Students explore the effects of putting a point charge at various places inside, outside, and on the surface of a cubical Gaussian surface. The Mathematica worksheet or Sage activity shows the electric field due to the charge, then plots the the flux integrand on the top surface of the box, calculates the flux through the top of the box, and the value of the flux through the whole cube.
Visualizing Flux through a CubeComplete this Sage activity or this Mathematica worksheet to explore the flux of the electric field from a point charge through a cube.
We usually walk/talk the students through the worksheet with the charge at the center of the box and then encourage small groups to try putting the charge in other places.
Discuss the relationship between electric flux and the charge enclosed by the surface (namely, Gauss's Law).
This activity is part of two sequences of activities: Geometry of Vector Fields Sequence and Flux Sequence.