Magnetism
When current flows threw a wire,
a magnet field is created around the wire
Ferromagnetic materials are
metals that are easily magnetized. Iron, nickel, cobalt, and manganese
Paramagnetic materials are
metals that can be magnetized, but not as easily as ferromagnetic materials. Platinum, titanium, and chromium
Static charges are sometimes called:
A nuisance. Examples: Cars as they move through dry air, Accumulated on a person's body as they walk across carpet, accumulates on clothes in dryer
If a Permanent magnet is cut into pieces, each piece is:
A separate magnet
The strength of an electromagnet is primarily proportional to its
Ampere turns
If an object is place in the field of a strong electromagnet connected to an AC line, the object will
Be Demagnetized
The three ways to demagnetize an object are
By placing it in an AC magnetic field and pulling it away, by striking it, by heating it
What type of magnet depends on flowing current to produce a magnetic field?
Electromagnet
True or False - The north pole of a compass needle points in the direction of the south geographic pole
False
The three basic types of magnetic material are:
Ferromagnetic, Paramagnetic, Diamagnetic
Magnetic lines of force are called?
Flux
Magnetic lines of force are referred to as
Flux
Magnetic strength is measured in terms of
Flux density
The magnetic poles of the earth and the axes poles are
Not the same
What type of magnet do not require any power or force to maintain their field?
Permanent Magnet
The strength of the electromagnet is determined by:
The ampere-turns
The angular difference between true north and magnetic north is known as the
angle of Declination
Diamagnetic materials
are either metal or nonmetal materials that cannot be magnetized. The magnetic lines of force go around them instead of through them. Copper, brass, and antimony
Static means:
not moving or sitting still
The north magnetic pole of a compass needle is attracted to
the South magnetic pole of the earth
Flux density is
the number of magnetic lines contained in a certain area.
The direction of current flow through the wire determines
the polarity of the magnetic field
The basic law of magnetism states
unlike poles attack, like poles repel
Early natural magnets were known as
Lodestones
The measure of the materials ability to be magnetized is
Permeability
True or False - Earth contains magnetic poles
True
The lines of flux
repel each other and never cross
What are the three different systems used to measure magnetic values:
The English system, The CGS system, The SI System
Man-made magnets
retain their magnetism longer
Magnetism can be explained in terms of
Electron spin patterns
The type of core material used in an electromagnet can:
increase its strength