Electric Flux

The electric flux

%5CPhi_E

through the cube is given by the formula:

%5CPhi_E%20%3D%20E%20%5Ccdot%20A

where

E

is the electric field and

A

is the area of one face of the cube. Since the cube has 6 faces and the electric flux is through each face, the net flux through all the faces is:

%5CPhi_E%20%3D%20E%20%5Ctimes%20A%20%5Ctimes%206

Given that:

E%20%3D%203%20%5Ctimes%2010%5E3%20%5C%2C%20%5Ctext%7BNC%7D%5E%7B-1%7D%2C%20%5Cquad%20A%20%3D%20(0.20%20%5C%2C%20%5Ctext%7Bm%7D)%5E2%20%3D%200.04%20%5C%2C%20%5Ctext%7Bm%7D%5E2

The total flux is:

%5CPhi_E%20%3D%203%20%5Ctimes%2010%5E3%20%5Ctimes%200.04%20%5Ctimes%206%20%3D%2030%20%5C%2C%20%5Ctext%7BNm%7D%5E2%20%5Ctext%7BC%7D%5E%7B-1%7D

Thus, the net electric flux is

%5Cboxed%7B30%20%5C%2C%20%5Ctext%7BNm%7D%5E2%20%5Ctext%7BC%7D%5E%7B-1%7D%7D

Chapter Questions
1 MCQs