The main reason that the angular resolution of a 20-m diameter radio telescope is worse than that of a 0.5-m diameter optical telescope is that
A) angular resolution becomes worse as wavelength decreases.
B) angular resolution becomes worse as wavelength increases.
C) an optical mirror suffers from chromatic aberration.
D) angular resolution becomes worse as mirror size increases.

Question

Quizplus · Accepted Answer

The angular resolution of a telescope, which determines its ability to distinguish between two closely spaced objects, is directly proportional to the wavelength of the observed light and inversely proportional to the diameter of the telescope's aperture. Since radio waves have much longer wavelengths than visible light, a radio telescope has worse angular resolution than an optical telescope of the same size. Therefore, despite its larger size, a 20-m diameter radio telescope has worse angular resolution than a 0.5-m diameter optical telescope because radio wavelengths are much longer than optical wavelengths.

The Main Reason That the Angular Resolution of a 20-M