What is the difference, apart from the Meissner effect? What are the practical consequences of Meissner effect? How can I, by experiment, deduce whether a material is an ideal conductor or superconductor? superconductor has zero resistivity. So what happens when we apply a potential difference at the ends of a superconductor? Surely infinite current does not flow, since anyway if current density > critical current density then it would no longer be a superconductor. How do we induce current in a superconductor?