On Sun, Jun 1, 2008 at 11:47 PM, Robert Derman <[EMAIL PROTECTED]> wrote:
> Pat McBride wrote: > >> Ian; >> >> I once learned a poem - Twinkle, twinkle, little star >> Power = I sqared R >> >> And I got beat about the head and shoulders by a math teacher, it finally >> sank in that anything multiplied by zero is zero. >> >> Soooooooooo, you must be talking about the power loss in a >> superconductive >> circuit???? However, you'll agree, I hope, that there'll be a small loss >> in >> power; otherwise we'd have the Perpetual Motion effect. There's going to >> be >> a small loss in power, because I don't really think there'll ever be such >> a >> thing as a perfect superconductor. >> >> >> > Superconductors are one of those odd things in physics that don't abide by > the usual rules. There is in fact NO significant loss of power from any > material when it is operating as a true superconductor. The only limitation > seems to be that superconductivity can only occur at cryogenic temperatures. > > Wouldn't you still get some kind of inductive/capacitive losses? Not nearly as much with AC but unless the current draw is dead constant you will still have a varying current creating a magnetic field. Rod
