42 terms

Abeka Physics Chapter 23

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magnetite
term for a magnetic form of iron ore
lodestone
term used for any piece of magnetized rock since it had value in giving direction
north (north-seeking) pole
term for the end of a lodestone that gains a north-ward direction
south (south-seeking) pole
term for the end of a lodestone that gains a southward direction
dipolar
A magnetic pole is always paired with its opposite; thus, every magnet is ____.
monopoles
term for isolated north poles and south poles that might occur somewhere in nature
law of magnetic poles
the law that states that unlike poles attract whereas like poles repel
contact and induction
two ways to magnetize an object
contact
Magnetizing an object by stroking or touching it with an existing magnet is called magnetization by ____.
induction
Magnetizing an object by bringing it into the presence of an existing magnet is called magnetization by _____.
keeper
term for a piece of soft iron that can be placed across the poles at the end of each pair of magnets when they are put away
temporary magnets
term for iron magnets and other easily demagnetized magnets
permalloy
the best material to make a magnet rapidly gain and rapidly lose magnetization; an alloy of nickel and iron in approzimately a 3 to 1 ratio
alnico
term for an alloy of aluminum, nickel, cobalt, and iron in various proportions, of which many permanent magnets are made
lines of flux
term for lines on diagrams or drawings that show which ways the north and south poles point
tangent
The direction of field strength acting on an isolated north pole is _____ to a line of flux at every point.
closed loops
Lines of flux must be drawn as ___ ___.
stronger
The lines of flux are more concentrated where the magnetic field is ____.
magnetic induction
term for the field strength at a particular point in a magnetic field
permeability
The extent to which a material absorbs lines of flux is related to its _____, or how strongly it is magnetized by a magnetic field.
magnetic insulators
term for highly permeable materials that resist penetration by lines of flux
spin magnet
term for an electron that rotates on its own axis
magnetic moment
term for when an electron seems to spin but does not actually spin
orbital magnets
term for magnetic moment produced by electrons
domain
term for a small region containing billions or trillions of atoms with aligned magnetic poles
saturation
term for the spin axes of all the unpaired electrons pointing in the same direction
diamagnetic
term for a material that is repelled by a magnet
paramagnetic
term for a material that has only one unpaired elctron per atom, and is weakly attracted to a magnet
ferromagnetic
term for a material that is strongly attracted to a magnet because it has two or more unpaired electrons per atom
conventional current
term that describes electricity through a circuit as positive charges flowing from positive to negative
True
True or False: Electrons flow from negative to postive.
Hans Oersted
Danish physicist who found that an electric current affects the magnetic meedle of a compass
right-hand rule
the rule that states that if the thumb of the right hand is pointed along a conductor in the direction of positive current, the fingers encircle the conductor in the direction of the north-moving field
solenoid
term for a long series of adjacent loops in the form of a helix or a loose coil; becomes a magnet when current passes through the wire
electromagnet
term for a solenoid with a core of iron, permalloy, or similar material
1.26 x 10^-6 N/A^2
the value of the permeability constant for a vacuum
ampere
term for the current that, when flowing in each of two long, parallel conductors spaced one meter apart in a vacuum, would give rise to a force of exactly 2 x 10^7 N upon any meter length of either conductor
coulomb
term for the amount of charge that, in each second, passes a given point on the conductor
right-handed three finger rule
the rule that states that if you point your right thumb in the direction of positive current, your extended index finger points in the direction of magnetic induction
left-hand rule
the rule that says that negative current flows the oposite direction of positive current
magnetic flux
term for the total number of lines falling on any surface, or the total magnetic influence playing oupon a surface
flux density
another term for magnetic induction