All Questions
14
questions with no upvoted or accepted answers
1
vote
0
answers
261
views
Magnetic field due to circular surface current density
I am trying to find the magnetic field between two coaxial cylindrical shells of radius $a$ and $b$ respectively. They have a surface current density of $K = K_0cos(\theta)\hat{\theta}$ and $K=-K_0cos(...
- 324
1
vote
0
answers
58
views
How do I know if a solution of Maxwell Equations is caused solely by the charges?
My question is very general and it isn't limited to the system that I calculated the fields. I need a general answer or a particular answer for my problem. I found two fields $\mathbf E,\mathbf B$ ...
- 277
1
vote
0
answers
1k
views
Electric field produced by a charged ring
I have a question I couldn't find an answer for anywhere. There is a ring of radius $R$ which is charged uniformly with linear density $\lambda$, and I have to find the electric field on any point of ...
- 31
1
vote
0
answers
2k
views
Electric potential on a uniformly charged tube
A hollow cylinder, with no top or bottom, of radius $R$ and length $L$ is uniformly charged with density $\sigma>0$. I have to find the point on space where a point charge $q>0$ has to be drawn ...
- 31
0
votes
0
answers
34
views
Is there a $H$-field formed by a uniformly moved, charged ball?
Imagine a charged ball with surface charges. Let it travel with a constant velocity $v$.
Imagine a point outside the ball. Since the charge is moving, there is a electric displacement displacement ...
- 363
0
votes
1
answer
35
views
Potential of an alternating electric field in a capacitor
My question comes from a problem of electrodynamics where there's a relativistic particle with a given 4-momentum ($p^\mu=(\varepsilon,\vec{p})$) which enters a capacitor with an alternating electric ...
0
votes
0
answers
43
views
How to connect $x$, $y$ component of 2D electromagnetic wave equation?
I want to solve following Maxwell's equation.
$$
\triangledown ^{2}E+\frac{\omega^{2}}{c^{2}}E=0
$$
But, Electric field has x, y component in 2D geometry.
So, it will be
$$
\frac{\partial^{2} E_x}{\...
- 1
0
votes
1
answer
66
views
How is a current induced in this translating wire?
I am familiar with the principles of electromagnetic induction, but I am stuck on the scenario below: a long straight wire is translating in a uniform magnetic field. According to my book, this causes ...
- 368
0
votes
0
answers
77
views
Find the electric field from a distance of a positively charged metal sheet
A square metal sheet with area $2\,\mathrm{m^2}$ and thickness $10\,\mathrm{mm}$ has gained a positive charge of $10\,\mathrm{pC}$. Find an the electric field $15$ meters above the metal sheet.
I don'...
- 67
0
votes
0
answers
87
views
Obtain magnetic field component from time-harmonic electric field
I have the electric field $\vec{E} = E_0\cos(\omega t + k_oy+\phi)\vec{a}_z$ and I need to find the magnetic field ($H$ field). I know the answer, it's $\vec{H}=-Z_0^{-1}E_0\cos(\omega t +k_0y +\phi)\...
- 101
0
votes
0
answers
81
views
Why is $\vec E_{\text{Vacuum}}=\epsilon_{r}\cdot\vec E_{\text{Dielectric}}$?
Basically, I'm asking why the electric field in a vacuum (or the applied electric field) is related to the electric field in a dielectric by the relative permittivity $\epsilon_{r}$.
For context I'll ...
- 2,470
0
votes
0
answers
71
views
Longitudinal waves in matter
What would be the best way to show that longitudinal waves satisfy the following equation: $$\nabla ^2 \textbf E\space - \space \frac{1}{c_0^2}\frac{\partial^2 \textbf E}{\partial t ^2}=\frac{1}{c_0^2}...
- 789
-1
votes
1
answer
37
views
Conducting wire swinging in magnetic field
Imagine a situation where a conducting wire is swinging around one of its ends, in a uniform magnetic field that is perpendicular to the plane of rotation, and i want to find the potential that is ...
- 99
-2
votes
1
answer
122
views
What's the third equation that allows solving the closest approach of two electrons?
Lately, I have been thinking about the following situation: in one-dimensional space, if we have two electrons, and one of them is stationary while the other approaches with some velocity, what would ...
