Astronomy quiz question: volcanic terrestrial planet?

Astronomy 210 Quiz 7, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

A terrestrial planet __________ would be most likely to have active volcanoes today.
(A) close to the sun.
(B) that is massive.
(C) with a low density crust.
(D) with liquid metallic hydrogen.

Correct answer: (B)

Massive planets are will cool off at a slower rate than less-massive planets, such that it will retain more core heat, and more likely to be volcanically active in the present-day (i.e., The "Turkey/Cornish Hen Effect").

Section 70158
(A) : 8 students
(B) : 14 students
(C) : 17 students
(D) : 2 students

Success level: 38% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.50

Section 70160
(A) : 4 students
(B) : 24 students
(C) : 10 students
(D) : 3 students

Success level: 63% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.30