How does resistivity vary with temperature in a superconductor ?

Question

How does resistivity vary with temperature in a superconductor ?

Answer 1

A superconductor has no resistivity.

Answer 2

if it's still superconducting then it wont vary at all!

if the temp increases about the critical temp, then obviously the restivity will increase!

Answer 3

freewill and nobody are correct.

when a substance is in a superconducting state, there is no resistance to electrical flow. if there is no resistance, then there is nothing to vary. superconductors require very cold temperatures to operate. even the ones said to operate at high temps are extremely cold. the temperature can vary from absolute zero to the high end of the substances superconducting temperature without a change  in resistance. above the high end temperature you know longer have a super conductor. for lack of a better description; super conductors are all or nothing. there is no in betweens.