Magnetic Field around two magnetic boxes

In summary, the conversation discusses a problem involving four planes with two different sets of capacitors. The problem involves finding the magnetic field in the presence of these capacitors. The solution is that in cases where the dimensions are much larger than the distance between the planes, the magnetic field will be zero everywhere except in the material where the magnetic field is equal to -M. This is due to the magnetic charges from the capacitors cancelling each other out. The conversation also mentions the use of Gauss' law to help solve the problem.
  • #1
DaniV
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Homework Statement
Two magnets with magnetization Mz $\hat$ are placed on a surface parallel to
the xy plane, and are almost adjacent to each other, as illustrated. The
length and width of each magnet is w, the height is h, and the distance
between the magnets is d. w >> h >> d, and you can assume that w → ∞.
Find the magnetic field everywhere in space (above and below the magnets,
inside the magnets, and between them).
Relevant Equations
this question using fictive charge method:
the basic equation is $B=\mu_{0}(M\vec+H\vec)$
$\vec H =-\nabla\psi$
$\psi =\frac{1}{4\pi}\intagral \integral\integral\frac{\ro(x)_{fictive}}{|\vec x-\vec x`| }d^3x'$+\frac{1}{4\pi}\integral \frac{\sigma(x)_{fictive}}{|\vec x -vec x'|}dl'$
I tried to look once at the zy axis and saw a two infinite capacitors with fictive charge density of M on the upper plane, and -M in the lower with a distance of h from each other, the two capacitors saparated with d in the y axis,

but when I look in xy axis there was 2 another capcitors the first with the same fictive charge density M on the left and right plane with distance of d between them, the second one sapareted by h in the z axis show another capacitor with -M on the right and left planes

how I preform such a superposition of fields because there are 4 planes and for which we can preform 2 different ways to look on the same problem (different capacitors) to find $\vec H$?
 

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  • #2
This is kind of an odd problem. If ## w >>h ## and ## w>>d ##, basically the magnetic field ## \vec{B} ## will be zero everywhere. ## \\ ## The ## H ## from the plus magnetic charges (fictitious) will (approximately) cancel the ## H ## from the minus magnetic charges, except in the material where the ## H=-M ##, so that ## B=\mu_o(H+M)=0 ## also. I know I'm not supposed to furnish the answer, but that is the only way I can supply the necessary feedback here. ## \\ ## Note: on the faces parallel to the x-y plane, ## \sigma_m=\vec{M} \cdot \hat{n} ##, (comes from ## -\nabla \cdot M=\rho_m ## and Gauss' law), and also ## B=\mu_o(H+M ) ## , with ## \nabla \cdot H=- \nabla \cdot M ## gives with ## H_{outside}=0 ## that ## H_{inside}=-M ##, by Gauss' law. ## \\ ## Perhaps someone else may see a different solution, but this is what I get from working it.
 
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1. What is a magnetic field?

A magnetic field is a region in space where a magnetic force can be detected. It is created by moving electric charges, such as those found in magnets.

2. How is a magnetic field measured?

A magnetic field is measured using a device called a magnetometer, which can detect the strength and direction of the magnetic field.

3. What is the relationship between two magnetic boxes and their magnetic fields?

The magnetic fields of two magnetic boxes interact with each other, creating a combined magnetic field. The strength and direction of this combined field depends on the strength and orientation of the individual magnetic fields of the two boxes.

4. How does the distance between two magnetic boxes affect their magnetic fields?

The strength of the magnetic field decreases as the distance between two magnetic boxes increases. This is known as the inverse square law, where the strength of the field is inversely proportional to the square of the distance between the two boxes.

5. Can the magnetic field around two magnetic boxes be manipulated?

Yes, the magnetic field around two magnetic boxes can be manipulated by changing the strength or orientation of the individual magnetic fields of the boxes. This can be done by using external magnetic fields or by physically moving the boxes closer or further apart.

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