Physics gcse

• Circuit symbols

  • e
  • LDR
  • LED
  • ac.power supply
  • dc.power supply
• Generating electricity

  Fuel is burned to heat water to make steam. The kinetic energy of the steam turns a turbine. The turbine then drives a generator which produces electricity
• Efficiency

  If something is 100% efficient then the input energy supplied is not lost or wasted. % efficiency is the % of the input energy transferred to useful output energy
• National Grid

  A network of power stations, transformers, sub-stations and power lines all joined together supplying electricity to consumers
• National Grid

  • It is a reliable supply
  • It maintains supply in the case of a breakdown
  • It can respond to changing demand
  • It has back-ups in case of demand or breakdown
  • It can import electricity from abroad if needed
  • It works 24 hours a day
• The National Grid consists of a network of power stations, transformers, sub-stations and power lines all joined together supplying electricity to consumers
• Variable d.c power supply