Certain substances loose their electrical resistance completely at super low temperature. Such, substances are called. (1) Super conductors (2) Semi conductors (3) Dielectrics (4) Perfect conductors
(1) Super conductors Explanation: Superconductors are materials that carry electrical current with little or no resistance when cooled, below a certain temperature. While conventional superconductors need to be cooled close to absolute zero (-273.15 °C) before they superconduct, high temperature superconductors do so above the boiling point of liquid nitrogen (-196 °C).