Questions tagged [maxwell-equations]
A set of four equations that define electrodynamics. They comprise the Gauss laws for the electric and magnetic fields, the Faraday law, and the Ampère law. Together, these equations uniquely determine the electric and magnetic fields of a physical system. DO NOT USE THIS TAG for the Maxwell-Boltzmann distribution, or the thermodynamical equations known as Maxwell's relations.
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How can $\nabla\cdot B = 0$ tell that magnetic monopoles do not exist?
I tried looking it up online but didn’t find much. I also checked Wikipedia, but I don’t have a clear cut understanding of divergence operators. I apologise for this question but is it possible to ...
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Why is Gauss's Law true regardless of the volume's shape? [migrated]
I had a question about why Gauss's Law holds for any type of surface shape?
$$\Phi_E = \oint \vec E\cdot d\vec A = \frac{Q_\mathrm{encl}}{\epsilon_0}$$
My current understanding:
Surfaces:
What I do ...
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The Fundamental $B$-$H$ Relation in Hard Magnetic Materials
I'm confused about the most fundamental and universally correct relationship between the magnetic fields $B$ (magnetic flux density) and $H$ (magnetic field strength) inside a hard magnetic material. ...
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Does the magnetic field of a uniformly moving charge excite an electric field and why?
For a point charge $ q $ moving at constant velocity $\mathbf{v}$, the electric and magnetic fields can be described by Maxwell's equations.
My questions are:
Why the electric and magnetic fields &...
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Can a propagating radial electric field be derived from Maxwell's equations? [closed]
Using Maxwell's equations one can derive the following inhomogeneous wave equation for the electric field $\mathbf{E}$ with sources:
$$\nabla^2 \mathbf{E} - \frac{1}{c^2} \frac{\partial^2 \mathbf{E}}{\...
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Electromagnetic induction and relative motion of circular coil (conductor)
Let us assume a uniform magnetic field in z direction but varying with time. Now let us consider a circular closed coil (conductor) which is placed in x-y plane. in a simple case an emf is induced (...
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Does the electric field of a parallel-plate capacitor change as it accelerates?
Assume that the two plates of an infinitely large parallel-plate capacitor accelerate along the field lines simultaneously in the lab frame. (Fringing effects are excluded.) Is the uniform electric ...
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Maxwell equations with differential forms and signature $(+,+,+,+)$
When formulating Maxwell equations using differential forms, you can use a Lorenztian manifold with signature $(-,+,+,+)$ or $(+,-,-,-)$, and you get things like:
$$dF = 0$$
$$d \star F = J.$$
Is it ...
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Does an EM wave "turn around" and go inside an open-ended tube?
I am struggling to resolve a thought experiment that deals with the behavior of an EM wave as it reaches the end of a tube.
Assume a wave starts out traveling along the outside of a copper tube. The ...
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Is it possible to explain how electromagnetic waves propagate through a vacuum solely using classical physics? [closed]
I'm struggling to understand how electromagnetic waves are able to sustain through a vacuum without thinking of them as photons instead of waves.
Am I right in thinking of the situation as the wave ...
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Does Gauss's law need a displacement charge term? [closed]
Maxwell's equations:
Gauss's law
$$\nabla \cdot \mathbf{E}=\frac{\rho}{\varepsilon_0}.\tag{1}$$
Gauss's law for magnetism
$$\nabla \cdot \mathbf{B}=0.\tag{2}$$
Faraday's law of induction
$$\nabla \...
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Electric field around a wire
Does an electric field exist outside a non-perfect conductor wire with a constant current flowing through it? I think there might be an electric field parallel to the wire because current in the wire ...
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Ampere-Maxwell law seems to contradict causality? [duplicate]
Let us take the Ampere-Maxwell law
$$\nabla \times \mathbf{B} = \mu_0\,\mathbf{J}+\frac{1}{c^2}\frac{\partial \mathbf{E}}{\partial t}.\tag{1}$$
Assume we produce a spark that is so fast that the $\...
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Could there be multiple fields obeying the same symmetry?
For example, according to the gauge theory a massless, spin 1, Abelian field must be electromagnetic field, but could there be another field which obeys the very same Maxwell’s equation, except that ...
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How the last two Maxwell equations imply a delay and propagation of changes in $E$ and $B$ rather than instant setting of fields? [duplicate]
How do these Maxwells equations :
$$
\begin{align}
\nabla \times \mathbf{E} &= -\,\frac{\partial \mathbf{B}}{\partial t} \\
\nabla \times \mathbf{B} &= \mu_0 \mathbf{J} + \mu_0 \epsilon_0 \...
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