Magnetic moment Definition and 181 Threads

This is not a homework question I encountered this while revisiting the Electric Dipoles . First of all if someone explains me why the dipole So in the image above which way should the dipole rotate ? Anti Clock Wise or Clock Wise . What My intuition says is the Energy of a dipole is U...

A charged particle - like an electron - has a magnetic moment. This moment changes depending on where the electron is. If you apply a magnetic field to an object with a magnetic moment, it experiences a torque. It turns. This turning motion is not included in the overall motion of the...

Just for clarification, I was wondering if someone could clarify what the difference between a magnetic moment and magnetic domain is. My understanding is a magnetic moment is when the atom aligns it's subatomic particles relative to the magnetic field, and that a magnetic domain is groups of...

Hello, calculating the magnetic moment of a current loop is trivial, but I want to do it with the general formula \vec m = \frac{1}2 \int \vec r \times \vec J(\vec r) d^3\vec r The only thing which is stopping me is to find a good argument on why \frac{1}{2}\int \vec r d\vec r = \vec A where...

Homework Statement d\hat{S}/dt = γ\hat{S} \times \hat{B} What is the physical interpretation of this equation i.e. what is the behavior of the magnetic moment in an uniform magnetic field?Homework Equations I don't think I need any equation for this, just intuition or vector calculus identity...

I've read that the neutron has a magnetic moment because it is made of composite particles, namely 1 up and 2 down quarks. But why does the neutrino, which is electrically neutral and a fundamental particle, have a nonzero (albeit very small) magnetic moment? How is that even possible? Does...

Homework Statement Consider the Hydrogen atom in a magnetic field of 2T. If the atom is in its ground state (orbital angular momentum L=0): (a) Write down the magnetic moments of the proton and the spinning electron. [1]Homework Equations I am aware that the magnetic moment μ =...

Does anyone know the magnetic moments of the up and down quarks? I am interested only in the best experimental data, not theoretical estimates.

I thought the external magnetic field had to vary within an object in order for that object's magnetic moment to line up with the field.

Homework Statement Assume that an electron is a sphere of uniform mass density \rho_m=\frac{m_e}{\frac{4}{3} \pi r_e^3}, uniform charge density \rho_e=\frac{-e}{\frac{4}{3} \pi r_e^3}, and radius r_e rotating at a frequency \omega about the z-axis. m_e=9.109*10^{-31} kg and e=1.602*10^{-19} C...

Homework Statement A slender, 200- g bar magnet 15.0 cm long has a magnetic moment of 5.50 A m2. It is held at an angle of 45 o to the direction of a uniform magnetic field. When released, it begins to rotate about its center with an initial angular acceleration of 8.40×103 rad/s2. What is the...

A friend asked me this but I'm not sure of my answer. On a particle level, I said that the value of the magnetic moment determines how the probability is that the particle absorbs/emits an electron. Is this right? Thanks

Homework Statement Show for a solid spherical ball of mass m rotating about an axis through its center with a charge q uniformly distributed on the surface of the ball that the magnetic moment \mu is related to the angular momentum \vec{\mu}={\frac{5q}{6mc}}\vec{L} Homework...

I was trying to find the value of the magnetic field at a distance x from a rare-earth magnet and came across this equation: B=\mu_o*2\mu/(4\pi*d^3) Does anyone happen to know the magnetic moment, \mu, of a rare-earth magnet? Nothing specific, an order of magnitude value is fine. Thank...

Hi could someone please explain the story (if there is one) about the Dirac equation with an anomalous magnetic moment term, I have seen this in several old papers but it never seems to be mentioned in textbooks. Was this an old confusion in formulating QFT. In this context I believe the Dirac...

Protons have a magnetic moment of 2.8 μN, Neutrons have a magnetic moment of −1.9 μN. What is the meaning of the negative sign? Does the Neutron go a different direction in a magnetic field? How do they know it isn't just upside down? Is there any kind of a visual picture of a magnet that...

