Cuesta College, San Luis Obispo, CA
A red giant is __________ than the sun.
(A) cooler and dimmer.
(B) cooler and brighter.
(C) hotter and dimmer.
(D) hotter and brighter.
Correct answer (highlight to unhide): (B)
From Wien's law, the red giant is cooler than the sun, which is yellow-hot. An H-R diagram is provided with this quiz.
As shown below, all giants would have a luminosity greater than the sun. Thus a red giant must be cooler and brighter than the sun.
The entries for the "box method" of comparing relative Stefan-Boltzmann parameters are listed below.
Exam code: quiz05n3Ne
(A) : 5 students
(B) : 15 students
(C) : 2 students
(D) : 3 students
Success level: 63% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.75
Exam code: quiz05suN7
(A) : 8 students
(B) : 26 students
(C) : 3 students
(D) : 2 students
Success level: 69% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.43