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

Short Solution (Best for NEET):

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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