Lesson Plan

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Lesson Plan
Grade: Date: 01/12/2025
Subject: Physics
Lesson Topic: use Kirchhoff’s laws to solve simple circuit problems
Learning Objective/s:
  • Describe Kirchhoff’s Current Law (KCL) and Voltage Law (KVL) and their physical basis.
  • Apply KCL and KVL to set up equations for circuits with multiple loops and junctions.
  • Solve simultaneous equations to determine unknown currents and voltages in simple resistor networks.
  • Interpret the sign of calculated currents to infer the actual direction of flow.
Materials Needed:
  • Projector or interactive whiteboard
  • Slide deck covering KCL and KVL
  • Printed worksheets with circuit diagrams and practice problems
  • Resistor network kit or simulation software (e.g., PhET)
  • Calculator
  • Multimeter (optional for demonstration)
 Introduction:
Begin with a quick demonstration of a simple circuit where a battery powers two parallel resistors, asking students what happens at the junction. Recall that charge cannot accumulate and energy is conserved, linking these ideas to the upcoming laws. Explain that by the end of the lesson they will be able to use Kirchhoff’s laws to analyse any similar circuit and check their results against a clear success criterion.
Lesson Structure:
  1. Do‑now (5’) – Students solve a short KCL prompt on a worksheet to activate prior knowledge.
  2. Mini‑lecture (10’) – Introduce KCL and KVL with real‑world analogies and display equations.
  3. Guided example (15’) – Walk through the 12 V battery, three‑resistor problem, modelling each step and solving together.
  4. Collaborative practice (15’) – In pairs, students use the resistor kit or simulation to set up and solve a new circuit; teacher circulates for questioning.
  5. Check for understanding (5’) – Quick quiz (exit ticket) with two items: write the KCL equation for a given node and the KVL equation for a loop.
  6. Reflection (5’) – Class discussion of common errors and how sign conventions indicate current direction.
Conclusion:
Summarise how KCL ensures charge balance at junctions and KVL enforces energy conservation around loops, reinforcing the systematic approach demonstrated. Collect the exit tickets as a retrieval check and assign a worksheet of three additional circuits for homework, encouraging students to practice both setting up and solving the equations.