GCSE Physics (AQA)

346 videos | 23 hours

Energy Energy changes in a system, and the ways energy is stored before and after such changes

Work Done by a Current

3:44 Energy, Systems and How to Transfer Energy
Spec 4.1.1.1 4.2.4.2
Previous Forces & Work Next Power
  • Most modern technology is powered by electric currents.
  • Devices like light bulbs, electric heaters, and loudspeakers transfer energy from electric currents to other forms.
  • Light bulbs transfer energy to light waves, heaters store it as thermal energy, and loudspeakers transfer it as sound waves.
  • Understanding these devices and energy transfers is important for exams.
  • Electric currents are generated by converting other forms of energy through electrical power supplies.
  • Batteries convert chemical energy to electric current.
  • Currents can also be generated through motion using magnets, such as in hamster wheels or bike wheels.
  • Generators transfer energy from fossil fuels or other resources to kinetic energy to generate a current.
  • Power supplies do work on charge carriers, usually delocalized electrons, to give them energy.
  • Charge carriers move around the circuit, constituting the electric current.
  • A power supply doing work means giving energy to charge carriers.
  • Charge carriers transfer energy to circuit components, which then convert it to other forms like light and heat.
  • Circuits must be a closed loop for charge carriers to travel and transfer energy.
  • Work on a charge means energy is given to charge carriers, while work by a charge means charge carriers give energy away.

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