Astronomy quiz question: phase during total lunar eclipse

Astronomy 210 Quiz 2, fall semester 2011
Cuesta College, San Luis Obispo, CA

An observer in San Luis Obispo, CA, is watching a total lunar eclipse. During this total lunar eclipse, the moon will be in its __________ phase.
(A) new.
(B) first quarter.
(C) full.
(D) third quarter.
(E) (Depends on the time of day.)

Correct answer (highlight to unhide): (C)

During a total lunar eclipse, the moon is completely within Earth's umbra (Earth being between the sun and the moon). Since the moon lined up with the sun and Earth on the night side of Earth, it must be in its full phase.

Section 70160
Exam code: quiz02n3rE
(A) : 7 students
(B) : 0 students
(C) : 20 students
(D) : 0 students
(E) : 0 students

Success level: 74% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.29