Lenz' Law

The direction of an induced current is such that the magnetic field it produces (the induced magnetic field) will oppose (or try to compensate for) the change in the magnetic field which causes the induced current and induced magnetic field.

That is the meaning of the "minus sign" in

and

Faraday's Law

Moving Conductor

Return to Ch 21, Electromagnetic Induction
(c) Doug Davis, 2003; all rights reserved