A small telescope has an objective of focal length \(140~\text{cm}\) and an eyepiece of focal length \(5.0~\text{cm}.\) The magnifying power of the telescope for viewing a distant object is:
1. \(28\)
2. \(17\)
3. \(32\)
4. \(34\)
Subtopic:  Telescope |
 75%
Level 2: 60%+
NEET - 2024
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An observer is using an astronomical refracting telescope to observe planets in normal adjustment. The focal lengths of the objective and eyepiece used in the telescope construction are \(20​​\text{m}\) and \(2​​\text{cm}\) respectively. Consider the following statements about the telescope:
(a) the distance between the objective and the eyepiece is \(20.02​​\text{m}.\)
(b) the magnification of the telescope is \(-1000\).
(c) the image of the planet is erect and diminished.
(d) the aperture of the eyepiece is smaller than that of the objective.
 
The correct statements are:
1. (a), (b), and (c) 2. (b), (c), and (d)
3. (c), (d), and (a) 4. (a), (b), and (d)
Subtopic:  Telescope |
 68%
Level 2: 60%+
NEET - 2022
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A lens of large focal length and large aperture is best suited as an objective of an astronomical telescope since:

1. a large aperture contributes to the quality and visibility of the images.
2. a large area of the objective ensures better light-gathering power.
3. a large aperture provides a better resolution.
4. all of the above.

Subtopic:  Telescope |
 80%
Level 1: 80%+
NEET - 2021
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An astronomical refracting telescope will have large angular magnification and high angular resolution when it has an objective lens of:

1. small focal length and large diameter.
2. large focal length and small diameter.
3. large focal length and large diameter.
4. small focal length and small diameter. 

Subtopic:  Telescope |
 62%
Level 2: 60%+
NEET - 2018
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An astronomical telescope has an objective and an eyepiece of focal lengths \(40​​\text{cm}\) and \(4​​\text{cm}\) respectively. To view an object \(200​​\text{cm}\) away from the objective, the lenses must be separated by a distance:
1. \(46.0​​\text{cm}\) 2. \(50.0​​\text{cm}\)
3. \(54.0​​\text{cm}\) 4. \(37.3​​\text{cm}\)
Subtopic:  Telescope |
 63%
Level 2: 60%+
NEET - 2016
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In an astronomical telescope in normal adjustment, a straight line of length \(L\) is drawn on the inside part of the objective lens. The eye-piece forms a real image of this line. The length of this image is \(l.\) The magnification of the telescope is:
1. \(\frac{L}{l}+1\)
2. \(\frac{L}{l}-1\)
3. \(\frac{L+1}{l-1}\)
4. \(\frac{L}{l}\)

Subtopic:  Telescope |
 61%
Level 2: 60%+
NEET - 2015
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The magnifying power of a telescope is \(9\). When it is adjusted for parallel rays the distance between the objective and eyepiece is \(20~\text{cm}\). The focal length of the lenses is:
1. \(10~\text{cm}, ~10~\text{cm}\)
2. \(15~\text{cm}, ~5~\text{cm}\)
3. \(18~\text{cm}, ~2~\text{cm}\)
4. \(11~\text{cm}, ~9~\text{cm}\)

Subtopic:  Telescope |
 85%
Level 1: 80%+
AIPMT - 2012
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