Astronomy quiz question: total lunar eclipse phase

Astronomy 210 Quiz 2, Spring Semester 2009
Cuesta College, San Luis Obispo, CA

[4.0 points.] What phase is the Moon in during a total lunar eclipse?
(A) New.
(B) Full.
(C) (The phase depends on whether the total lunar eclipse occurs at sunrise, midnight, or sunset.)
(D) (The Moon does not have a phase during a total lunar eclipse.)

Section 30674
(A) : 10 students
(B) : 21 students
(C) : 4 students
(D) : 2 students
(No response: 1 student)

Correct answer: (B)

The Moon will be behind Earth with respect to the Sun, and thus will be full during a total lunar eclipse.

"Difficulty level": 58% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.64