Safety boundary
Use simulations or supervised low-voltage coil/magnet activities only. Do not use mains electricity, high-current coils, or improvised high-voltage equipment.
Explicit physics instruction
Magnetic phenomena use two complementary ideas: magnetic fields exert forces on moving charges/currents, and changing magnetic flux can induce electric effects.
Generators and motors connect these models through energy transfer.
A strong explanation identifies which effect is acting, the direction rule, and the energy source.
Vocabulary: field; force; induction; energy conversion; model choice.
Worked example
A motor question begins with current in a magnetic field; a generator question begins with changing flux. Both require energy accounting.
Guided question
Given an unfamiliar electromechanical device, which model would you test first and why?
Independent work
- Solve one magnetic-force reasoning problem.
- Interpret one induction graph.
- Draw one generator/motor energy flow.
- Record one correction.
Spiral retrieval bridge
- From Week 30: connect voltage with energy per charge.
- From Week 29: distinguish field from force.
- From Week 21: connect external torque with angular-momentum change.
Misconception check
Magnetic force and electromagnetic induction are related but not interchangeable explanations.
Formative check
What distinguishes a motor model from a generator model?
Reveal response
Motors use magnetic force on current to produce motion; generators use changing flux to produce emf.
Mentor evidence conference
Ask Archaemenes to audit direction rules, rate reasoning, energy source, and model scope.
Teacher guidance
Foundation: Use a model-choice organizer.
Core: Integrate force, induction, and energy.
Extended: Evaluate design tradeoffs and model limits.