Superconductivity

• What is superconductivity?

  A phenomenon where resistivity disappears
• Why do materials heat up when electricity flows through them?

  Because of resistance converting energy to thermal energy
• How can the resistivity of a material be lowered?

  By lowering its temperature
• What happens to a material's resistivity when cooled below the critical temperature?

  It disappears entirely, becoming a superconductor

  
• What defines a superconductor?

  A material with no resistance below a critical temperature

  
• What is the critical temperature?

  The temperature at which superconductivity occurs

  
• What is a common superconducting material?

  Mercury
• What is the critical temperature of mercury?

  4.2 K
• How does the resistivity of a normal metal compare to a superconductor with temperature?

  • Normal metals have increasing resistivity with temperature
  • Superconductors have zero resistivity below critical temperature

  
• What is the transition temperature in superconductivity?

  The temperature threshold for superconductivity
• What are the applications of superconductors?

  • Production of strong magnetic fields
  • Reduction of energy loss in power transmission
  • Used in MRI scanners, transformers, motors, etc.
• Why are superconductors useful for applications requiring large electric currents?

  They have no resistance, reducing energy loss
• What are some specific applications of superconductors?

  • MRI scanners
  • Transformers and generators
  • Motors
  • Maglev trains
  • Particle accelerators
  • Fusion reactors
  • Electromagnets
  • Power cables
  • Microchips
• How do maglev trains utilize superconductors?

  They use strong electromagnets to levitate
• What speeds can maglev trains achieve?

  Up to 603 km/h
• In which countries do maglev train systems currently exist?

  Japan, South Korea, and China
• What is required for maglev trains to levitate?

  Extremely strong electromagnets
• Why is it important to avoid stating 'little resistance' in superconductivity?

  Because superconductivity means no resistance at all