3.01 Flashcards
Electromagnetism
Magnetic Fields
region or space in which magnetic effects are present.
Lines of Force
lines that make up the magnetic field
Magnetic Flux
total number of lines of force in a magnetic field
Unit of measure for Magnetic Flux?
the Weber
Magnetic poles
considered to be at the ends, where the magnetic flux is concentrated
Flux density
number of flux lines per square meter
Telsa
defined as the flux density when one Weber of flux occurs in a plane of one meter squared
Domain Theory of Magnetism
each domain within a magnet acts like its very own small magnet and are randomly aligned in a non-magnetized material but when a material becomes magnetized by an external magnetizing force, it causes these domains to align thus the material becomes magnetized
Permeability
inherent ability of a material to concentrate lines of force or the ease at which lines of force can be established within a material
Permeability of free space
has a fixed value that never changes and is equal to 4n * 10^-7 or 1.257 * 10^-6
Relative Permeability
Ratio of the number of lines of force set up in a core material to the number of lines of force set up in air (free space)
Reluctance
opposition to the establishment of magnetic lines of flux
Retentivity
the ability of a material to hold its magnetism after a magnetizing force has been removed
Left hand rule for current carrying conductors
the thumb points in the direction of current flow which allows the curve of the fingers to indicate the direction of the magnetic field
Left hand rule for coils
when the fingers of a left hand are wrapped around the coil and point in the direction of current flow the thumb will point toward the north pole
