Electromagnetic Induction (Physics)

Recall cards on electromagnetic induction. Faraday's law: magnetic flux and the weber, the induced emf as the negative rate of change of flux, and the N-turn coil form. Lenz's law: the induced current opposes the flux change, the negative sign, the like-pole repulsion of an approaching magnet, and the energy-conservation basis. Motional emf: epsilon = Blv, the induced current and retarding force on a moving rod, and the mechanical-to-electrical power balance. Induced electric fields: the line-integral form of Faraday's law, the nonconservative character with no associated potential, and the field around a circular path. Eddy currents: magnetic damping, slotted plates, metal detectors, eddy-current braking, and induction cooktops. Electric generators and back emf: the rotating-coil emf, peak emf, motor-versus-generator energy conversion, and how back emf sets a motor's current. Applications: hard disk read heads, giant magnetoresistance, magnetic stripes, graphics tablets, regenerative braking, and transcranial magnetic stimulation.