- #1
breez
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Homework Statement
A point charge is placed at a corner of a cube. What is the net flux through all faces of the cube?
Homework Equations
The Attempt at a Solution
[tex]\phi = \frac{q}{\epsilon_0}[/tex]
or perhaps
[tex]\phi = \frac{q}{8\epsilon_0}[/tex]
The latter solution is based on the fact that for 3 faces on the cube, no flux will be present as the e field is parallel to the faces. Place 7 other cubes about this cube to force a cube with the charge in the middle, and each cube individually will only have flux through 3 of the cubes. A charge enclosed in a gaussian surface must result in a flux of [tex]\phi = \frac{q}{\epsilon_0}[/tex] for the surface. There are 8 cubes, and our original situation is 1/8 of the entire cube, and hence: [tex]\phi = \frac{q}{8\epsilon_0}[/tex]