the needles exhibit a time which appears to be 8:20. Then the actual time will be:
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