Astronomy quiz question: maximizing x-rays received by x-ray telescopes

Astronomy 210 Quiz 3, spring semester 2017
Cuesta College, San Luis Obispo, CA

In order to maximize the amount of x-rays received, x-ray telescopes should be:
(A) placed in outer space.
(B) used without eyepieces.
(C) made with long primary focal lengths.
(D) used during nights with no winds.


Correct answer (highlight to unhide): (A)

X-rays cannot be detected at sea level (the bottom edge of the graph), due to absorption of these wavelengths by the atmosphere. Some x-rays may be detected at very high elevations in the upper atmosphere, and is best detected in space, above the atmosphere.

Section 30674
Exam code: quiz03n5By
(A) : 18 students
(B) : 0 students
(C) : 4 students
(D) : 1 student

Success level: 79% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.50

Section 30676
Exam code: quiz03s4adD
(A) : 27 students
(B) : 0 students
(C) : 10 students
(D) : 4 students

Success level: 67% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.55