Brainlag PlusHow electricity gets from a power station to your home, why the cables run at hundreds of kilovolts, and the transformer equation.
From power station to plug
The National Grid is the network of cables and transformers that links power stations to homes, shops and factories.
- Power station: generates at about 25 kV
- Step-up transformer: raises the p.d. to hundreds of kV (400 kV on the main lines)
- Transmission cables: carry the energy across the country
- Step-down transformers: lower the p.d. in stages near the towns
- Homes: 230 V
A step-up transformer makes the p.d. bigger; a step-down transformer makes it smaller.
The rest of this lesson and its 9 practice questions are in Plus.
Screen 1 of 5, free to read.
- 9 exam-style questions, marked as you go, each with a worked solution
- The Ohm's Law and Circuits Calculator beside every question
- Anything you get wrong is saved to your flashcards