All Questions
Tagged with electromagnetism potential-energy
129
questions
0
votes
4
answers
40
views
Comparing Electric Potential Energy of two Charges
I do not know what I am missing here and would appreciate a little help in figuring out the flaw in my logic. I have a row of positive charges and a row of negative charges as shown in the image above....
- 1
3
votes
0
answers
53
views
A question regarding Coulomb sum in two dimension
The following arguments can be found in texts about Laughlin's wavefunction and theta function such as Laughlin's paper "Spin hamiltonian for which quantum hall wavefunction is exact". It is ...
- 51
0
votes
1
answer
29
views
The electron potential energy of a single electron (in $H^+_2$ ) at any point
In my book it says:
We can choose a convenient reference by noting that the coulomb force at infinite distance is zero. It makes sense for this case, then, to choose $r=\inf$ as the vacuum level $E_v$...
- 107
1
vote
3
answers
116
views
Charge Distribution and Stability in a Conductive Solid Sphere
My friend came to me with a simple question: What is the charge distribution on a conductive solid sphere? Of course, I answered: 'Since the solid sphere is conductive, the electric potential would be ...
- 113
1
vote
1
answer
65
views
Potential energy of a permanent magnet
A friend and I had a discussion about the potential energy of a permanent magnet, and we want to find out which of our views is right, but we can't seem to find information to confirm/disprove either ...
- 11
0
votes
3
answers
404
views
Potential energy of a particle inside a magnetic vector potential
Why is the potential energy of a particle inside a magnetic vector potential equal to $-\frac{e}{c}\cdot\vec{A}(\vec{x}(t))\cdot\dot{\vec{x}}(t)$? It appears for example inside the lagrangian of the ...
- 189
0
votes
1
answer
78
views
The magnetic force is conservative when the magnetic field is static, what is its potential function then?
The magnetic force $\vec{F}$ can be conservative when the magnetic field is a static. That is $\vec{\nabla} \times \vec{F}=0$, so it follows that there is a scalar function $f$ such that $\vec{F}=q \...
- 959
2
votes
1
answer
90
views
How to calculate magnetic force using differentiation of magnetic energy?
I tried to calculate the magnetic force between two circular current loops using numeric integration and differentiation of magnetic energy:
$$ \int d^3\vec{r} \frac{1}{2 \mu_0} \vec{B}^2 \,\,\,\,\,\,...
- 425
0
votes
1
answer
120
views
Violation of energy conservation due to Lorentz Force?
We know that work done by Lorentz Force $q(\vec{v}\times\vec{B})$ is $0$ on moving charge in magnetic field as velocity is always perpendicular to the force. This means that kinetic energy remains ...
- 1,168
0
votes
0
answers
13
views
Potential inside a Charged Conductor near another Charge
Let's say that we have a solid conducting sphere with radius r and this conductor is given a positive charge of q1. We know that the charge will get distributed on the surface to reduce field inside ...
4
votes
4
answers
411
views
Where would the extra mass due to mass-energy equivalence for a system of two charged particles come from? How could that statement make any sense?
Suppose we have two point charges of rest masses $m_{1}, m_{2}$ and charges $q_{1}, q_{2}$. The electrostatic potential energy of the two objects is $U = k\cdot q_{1}q_{2}/r$ where $r$ is the distance ...
- 8,640
3
votes
2
answers
621
views
How can we define Magnetic Potential Energy if it is non-conservative?
I recently learnt that for a circular wire carrying electric current or for a magnetic dipole, if it is kept in a uniform magnetic field, we can define its magnetic potential energy. This would mean ...
- 301
1
vote
1
answer
81
views
On generalised potential in Electrodynamics
I'm studying Lagrangian Mechanics from Goldstein's Classical Mechanics. My question concerns Section 1.5 which talks about velocity-dependent potentials.
I am actually unsure about how Equation 1-64' ...
- 1,640
0
votes
2
answers
101
views
How to understand "the potential energy in an EM field is determined by $\phi$ alone"?
Goldstein page 342,
Consider a single particle (non-relativisitic) of mass $m$ and charge $q$ moving in an electromagnetic field.
The Lagrangian is
$$ L = T-V = \frac{1}{2}mv^2-q\phi +q\vec{A}\cdot \...
- 1
1
vote
1
answer
146
views
Confusion pertaining to the electric potential energy
First I'd like to explain why I don't think this question is a duplicate of the many other questions about the electric potential and potential energy. Despite there being many questions and answers ...
- 125