Electricity

• Superconductors are materials with a resistivity of zero below a critical temperature.
• • Because the resistance of a piece of a superconductor is zero, there are no heat losses for currents through them.
  • This means that the current could flow forever.
  • But most superconductors must be cooled to temperatures only a few Kelvin above absolute zero.
  • This is very expensive and limits the use of superconductors.
• • Superconductors are used in magnets needing high currents, such as in MRI machines.
  • If we could make our power lines superconductors they would cut energy losses in power transmission.