Astronomy quiz question: giant vs. main-sequence star

Astronomy 210 Quiz 5, fall semester 2015
Cuesta College, San Luis Obispo, CA

A giant will be ___________ compared to a main-sequence star that has the same temperature.
(A) smaller and dimmer.
(B) smaller and brighter.
(C) larger and dimmer.
(D) larger and brighter.

Correct answer (highlight to unhide): (D)

An H-R diagram is provided with this quiz.


These stars are plotted on an H-R diagram below. The giant has a brighter luminosity and a larger size than the main-sequence star, in order for them to have the same temperature.


The entries for the "box method" of comparing relative Stefan-Boltzmann parameters are listed below.

	Lum.	=	size	×	Temp.4
giant	↑		↑		=
m.s. star	↓		↓		=

Section 70158
Exam code: quiz05s3T1
(A) : 3 students
(B) : 1 student
(C) : 5 students
(D) : 31 students

Success level: 78% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.60

Section 70160
Exam code: quiz05ne7A
(A) : 0 students
(B) : 1 student
(C) : 8 students
(D) : 15 students

Success level: 63% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.57