Gauss law two infinite plane question

[Clara Chung]

Homework Statement

Homework Equations

The Attempt at a Solution

How do you know the left plate (or the right plane) produces a field (1/2ε) σ to the left and right? How do you apply Gauss Law? For one infinite plane, we can use Gauss law because of symmetry, so we can assume the electric flux coming out from right or left of the plane are equal and uniform. In this case, how do we use the result of a single infinite plane? It should be possible that more field lines are coming out from the plane to the right hand side because a negatively charge plane is placed on the right.

 

[Doc Al]

How do you know the left plate (or the right plane) produces a field (1/2ε) σ to the left and right? How do you apply Gauss Law? For one infinite plane, we can use Gauss law because of symmetry, so we can assume the electric flux coming out from right or left of the plane are equal and uniform. In this case, how do we use the result of a single infinite plane? It should be possible that more field lines are coming out from the plane to the right hand side because a negatively charge plane is placed on the right.

You can use Gauss' Law for a single infinite plane to obtain the quoted field. Then just use superposition to combine the fields from multiple planes.