B, H fields due to a magnetized material everywhere

In summary, the answer is that \vec B = \mu_0 \vec M everywhere in the magnetic material, but \vec H can be non-zero depending on the geometry of the material. This means that while \vec H may be zero in some cases, it can also be non-zero due to the presence of induced surface or free currents.
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AxiomOfChoice
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If we consider a material with uniform magnetization [tex]\vec M[/tex], what are the [tex]\vec B[/tex] and [tex]\vec H[/tex] fields everywhere in the magnetic material? My first inclination is to say that [tex]\vec H = 0[/tex] since there are no free currents and that therefore [tex]\vec B = \mu_0 \vec M[/tex] everywhere, but I can think of situations where there's no free current but there's still an [tex]\vec H[/tex] field (e.g., inside and outside a uniformly magnetized sphere), so I'm probably wrong.
 
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The answer is that \vec B = \mu_0 \vec M everywhere in the magnetic material, but \vec H can be non-zero depending on the geometry of the material. For example, inside a uniformly magnetized sphere, \vec H will be non-zero due to the presence of surface currents induced by the uniform magnetization. Outside the sphere, \vec H will be non-zero due to the presence of free currents induced by the uniform magnetization.
 

FAQ: B, H fields due to a magnetized material everywhere

How does a magnetized material create a B field?

A magnetized material has microscopic regions called magnetic domains, where the electrons align their spins in the same direction. These aligned electrons create a magnetic dipole moment, which produces a B field around the material.

What is the difference between B field and H field?

The B field, also known as the magnetic flux density, represents the strength of the magnetic field. The H field, or magnetic field intensity, represents the amount of magnetic force acting on a unit of current. In other words, B field measures the strength of the field, while H field measures the effect of the field on the surrounding objects.

Can a magnetized material have a B field of zero?

No, a magnetized material will always have a nonzero B field, even if it is very weak. This is because the magnetic dipoles in the material will still create a magnetic field, even if they are not all perfectly aligned.

How does the B field change when a magnetized material is placed in different environments?

The B field around a magnetized material can be influenced by the presence of other magnetic materials, as well as external factors such as temperature and electrical currents. These factors can cause the B field to either strengthen or weaken, depending on the specific conditions.

Can the B field of a magnetized material be shielded or blocked?

Yes, certain materials such as iron or steel can act as magnetic shields, effectively blocking or redirecting the B field. This is why we often see magnetic materials used in the construction of devices such as MRI machines, to prevent interference from external magnetic fields.

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