NEET 2021 · PhysicsPrevious Year Question
A lens of large focal length and large aperture is best suited as an objective of an astronomical telescope since
Answer: (D) All of the above. Answer: (D) All of the above Solution: A large aperture (large objective diameter) collects more light, giving better light-gathering power and brighter, clearer images.
- A.A large aperture contributes to the quality and visibility of the images
- B.A large area of the objective ensures better light gathering power
- C.A large aperture provides a better resolution
- D.All of the above✓
Correct Answer
(D) All of the above
Solution & Explanation
Answer: (D) All of the above Solution: A large aperture (large objective diameter) collects more light, giving better light-gathering power and brighter, clearer images. A large aperture also reduces the diffraction limit (≈ 1.22λ/D), improving the resolving power of the telescope. Thus a large aperture improves image quality and visibility, light-gathering power, and resolution simultaneously. Hence all of the listed statements are correct.
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