2021
Physics Current Electricity Level: High School
Which one of the following statements concerning superconductors is false ?a) Below is critical temperature, the resistivity of a superconductor is zero ohm-m
b) Critical temperatures for some superconductors exceed 100 K .
c) All materials are superconducting at temperatures near absolute zero Kelvin .
d) A constant current can be maintained in a superconducting ring for several years without an emf .
e) Superconductors are perfect conductors .
c) All materials are superconducting at temperatures near absolute zero Kelvin .(only a certain class of materials behave as superconductors . )