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In general terms, a _____ is a special bar of iron that can attract and hold other pieces of iron to it.
_______ - The power of attraction between a magnet and iron; It's caused by the motion of electric charges; It's the force exerted by magnets when they attract or repel each other
The term _____ is used to refer to both natural and artificial magnets.
______ magnets are ores that have the unusual ability to attract pieces of iron placed close to them.
Natural magnets are sometimes called ______.
An ______ magnet is simply a man-made magnet that has all the properties of a natural magnet.
Straight artificial magnets are called ____ magnets.
Curved artificial magnets are called _____ magnets.
Artificial magnets that keep their properties for long periods of time are called _____ magnets.
Very strong artificial magnets can be made by compressing magnetic powder under high pressure and temperature. These magnets are called _______ magnets and are used in devices such as DC motors and high-power loudspeakers.
When a magnetic metal core is wrapped in a coil of wire and electric current is applied to the wire, a magnetic field forms around the core. This device is called an _________ and is used to create mechanical motion. (ex. relays & motors)
The ends of a magnet are called the _____.
There are two opposite poles on a magnet: the _____ pole and the _____ pole.
The strongest force of magnetic attraction is located at the _____ of a magnet.
The ____ is the imaginary line that's drawn through the center of a magnet.
The _______ is the point that falls exactly halfway between the poles of a magnet. Little magnetic force is present at this spot.
A piece of soft iron called a _____ joins the two ends of a horseshoe magnet. This piece helps the magnet retain its magnetism for long periods of time when it's not in use.
In an _______, the location of the poles depends on the direction of current flow in the wire coil.
Magnets and electromagnets always attract _____ metals.
Ferrous metals are metals that contain _____.
Copper, brass, aluminum, and some types of stainless steel are unaffected by magnets. These materials are often referred to as _______.
The forces of magnetic attraction and repulsion flow in definite directions or "lines" around a magnet. These lines of magnetic force are called ________.
The area of space around a magnet in which the lines of force move is called a _________.
The lines of force move in a specific path around a magnet. This path is called the magnetic _____. Each line of force leaves the from north pole, makes a complete path around the magnet, then returns in the south pole. From there it goes through the magnet to the N. pole again.
Materials that have very little opposition to lines of force are called _____ or __________ materials.
Materials that have a strong opposition to lines of force are called ________ materials.
The process by which an object is magnetized by the magnetic field of a magnet is called ____________.
Three types of magnetic circuits are: ____, ______, and _____.
A _____ magnetic circuit is a circuit in which all the lines of force are contained within the magnetic material.
A _____ magnetic circuit is a circuit that consists of two or more magnetic materials
A _____ magnetic circuit is composed entirely of magnetic material. The lines of force don't pass through an air gap or any other nonmagnetic material.
Magnetic ____ is a measurement of the total magnetic field which passes through a given area.
The standard unit of magnetic flux is the ______. One of these units is equal to one line of force.
A large unit of magnetic flux is the ______. One of these units is equal to 100-million maxwells, or 100-million lines of force.
_________ is the number of lines of force in a given unit area.
Flux density is expressed in a unit called ____. One of these units is equal to one maxwell per square cm.
A large unit of flux density is a ____ which is equal to one weber per square meter.
____________ is what pushes magnetic flux through a magnet. (voltage for magnets :D)
The abbreviation for magnetomotive force is ____.
In a magnetic circuit, the materials opposition to magnetic flux is called ______.
The MMF that pushes flux through an electromagnet is measured in _______.
The MMF exerted per unit of length of magnetic material is called the magnetic ________.
Magnetic field intensity is represented by the letter H and is measured in units called ____________.
In any magnetic material, the relationship between the magnetic field intensity and the flux density can be illustrated by the ___________.
A __________ is needed to demagnetize a magnetic material.
