Lesson Plan

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Lesson Plan
Grade: Date: 17/01/2026
Subject: Physics
Lesson Topic: Describe the use of transformers in high-voltage transmission of electricity
Learning Objective/s:
  • Describe why high‑voltage transmission reduces power loss.
  • Explain how step‑up and step‑down transformers operate using turns ratio and electromagnetic induction.
  • Calculate current and power loss before and after voltage transformation.
  • Evaluate efficiency factors and safety considerations of transmission transformers.
Materials Needed:
  • Projector and screen for slides/diagrams
  • Whiteboard and markers
  • Printed worksheet with example calculation
  • Transformer models or virtual simulation access
  • Scientific calculators for students
  • Safety poster on high‑voltage precautions
 Introduction:
Begin with a short video of a power line humming and ask students why electricity can travel such long distances. Recall that power loss depends on current (I²R) and that voltage can be changed with transformers. Today’s success criteria: students will be able to explain the role of step‑up and step‑down transformers and perform basic transmission calculations.
Lesson Structure:
  1. Do‑now (5') – answer a quick question on I²R losses on a worksheet.
  2. Mini‑lecture (10') – explain high‑voltage transmission rationale and introduce transformer principle with diagram.
  3. Interactive simulation (10') – students adjust turns ratio on a virtual transformer to observe voltage/current changes.
  4. Guided example (12') – work through the 500 MW calculation in pairs.
  5. Group discussion (8') – discuss real‑world losses, efficiency, cooling and safety features.
  6. Check for understanding (5') – quick quiz (exit ticket) with 2–3 questions on concepts.
Conclusion:
Summarise that stepping up voltage dramatically cuts I²R losses, enabling efficient long‑distance power delivery, while step‑down transformers make the voltage safe for consumers. Students will hand in an exit ticket answering one calculation and one conceptual question. For homework, assign a problem to design a transformer system for a 200 MW plant, specifying the required turns ratio.