Recent content by tapsanit

I think what we feel when we rub hands together is heat but not plasma. The plasma is the flowing of ionized charge. Our hands are dielectric material, so it is not reasonable to have ions by rubbing hand.

May be It is just my misunderstanding, the force acting upon the electron at point r are due to the electric field in the material at point r, F(r) = qE(r). I had thought that the force is due to the external field, F = qE0 because we always assume the harmonic time-dependence of E to be the...

I am sorry. Let's me clarify this problem. Let's consider the classical Drude model. You have known that the metal is absorbing dielectric. That means the dielectric constant is complex. The Drude model can give the complex dielectric constant. It treats the electrons in the metal as free...

Thank you Jano L. for replying but I am still confusing. If there is the external field E0, the electric field E in the definition of the displacement field should be the sum of the macroscopic Em, that is, E = E0 + Em. This relation is derived from the Gauss's law as described in Griffith's...

I assume that everyone knows the constitutive relation of dielectric material : D = ε_0E + P where D is the electric field displacement ε_0 is permittivity of vacumm E is the electric field (or may be the electric ) and P is the polarization (density*dipole) I am...

Thank you for your replying, I think this is very good answer applied to the case of conductor.

Lets me show the example, the metallic sphere is embeded within the vacuum, it is applied by the static electric field amplitude E0 polarized in z direction . Assume the perfect conductor, there is just the induce the surface charge generating the internal electric field to cancel the external...

I asked the first question that if there was no surface current, there would not have the surrface charge density? The answer were,there was the surface charge density, and you can calculate it from the boundary condition of normal conponent, so perhap the origin of the surface charge density...

clem : Could you describe why it is wrong, or it is just wrong because it dose not satisfy Born2bwire.

So, what I think is the surface charge density could be generated by the polarization of cloud electrons relative to the positive core in conductor. This indicates that even no having the surface current, we can have the surface charge density according to "clem".

I do agree with you in the sense that the normal component of electric field might be considered to generate the surface charge. Actually, I think we can obtain the solution of the normal component by dealing with just the boundary condition in tangential component without the surface current...

So, in the case of ohmic conductor in which the conduction current plays the important row than the surface current, then the surface current could be vanished, the surface charge density should also be vanished, because the changing of surface charge density defines the surface current due to...

How's about the surface charge density. Does it follow discussed idea so far? I mean there is induced surface charge density if and only if there is current flowing on the surface. But we can not expect the surface charge under the ohmic conductor, finite conductivity?