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AC Components and Circuits
Inductance

Section 1-1 The Laws of Faraday and Lenz

Whenever a conductor is moving through a magnetic field, a voltage is induced in the conductor.

Faraday's Law

When a conductor moves through a field of magnetic flux, a voltage (emf) is induced in the conductor. This is basically how an electrical generator works—by moving a coil of wire through a strong magnetic field.

The faster the conductor moves, the greater the amount of emf induced in it.

The polarity of the induced emf depends on the direction of motion.

The motion between conductor and a magnetic field is relative—the field might be motionless  and the conductor is moving, or the conductor is motionless and the magnetic field is moving.

When there is no change in flux, there is no induced voltage.

Faraday's Law for a Coil of Wire 

The amount of induced voltage is proportional to the rate of change of flux and the number of turns of wire. 

Where: 

Vind = the amount of induced voltage in volts (V)

N = the number of turns of wire

= the rate of change of flux cutting the conductor in webers/second (Wb/sec)