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प्रश्न
Draw a labeled ray diagram of a reflecting telescope. Mention its two advantages over the refracting telescope.
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उत्तर
Reflecting Telescope,
Its two advantages over Refracting telescope:
1. It reduces the spherical aberration and forms a clear focused image.
2. It doesn’t require a lens of very large aperture as refracting type requires that cannot be manufactured easily.
संबंधित प्रश्न
A small telescope has an objective lens of focal length 144 cm and an eyepiece of focal length 6.0 cm. What is the magnifying power of the telescope? What is the separation between the objective and the eyepiece?
- A giant refracting telescope at an observatory has an objective lens of focal length 15 m. If an eyepiece of focal length 1.0 cm is used, what is 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 3.48 × 106 m, and the radius of lunar orbit is 3.8 × 108 m.
Write two important limitations of a refracting telescope over a reflecting-type telescope.
Draw a labelled ray diagram of an astronomical telescope in the near point adjustment position. A giant refracting telescope at an observatory has an objective lens of focal length 15 m and an eyepiece of focal length 1.0 cm. If this telescope is used to view the Moon, find the diameter of the image of the Moon formed by the objective lens. The diameter of the Moon is `3.48 xx 10^6`m, and the radius of the lunar orbit is `3.48 xx 10^8`m.
Draw a ray diagram of astronomical telescope for the final image formed at infinity.
The magnifying power of an astronomical telescope in normal adjustment is 2.9 and the objective and the eyepiece are separated by a distance of 150 cm. Find the focal lengths of the two lenses.
An optical instrument that uses objective and eyepiece lenses to magnify distant terrestrial or celestial objects is called a:
In an astronomical (refracting) telescope, the objective lens has:
For a telescope, the object's visual angle is measured from its own position, which is effectively:
Modern telescopes often use a concave mirror rather than a lens for the objective primarily because:
