Michel Jullian wrote: > I agree with all the interesting comments below, both Stephen's and yours, relative to the unavoidable antenna aspect of a coil, which makes it non purely inductive to some extent when current varies with time. > > However, may I remind you that my initial statement, which you deemed 100% incorrect, simply said that "keeping the current going" in an isolated non-resistive current loop would not consume energy. > In which case i is constant in time, so the frequency f of the signal is zero, so the wavelength lambda = c/f is infinite, so the radiation resistance: > > Rr= 31171 * A^2/lambda^2 (with A the area of the circular loop) is zero. > > So the power Rr*i^2 consumed in Rr is zero too. This still doesn't make my loop consume energy.
Your Quote, --- "You keep telling us electromagnets consume energy, true but that's only because the wires are resistive. A non-resistive current-loop would not consume any energy to keep the current going." --- LOL ... this is hopeless. Again --> You state the only consumed energy in an electro-magnetic is because the wires are resistive. Besides the fact you missed other factors such as radiation resistance lets focus on the fact that a magnet attracted and accelerating toward the wire resistive current loop would *indeed* induce an opposing voltage, which would consume energy. The gained KE comes from the wire resistive current loop. Regards, Paul Lowrance ____________________________________________________________________________________ Expecting? Get great news right away with email Auto-Check. Try the Yahoo! Mail Beta. http://advision.webevents.yahoo.com/mailbeta/newmail_tools.html
