Revision Notes

4.6.5 Transmitting Electricity

High-Voltage Transmission

  • When electricity is transmitted along overhead cables, it is done at high voltages
    • A step-up transformer is used to raise the potential difference (voltage) before transmissions
    • A step-down transformer is then used to step the potential difference back down to normal levels when it reaches its destination


power-lines, IGCSE & GCSE Physics revision notes

Electricity is transmitted at high voltage, reducing the current and hence power loss in the cables


Extended Only

How High Voltage Reduces Power Loss

  • When electricity is transmitted over large distances, the current in the wires heats them, resulting in energy loss
  • By raising the voltage at which the electricity is transmitted at, the same amount of power (energy per second) can be transmitted using a much smaller current ()
  • This results in less heat being produced in the wire and hence less energy loss


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