How transformers work

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

  To increase or decrease the voltage of electricity
• Why is electricity generated at high voltages in the national grid?

  To minimize energy losses during transmission
• What voltage does electricity get stepped up to in the national grid?

  Around 400,000 volts
• What voltage is electricity stepped down to for safe use in homes?

  Around 230 volts
• What is the role of a step-up transformer?

  To increase the voltage of electricity
• What is the role of a step-down transformer?

  To decrease the voltage of electricity
• How does a transformer transfer current from the primary coil to the secondary coil?

  Through induced magnetic fields
• What is the iron core in a transformer used for?

  To connect the primary coil to the secondary coil and enhance the magnetic field
• What happens when an alternating potential difference is applied across the primary coil?

  A current flows and generates an alternating magnetic field
• Why does the direction of the magnetic field alternate in a transformer?

  Because the potential difference applied is alternating
• What does the alternating magnetic field in the primary coil induce in the iron core?

  An alternating magnetic field
• What does the magnetic field of the iron core induce across the secondary coil?

  A potential difference
• Why can't electricity just conduct straight across from the primary to the secondary coil?

  Because the wires are insulated in plastic
• If a step-up transformer has twice as many turns in the secondary coil as in the primary coil, what happens to the voltage?

  The voltage is doubled
• In a step-down transformer, what happens to the voltage if there are fewer turns in the secondary coil than in the primary coil?

  The voltage is decreased
• What are the key components of a transformer and their functions?

  • Primary coil: Receives the input voltage
  • Secondary coil: Delivers the output voltage
  • Iron core: Enhances the magnetic field and connects the coils
• What is the process of how a transformer works step by step?

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