Astronomy quiz question: sunset/sunrise location

Astronomy 210 Quiz 1, fall semester 2012
Cuesta College, San Luis Obispo, CA

[Version 1]
An observer in San Luis Obispo, CA notices the sun rising on the horizon at a point between northeast and east. Approximately how much time elapses until the sun sets on the horizon between a point between southwest and west?
(A) 10 hours.
(B) 12 hours.
(C) 14 hours.
(D) One month.
(E) Three months.
(F) Six months.

Correct answer: (F)

The sun rising between northeast and east means summer solstice for San Luis Obispo, CA (later that day the sun will set between west and northwest). The sun setting between southwest and west means winter solstice for San Luis Obispo, CA (earlier that day the sun rose between east and southeast). Thus six months must elapse between rising between northeast and east and setting between southwest and west.

Section 70158
Exam code: quiz01sL3e
(A) : 11 students
(B) : 14 students
(C) : 7 students
(D) : 1 student
(E) : 0 students
(F) : 4 students
(No response) : 1 student

Success level: 13% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.45

[Version 2]
An observer in San Luis Obispo, CA notices the sun rising on the horizon at a point between east and southeast. Approximately how much time elapses until the sun sets on the horizon between a point between southwest and west?
(A) 10 hours.
(B) 12 hours.
(C) 14 hours.
(D) One month.
(E) Three months.
(F) Six months.

Correct answer: (A)

The sun rising between east and southeast means winter solstice for San Luis Obispo, CA. Later that day the sun will set between southwest and west. Since the winter solstice has 10 hours of daylight (and 14 hours of night) for San Luis Obispo, CA, 10 hours will elapse between sunrise and sunset.

Section 70160
Exam code: quiz01NaV3
(A) : 16 students
(B) : 8 students
(C) : 3 students
(D) : 1 student
(E) : 1 student
(F) : 3 students
(No response) : 1 student

Success level: 52% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.71