8
votes
From what equations is magnetic field uniquely determined for a given current distribution?
The domain is important. The solution is given by Biot-Savart if it is the entire $\mathbb R^3$ space, with some assumptions on the regularity and decay of $B$ (e.g. $L^2$). In this case, you can ...
- 13.1k
4
votes
The puzzling interaction between an anapole moment and external fields
Mathematically, a dipole can be seen as a small current loop. Given the dipole moment $m$ this gives the magnetisation and current density:
$$
M = m\delta \quad j = \nabla\times M = \nabla\times (m\...
- 13.1k
2
votes
The puzzling interaction between an anapole moment and external fields
A pure anapole produces no radiation, no matter how it is varied or rotated, and has no interaction with free external fields. Sources online seem to disagree on this point, but it might be because of ...
- 103k
1
vote
Accepted
Flux change through a loop
This comes from Faraday's law. I believe it is only valid in quasistatic (no radiation generated) situations.
Faraday's law in differential form is
$$-\frac{d\Phi_B}{dt} = \varepsilon.$$
If you have a ...
- 978
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