Instructables

Is the copper on electric wire negative or positive?

On elecric wire there are two kinds of metal. One is copper and the other is iron. Okay, now on a battery there is the positive side (+) and the negative side (-). Wich wire goes where?

Dr.Bill5 years ago
Red is positive black is negative. Search Instructables for a Polarity Checker.
For all intensive purposes electrons typically dont care about the kind of metal they go through. Going deeper into it, your Iron wire is probably tinned copper. To figure out which goes where, you need a multimeter. But if you are connecting a wire across two terminals, be ready for a nasty burn! So put a resistor in your circuit.
Wesley6665 years ago
AC
Black-hot
White-cold/neutral
Green-Ground

DC
Black-negative
white/red-positive

Note most AC items don't require hot and neutral to be in a specific spot, but some do.
If one end of the wire is attached to some gadget, then obviously you have to read the directions or pull out your multitester or testing LED. But If you control what attaches to both ends of the wire, the choice is totally arbitrary. Still, you do want to remember what you chose. Standard colors for a pair of polarized wires (jumper cables, for instance) are red for positive and black for negative. So I would pick copper for positive because the copper wire is more red than the other. That is the memory aid I would use.
sound915 years ago
As said before, it really shouldn't matter. The one thing that you might be thinking of could possibly be when creating a voltage between two metals. The steel or iron is negative, and the copper is positive. This is more or less similar to the basic idea of a battery.
lemonie5 years ago
Iron? I don't think so, tinned copper maybe.

Like the other guy: wires don't care about +ve/-ve unless you're making electrolytic cells.

L
fwjs285 years ago
it doesn't matter (i think) usually both wires are copper....