Speed of EMF Through Different Materials

No. It travels at 186,282 miles per second.

Certainly not.

I believe it is not as simple as some of the previous commments suggest. If the speed of EMF in a material is related to the rate of magnetization of the material, that is where the permeability of the material comes into play. I would assume that the difference of EMF speed in different metals is probably negligible, but when comparing metals with non-metals, the difference could be significant.

I suspect that this will change with the speed of light in that material. Now since this will always be within an order of magnitude of the speed of light in a vacuum, I cannot think of a scenario that this will be of consequence to any application. But one day this maybe relevant. Who knows, maybe the velocity of fields will be the lynch pin that finally refutes or confirms string theory?

Suppose you have a very long loop of copper coated steel wire, and apply an alternating current and voltage. Over a long distance, will the EMF from the two conductors get out of phase?

You get the exact same thing that happens when an unterminated transmission line sends back a reflected wave. Reflections will cause phase cancellations and amplifications at certain frequencies and locations.

So if you were to tune the length/frequency/materials just right, you could get a boost in EMF?

Would the out of phase waves cause an induced voltage in the conductors in addition to the main current?

Close, you only got the phasing backwards. The out of phase waves would approach 0 while in phase waves will increase.

So if you were to tune the length/frequency/materials just right, you could get a boost in EMF?

Yes, it's called resonance.

Yes^[1]. The speed of light depends on the refractive index of the medium through which it is passing.

Since nothing^[1] can travel faster through a medium than the (local) speed of light, the speed of EMF (assuming that you may mean "Electro-Motive Force") must vary, depending on the material though which it is passing.

[1] As far as we know.

Nothing can sustain a velocity faster than the speed of light in a medium but don't forget about Cherenkov radiation. A charged particle moves faster than the speed of that medium for a brief amount of constantly loosing energy in the form of light.

Give you that - but it's not very pertinent to this discussion.

Yes. For instance, an electromagnetic wave in air travels about a foot in a nanosecond, about half that in copper on a printed circuit board. In some of those fancy new exotic materials they can even slow it to a stop.

As was said uphere n•v=c where n is refract.index not matter if material is dark or not to some wavelength or if it is conductive or not;2)If it is a conductor is not an ideal conductor, electrons have mass and theorically a delay should be expected,perhaps a phase difference other than mentioned uphere (this effect is never considerated for technical purposes into my knowledge);3)a common antenna,a tv antena, have a reflector element, in the "yagi" types still used uhf (vhf normally use other type) you can distinguish the refflector as the element on one side of the main and conected element:the dipole, sometimes a double one.-

I suspect that the safe "guess" to your question is, "YES", and then of course you will want to now, "by how much?"

The max reference speed will be the speed of light in space - but the emf velocity is likely to be slower than this for the same/similar reasons that light travels at lower velocities in mediums like diamond, glass and water - and as one post indicates, at very low velocity in some exotic materials.

On the assumption that your metallic medium is not compromised by capacitive circuit effects, it seems likely that there will be no great difference between the velocity of emf in silver and gold and the like, but it is not so likely that the velocity in magnetic materials was "the same" as it is certainly the case that magnetic changes take time and so are likely to slow the transmission of emf in magnetic materials.

There is a significant difference in the two, due to the microscopic interactions (lights) vs macroscopic interactions (electricity) of the two electromagnetic waves,

The macroscopic effects of the dielectric const and the permeability (one affecting the electrical portion of the wave and the other the magnetic portion) causes the delays in passing through and that at high frequency macroscopic level converts itself to the refractive index.

The maxwell's equation does address to it in the EM propogation velocity.

MAxwell adresses it correctly. It is slowed from the vacuum speed of light, proportional to the square root of epsilon (capacitive factor) and the square root of mu (magnetization factor). Your problem - if any - to measure them correctly. But, for estimation, what I said is enough.

Providing you're talking about Electro Motive Force and not having any experience to suggest magnetic field lags or precedes the electric field that goes with it and no theoretical background to challenge for anything different I'll go for 'same speed of the corresponding electric disturbance in the specific material', until CERN proves me wrong. What's the prize? S.M.

Looking into the mirror?!?

You are right, though I suspect the OP has used the wrong terminology.

It is the speed of Electric Field (or its set-up) that would vary depending upon the media and that would affect the voltages at different points of a very very long circuit (to be measurable significantly) which would take some time to settle down.

For example if one draws a cable from here to say Neptune and back and connects a 12V power source across it, the voltage at Neptune won't immediately rise to 6V (with reference to source of course) It would take its time for the field to set up across the whole cable and that would depend on the two factors - slowing down through the Electric and slowing down through magnetic properties.