Energy Transferred by Working
Electricity and Magnetism

Devices at work

Physics Narrative for 14-16 Supporting Physics Teaching

Devices and pathways

Devices switch pathways, allowing you to change the power in the pathways connected by the device. Often these devices are very carefully engineered, requiring detailed knowledge beyond the principles outlined in this episode.

The power in one pathway is switched to power in another by a device

Here is a summary of the devices introduced, listed with the switching for which they were designed:

  • Light bulb: electrical working switched to heating by radiation (visible radiations only – that is, the range of frequencies we're interested in).
  • Heater: electrical working switched to heating by particles or, for radiant heaters, heating by radiation.
  • Motor: electrical working switched to mechanical working.
  • Transformer: electrical working to electrical working.
  • Generator: mechanical working switched to electrical working.
Energy Transferred by Working
appears in the relation dU=dQ+dW
is used in analyses relating to Working Engines Thermionic Emission
is a special case of Work
has the special case Potential Energy Kinetic Energy
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