Lesson Plan

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Lesson Plan
Grade: Date: 25/02/2026
Subject: Physics
Lesson Topic: define electric potential at a point as the work done per unit positive charge in bringing a small test charge from infinity to the point
Learning Objective/s:
  • Describe the definition of electric potential as work per unit positive charge.
  • Derive the relationship between electric field and potential using the line integral.
  • Calculate electric potential for a point charge and interpret its distance dependence.
  • Distinguish scalar electric potential from vector electric field and relate potential energy to potential.
Materials Needed:
  • Projector or interactive whiteboard
  • Slides/PowerPoint on electric potential
  • Worksheet with derivation and example problems
  • Calculator or simulation software
  • Whiteboard and markers
  • Printed diagram of a point charge with field lines
 Introduction:
Begin with a quick visual of a charge surrounded by field lines and ask students how they would measure “how high” the field is at a point. Recall that they already know work‑energy concepts for forces. State that by the end of the lesson they will be able to express that “height” as electric potential and use it to solve problems.
Lesson Structure:
  1. Do‑now (5'): Students answer a short question on work done by a constant force.
  2. Mini‑lecture (10'): Present the definition V = W/q and discuss the zero‑potential reference at infinity.
  3. Guided derivation (15'): Walk through the line‑integral derivation dV = –E·ds and integrate for a point charge.
  4. Example calculation (10'): Solve V(r) for a point charge together, highlighting the 1/r dependence.
  5. Guided practice (15'): Students complete a worksheet problem on finding potential at a given point for a known field.
  6. Exit ticket (5'): Write one sentence summarising why electric potential is a scalar quantity.
Conclusion:
Recap the key points: definition, relation to electric field, and the point‑charge formula. Collect exit tickets to check understanding and assign a homework task to calculate potentials for multiple charge configurations. Remind students that mastering potential simplifies many later A‑Level problems.