O Levels/IGCSE Physics Lesson Plan 4.5

Section	Details
Objective	– Understand that a conductor moving across a magnetic field or a changing magnetic field induces an e.m.f.– Describe an experiment to demonstrate electromagnetic induction.– Identify factors affecting the magnitude of induced e.m.f.
Activities	Starter (5 mins): Show a moving magnet near a coil connected to a galvanometer and observe the needle movement. Ask why the needle moves.Main (25 mins): 1. Explain the concept of electromagnetic induction and the role of moving conductors or changing magnetic fields.2. Demonstrate electromagnetic induction using a magnet and a coil.3. Discuss factors affecting induced e.m.f. (e.g., speed of movement, number of turns in the coil, and strength of the magnetic field).Plenary (10 mins): Students summarize factors affecting induced e.m.f.
Resources	Magnet, coil, galvanometer, whiteboard for diagrams.
Time	40 minutes
Homework	Write a paragraph explaining how the speed of motion affects the induced e.m.f.
Assessment	Students describe the experiment and explain factors affecting induced e.m.f.
Past Paper Practice	IGCSE Physics 0625/21/M/J/20 Q4(a).

Section	Details
Objective	– Understand that the direction of induced e.m.f. opposes the change causing it.– Use the relative directions of force, field, and current to determine the direction of induced e.m.f.
Activities	Starter (5 mins): Ask students to predict what happens to the direction of current if a magnet’s poles are reversed near a coil.Main (25 mins): 1. Explain Lenz’s Law and its role in determining the direction of induced e.m.f.2. Use Fleming’s Right-Hand Rule to determine the direction of force, field, and current.3. Solve problems to practice determining the direction of induced e.m.f.Plenary (10 mins): Students apply Lenz’s Law to predict the behavior of an induced current.
Resources	Magnet, coil, galvanometer, diagrams for force/field/current directions.
Time	40 minutes
Homework	Solve problems using Fleming’s Right-Hand Rule to determine the direction of induced current.
Assessment	Students explain Lenz’s Law and correctly determine the direction of induced e.m.f.
Past Paper Practice	IGCSE Physics 0625/42/M/J/19 Q5(a).

Section	Details
Objective	– Describe the structure and working of an a.c. generator.– Sketch and interpret graphs of e.m.f. against time for a simple a.c. generator.
Activities	Starter (5 mins): Show a simple generator model or animation and ask students how it generates electricity.Main (25 mins): 1. Explain the working of an a.c. generator with slip rings and brushes.2. Relate the position of the coil to the peaks, troughs, and zeros of the generated e.m.f.3. Sketch e.m.f. vs. time graphs and discuss how the graph changes with coil rotation.Plenary (10 mins): Students explain the graph and relate it to coil movement.
Resources	Generator model, e.m.f. vs. time graphs, whiteboard for sketches.
Time	40 minutes
Homework	Draw and label the parts of an a.c. generator, and sketch the corresponding e.m.f. graph.
Assessment	Students describe the working of an a.c. generator and interpret e.m.f. graphs.
Past Paper Practice	IGCSE Physics 0625/32/M/J/20 Q6(b).

Section	Details
Objective	– Describe the pattern and direction of magnetic fields around straight wires and solenoids.– Conduct experiments to identify field patterns.
Activities	Starter (5 mins): Show a compass near a current-carrying wire and observe its deflection. Ask why this happens.Main (25 mins): 1. Use iron filings and compasses to demonstrate the magnetic field around straight wires and solenoids.2. Discuss how field strength varies with current magnitude and direction.3. Relate solenoids to practical applications like relays and loudspeakers.Plenary (10 mins): Students summarize the factors affecting field strength.
Resources	Power supply, wires, solenoids, iron filings, compasses.
Time	40 minutes
Homework	Draw and label the magnetic field patterns for a straight wire and a solenoid.
Assessment	Students correctly draw and explain the observed magnetic field patterns.
Past Paper Practice	IGCSE Physics 0625/21/M/J/20 Q5(c).