Thermography difference between AC current wire and DC current wire?

Question

Is there thermographic difference between AC current flowing wire and DC current flowing wire? And thermogramic differences for drift velocities?

Answer 1

If the wire is not a superconductor, where current is flowing, power is being dissipated as heat. For the DC case you can expect current in the wire to be fairly uniform, and thus a uniform heating of the wire will occur.

For the AC case the current will not flow uniformly throughout the wire at high frequency. Two effects come into play, the skin effect and the proximity effect. Pictured below is the proximity effect. If the current is not flowing uniformly then the energy being dissipated as heat in the wire will also not be uniform.

So yes, I imagine the two cases could look different, but in either case I think heat dissipation by the wire would be difficult to see with thermal imaging equipment. Even then it will be averaged fairly rapidly by conduction in the metal wire and the insulation covering the wire. So the experiment would work in some special cases, but not in most practical cases.