Suppose that a symmetry argument of some kind tells us that the electric field in a certain region points directly away from the nearest point on the $y$ axis and has a magnitude that depends only on $r$, the distance to that nearest point. For which of the gaussian surfaces listed, would it be easiest to calculate the net flux of the electric field through that surface?
A) A cubical surface oriented so that two opposite faces are perpendicular to the $y$ axis.
B) A spherical surface.
C) A cylindrical can-like surface oriented with its central axis perpendicular to the $y$ axis.
D) A cylindrical can-like surface oriented with its central axis parallel to the $y$ axis.
E) A cone-like surface oriented with its central axis parallel to the $y$ axis.

Question

Quizplus · Accepted Answer

Given the symmetry of the electric field pointing directly away from the nearest point on the $y$ axis and its magnitude depending only on $r$, a cylindrical can-like surface oriented with its central axis parallel to the $y$ axis (choice D) would allow for a uniform electric field across its curved surface, simplifying the calculation of net flux.

Suppose That a Symmetry Argument of Some Kind Tells Us yyy

Suppose That a Symmetry Argument of Some Kind Tells Us $y$