Question

The resolving power of refracting telescope increases with the size of its objective lens. What other advantage is gained with a larger lens?

a) Larger lenses provide a wider field of view.
b) Larger lenses increase the brightness of observed objects.
c) Larger lenses reduce chromatic aberration.
d) Larger lenses decrease the weight of the telescope.

Answer 1

A larger objective lens in a refracting telescope not only improves resolution but also increases the brightness of observed objects due to its greater light-collecting surface area.

Step-by-step explanation:

The resolving power of a refracting telescope indeed increases with the size of its objective lens. Along with better resolution, another significant advantage of a larger lens is that it increases the brightness of observed objects. This is because larger lenses have a greater surface area to collect light, which allows for more light from the observed object to enter the telescope, thus making the object appear brighter. This can be particularly beneficial when viewing dim stars or distant galaxies. The increased brightness does not necessarily imply a wider field of view, reduce chromatic aberration, or decrease the weight of the telescope; therefore, the correct answer to the student's question is b) Larger lenses increase the brightness of observed objects.