Lesson Plan

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Lesson Plan
Grade: Date: 17/01/2026
Subject: Physics
Lesson Topic: recall and use F = BQv sin θ
Learning Objective/s:
  • Recall the magnetic force equation F = BQv sin θ and its derived form F = B I L sin θ.
  • Explain how charge, current, conductor length and the angle θ affect the magnetic force on a straight wire.
  • Apply the equation to calculate the magnitude and direction of the force in A‑Level style problems, using the right‑hand rule.
  • Identify and avoid common pitfalls such as omitting the sin θ factor or mis‑applying the right‑hand rule.
Materials Needed:
  • Projector or interactive whiteboard
  • Printed worksheet with practice questions and space for calculations
  • Diagram handout showing a current‑carrying wire in a magnetic field
  • Scientific calculators
  • Rulers and protractors (for sketching angles)
  • Sticky notes for exit tickets
 Introduction:
Begin with a quick demonstration of a simple motor to spark curiosity about how electricity can produce motion. Ask students what they already know about magnetic fields and forces on moving charges, linking to prior work on vectors. State that by the end of the lesson they will be able to reliably calculate both magnitude and direction of the magnetic force on a straight conductor using F = B I L sin θ.
Lesson Structure:
  1. Do‑Now (5 min): short quiz on magnetic field symbols and the basic force formula F = BQv sin θ.
  2. Mini‑lecture & derivation (10 min): derive F = B I L sin θ from F = BQv sin θ, highlighting each variable and showing the right‑hand rule.
  3. Guided worked example (10 min): walk through the provided 0.30 m wire problem, modelling each step on the board.
  4. Paired practice (15 min): students complete the three practice questions on the worksheet, checking units and direction together.
  5. Check for understanding (5 min): ask targeted questions about common pitfalls; clarify any misconceptions.
  6. Summary & exit ticket (5 min): each student writes one key takeaway and solves a quick “force on a wire” problem on a sticky note.
Conclusion:
Recap the link between charge motion, current, and magnetic force, emphasizing the role of sin θ and the right‑hand rule for direction. Collect exit tickets to gauge individual understanding and assign a homework task: complete a set of five additional force‑on‑conductor problems, including one involving a rectangular loop, to reinforce the concepts.