Question

A cube of side L is place in a uniform electric field E = 4800 N/C. What is the net flux through the cube. Assume the electric field lines are parallel with the edges of the cube.

Answer 1

a)Assuming that there is no charge contained within the cube, then the net flux through the cube is 0 ,since All of the field lines that enter the cube also leave the cube .

Net flux phi_net=0

b)

A =L^2

There are four faces that have no flux through them,because none of the field lines pass through those faces. In the diagram shown, the left face has a positive flux and the right face has the opposite amount of negative flux.

phi_1 =EA = (4800*L^2) N-m^2/C

phi_2=-EA = -(4800*L^2) N-m^/C

phi_3=phi_4 =phi_5=phi_6=0 N-m^2/C