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• Users: mairzydoats
• In Electromagnetism
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Okay
2. ### In magnetism, what is the difference between the B and H fields?

When the cylinder is embedded, a secondary layer of bound densities is formed around it which oppose those of the P or M whose influence would otherwise be prevalent. That is why the method will measure H or D rather than E or B Too see what I mean you can try a thought experiment using my...

How so?
4. ### In magnetism, what is the difference between the B and H fields?

...which is model independent
5. ### In magnetism, what is the difference between the B and H fields?

...and so they are the usual assumptions for a good reason-they are the correct assumptions for the subject matter under discussion.
6. ### In magnetism, what is the difference between the B and H fields?

And besides, trying to discuss vector H on the quantum level doesn't even make any sense. H is defined as: H = B/μ° - M And M is by definition a macroscopic value. It is the magnetic dipole moment per unit volume. Undefined on the quantum level, and hence so too is H.
7. ### In magnetism, what is the difference between the B and H fields?

Yes, the usual assumptions in the macroscopic model.
8. ### In magnetism, what is the difference between the B and H fields?

The boundary condition which states that the discontinuity in the tangential component of the H at the border between two mediums is equal to the free surface current density J follows directly from the relation ∇ x H = Jfree + ∂D/∂t
9. ### In magnetism, what is the difference between the B and H fields?

But inside of a perfect conductor, there is no "polarization/magnetization" by definition. All charges/currents are "free charges/currents" and are at the surface. Where does choice come in? ...And what would you "shuffle" to change the conclusion you would be unavoidably directed to about...
10. ### In magnetism, what is the difference between the B and H fields?

Nope. https://en.wikipedia.org/wiki/Interface_conditions_for_electromagnetic_fields#Interface_conditions_for_magnetic_field_vectors At the interface between two mediums, the free surface current J is equal to the difference between the tangential components of H, on either side of the...
11. ### In magnetism, what is the difference between the B and H fields?

The only problem with saying H is just a mathematical construct and not a real field is that H can actually be directly measured by experiment at a particular point in space, and all without needing to know either B or M or even J locally. In this respect it is just as fundamental as E or B...
12. ### Ampere's circuital law

But if in the local rest frame of each wire element there is a magnetic field B-prime, then presumably a compass situated one of the elements and riding along with it would be accordingly deflected. With no B-field in the lab frame, what is there in the body of electromagnetic law to account...
13. ### Ampere's circuital law

Not an imaginary artifact. We have to be able to determine, yes or no, if compasses situated along the perimeter of the shrinking loop in the constant E field would deflect. Either they would or they wouldn't.
14. ### Ampere's circuital law

is this a yes?
15. ### Ampere's circuital law

The amount of E passing through a surface enclosed by the shrinking loop is lessening even though E itself is time-constant inside of it. Would that be like a displacement current through it? After all, in a Faraday law analogy, if it were a loop perpendicular to a B field, there would be 2...
16. ### Ampere's circuital law

Imagine an E field coming out of your screen that is constant everywhere in space and time (∂E/∂t=0). And in your reference frame, let's say that this the only field there is -- there is no B. Say there is a loop in the plane of your screen, and so the plane of this loop is perpendicular to...
17. ### Maxwell's curl equations

∂∂∂ Thank you very much for your reply! Getting back to my shrinking loop of wire in an area of time-constant B field, would the following analysis be correct, in light of what you've said? (Let us assume either no induced current, or negligible induced current in my shrinking loop, so it...
18. ### Maxwell's curl equations

If I may make a quick correction, I should have presented the integral form as ∫(closed)E⋅dl=-d/dt[∫B⋅dA], and not as ∫(closed)E⋅dl=-d/dt[∫(closed)B⋅dA] like I did, because the surface integral on the right is NOT around a closed surface. (sorry).
19. ### Maxwell's curl equations

I first learned Maxwell's equations in their integral form before I was introduced to the differential form, i.e. w/curl & divergence. As I understand, in order to derive the curl form from the integral form, apply Stokes Theorem to the integral form of ∫(closed)E⋅dl=-d/dt[∫(closed)B⋅dA], and...