Hi. I have a question concerning the magnetic momentum of a current loop. We know that if we have a circular current loop (a solenoid with N=1), there is a magnetic moment (mu) in the center of the loop given by "mu=S I" (I=current, S =surface enclosed by the loop). So, if there is an external...

I'm trying to show that for an electron of uniform charge and mass distributions spinning about a fixed axis that the classical calculation for the magnetic moment is μs = -(e/2m)S where S is the spin angular momentum. Now I know that the moment for any given current loop is μ = iA. So...

Homework Statement Suppose that an electron is a small spherical shell of mass m with a charge e spread over its surface. Show that the ratio of the magnetic moment to angular momentum of such an electron should be e/2m whether the electron is a) moving in a circular orbit or b) spinning...

it is obvious that the hamiltonian of an atom is time reversal invariant but how can an atom have non-zero magnetic moment?

I ran across the fact that the magnetic moment of the neutron is approx 9.66e-27 J/T. When I plug it into the formula for attractive/repulsive force between 2 magnetic dipoles within 1 femtometer of each other (nuclear dimensions) I get almost 9000N, and the energy to separate them (if...

Homework Statement A particle of charge q is rotating in a circular orbit of radius r with angular velocity omega. determine the magnetic moment associated with the motion of the charge Homework Equations M=IS The Attempt at a Solution M=I*(pi*r^2) hav no idea how to get rid of...

Homework Statement A solenoid runs in z direction through x-y plane. As it passes through plane current is running counter-clockwise with an amount of I(t)=2.3 A/s2t2 (increasing over time counter-clockwise). Also, n=7 x 104/m for solenoid. A wire shaped as a square with sides of 1.2 meters...

What would be a typical value of the magnetic moment of a compass needle (in SI units)? Thanks :-)

Homework Statement Calculate the ground state magnetic moment of 7Li using the below equations. The spin value is 3/2. Homework Equations mu_J = gamma_J * J* hbar = g_J * u_N with g_J = [g_l + (g_s - g_l)/(2l + 1)] where g_l and g_s are orbital and intrinsic spin g factors for...

I am taking a class which discusses orbital angular momentum in a pseudo-quantum way, and it was explained that the orbital angular momentum is zero if the time average of the individual "L vectors" sum to zero. I am considering p-orbitals. The argument is that, if there are 3 electrons in the...

Why neutrino may have magnetic moment? Even if it is massive... it is not composite and it is electrical neutral...

Homework Statement Need to calculate magnetic moment of FeRh from the curie constant which was obtained from a linear fit of inverse susceptibility data. CGS units! C = 68 (cm3K)/mole N = Avogadro constant 6.022E23 atoms/mole K = Boltzmann constant 1.38E-16 erg/K uB = Bohr magnetons...

Homework Statement An electron has a magnetic quantum number m=2.What is the magnitude of the orbital magnetic moment. Homework Equations mu=eL/2m The Attempt at a Solution Now i figured that the above equation gives the magnitude of the orbital moment and the equation for the z...

Hi The magnetic force applied to electron spin magnetic moment is interpreted by Lorentz force qvXB ? I do not think so. If not, we easily understand why magnetic force can work. Regards.

I'm trying to get a better understanding of a magnetic moment . The magnetic moment of a particle is its willingness to align with the B field. Can we think of it as its magnetic moment of inertia or is this incorrect.

What causes the neutron to have a magnetic moment , and is it paramagnetic or diamagnetic.

Homework Statement A small magnetic moment \vec{m}(t) fixed at position \vec{r} varies in a complicated way as a function of time. (a) Show that if the time variation is "slow enough", the voltage generated around an arbitrary loop of wire near the origin is E(t)=\alpha...

Consider a situation. If an electron is moving on your computer screen from top to bottom and the magnetic field is acting outwards towards your face, the electron revolves in anti-clockwise direction.. So we can say that the current is flowing in clockwise direction. Magnetic moment when...

Could someone show me how to calculate the magnetic moment of a solenoid, it's an air gap solenoid, 12V power supply, 1200 turns, 6cm long, the current works out to around 5-7 A and uses 1mm wire (18 AWG or 19 SWG). the flux density works out at about 3 Teslas. If what I'm using it for...

