Final answer:
Superconductors are known for having no electrical resistance which leads to no energy loss during electricity transmission. They are used in applications like MRI machines but their use is limited due to the cooling costs. Recently, there has been progress in developing high-temperature superconductors.
Step-by-step explanation:
Superconductors are materials characterized by their ability to conduct electricity with no resistance whatsoever. This fascinating physical property entails that when cooled below a certain critical temperature, superconductors have a resistivity of zero. As a result, they are extremely efficient, experiencing no heat losses when currents pass through them, making them highly sought after for use in situations requiring high currents like MRI machines and potentially for reducing energy losses in power transmission. However, the practical application of superconductors is often limited by the need to cool them to temperatures near absolute zero, which is an expensive process. Within the last decade, there have been significant advancements in creating high-temperature superconductors, raising the hopes for the development of room-temperature superconductors.