Questions tagged [electromagnetism]
The classical theory of electric and magnetic fields, both in the static and dynamic case. It also covers general questions about magnets, electric attraction/repulsion, etc. Distinct from electrical-engineering.
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Terminal velocity of a bar magnet in a long conducting tube (quantitative)
If a bar magnet is dropped into a copper (conducting) tube, it reaches a terminal velocity. I'm trying to derive this terminal velocity.
We know from Lenz's law that $e=\frac{-d\phi}{dt}$.
I'm facing ...
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What actually happens when light goes into a waveguide?
I have only dealt with a rudimentary theoretical treatment of how light propagates inside a waveguide, such as those available in Griffiths.
One thing bugging me is that I still do not know how ...
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Flux change through a loop
I'm having difficulties understanding this thing. It would be lovable if someone could show me its derivations and prove it:
In a conducting loop, there is a relationship between the total displaced ...
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I am trying to derive an expression for the magnetic field of charged particles travelling at significant fractions of speed of light [closed]
I tried using lorentz transformation , which gives me correct answer for speed of light c but when i try to input any other values nearby c it becomes a constant
B = 10-7 . q/r² ( (v - u)/ 1- uv/c²)
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Permittivity real and imaginary parts with similar value possible?
Here's the context; I'm studying biological tissues that are supposed to behave like dielectrics. Using the modified cole-cole equation for theoretical predictions:
$$\tilde{\varepsilon}_r (\omega )= \...
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Why electric field increase near the cable connected in AC 220V socket even current is zero?
If I put low frequency electric field meter near the connected cable in AC 220V socket, he show 1200 V/m even if device is turn OFF(zero current), if disconnect cable from socket, field drop to 8 V/m.
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Assessing Error Step Size in Continuous Charge Distributions
For obtaining the electric field for bodies at the macroscopic scale, the discontinuities in the charge distributions are ignored. A continuous function for the charge distribution is considered.
But ...
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Force acting on an infinite wire with current inside a magnetic medium
I've recently stumbled on an electromagnetics problem that I don't quite understand.
There is an infinite wire carrying current I that is placed inside a medium with magnetic permittivity μ1. At a ...
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Displacement current and magnetic field in capacitor with dielectric
I have a capacitor with round plates of radius $r_{2}$ kept at a distance $d$, with a voltage $V\left(t\right) = V_{0} \cos \left(\omega t\right).$ Inside, there is cylindrical material with a certain ...
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Seeking Advanced Study Guidance in Electromagnetism [closed]
I hope this post doesn't break any community rules, I've tried to look for such but couldn't find.
I am concluding my first undergraduate course in Electromagnetism next week. I am confident in my ...
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About the notation for TEM waves
I just came across this article where the term "$\mathrm{TE}_{101}$ microwave mode" is mentioned. Other than the basics of TEM waves which I learned in Griffiths, this is the first time I ...
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A question on perturbed flux function
Given a magnetic field $\mathbf{B}=B_{0}\left(\dfrac{xz}{z_{s}^{2}},\dfrac{yz}{z_{s}^{2}}, 1-2\left( \dfrac{x^{2}}{r_{s}^{2}}+\dfrac{y^{2}}{r_{s}^{2}}\right) -\dfrac{z^{2}}{z_{s}^{2}}\right)$ with the ...
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How do I find the wavelength of an EM wave derived from an accelerating electron, given its acceleration?
I understand the Larmors formula, but I can't find any material regarding wavelength of a single photon.
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What is radial and axial component of magnetic induction of a coil? [closed]
I am sorry if my question is stupid, but can someone explain what are the radial and axial component of magnetic induction of a coil. I am reading an article about the magnetic field generated by coil....
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What are the operators here and how are these formulas derived? [closed]
In (23), are grad and div some kind of scalar operators comparing to $\nabla$ and $\nabla\times$? because tbh I dont know how $\text{curl}(\mu^{-1}\text{curl}\textbf{A})$ turns into $\text{div}\mu^{-1}...
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