This is correct. Resistance in a superconductor is exactly zero. However if the current reaches a critical level the superconductor will ["quench"](https://en.w

This is correct. Resistance in a superconductor is exactly zero. However if the current reaches a critical level the superconductor will ["quench"](https://en.wikipedia.org/wiki/Superconducting_magnet#Magnet_quench https://en.wikipedia.org/wiki/Superconducting_magnet#Magnet_...) and rapidly drop out of the superconducting state. When that happens, it regains its normal resistance and because there is still a lot of current going through it, the material will heat up rapidly, thus pushing it away from superconductivity even further. This can damage or even destroy the coil if the energies involved are large enough.