It's certainly true ... but a few cautions.
First off, the coil makes a LOT of noise. BUZZZZZ. It can 'walk' itself right off the table. It also gets hot - after a few moments the insulation can be damaged. Don't ever plan on actually using the wire.
I used the usual 500-ft. spools of wire. How much wire you have has a direct effect on just how much impedence is created; you can demonstrate this by pulling 50-ft or so off the spool and laying that part out flat; compare amp readings.
My own personal favorite way of demonstrating these principles was with a common $30 bench grinder. I slit the cord jacket, so I could put an amp-clamp on the neutral. I also used a "Kill-A-Watt" meter where the cord was plugged in.
We would measure the resistance of the grinder and calculate the amp draw. Then we would plug it in and actually measure the current drawn. The difference reflected the impedance. Since my grinder also had a (incandescent) light, I could show the difference between a resistive load and a reactive one.
Unplug the assembly, and the Kill-a-watt would show a declining voltage, as the grinder slowed down. Inductive reactance there.
The simple coil of wire demo is great, because "it's only wire," and there's nothing magnetic anywhere in it. Everyone can look up / measure / calculate the current draw beforehand, and most will anticipate a load of about 100-amps for what is essentially a "dead short." Then they get to watch in wonder as the dancing spool fails to trip any breaker - and draws something like 18 amps. (Total disclosure here: my roll was of unknown total length, and had at least two different sizes of wires in it).
