Electromagnetics

Magnetism

One of the fundamental forces associated with magnetic fields.

Orbital magnetic moment

The magnetic moment caused by the orbital motion of electrons.

Spin magnetic moment

The effect created by the movement of electrons spinning on their axes.

Magnetic dipoles

Groups of atoms with their magnetic field moving in the same direction, also known as magnetic domains.

Quantity of electrons in dipoles

10^15 electrons

Lines of force

The force fields created when magnetic dipoles orient, also called lines of flux.

Weber (Wb)

The SI unit of magnetic flux, where 1 Wb = 10^8 lines of flux.

Flux density

Measured in Tesla (T) and Gauss (G), quantifies the strength of a magnetic field.

Natural magnets

Magnets created from iron oxide when it remains in the earth’s magnetic field for an extended period.

Artificial permanent magnets

Manufactured magnets made from steel alloy called alnico. Aluminum, nickel and cobalt.

Electromagnets

Temporary magnets produced by the movement of electric current.

Inverse Square Law

Greater distance from source less effect. Less distance from source greater effect.

Permeability

The ease with which a material can be magnetized.

Retentivity

The ability of a material to remain magnetized.

Four classifications of materials.

Ferromagnetic, paramagnetic, diamagnetic, nonmagnetic.

Ferromagnetic materials

Materials that can be magnetized easily.

Electromagnetic induction

The process by which a changing magnetic field induces a current in a conductor.

Faraday’s Law

Describes how the induced electromotive force in a circuit is proportional to the rate of change of the magnetic flux through the circuit.

Lenz’s Law

States that induced current flows in a direction that opposes the change causing it.

Mutual induction

The process where a changing current in one coil induces a current in a nearby coil.

Self-induction

The phenomenon where a changing current within a coil induces a voltage in itself.

Generators

Devices that convert mechanical energy into electrical energy.

Motors

Devices that convert electrical energy into mechanical energy.

Transformer

A device that applies mutual induction to increase or decrease voltage in alternating current circuits.

Transformer Law

Relates the voltage in the secondary coil to the number of turns in the coils.

Capacitors

Devices that store electrical energy in an electric field.

Rectification

The process of converting alternating current (AC) into direct current (DC).