20160316

Physics quiz question: charge transfer between conductors

Physics 205B Quiz 3, spring semester 2016
Cuesta College, San Luis Obispo, CA

A positively charged metal rod is brought in contact with a neutrally charged metal sphere. (Both rod and sphere are electrically isolated from the environment.) After being in contact with each other and then separated from each other, the __________ will be negatively charged.
(A) rod.
(B) sphere.
(C) (Both of the above choices.)
(D) (Neither of the above choices.)

Correct answer (highlight to unhide): (D)

Positive charge will be transferred from the metal rod to the initially neutral conducting sphere, evenly distributing between the two objects such that they are both positive. This means that negatively charged electrons were transferred from the conducting sphere (making it positive) to the metal rod (reducing the amount of its positive charge), such that after they are separated from each other, neither of these objects will be positively charged.

Section 30882, 30883
Exam code: quiz03Ccf7
(A) : 9 students
(B) : 10 students
(C) : 1 student
(D) : 20 students

Success level: 50%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.19

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