# Tagged Questions

The classical theory of electric and magnetic fields, both in the static and dynamic case. Also covers general questions about magnets, electric attraction/repulsion etc. Distinct from electrical-engineering.

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### Modeling magnetic field shielding

I am wondering what is the best way to model magnetic and electric field shielding from a magnetic dipole in the near field? For example, let's say you have a coil of current carrying wire in the x-y ...
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### If you spin a magnet in space, far from any magnet field, would it spin forever, being able to produce electricity forever?

This is of course a purely theoretical question and it would take energy to get the magnet moving in the first place but once it's moving in the vacuum of space, with no gravity or magnetic field ...
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### protons and electrons

I am a novice in physics and a few things are not clear to me in electromagnetism: Consider the experiment of giving a piece of metal positive charge (which I assume consists of protons), by keeping ...
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### Why uncharged particles do not feel the Lorentz force? [closed]

Why uncharged particles do not feel the Lorentz force? Please do not answer with the formula $\vec F = q\left( \vec E + \vec v \times \vec B \right)$. Edit after an answer which is an circular ...
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### Dimensional Analysis in Electromagnetism (SI vs Gaussian-cgs)

Looking at Konopinski's formula for conjugate momentum (in the comment after equation 3 of "What the Vector Potential Describes"): p = M v + q A /c it is plain enough that M v is momentum, but if we ...
310 views

### Why three families of multipole moments?

There are three families of multipole moments: The electric multipole moments, the magnetic multipole moments and the toroidal multipole moments. Is there any reason why there are this three families ...
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### Why does Snell's law not factor in wavelength?

If dispersion is caused due to different wavelengths bending with different angles, how is Snell's law right in generalizing it as $\sin(i) / \sin(r)$? Or am I missing something?
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### Is the electron magnetic moment responsible for the Lorentz force?

My question about the sum of the electrons' magnetic moments in a wire(What is the sum of the electrons' magnetic moments in a wire?) had an answer which disappeared later. The answer was - if I ...
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### Why can I blow up other potentials at the origin but not the one inside a dielectric sphere in an electric field?

While solving the electrostatic field for a dielectric in an electric field, we take the potential at origin to not blow and thus, we eliminate the inverse powers of r in the expression for general ...
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### Magnetic flux and flow of electrons

What does change in magnetic flux mean? How can you change magnetic flux? How does a change in magnetic flux influence a current of electrons (electricity)?