A magnetic dipole is the limit of either a closed loop of electric current or a pair of poles as the size of the source is reduced to zero while keeping the magnetic moment constant. It is a magnetic analogue of the electric dipole, but the analogy is not perfect. In particular, a true magnetic monopole, the magnetic analogue of an electric charge, has never been observed in nature. However, magnetic monopole quasiparticles have been observed as emergent properties of certain condensed matter systems. Moreover, one form of magnetic dipole moment is associated with a fundamental quantum property—the spin of elementary particles.
The magnetic field around any magnetic source looks increasingly like the field of a magnetic dipole as the distance from the source increases.
Let's say that an electron is moving with constant velocity through a magnetic field. If the magnitude of the field is the same everywhere in space and if it is perpendicular to the velocity of the particle everywhere, the electron will follow a circular path. We all know that. What I need to...
What is the nature of magnetic dipole radiation?
Does a rotating bar magnet give rise to electromagnetic radiation(magnetic dipole radiation to be more specific)??
I'm seeking some clarification on a topic found in Jackson 'Classical Electrodynamics' Chapter 5. This deals with the magnetic field of a localised current distribution, where the magnetic vector potential is given by
\vec{A}(\vec{x}) = \frac{\mu_0}{4\pi}...
I've run across a diagram that really is driving me crazy. The torque on a mag. dipole should be simply be τ = m X B, where B is the external field as usual.
In the image I've attached, there is a large external field, not shown, in the direction of Z which is holding the dipole in the +Z...
Guys,
I don't quite understand the concept of magnetic dipole moment as a vector.
Suppose we have a magnet (like a rod) in 3 dimensional space. North pole at (0, 0, 0) and South pole at (0, 1, 0).
How would the magnetic dipole vector \vec{m} be oriented?
Thanks.
[SOLVED] Griffiths 5.58
Homework Statement
A uniformly charged solid sphere of radius R carries a total charge Q, and is set spinning with angular velocity \omega.
What is the magnetic dipole moment of the sphere.Homework Equations
The Attempt at a Solution
The magnetic dipole moment of a...
Homework Statement
Show that the magnetic dipole moment M of an electron orbiting a proton nucleus of a hydrogen atom is related to the orbital angular momentum M=(e/2m)L
Homework Equations
M=NIA, Torque =MB, F=qvB=v^2/r, L=Iw=mrv=rp (where p=mv)
N=1 in this case I assume?
The...
There has been some dispute in the past about the validity of the electric current model of a magnetic dipole producing a force \nabla (\vec{m}\cdot\vec{B}) versus the magnetic pole model producing (\vec{m}\cdot \nabla)\vec{B} (see e.g. Boyer `87). I think for elementary particles this dispute...
Homework Statement
A uniformly charged solid sphere of radius R carries a total charge Q, and is set spinning with angular velocity \omega about the z axis. (a) What is the magnetic dipole moment of the sphere?
Homework Equations
\vec{m} = I \int d\vec{a}
The Attempt at a...
This isn't a homework problem, I'm just doing this as practice.
Homework Statement
A magnetic dipole is oriented in a loop of wire of N turns and radius a so that the dipole vector is parallel to the normal of the loop. The loop is connected to a galvanometer, and the active resistance of...
Homework Statement
1) In the case of a bar magnet, outside it, the magnetic lines of forces start from North Pole and end on South Pole. But inside it, the lines of force start from south and end on North Pole. According to definition of direction of lines of force, it is the direction in...
Homework Statement
Find the magnetic dipole moment of a spherical shell of radiu R carrying a uniform surface charge sigma, set spinning at angular velocity omega.
Homework Equations
\vec{m} = \frac{1}{2} \int_{S} \vec{r'} \times \vec{K} (\vec{r'}) da'
The Attempt at a Solution
So...
Homework Statement
A phonograph record of radius R carrying a unifrom surface charge sigma is rotating at a cosntant angular velocity omega. Find its magnetic dipole momentHomework Equations
m = int I \bullet da The Attempt at a Solution
Need to find the current first
well the sruface charge...
For a current loop, the magnetic dipole moment is defined as i \int d\vec{a}
Now, if I'm given a surface current 'K', how can I find the magnetic dipole moment? For example, if a disc of surface charge [itex] \sigma [/tex] is rotating with angular velocity [itex] \omega [/tex], what is it's...
Take the example of a magnetic dipole in a magnetic field. The dipole will experience a torque that will tend to align its magnetic moment with the field lines of the magnet. So why on Earth is there no mention made of this torque in any of the countless descriptions of the Stern Gerlach...
I have some trouble with this electromagnetism problem: I need to transform the four-potential of a magnetic dipole at rest, in order to obtain it's value in a reference frame (I understand it's the Lab frame) where we see the dipole moving at v.
I know what the magnetic vector potential is...
Hello, i have absolutely no clue on how to start this one:
a sphere of radius R has a uniform volume charge density \rho.
Determine the magnetic dipole moment of the sphere when it rotates as a rigid body with angular velocity \omega about an axis through its center.
thanks for the help...
Magnetic Dipole Moment does not include the permeability of free space?
Hi,
The formula for a magnetic field in a current loop involves the permeability of free space.
But the formula for the magnetic dipole moment which seems to represent the flux through a current loop does not...
For an undergraduate electrodynamics homework problem we were asked to derive the following:
(griffiths 6.21)
show that the energy of a magnetic dipole in a magnetic field B is given by -
U = -m.B
where
B is the magnetic field
and
m is the dipole moment.
I went about this...
Hi All,
Please show me the derivation of the vector potentiol A for the magnetic dipole.
from equation 8.21 to 8.21a
This page is taken from Sadikus book.
** i tried all day and couldn't manage to obtain it. i need the derivation step by step **
thanks
newbie...
i received this problem from my lecturer
A solenoid is wound with 2200 turns per meter, and carries a current 2.5A. Take the axis of the solenoid to the solenoid to be parallel to the z-axis. A magnetic dipole moment given (m)=(20A.m^2)i+ (30A.m^2)k is located inside the solenoid.
i)how...
I need to find the field of a magnetic dipole embedded in the center of a linear magnetic sphere of radius R. My idea was that the field would be identical to that of a superposition of a dipole in a linear magnetic material throughout space and a surface current on the sphere equal to the...