National High Magnetic Field Laboratory
Magnet Academy: Emf in Inductors
Electromotive Force (EMF) and its sidekick, back EMF, are interesting electromagnetic phenomena that aren't really forces at all. (Java tutorial)
CK-12 Foundation
Ck 12: Lenz's Law
[Free Registration/Login may be required to access all resource tools.] Lenz's law is explained and demonstrated. It states that a magnetic field is produced in opposition to an induced current.