is this an EM wave

First get the infinitely long straight wire !!!

Yes - but it doesn't have to be infinitely long or perfectly straight.

A radio receiver?

An infinitely long wire would have infinite resistance therefore zero current would pass through it therefore no waves of any kind would be produced.

Really? Ever heard of a transmission line?

the signal through a transmission wire needs to be buffered or repeated

Think about what you've written again. Do the Voyager probes need to "buffer or repeat" what they've sent?

No, a transmission line looks like its characteristic impedance to the driver, no matter *how* long the line is. Current *will* travel in the line until it's absorbed by the R and D components, even beyond detection.

If you want anyone to read what you've written (and I assume you do since you toook the time), do *NOT* post HTML. Only a fool will bother.

You posted with HTML, which is unreadable by most and certainly not a Usenet norm. Post in test only, moron! Oh, you won't listen because you plonked me, rather than learning from *YOUR* misteaks. Go figgr.

As a hint, this is what you posted (looks like HTML to me...:

Yes, but he implies that a current is being drawn whih implies an infinitely high voltage must be present. TimPerry wrote: "dysfunctionally_yours" < snipped-for-privacy@gmail.com> wrote in message news: snipped-for-privacy@u72g2000cwu.googlegroups.com... if i pass alternatin current through an infinitely long and perfectly straight wire, would i get an electromagnetic wave? is there any manner in which i can detect whether or not these waves are produced?

An infinitely long wire would have infinite resistance therefore zero current would pass through it therefore no waves of any kind would be produced.

-- Joe Leikhim K4SAT "The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason? For if it prosper, none dare call it treason."

"Follow The Money" ;-P

...you may apologize now.

-- Keith

I got it alright but some still receive "plain text" so the formatting is lost and HTML headers come through as extraneous header information. Plain text is simply a courtesy to those that have HTML problems. It is too bad because HTML does allow more latitude in what is sent.

This is HTML while the previous was plain text

I got it alright but some still receive "plain text" so the formatting is lost and HTML headers come through as extraneous header information(look like garbage). Plain text is simply a courtesy to those that have HTML problems. It is too bad because HTML does allow more latitude in what is sent.

Only if seven angels can dance on the head of a pin.

Bill

-- Ferme le Bush

ok. im not sure where this is heading, but if the line is a superconductor, and has no impedance, and i somehow inject a current into it, will i get an EM wave?

as far as transmission lines are concerned , thoough i cannot say for sure, there is one EM wave which moves along the length of the line uptil the point it is terminated, and another may be due to corona

A superconducting transmission line will still have an impedance. In a super conductor 'R' may go to zero, but there is still a non- zero 'C', 'L', and 'D' term. Where there no inductance, for example, we wouldn't have superconducting magnets nor SQUIDs.

If the transmission line is infinitely long, there is no terminator. ;-)

I'd have to think about corona some more, but first SWAG I'd lump it in with the 'D' term.

as far as inductive emf is concerned, though i may not be right , but i believe that it comes into the picture only if the magnetic field of the current carrying conductor links itself. if the line were perfectly straight ( and note that my original question was purely conceptual, assuming all ideal cases) the magnetic field of the conductor would not link any part of the conductor and hence no effect.

would there be any inductance if there were absolutely, and ideally no twists and turns?

no: the short circuit will burn up the current source.

(plus an infinitely long wire that had any mass/distance would fill all available space in the universe)

do you have a practical objective in mind or are you just wondering?

Yes. Even free space has a characteristic impedance (377ohms, if memory serves).

Well, those long transmission lines from Labrador, through Quebec and into New England may not be infinite but they are pretty long, and the 60 Hz AC in them certainly radiates something that makes my portable frequency meter read 60 Hz when I drive under them.

Dave