Astronomy quiz question: Large Binocular Telescope interferometry

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

Consider the Large Binocular Telescope located at Mt. Graham, AZ. The mirrors of these two optical telescopes are separated from each other to improve:
(A) light-gathering power.
(B) resolving power.
(C) magnifying power.
(D) (Two of the above choices.)
(E) (All of the above choices.)
(F) (None of the above choices.)

(Image credit: Large Binocular Telescope/NASA, http://www.nasa.gov/topics/universe/features/lbti20101206-i.html.)

Correct answer: (B)

Increasing the distance between connected telescopes creates a much larger effective diameter to increase resolving power.

Section 30674
Exam code: quiz03n0T7
(A) : 5 students
(B) : 23 students
(C) : 2 students
(D) : 3 students
(E) : 0 students
(F) : 0 students

Success level: 73% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.89

Section 30676
Exam code: quiz03SL3w
(A) : 12 students
(B) : 18 students
(C) : 2 students
(D) : 4 students
(E) : 2 students
(F) : 2 students

Success level: 50% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.60