# Electric field between conducting and non-conducting sheets

## Homework Statement

Two infinite sheets of charges are placed parallel to each other. If the sheet on the left is non conducting and have a uniform charge density 3(sigma) and the one on the right is conducting and has a uniform charge density (sigma). If the area on both plates is 1m^2 then calculate the value of electric field at (a) to the left of left sheet (b) in between the sheets (c) to the right of right sheet.

## Homework Equations

gauss law E= (sigma)/2€o
E=(sigma)/€o

## The Attempt at a Solution

I am attempting it to do it by definitions. I think that the field at the right of the right sheet will be 0 because right sheet is conducting but I don't know if at the left of left sheet the value will be sum of two fields of the sheets or not and what will be the electric field at middle

Doc Al
Mentor
the one on the right is conducting and has a uniform charge density (sigma)
This is unclear: Does this include the charge density on both sides of the plate? (I would assume so: The total charge density is sigma.)

I think that the field at the right of the right sheet will be 0 because right sheet is conducting
The field within the material of the conducting plate must be zero, but not outside it.

This is unclear: Does this include the charge density on both sides of the plate? (I would assume so: The total charge density is sigma.)
yes I guess so. But its not mention in the question.

Doc Al
Mentor
So you're saying that the charged sheet has a surface charge of 3σ and the conducting sheet has a charge of σ?

berkeman
Mentor
Two infinite sheets of charges
If the area on both plates is 1m^2
??

Doc Al
Mentor
Yeah, quite a bit about this problem statement is not quite clear. Can you post it exactly as it appears, word for word?

you're
yes. they have given us symbols inspite of numeric values. We have to drive formulas for it. and thats the exact wordings that are written in my note book.

Doc Al
Mentor
Well, ignoring the fact that the "infinite" sheets have an area of 1 m^2, you can just treat them as infinite sheets of charge. Unless there is more to this question, the fact that one is a conducting sheet is irrelevant.

Delta2
Homework Helper
Gold Member
I think if the conducting sheet has some small width ##\Delta x## then we ll have to calculate the induced charged density on it and we can speak of the inner and outer surface charge densities on it.. However If its width is zero , so it is purely 2Dimensional then we don't have to bother with that.

Doc Al
Mentor
Assuming you're given the total surface charge on the conducting plate (both sides total), you won't have to worry about any induced surface charges since they don't ask for that.