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From: David Jefferies
Date: 13 Dec 2002
Time: 16:39:34
Remote Name: 195.92.168.170
Bill, Alan, Michele, <><><> Greetings. I hesitate to enter this discussion.<><><> But let us consider a small (compared to the wavelength of 6000 km) paper capacitor of 10 microfarads at UK mains frequency of 50Hz. Simple application of the formula for the reactance of a capacitor puts this capacitor's impedance at -j 318.3 ohms. So, we connect it across a 240 volt r.m.s. mains supply and measure the current through it with an ammeter (OK, moving iron if you like). We measure 240/318.3 = 0.75 amps, very nearly. Three quarters of an amp is flowing through this capacitor. Do you prefer the displacement current model, or some construct involving transmission lines that are at most 10^-8 wavelengths long? Bill? Please? Or perhaps you'd like to throw away the concept of Kirchoff's laws and current continuity in a circuit? <><><> Best wishes, <><> David Jefferies.