ODP: one for the theorist

[Martin Czech]

:::> Temat:	one for the theorist
:::> 
:::> I've recently read a book where the inductance of a single piece of wire
:::> was given. This is strange, I thought, because you can only speak of the
:::> inductance of a loop. And, after all what I know, the magnetic energy
:::> of a single wire without "back" current path goes towards infinity and
:::> so does L. 
:::	[Roman Sowa] 
:::	Current flowing through every wire causes magnetic field around it.
:::	H file lines are circles around the wire. When current changes,
:::	the H file also changes, so you basically change H file energy
:::	which is what inductors do. Btw, the E file also appears then, but
:::	that's a whole different story. When wire is looped, H vectors
:::	are summed inside the loop, thus bigger H energy.
:::	BTW, have you seen UHF transformers in an old TV set maybe?
:::	Those are few straight wires in paralel. 
:::

Ok, could you please show me how to compute L of a pice of wire in vacuum.
This should be easy, since the H-Field is almost trivial, as you said.


m.c.