# Questions tagged [magnetic-moment]

The magnetic moment of a magnet is a quantity that determines the force that the magnet can exert on electric currents and the torque that a magnetic field will exert on it. A loop of electric current, a bar magnet, an electron, a molecule, and a planet all have magnetic moments.

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### I Bring 1 kg of Iron to a Flux Density of 1 T. How Much Energy Does That Take?

I'm an EE, not a physicist, so please forgive if this question is dumb. I learned a bit of magnetics when I took motors 20 years ago, but I don't remember much. I'm reaching out to the physics ...
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### Magnetic moment [closed]

I'm not calculating a magnetic moment of even nuclear (odd protons+odd neutrons). results of taking according to a nucleon shell-model of Shmidt do not match experimentl resauls for calculating ...
65 views

### How does the Lagrangian work with a magnetic field?

I was told the following Lagrangian is for a charged particle with spin moving in a constant magnetic field: $$L = \frac{\left ( \vec p \right ) ^2}{2m} + \vec \mu \cdot \vec B$$ Let's just say $B$ ...
1 vote
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### Absorption Cross Section for Two-Level Spin System in an AC Magnetic Field - Photon Picture

For a two-level spin with a energy difference of $E = h f$, where the two levels have zero dipole electric coupling and can only be driven by a magnetic field, how do I calculate the absorption cross ...
1 vote
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### How to interpret Magnetic Susceptibility as the ratio of two vectors $M$ and $H$, as division of two vectors is not defined in mathematics?

Magnetic Susceptibility, denoted as χ is defined as a scalar, represents the ratio between the Magnetization vector ($\vec {M}$) and the Magnetic field strength vector ($\vec{H}$). However, in ...
1 vote
136 views

### Intuition for magnetic dipole moment

The definition of the electric dipole moment of a system of charges makes sense intuitively - $$\boldsymbol {\bf p} = \int_{V} \boldsymbol {\bf r} \rho (\boldsymbol {\bf r})dV$$ describes the overall ...
1 vote
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### Explanation of why Kinetic Energy Increases when Particle Reaches the End of the Magnetic Bottle?

I don't understand how to explain why kinetic energy increases using Faraday's Law as a charged particle reaches the end of a magnetic bottle. I know that along the field line in the bottle, the ...
21 views

### Do magnetic fields cause rotational inertia proportional to their magnetic moment?

If I have a stick that has a spinning disc on the end of it, and I try to rotate the stick, I will feel more inertia the faster the disc is spinning because I have to transform its rotational energy ...
28 views

### What is the physics behind Oasis Mini?

A ball placed in the sand is moving around and drawing magnificent art. In the video below it draws a dolphin. It is very precise. How does it work? https://www.youtube.com/shorts/2b291H4uHAY
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### Can the electron $g$-factor be understood as electrons having roughly twice as much momentum as the Bohr Magneton?

I'm trying to make sure I understand the $g$-factor of the electron, so if my question is flawed please don't just point out my flaws, but help me correct my understanding If I understand correctly ...
52 views

### Why is magnetic field due to magnetization $M$ (net dipole moment per unit volume) of a material given by $B=\mu_0M$?

(Magnetization $M$ of a sample is defined as the net magnetic dipole moment per unit volume.) If, for example, the interior of a solenoid is filled with a material of non zero magnetization, the field ...
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### Magnetic Force on a Ferromagnetic Material

Consider a ball or bullet made of a Ferromagnetic material (such as pure iron) in a Magnetic Field, Does the Magnetic Force applied to the ball calculate via this formula? $$F = \nabla(m.B)$$ Can ...
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### How does magnetic moment vector arise from spin 1/2 spinors?

In NMR a hydrogen proton magnetic moment is a vector due to spin, but spin 1/2 like protons are spinors, not vectors, so how does spin 1/2 spinor give rise to an actual magnetic moment?
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### Does this basic example of two bar magnets preserve angular momentum conservation?

Let's say I hold two bar magnets side by side both vertically aligned ($z$-axis). I don't want to worry about their shapes, so let's approximate them as dipoles. I will use the dipole formula rather ...
1 vote
### Prove $\frac{\mu}{L}=\frac{\frac{Q}{2}}{M}$ [closed]
I was studying magnetism. I encountered a relation but with no proof. It was a statement. It says If for a body, charge and mass distribution is same then $$\frac{\mu}{L}=\frac{\frac{Q}{2}}{M}$$ ...