Use of Transformers (AQA GCSE Combined Science: Trilogy: Physics): Revision Note

Use of Transformers

• The type of current produced in power stations is alternating current (AC) which is transferred to homes via the National Grid

• Transformers are used to increase and decrease the potential difference of the supply before and after transmission across the National Grid

A step-up transformer

• Step-up transformers increase the potential difference and decrease the current in the transmission cables

  • A smaller current means less energy is transferred to the surroundings by heating, so the National Grid is more efficient

• Step-down transformers decrease the potential difference, to a much lower value, from the transmission cables

  • This makes the supply to homes, offices and shops a safe value