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Q28 (CDS-II/2025) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Geometrical optics Answer Verified

In a simple astronomical telescope, the objective and the eyepiece used respectively, are :

Result
Your answer: —  Â·  Correct: D
Explanation

A simple astronomical telescope, also known as a Keplerian telescope, consists of two converging (convex) lenses [1]. The objective lens, which faces the distant object, has a long focal length and a large aperture to gather sufficient light. It forms a real, inverted, and diminished image of the distant object at its focal plane. The eyepiece, which is the lens closer to the observer's eye, has a shorter focal length and acts as a simple magnifier [1]. It produces a final magnified virtual image that is inverted relative to the original object. While a Galilean telescope uses a divergent (concave) lens for the eyepiece to produce an erect image, the standard 'simple astronomical telescope' specifically utilizes two convergent lenses to achieve higher magnification and a wider field of view [1].

Sources

  1. [1] https://www.ncbi.nlm.nih.gov/books/NBK599512/
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