Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

All Questions

0
votes
1answer
31 views

How do I solve for the voltage on a geometry that has varying thickness of a conductive metal?

I currently have a 3D geometry which is made from an isotropic material. In my case this material is simply a highly conductive metal. We can think of this geometry almost as a thin film with slightly ...
0
votes
1answer
205 views

Difference between bound and free charge/current in a perfect conductor

For the case of charge, it seems clear that in a perfect conductor the free charge refers to the excess charge that has been dumped into the conductor, while the bound charge refers to the charge that ...
1
vote
2answers
243 views

The consequence of electric field lines not being perpendicular to conductor (assuming a spherical one)

The following statement is from University Physics (chapter "Electric Potential"): "In particular, at any point just inside the surface the component of E vector tangent to the surface is zero. It ...
2
votes
2answers
596 views

Why does Griffiths's book say that there can be no surface current since this would require an infinite electric field for an incident wave?

In sec. 9.4.2 Griffiths shows the well known boundary conditions for E and B fields, one of them is this: $$\frac{1}{\mu_{1}}\textbf{B}_{1}^{\parallel}-\frac{1}{\mu_{2}}\textbf{B}_{2}^{\parallel}=\...
-1
votes
1answer
367 views

A point charge near an infinite conducting plane

I want to calculate (with Poisson's equation) the electric field in the region containing a point charge near an infinite conducting plane with 0 potential. My textbook uses V(x,y,z)= 0 for every x,y,...
0
votes
2answers
370 views

Boundary condition in a real conductor

The boundary condition $\textbf{n}\times \textbf{H}=\textbf{K}$ (A/m) is valid in the surface of a perfect conductor (where the conductivity $\sigma$ is infinity). Is it satisfied for the surface of a ...
2
votes
1answer
209 views

Can't see any difference between Dirichlet and Neumann boundary conditions on the surface of a perfect conductor?

If we consider the Helmholtz equation for electromagnetic wave propagation and let $\partial \Omega$ be the surface of a perfect conductor with Dirichlet boundary conditions, ie. $u(x) = 0$ for $x \in ...
1
vote
1answer
322 views

Why Does Electric Potential Approach Zero at Infinity: Boundary Conditions for Infinite Conducting Sheets

Imagine an infinitely long conducting "trough," as shown in the figure. The two sides are grounded, and the bottom strip is maintained at potential $V_0$. Suppose we want to know the electric ...
2
votes
1answer
1k views

Refraction of the electric field lines, at the interface of separation between two conductive media

Suppose we have 2 media with electrical parameters ${\varepsilon _1},\,{\sigma _1}$, respectively ${\varepsilon _2},\,{\sigma _2}$, separated by the plane surface $\Sigma $; electrical charge surface ...
1
vote
3answers
474 views

What is the electric field exactly on the surface of a conducting sphere?

Within a conducting sphere, the electric field is 0, but is the electric field still 0 exactly on the surface?
3
votes
2answers
5k views

Why do electric field lines start and end at 90 degree at the surface of a conductor? [duplicate]

There is one property of electric lines of forces which states that: Electric field lines start and end at 90 degree at the surface of the conductor. But why is that so? Is there any proof for ...
0
votes
1answer
75 views

Wave guide boundary conditions

Why only the normal component of Electric field and the parallel component of Magnetic field exist at the surface of a wave guide or any conductor?
4
votes
4answers
2k views

Rigorously prove that electric field is zero in a perfect conductor

I have ran into a problem while trying to prove that the electric field is zero in a perfect conductor My argument went something like this: We know that: $$\vec J = \sigma \vec E$$ In a ...
1
vote
1answer
156 views

Does charge distribute itself uniformly on a conductor?

An excerpt from a beginning E&M book [...] In other words, the surface of a conductor is an equipotential surface under static conditions. [...] Summarizing the boundary conditions at the ...
2
votes
1answer
255 views

Magnetic Field in the presence of a conductor

I am studying for my quals and came across an old question that reads like the following: There are two regions in space separated by an infinite conducting plane. Region 1 has a magnetic dipole ...
10
votes
6answers
48k views

Why is the electric field perpendicular to every point on the surface of a conductor?

I am reading Berkeley Physics Course, Volume 2 (Electricity and Magnetism by Edward M. Purcell). I am in chapter $3$, page $92$, and the book discusses conductors. The following is from the book: ...