The square represents a cross section of a cube. Use the test charge to explore the
direction of the electric field inside the cube. Click the cursor anywhere inside the cube to
measure the magnitude of the electric field. Use it also to determine the dimensions of the
cube. Find the flux through each side of the cube.
Top: X [0 ] Left: X [-8]
Right: X  Bottom: X [0 ]
Top: X [0 ] Left: X 
Right: X  Bottom: X 
Physlet problem authored by Scott Bonham.