Lesson Plan

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Lesson Plan
Grade: Date: 25/02/2026
Subject: Physics
Lesson Topic: recall and use the fact that the electric field at a point is equal to the negative of potential gradient at that point
Learning Objective/s:
  • Describe the relationship E = ‑∇V and explain its physical meaning.
  • Apply the gradient operator to a given potential function to obtain the electric field.
  • Analyse common charge configurations (point charge, uniform field, line charge) using the potential‑gradient method.
  • Identify and correct typical mistakes such as sign errors and unit mismatches.
Materials Needed:
  • Projector and screen
  • Whiteboard and markers
  • Printed worksheet with potential functions and space for calculations
  • Scientific calculators
  • Handout of equipotential‑field diagram
  • Sticky notes for exit tickets
 Introduction:
Imagine measuring the voltage between two points and instantly knowing the direction of the electric field. Students already know the definitions of electric potential and electric field, so we will connect these ideas. Success will be shown when learners can write E = ‑∇V and use it to find the field for a simple charge distribution.
Lesson Structure:
  1. Do‑now (5'): Quick quiz on the definitions of V and E and the units they use.
  2. Mini‑lecture (10'): Derive E = ‑∇V from the work‑energy argument, introduce the gradient operator.
  3. Guided example (15'): Work through the point‑charge problem step‑by‑step, students calculate ∇V and obtain E.
  4. Group activity (10'): Each group receives a different potential function (uniform field, line charge) and determines the corresponding E using ‑∇V.
  5. Check for understanding (5'): Exit‑ticket on a sticky note – write the relationship and one common mistake to avoid.
  6. Summary & recap (5'): Highlight key steps, unit checks, and sign conventions.
Conclusion:
We recap how the electric field follows directly from the spatial change of potential and why the negative sign is essential. Students hand in their exit tickets and receive a short homework sheet containing three new potential functions to solve. This reinforces the gradient method and prepares them for the upcoming A‑Level exam questions.