Magnets

1
(No Transcript)
2
3.01 Observe and investigate the pull of magnets
on all materials made of iron and the pushes or
pulls
on other magnets.
3
Essential Question
What are the characteristics of magnets?
4
Materials not attracted to magnets are called
nonmagnetic. Such materials cannot be
magnetized. Only magnetic materials can be
magnetized. The most common magnetic materials
are iron and steel.
5
Vocabulary Words
Magnet
An object that attracts certain objects, usually
objects made of iron or steel
Magnetic Pole
The end of a magnet
Magnetic Field
The space around a magnet where the force of the
magnet can act
6
What are the main types of magnets?
There are three main types of magnets   
Permanent magnets    Temporary magnets   
Electromagnets
7
    Permanent Magnets
Permanent magnets are those we are most
familiar with, such as the magnets hanging
on our refrigerator doors.  They are permanent
which means that once they are
magnetized, they retain a level of magnetism. 
Here are some examples
8
Temporary Magnets
Temporary magnets act like a permanent
magnet when they are within a strong magnetic
field, but lose their magnetism when the magnetic
field disappears. 
Here are some examples
9
        Electromagnets
An electromagnet is a tightly
wound helical coil of wire, usually with an
iron core, which acts like a permanent magnet
when current is flowing in the wire.
Here is an example
10
A magnet has two ends called magnetic poles.
Magnets have a north-seeking pole and a
south-seeking pole.
11
What is the behavior of magnetic poles?
N
S
S
N
Opposite poles attract.
N
S
S
N
Like poles repel.
12
Which objects are magnetic?
13
How do people use magnets?
Magnets are very useful. People use magnets to
find directions. Earth acts like a giant bar
magnet. A compass needle points along an
imaginary line connecting the North and South
poles.
14
Lets review!
What are the tree types of magnets?
When do magnets attract and repel each other?
How do people use magnets in everyday life?