Lesson Plan

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Lesson Plan
Grade: Date: 25/02/2026
Subject: Physics
Lesson Topic: recall and use E = Q / (4πε0 r 2) for the electric field strength due to a point charge in free space
Learning Objective/s:
  • Recall the formula E = Q / (4π ε₀ r²) and identify each variable.
  • Explain how the direction of the electric field depends on the sign of the point charge.
  • Apply the formula to calculate the magnitude of the electric field for given Q and r, including correct units and direction.
  • Analyse common errors such as forgetting to square r or mixing units.
Materials Needed:
  • Projector and screen
  • Whiteboard and markers
  • Printed worksheet with practice problems
  • Scientific calculators
  • Point‑charge demonstration kit (charged spheres)
  • Handout of the formula and constant values
  • Laptop with PhET electric field simulation
 Introduction:
Imagine a charged balloon pulling tiny pieces of paper toward it – a visible sign of an electric field. Students already know Coulomb’s law and basic vector ideas, so we’ll link that knowledge to the field concept. By the end of the lesson they will be able to compute E for any point charge and state its direction correctly.
Lesson Structure:
  1. Do‑now (5') – short quiz on Coulomb’s law, units, and vector notation.
  2. Mini‑lecture (10') – derive E = Q / (4π ε₀ r²), discuss the role of ε₀ and the radial unit vector.
  3. Guided practice (12') – work through the textbook example together, students fill in each step on the board.
  4. Pair activity (10') – worksheet with three different Q and r values; calculate E and indicate direction.
  5. Concept check (5') – exit‑ticket question targeting a common mistake (e.g., forgetting to square r).
  6. Summary & Q&A (3') – recap key points and answer lingering questions.
Conclusion:
We’ll recap the inverse‑square nature of the electric field and the importance of correct units and direction. Students will submit an exit ticket that reinforces the main calculation steps. For homework, they will complete additional problems from the textbook and bring any uncertainties to the next class.