The formula of magnification power and resolving power of a telescope is, M.P.=\frac{{f}_{0}}{{f}_{e}}&R.P.=\frac{a}{1.22\lambda }. A large aperture(a) of the objective lens provides better resolution so, the good quality of the image is formed, and also it gathers more light. The larger the objective, the lighter the telescope collects and increases the brightness of the image and large focal length enhances the magnifying power of the telescope.
A lens of large focal length and large aperture is best suited as an objective of an astronomical telescope since:
NEET UG 2021 — Physics Optics
2021mcqeasy
A lens of large focal length and large aperture is best suited as an objective of an astronomical telescope since:
Official previous-year question
Held on 30 Apr 2021 · Verified 9 Jul 2026.
Options
- 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.
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