transformers

• Transformer


  A device used to change the potential difference of an electricity supply
• Transformer


  • Consists of two coils of wire - a primary coil and a secondary coil
  • The two coils are wrapped around an iron core
  • The primary coil is connected to an alternating current supply
• How a transformer works

  1. The alternating current in the primary coil generates a changing magnetic field

  2. The changing magnetic field passes through the secondary coil and induces a potential difference in the secondary coil
• Transformer


  • The iron core increases the strength of the magnetic field
  • Transformers only work with alternating current, not direct current
• Step-up transformer


  A transformer with more turns in the secondary coil than the primary coil, which steps up the potential difference
• Step-down transformer


  A transformer with fewer turns in the secondary coil than the primary coil, which steps down the potential difference
• Number of turns in secondary coil compared to primary coil

  Determines whether the transformer is step-up or step-down
• Transformers are not 100% efficient, there is some energy lost
• This video is for triple physics higher-tier students only