An interesting (or not!) factoid is to do with how slow electrons move in a copper wire. A DC current of 10A flowing in a typical conductor for that purpose only moves at about a quarter millimeter per second, or about 2km per year. The reason is that every copper atom in the wire contributes one electron - so there an awful lot of free electrons in there.
Cut the current to 1mA, and the electrons flow at 20cm per year - the span of your hand.
Of course if the current is AC, all the electrons do is shuffle back and forth. So a 10A rms current at 50Hz will shuffle the electrons back and forth by 350 microns peak to peak.
Cut the current to 1mA, and the electrons flow at 20cm per year - the span of your hand.
Of course if the current is AC, all the electrons do is shuffle back and forth. So a 10A rms current at 50Hz will shuffle the electrons back and forth by 350 microns peak to peak.
