magnetism and electromagnetism key terms

the SI unit of magnetomotive force (mmf)

a formation of a group of magnetic lines of force surrounding a conductor created by electrical current in the conductor

the opposition to the establishment of a magnetic field in a material

an electromagnetically controlled mechanical device in which electrical contacts are opened or closed by a magnetizing current

the measure of ease with which a magnetic field can be established in a material

the cause of a magnetic field, measured in ampere turns

the lines of force between the north and south poles of a permanent magnet or an electromagnet

a force field radiating from the north pole and south pole of a magnet

a physical law that states when the current through a coil changes, the poloraity of the induced voltage created by the changing of the magnetic field is such that it always opposes the change in current that caused it. The current cannot change instantaneously

voltage produced as a result of a changing magnetic field

a characteristic of a magnetic material whereby a change in magnetization lags the application of the magnetic field intensity

a law stating that the voltage induced across a coil equals the number of turns in the coil times the rate of change of the magnetic flux

the ability of a material, once magnetized, to maintain a magnetized state without the presence of a magnetizing force

an electromagnetically controlled device in which the mechanical movement of the shaft or plunger is activated by a magnetizing current

an electromagnetic device that converts electrical signals to sound waves

the si unit of magnetic flux, which represents 10 8th lines