Lesson Plan

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Lesson Plan
Grade: Date: 25/02/2026
Subject: Physics
Lesson Topic: understand and explain experiments that demonstrate: • that a changing magnetic flux can induce an e.m.f. in a circuit • that the induced e.m.f. is in such a direction as to oppose the change producing it • the factors affecting the magnitude of the
Learning Objective/s:
  • Describe Faraday’s law and how a changing magnetic flux induces an e.m.f.
  • Explain Lenz’s law and predict the direction of induced current in each demonstration.
  • Analyse how coil turns, area, magnetic field strength and speed of motion affect the magnitude of the induced e.m.f.
  • Carry out the three experiments, record observations and relate them to theory.
  • Solve typical A‑Level problems involving induced e.m.f. and magnetic damping.
Materials Needed:
  • Single‑turn coil and multi‑turn rectangular coil
  • Bar magnet and strong neodymium magnet
  • Galvanometer or sensitive voltmeter
  • Horseshoe magnet
  • Copper tube (vertical)
  • Stopwatch or motion sensor
  • Projector and worksheet for students
  • Resistors and power supply (optional for load tests)
 Introduction:
Begin with a quick demonstration of a magnet being slammed into a coil, asking students to predict the needle movement. Review prior knowledge of magnetic fields, flux and Faraday’s law. State that by the end of the lesson they will be able to explain the experiments, apply Faraday’s and Lenz’s laws, and predict the factors influencing induced e.m.f.
Lesson Structure:
  1. Do‑now (5') – short quiz on magnetic flux and Faraday’s law.
  2. Demo 1 – Moving a magnet into/out of a coil (10') – observe galvanometer deflection, discuss direction and Lenz’s law.
  3. Demo 2 – Rotating coil generator (15') – set‑up, measure alternating e.m.f., calculate 𝓔ₘₐₓ = NABω, explore effect of speed and turns.
  4. Demo 3 – Falling magnet through copper tube (10') – time the fall, compare with a non‑magnetic object, link to eddy‑current damping.
  5. Guided analysis of factors (10') – groups predict how changing N, A, B, ω alters the e.m.f. using the provided table.
  6. Practice problems (10') – solve two exam‑style questions individually.
  7. Check for understanding (5') – exit ticket: one sentence explaining why the induced e.m.f. opposes the change.
Conclusion:
Recap that a changing magnetic flux produces an e.m.f. whose direction opposes the cause, and that its magnitude depends on the rate of change, number of turns, coil area and field strength. Students complete the exit ticket and are assigned a worksheet to design a simple generator for homework.