Telescope Objective Aperture – Rankers Physics

Reflection by Spherical Mirrors: Practice Problem & Solution

Assertion (A): In telescopes objective lens is taken of large diameter or aperture. Reason (R): Larger aperture remove spherical aberration.  
Both (A) & (R) are true and the (R) is the correct explanation of the (A)
Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
(A) is true but (R) is false
Both (A) and (R) are false

Solution Explained:

To solve this problem, we apply the core principles of Reflection by Spherical Mirrors. Understanding the underlying formula is key to arriving at the correct answer below:

A large diameter objective lens in telescopes increases the light-gathering power and improves resolving power, allowing observation of fainter and finer details. Hence, Assertion (A) is true. However, spherical aberration generally *increases* with larger apertures, as rays further from the principal axis are not focused at the same point. Thus, Reason (R) is false.

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