Transformer Calculations

• What do step-up transformers do?

  Increase the potential difference of electricity
• What do step-down transformers do?

  Decrease the potential difference of electricity
• How can you calculate the potential difference in the secondary coil?

  Using the turns ratio and primary voltage
• What must be conserved in transformers?

  Power must be conserved
• How is power calculated in transformers?

  Power = Voltage × Current
• How are transformers used in power transmission?

  • Step-up transformers increase voltage to 400,000 volts
  • High-voltage cables transmit electrical power
  • Step-down transformers reduce voltage to 230 volts for homes
  • Reduces power wastage in the National Grid
• What happens to power when a large current is used in transmission cables?

  Power is wasted as heat
• Why do we prefer high voltage over high current in power transmission?

  To minimize power loss as heat
• What is the main voltage for the main supply in UK homes?

  230 volts