A solid aluminum cube rests on a wooden table in a region where a uniform external electric field is directed straight upward. What can we say concerning the charge on the top surface of the
Cube?
A) The top surface is charged negatively.
B) The top surface is charged positively.
C) The top surface is neutral.
D) The top surface's charge cannot be determined without further information.

Question

Quizplus · Accepted Answer

In a conductor like aluminum, free electrons will move in response to an external electric field. Since the field is directed upward, electrons will move to the bottom surface, leaving the top surface positively charged.

A Solid Aluminum Cube Rests on a Wooden Table in a Region