Hi, I've an experiment in which I've some magnetic material place into a coil that's used as sensor. Say it's a cylindrical one for the sake of simplicity. I'm trying to evaluate the flux induced by the material into the coil so that I can optimize the coil parameters (size, position and...

1. A spherical shell of radius R has a constant surface charge density, sigma. It rotates about its diameter with angular speed, w. Find the magnitude of the magnetic moment of the rotating spherical shell. 2. Magnetic dipole moment u = NIA(normal vector) ; Torque = u X B; Spherical Volume...

What is the "net" magnetic moment per atom of a typical ferromagnet crystal ? I suspect the number will be different from those of "isolated" atoms because of band formation and spilling... But I am not very sure, this could be wrong. Is it 1 Bohr magneton per atom, 10 , 50 more ? Do...

I'm not sure if this is the proper location for this thread, but its for a math course and I think my issues concern the math portion of the problems. If it should be moved please do so. Note: I know the post is quite long, so I'll just pull out my few main issues from all the junk. 1)...

hi I am student of graduate and want to clear the picture of MAGNETIC MOMENT of electron in my mind.can someone tell me that if an electron is moving in its orbit constituting its intrinsic spin(1/2) ho can it forms dipole moment(to poles) when place in magnetic field?and what is the difference...

Hi all: I am confused about how far spin magnetic moment goes during a finite diffusion time (such as 100 ms). As we know, due to T2 relaxation mechanism in NMR, spin 1 and spin 2 can exchange magnetic moment but no energy transfer during this exchanging process due to dipole-dipole...

Homework Statement find the magnetic moment of a hydrogen atom given that the election moves at 0.10c around the nucleus and the radius is 0.5*10^-5 m Homework Equations n/a The Attempt at a Solution this is what i did. I = nev =ev (I = current e= charge of electron, v =...

I need to solve an exercise on Quantum Field Theory that reads as follows: Supousse that the electron has an anomalous magnetic moment, which makes the QED Lagrangian (density) to have an additional term: L'_I(x) = \frac{2ie}{m} \bar{\psi}(x) \sigma^{\alpha\beta} \psi(x) F_{\alpha\beta}(x)...

Our company had products certified by an ISO testing body for EU standards. One of the requirements is that a component have a minimum magnetic moment, expressed in A·M². The agency published the reports in CGS units and approved the products. A second body from another country (5 years later)...

Homework Statement a charge 5 x 10-6 C is located at the end of a 0.30m insulating rod. the rod rotates at w = 100 rad/s. find the magnetic moment of the charge. Homework Equations hint: the charge travels around a circle in a time equal to the period of the motion. The Attempt at...

Homework Statement A diatomic molecule such as O2, can be thought of as a rigid rotator (dumbbell molecule) if its energy is not too large. Assume that the rotator consists of two identical masses, M, separated by a constant distance, R. (a) Find the energy eigenvalues and eigenkets of the...

Quote from "Spin Stabilized Magnetic Levitation of Horizontal Rotors", L. A. Romero, from SIAM Journal of Applied Mathematics. "Suppose we have a rotor that has two equal dipoles on the axis of symmetry, each pointing in the direction of the axis of symmetry. We suppose that the magnets are...

A small sphere is uniformly charged throughout its' volume and rotating with constant angular velocity \omega. Show it's magnetic moment is given by m=\frac{1}{5}Q \omega a^2. the question doesn't say but I'm assuming a is the radius. Anyway, so far I have: m=\frac{1}{2} \int_V dV...

Hello everyone, this is my first post at Physics Forums! I am trying to understand electromagnetism, and when it comes to the magnetic moment, when reading around I see \mu = IA where A is area of a loop, which is an expression I can sort of understand. But when reading about magnetic drifts...

The magnetic moment of a deutron is 0.8574 u_n.Its ground state wave function is taken to be a mixture of S and D states.the expectation values of z-component of the magnetic mment in pure S and pure D states are 0.8797u_n and 0.3101u_n respectively.What is he contribution of the D state to the...