Magnetic Fields

Lenz’s Law

The direction of the induced emf opposes the change of magnetic flux that produces it

What is Lenz’s Law used for?

Determines the direction of induced emf

Faraday’s Law

The magnitude of the induced emf is proportional to the rate of change of magnetic flux linkage through the coil

What is Faraday’s Law used for?

Determines the magnitude of induced emf

Magnetic Flux linkage

=NΦ,

Total number of field lines through all of the coils, for a coil where magnetic field passes through multiple areas

Magnetic Flux density

force per unit current per unit length on a wire placed at 90 degrees to the direction of the magnetic field. (number of field lines per m²)

Magnetic Flux

magnetic flux density x area (number of field lines in a given area)

Motor effect

If a current-carrying wire is placed in a magnetic field, it will experience a force.

Tesla

One tesla is the magnetic flux density that causes a force of 1N to be exerted on every 1m length of a wire carrying 1A of current in a direction that is perpendicular to the field