AP Physics C: Electricity and Magnetism / Unit 13: Electromagnetic Induction
13.3 Induced Currents and Magnetic Forces
Notes
Induced currents create forces that oppose motion (magnetic braking, eddy currents). The work done against this force becomes electrical energy.
Practice
A magnet dropped through a copper tube falls slowly because:
Lenz's law.
A rod pulled at constant speed on rails in a field needs a steady applied force because:
Energy goes into the circuit.
The power delivered by the pulling force equals:
Energy conservation.
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