Question

An astronomical telescope has a large aperture to

• A. reduce spherical aberration
• B. have high resolution
• C. increase span of observation
• D. have low dispersion

Answer 1

Answer: (B)

have high resolution

The aperture of an astronomical telescope is defined as the diameter of the objective lens.
In telescopes since, the stars are very far away from away us and emit light internsities, we need a large aperture to increase the amount of light entering the telescope thereby increasing the resolution