Astronomy quiz question: low mass main-sequence star fusion rate

Astronomy 210 Quiz 5, fall semester 2012
Cuesta College, San Luis Obispo, CA

A low mass main-sequence star will have a slow fusion rate because of the ____________ pressure and ____________ temperature in its core.
(A) low; low.
(B) low; high.
(C) high; low.
(D) high; high.

Correct answer: (A)

Fusion in main-sequence stars requires sufficiently high enough pressures and temperatures such that nuclei move quickly enough to overcome repulsion. Higher pressures and temperatures will result in a faster fusion rate, due to the more rapid and frequent collisions between nuclei; in low mass main-sequence stars, the nuclei will move slower and collide less frequently, resulting in a slower rate of fusion.

Section 70158
Exam code: quiz05sNv4
(A) : 21 students
(B) : 7 students
(C) : 3 students
(D) : 2 students

Success level: 66% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.89

Section 70160
Exam code: quiz05N3w7
(A) : 22 students
(B) : 2 students
(C) : 3 students
(D) : 0 students

Success level: 83% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.43

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