Astronomy quiz question: brighter luminosity stars

Astronomy 210 Quiz 6, fall semester 2015
Cuesta College, San Luis Obispo, CA

A main-sequence star that is more massive than the sun would have a brighter luminosity due to __________ in its core.
(A) faster fusion rate.
(B) more convection.
(C) heavy elements.
(D) radioactivity.

Correct answer (highlight to unhide): (A)

The more massive a main-sequence star is, the higher pressures and temperatures there will be in core, such that the rate of hydrogen fusion will be faster, releasing more energy to make the star brighter.

Section 70160
Exam code: quiz06nUm6
(A) : 23 students
(B) : 3 students
(C) : 2 students
(D) : 0 students

Success level: 83% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.15