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

The correct option is B

have high resolution

The resolving power of an astronomical telescope is,$\frac{D}{1.22\lambda }$ Where D is the diameter of objective lens. In order to improve the resolution of an astronomical telescope: one has to increase the diameter, i.e., linear aperture of the astronomical telescope.