- #1
KFC
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In some textbook of fundamental electromagnetism, the relation between magnetic field [tex]\vec{B}[/tex] and so called magnetizing field [tex]\vec{H}[/tex] is
[tex]\vec{B} = \mu_0\vec{H}[/tex]
But later on, they introduce a so called relative permeability
[tex]\mu_r = \frac{\mu}{\mu_0}[/tex]
I might be wrong but my understanding of this definition is relative permeability is used to tell the 'capability to affect the field' of the object while comparing to something in free space? So [tex]\mu[/tex] is actually the total and absolute permeability of that object?
And I am quite confusing with [tex]\vec{H}[/tex] here. Now then we have the [tex]\vec{B}[/tex] to describe the magnetic field, why we need another field variable? Someone said it may related to magnetization. But if there is a magnetization so
[tex]\vec{B} = \mu_0(\vec{H} + \vec{M}) = \mu_0\vec{H}[/tex]
why we still have to use H ?
My last question is: if a material with relative permeability [tex]\mu_r=\mu / \mu_0[/tex] is considered, the relation between B and H will modified to
[tex]\vec{B} = \mu_r\vec{H}[/tex]
or
[tex]\vec{B}=\mu\vec{H}[/tex]
or
unchanged?
Thanks
[tex]\vec{B} = \mu_0\vec{H}[/tex]
But later on, they introduce a so called relative permeability
[tex]\mu_r = \frac{\mu}{\mu_0}[/tex]
I might be wrong but my understanding of this definition is relative permeability is used to tell the 'capability to affect the field' of the object while comparing to something in free space? So [tex]\mu[/tex] is actually the total and absolute permeability of that object?
And I am quite confusing with [tex]\vec{H}[/tex] here. Now then we have the [tex]\vec{B}[/tex] to describe the magnetic field, why we need another field variable? Someone said it may related to magnetization. But if there is a magnetization so
[tex]\vec{B} = \mu_0(\vec{H} + \vec{M}) = \mu_0\vec{H}[/tex]
why we still have to use H ?
My last question is: if a material with relative permeability [tex]\mu_r=\mu / \mu_0[/tex] is considered, the relation between B and H will modified to
[tex]\vec{B} = \mu_r\vec{H}[/tex]
or
[tex]\vec{B}=\mu\vec{H}[/tex]
or
unchanged?
Thanks