All Questions
Tagged with electromagnetismpotential
467 questions
-1votes
0answers
32views
Why does a constant vector potential along a circular direction have this form? [closed]
My question comes from page 202 in the book "String theory and M-theory" by Becker-Becker-Schwarz. In Exercise 6.2 in this page, the author says: "Consider a relativistic point ...
- 834
2votes
0answers
42views
Field and potential drop between equipotential surfaces [closed]
I have two conceptual confusions about conductors. My attempt: In the question numbered 24, I understand that at steady state a negative charge will be induced on the inner sphere because it must be ...
- 181
4votes
1answer
163views
Can you simply covariantize an expression to get it in all frames?
We have argued that the expression $$ A^\mu = \frac{q}{4\pi} \frac{u^\mu}{\sqrt{(x \cdot u)^2 - x^2 c^2}} $$ provides the four potential produced by a charge at the origin at time $t=0$ because the ...
- 1,205
7votes
1answer
129views
Point charge in the 3D torus: is there an approximate result for its potential?
Assume to have a unit point charge in a flat 3D torus of side $L$. There is also a uniform neutralising background, so that the total charge is exactly zero. Finding the electric potential means ...
- 5,501
0votes
0answers
74views
Increase in potential value due to a moving charge
We know that the charge density for a moving charge is taken as, $$\rho(\mathbf{r}, t) = q \delta(\mathbf{r} - \mathbf{r}_q(t_r)).$$ This gives us the retarded potential of $$\phi(\mathbf{r}, t) = \...
- 333
0votes
1answer
90views
How to use Gauss' Law to find the Magnetic Vector potential of a magnetized sheet?
I would like to use Gauss' Law to solve the problem of the uniformly magnetized infinite plane. I have never seen anyone solve this problem on youtube or google and I am not sure it will work, however,...
1vote
1answer
82views
Conceptual issue with how energy/energy density relates to the electromagnetic fields
this is a question that I've been thinking about for some time, and was wondering if anyone can shed light on it? For two point charges interacting, each provides an electric field which is related to ...
0votes
2answers
140views
Why is the divergence of Magnetic Vector Potential equal to zero?
I am studying about Magnetostatics from the Griffiths book. I don’t really understand the proof that he writes. ( Divergence of A = $0$) We can add any fucnction whose curl vanishes, with no effect on ...
- 15
1vote
2answers
159views
Does Griffiths err in the derivation of Lienard-Wiechert potential?
In the derivation of Lienard-Wiechert potential in Griffiths, he uses a geometrical argument to talk about the length of a train appearing longer. But if we apply that argument to a charge, won’t it ...
- 333
0votes
0answers
118views
Confused by non-conservative electric fields
As a preface, this is my first time posting a question on this site, so please bear with me and any mistakes I make. For a while, I've had some trouble understanding what an EMF (electromotive force) ...
1vote
1answer
73views
Is it possible to measure the potential difference between two regions that are far apart?
I’m an electronics engineering student with a growing interest in electrochemistry. I’ve learned that to measure the potential difference between two beakers, A and B, with different ion ...
- 13
0votes
3answers
78views
Is the electric force conservative in the presence of a changing magnetic field?
Is the electric force conservative in the presence of a magnetic field? Maxwell's Equations tell us that the curl of $E$ is zero unless there is a changing magnetic field. Conservative forces are by ...
- 309
1vote
2answers
132views
General form of the Faraday tensor
When deriving the Faraday tensor we use the fact that the two potentials with the Lorentz gauge $U$ and $\vec{A}$ can be written as one 4-vector potential $\vec{A}_4 \equiv (U/c\ ,\vec{A})$ and the ...
0votes
0answers
26views
Potential Energy and Potential for magnetic fields [duplicate]
I am bit of a confuse. What i did study in my 12th class is that potential energy and potential is only defined for conservative forces then why do we get to see quantities like magnetic potential ...
1vote
0answers
54views
Handling coordinate rotation in spherical coordinates with addition theorem
I'm working through a problem on the potential inside a hollow sphere of radius $a$ with a given boundary condition for the potential $\Phi$ on the surface, $$ \Phi(r=a,\theta)=\begin{cases}V&\...
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