Lesson Plan

• Describe the three conductors in a UK mains circuit (live, neutral, earth) and their functions.
• Explain why a switch must be installed on the live conductor for safe isolation.
• Identify the colour coding of live, neutral and earth wires (pre‑2021 and post‑2021).
• Analyse the hazards that arise if a switch is placed on the neutral side.
• Apply safety checks before working on a mains circuit.

• Projector and screen
• Printed diagram of a mains circuit
• Sample mains cable with colour‑coded conductors
• Single‑pole switch and lamp for demonstration
• Safety goggles
• Worksheet with labeling and short‑answer questions

Begin with a quick discussion about why we never touch a plug that appears “off”. Review students’ prior knowledge of basic circuit components. State that by the end of the lesson they will be able to identify live, neutral and earth wires and explain why the switch must be on the live side for safe operation.

1. Do‑now (5'): Quick quiz on colour coding of conductors displayed on the board.
2. Mini‑lecture (10'): Explain the roles of live, neutral and earth wires and show the colour tables.
3. Demonstration (10'): Use the sample cable and switch to show a lamp powered when the switch is on the live side versus the neutral side.
4. Group activity (15'): Students label a printed diagram and discuss the three hazards listed in the notes.
5. Check for understanding (5'): Exit‑ticket question – “Why must a switch be on the live wire?”
6. Summary (5'): Recap key points and answer any lingering questions.

Summarise that the live wire carries voltage, the neutral is near earth potential, and the earth wire provides safety. Collect exit tickets to gauge understanding and assign a short homework: label a blank mains circuit diagram and write a paragraph on the importance of switching on the live side.