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 is determined by the wavelength of the observed light and the diameter of the telescope's aperture. For a given wavelength, angular resolution improves as the diameter of the telescope's aperture increases. However, radio waves have much longer wavelengths than optical light, and therefore the same sized telescope has a much lower angular resolution for radio waves compared to optical light. Hence, the angular resolution of a 20-m-diameter radio telescope is worse than that of a 0.5-m-diameter optical telescope.

The MAIN Reason That the Angular Resolution of a 20-M-Diameter