How Transformers Work

• What is the primary function of transformers in the national grid?

  To increase or decrease voltage
• Why is electricity generated at huge power stations spread out across the UK?

  To ensure widespread electricity distribution
• What voltage do step-up transformers increase electricity to?

  Around 400,000 volts
• What is the purpose of increasing voltage in the national grid?

  To minimize energy losses during transmission
• What voltage do step-down transformers decrease electricity to?

  Around 230 volts
• Why is it safe to use 230 volts in houses?

  It is a lower, manageable voltage
• What are the main components of a transformer?

  • Primary coil
  • Secondary coil
  • Iron core
• What happens when an alternating potential difference is applied to the primary coil?

  A current flows and generates a magnetic field
• How does the magnetic field in the primary coil affect the iron core?

  It induces an alternating magnetic field in the core
• What does the iron core's magnetic field induce in the secondary coil?

  A potential difference across the secondary coil
• Why can't electricity pass directly from the primary to the secondary coil?

  Wires are insulated in plastic
• How does a step-up transformer increase voltage?

  By having more turns in the secondary coil
• If a step-up transformer has a 10 volt supply, what output voltage can be expected?

  20 volts
• How does a step-down transformer differ from a step-up transformer?

  It has fewer turns in the secondary coil
• What is the process of how transformers work step by step?

  1. Alternating potential difference applied to primary coil
  2. Current flows, generating a magnetic field
  3. Alternating magnetic field induces magnetic field in iron core
  4. Iron core induces potential difference in secondary coil
  5. Current flows in secondary coil if part of a complete circuit