Magnetism Flashcards
The first magnetic stones were found in ___, near ____
Magnesia, Asia Minor.
This stone is called ____
magnetite.
The earth’s axis poles(Geographic or “True”
poles) and magnetic poles are not aligned.
True or False
True
The _____ is the difference in
alignment between the earth’s magnetic
pole and the axis pole.
angle of declination
Natural magnets became
known as ____ or ____
“leading stones“
or lodestones.
Energy is required to create a magnetic field, but no energy is required
to maintain a magnetic field.
True or False
True
There are only three substances that form natural
magnets: ___, ___, and ____
iron, nickel, and cobalt.
One theory of magnetism states that electrons spin on their own axis
while orbiting the nucleus
True or False
True
This spinning action causes each electron to become a tiny permanent
magnet.
True or False
True
The electrons tend to form pairs spinning in opposite directions. These
pairs negate each other’s magnetism.
True or False
True
Magnetic materials have some electrons that do not have their
magnetism cancelled in a pair.
True or False
True
These magnetic materials (____, ___, and ____) have regions of magnetic
polarity called magnetic ______
iron, nickel, and cobalt, domains
When the magnetic domains are in disarray, the material is not magnetic
True or False
True
The atoms are disarrayed in a
piece of ____ metal.
nonmagnetized
There are 3 classes of magnetic materials:
–
–
–
–Ferromagnetic
– Paramagnetic
– Diamagnetic
Ferromagnetic materials are easily magnetized.
True or False
Examples of these materials are ___, ___ , ___ & ___
True, iron, nickel, cobalt &
manganese.
Paramagnetic materials are not as easily magnetized.
True or False
Examples are ___, ___, and ____
platinum, titanium, and chromium.
Diamagnetic materials cannot be magnetized
True or False
True
Diamagnetic materials can be metal or nonmetal.
True or False
- Magnetic lines of force tend to go around
diamagnetic materials. - Examples of diamagnetic materials are ___, ___, ___, and ____
True, copper, brass,
wood, and antimony
All magnets have two points opposite each other where the field force is strongest: two points where the magnetic flux is
more dense.
These points are referred to as the magnetic ___.
They are the points at which the magnetic lines of force enter and leave the magnet.
It is not possible to have one ___ without having the other
poles, pole
The property that opposes the setting up of flux lines is known as ____
reluctance.
Using this principle, you can construct a path that causes flux to divert around something that you are trying to shield from
magnetic lines of force.
This type of device is called a ____
magnetic screen.
The magnetic lines of force tend to align and concentrate within the ferromagnetic material.
True or False
This causes poles to be established at the points where the lines of force enter and leave the ferromagnetic material.
This process is referred to as magnetism by ____
True, induction.
If the ferromagnetic material is
* soft iron (iron with a low carbon content), the iron is easily magnetized. But it loses its magnetism as the
magnetic field is removed.
True or False
True