Astronomy quiz question: charge-coupled devices

Astronomy 210 Quiz 3, spring semester 2012
Cuesta College, San Luis Obispo, CA

Charge-coupled devices (CCDs) are more useful than photographic plates for optical telescopes because CCDs:
(A) can measure brightnesses more precisely.
(B) are cheap and disposable.
(C) do not produce diffraction fringes.
(D) are not susceptible to chromatic aberration.

Correct answer: (A)

Response (C) is a limitation on the resolving power of a telescope, which ultimately depends on the diameter of its primary mirror (or lens), and not on the media used to record images. Response (D) is a property of optical telescope lenses (but not of optical telescope mirrors).

Section 30674
Exam code: quiz03n0T7
(A) : 17 students
(B) : 1 student
(C) : 11 students
(D) : 4 students

Success level: 56% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.26