Astronomy quiz question: cause of moon phases

Astronomy 210 Quiz 1, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

What causes the different phases of the moon?
(A) Different amounts of the far and near sides of the moon as seen from Earth.
(B) Different amounts of the day and night sides of the moon as seen from Earth.
(C) Earth blocks light from the sun, casting a shadow on the moon.
(D) The slow, gradual rotation of the moon about its own axis.

Correct answer: (B)

Response (C) is the cause of lunar eclipses, responses (A) and (C) are related to the synchronously tidal-locked rotation of the moon as it keeps (nearly) the same side facing towards Earth.

Section 70158
(A) : 1 student
(B) : 9 students
(C) : 21 students
(D) : 12 students
(No response) : 1 student

"Success level": 25% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.20

Previous post:

• Astronomy clicker question: lunar phases
  (Summer session 2007)