All Questions
Tagged with magnetic-fields dipole
51
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Linear approximation of the magnetic dipole field
Summary: using 3 angles to represent a magnetic dipole's orientation is redundant because the rotation around the $z$-axis of the dipole does not change the magnetic field, there are only 2 DOFs for ...
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Orientation of Magnetic Induction of a Dipole Source in MEG
I am working with source-reconstructed MEG data, and what I would like to know is that
when we obtain the magnetic induction (using the right-hand thumb rule) of a dipole source, is it only the ...
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Equation relating the current carried by a solenoid to the force experienced by a magnetic dipole?
I am trying to find an equation or a series of equations that relates the current I carried by a solenoid of length L with turns N to the force F experienced by a magnetic dipole of strength M that ...
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The force on a magnetic dipole in a non-uniform magnetic field
Let's say there is a non-uniform magnetic field $B=(0,0,z)$ (i.e. the field is parallel to $z$-axis and the amplitude is linearly changing along $z$-axis). If there is a current loop (=magnetic dipole)...
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Classical dipole-dipole interaction in iron
I've been reading about the classical magnetic dipole-dipole interaction and I'm wondering how it would work in a ferromagnet element like iron (theoretically under the assumptions I will write below)....
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Earth magnetic field, WMM/IGRF
I am studying about World Magnetic Model (WMM) and International Geomagnetic Reference Field (IGRF) models. It is well known that, to a first approximation, earth magnetic field is a field of dipole. ...
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Non-parallel magnetic dipole falling throug copper tube
What happens with magnetic dipole while falling through copper cylinder?
If it's parallel to z-axis (shown on picture below with red color) we know that it stays parallel to the z-axis all the way ...
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Force components on dipole falling through copper ring
We have a magentic dipole parallel with z-axis (shown on the diagram below) falling through copper loop, because of changing magnetic flux there is induced current in cooper ring/loop and consequently ...
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Does the force between two magnetic poles ever reach zero?
If we hold two magnetic like-poles together and start to move them away, would the repelling force reach absolute zero at certain point?
In that scenario, as a layman, I think that there is something ...
user342647
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Magnetic field of dipole derivation
How can we derive the following formula:
$$\vec{B}(\vec{r})=\frac{\mu_0}{4\pi}\left[ \frac{3(\vec{m}\cdot\vec{r})\vec{r}}{r^5} - \frac{\vec{m}}{r^3}\right]\; ,$$
I want to derive it as a limit of a ...
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How to find field strength of magnetic field of an oscillating dipole without $x,y,z$ variables?
(For better viewing, visit https://lateral-bathroom-f63.notion.site/How-to-find-field-strength-of-magnetic-field-of-oscillating-dipole-without-x-y-z-variables-ea0d864f371e4649a21d6cf5d007f9ee)
I have ...
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Why is the magnetization inside a diamagnetic material antiparallel to the external field
Let's say I have a constant magnetic field and I dive into it a diamagnetic material. Griffiths says that in the presence of a magnetic field, matter becomes magnetized and it will be found to contain ...
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Formula for force on a magnetic dipole
Using the magnetic current model, the force on a magnetic dipole, commonly derived in textbooks, is found to be:
$$
\mathbf{F} = \nabla(\mathbf{m} \cdot \mathbf{B}) \tag{1}
$$
If the magnetic pole (&...
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Why magnet is always a dipole?
Why magnet is alway dipole
Even the atom of the magnetic substance is also dipole , how can small atom be dipole . Pls explain me
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Potential energy of magnetic dipole in non-uniform magnetic field
I want to understand why the potential energy of an ideal magnetic dipole with dipole moment $\boldsymbol{m}$ in a non-uniform magnetic field $\boldsymbol{B}$ (neglecting the term to keep the ...
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$H$ field formula
For a permanent bar magnet is there a formula for the magnetic field strength $H$? Just like the electric field strength $E$ can be calculated at a point in space, can we do the same for the magnetic ...
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Force on a magnetic dipole
How to deduce the force on a magnetic dipole given by $F = \nabla(m \cdot B)$ from the Lorentz force?
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Magnetic field around a magnetic dipole and circular current loop
Qualitatively, how does the magnetic field around an ideal dipole compare with the magnetic field around a circular current loop?
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Field of an infinitely wide magnetic dipole
Students commonly wonder about the near-analogies between electricity & magnetism. One such:
The field of an electric dipole in the limit of an infinitely wide plane tends to 0 outside the plane (...
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Uniform electric field formation in motional emf induction
Why is the electric field $E$ across the ends of a conducting rod, when it's moved with a uniform velocity $v$ in a magnetic field $B$, uniform? Wouldn't it vary non-linearly, since there are opposite ...
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Magnetic dipole in gradient magnetic field
I know that a magnetic dipole in a uniform magnetic field will precess.
What happens qualitatively (or quantitatively) to a magnetic dipole in a gradient magnetic field? According to Wikipedia, "...
user243050
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Measuring neodymium magnet strength with magnetometer sensor in phone
I try to measure neodymium magnet magnetic field strength, exactly - how it depends on distance to magnet, by using integrated magnetometer sensor in Huawei phone. My setup is like :
Then I move ...
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Is it possible to align a magnetic dipole completely in the direction of field?
considering $L$ is always greater than $L_z$ i.e angle between angular momentum/magnetic moment and magnetic field/z direction cannot be zero. Means $B$ and magnetic moment cannot be in same ...
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A Classical model for diamagnetism
I'm trying to derive a classical model to describe diamagnetism, and I'd like to understand if it is possible to understand the basic properties of diamagnetic materials with it i.e.:
''A diamagnetic ...
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Source of magnetic dipole potential energy
One of the basic expression that goes without much thinking is the potential energy expression of a magnetic dipole in a magnetic field, $$ U = -\mu\cdot B $$
In the case of electric and gravitational ...
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Can there be a torque-less net force on a dipole in a magnetic field?
I realise that a magnetic dipole moment is essentially defined on the basis of torque, which also seems to imply that a magnetic field imposed on a current-carrying closed loop can only induce a ...
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Why are domains formed as separate units?
I was reading about exchange coupling and domain formation in ferromagnetic materials. As far as I can understand, some of the dipoles in the ferromagnetic material align themselves in a group called ...
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Can we understand a moving charge as a dipole?
I work as a physics teacher at a high school and I have to explain these days the magnetic field of a curreny carrying wire. Of course I may just give the formulae and describe how the field $\vec{B}$ ...
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Is the vector potential component $A_\phi$ for a dipole necessarily 0 due to symmetry about the $z$-axis?
Consider an electric dipole (+$q(t)$, -$q(t)$) [where say $q(t)=q_0\cos\omega t$] is placed along the $\hat z$ axis. In the spherical polar coordinates, its vector potential $$\vec{A} = A_r \hat r + ...
user199113
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How to determine the best-fit magnetic dipole Gauss coefficient in a shifted coordinate system?
Introduction
A planetary magnetic field $\vec{B}$ can be described outside of the planet using Gauss coefficients $g_n^m$ and $h_n^m$ and a spherical harmonic expansion:
$$\vec{B} \;=\; -\vec{\...
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