Lesson Plan

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Lesson Plan
Grade: Date: 17/01/2026
Subject: Physics
Lesson Topic: State the advantages of high-voltage transmission
Learning Objective/s:
  • Describe why high‑voltage transmission reduces I²R losses.
  • Explain how voltage level influences conductor size and cost.
  • Compare the characteristics of low‑voltage and high‑voltage transmission.
  • Illustrate the role of step‑up and step‑down transformers in the power grid.
  • Evaluate the impact of high‑voltage transmission on distance and voltage regulation.
Materials Needed:
  • Projector or interactive whiteboard
  • PowerPoint slides with diagrams and tables
  • Worksheet with comparison table and short‑answer questions
  • Calculator for each student
  • Sample transformer model or video demonstration
  • Whiteboard markers
 Introduction:
Begin with a striking fact about energy loss in long‑distance power lines to hook interest. Prompt students to recall the relationship P = VI and what happens to current when voltage changes. State that by the end of the lesson they will be able to list and explain the key advantages of transmitting electricity at high voltage.
Lesson Structure:
  1. Do‑now (5'): Quick written response – “If power is constant, what happens to current when voltage is increased?” Collect answers.
  2. Mini‑lecture (10'): Review P = VI, derive I = P/V, and introduce I²R losses using simple examples.
  3. Group activity (12'): Using the provided comparison table, students fill missing data for low‑ and high‑voltage scenarios and discuss the advantages.
  4. Demonstration (8'): Show a short video or model of a step‑up/step‑down transformer and explain its function in the grid.
  5. Guided practice (10'): Worksheet problems calculating current and loss at different voltages; teacher circulates for support.
  6. Recap & Q&A (5'): Summarise the five main advantages and answer lingering questions.
Conclusion:
Recap the five advantages of high‑voltage transmission, emphasizing reduced losses and cost benefits. Ask students to write one advantage on an exit ticket and hand it in. For homework, assign a short problem set requiring calculation of current and loss for given power levels at low and high voltages.