Ed 713 22 Magnet Power Point Presentation 2 1

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Ed 713 22 Magnet Power Point Presentation 2 1 Powered By Docstoc
Mosharraf Hossain
 Tamara Shorter
 John Heyenga
                    Ed 713.22/ Summer ’08
Which items a magnet will attract?
Test the items listed below and
record your answers in your Book.
Next slide will reveal answers.
    Item          Yes         No
Paper Clip
Nuts & Bolts
What will make a magnet move?
     Item       Yes   No
 Paper Clip
 Nuts & Bolts

Will these items be attracted to a magnet?

 yes   NO         yes   No        yes   NO

 yes   no         yes no          yes    no
The power of magneti
Were you correct? Why were these things
attracted to the magnet?
    N                               S
    What will happen when the ends of the two
    bar magnets are placed close together?

N                   S         N                 S

    What will happen when the ends of the two
    bar magnets are placed close together?

N                   S         S                 N
The North and South poles of the magnet are
attracted to one another.

    N                S   N               S

Like poles of the magnet are not attracted, or
repel one another.

N                S           S                   N
     What is magnetism?
• Magnetism is the force of attraction
  between magnets and magnetic objects.
Graphic Organizer (K W L H Chart)
 What We Know        What We Want to   What We Learned    How Can We Learn
                           Learn                                 More
 They stick to       How do the         Why do they       BY doing hands
 refrigerators.      magnets stick      stick to           on activities.
 They stick to       together?          refrigerators?    Reading more
 metals.             What happens       What metals do     books.
 Sometimes they      when you break     they stick to?
 won't stick to      a magnet?          Why do some
 each other.         How do             ends push
 They come in        magnets make       away from each
 all sizes and       things move?       other? Why are
 shapes. We use                         the ends called
 them to hold                           poles? How do
 papers. They                           opposite poles
 can hold a lot of                      react to each
 stuff. Some                            other? How do
 ends stick to                          the same poles
 each other.                            react to each
 Some magnets                           other? How do
 have an N and                          we use
 an S on their                          magnets in our
 ends.                                  homes?
       Magnetic Field Lines
Magnetic field lines describe the structure of
magnetic fields in three dimensions. They are
defined as follows. If at any point on such a line
we place an ideal compass needle, free to turn in
any direction (unlike the usual compass needle,
which stays horizontal) then the needle will
always point along the field line.

Field lines converge where the magnetic force is
strong, and spread out where it is weak. For
instance, in a compact bar magnet or "dipole,"
field lines spread out from one pole and converge
towards the other, and of course, the magnetic
force is strongest near the poles where they
come together.
Magnet and Magnetic Field
• A temporary magnet          • A junkyard is one place to see
  made by passing               an electromagnet in action. A
  electric current              crane holding a huge
  through a wire coiled         electromagnet can be used to
  around an iron bar.
                                pick up scrap metal when
                                current flows through it. When
                                the crane operator wants to
                                drop the scrap, he or she will
Use link below to see a         simply shut off the current to
  example of how to             the electromagnet.
  make a temporary
  Students’ results of
electromagnetic testing
                                        Results of Electomagnetic test

       Number of Batteries               Number of Nail           Number of wrapes        Paper clips picked up
           1st turn      2nd turn        1st turn     2nd turn      1st turn 2nd turn         1st turn 2nd turn
   Group 1     0            2               1            1             0         15              0           6

   Groput 2     1                1          1             2              10     10              2         4

   Group 3      1                1          1             1              15     30              3         4

   Group 4      1                1          1             3              13     13              2         5

                                     Results of Electromagnetic test

                                                                               Group 1

                            20                                                 Groput 2
                            15                                                 Group 3
                            10                                                 Group 4









                                 Number                 Number
                                    of    Number     of wrapes Paper
                                 Batteries of Nail              clips
 What is the relationship between
     electricity and magnetism?
Electricity and magnetism controls much
of our current technology (e.g. computers).
 Electricity and magnetism are linked
       on a fundamental level.
Magnets are used to generate, or produce,
Spinning a coil of wire inside a magnetic field
produces an electric force between the ends of
the coil.
In a similar way, an electric current produces a
magnetic field around it.
      Magnetic Forces Scavenger Hunt
              1) Write three questions for the class from this video.
                           Experimenting With magnets.

       2) Write three questions about different experiments that deal with earth's
                                magnetic force.
3) Examine the different photos and come up with two questions about Auroras.
                 The Auroras are connected to magnetic forces.

                       A game about magnetic forces.
          Write two questions for the class about what you observed.

Hunt for Magnetism: A treasure hunt on magnetism

     The scavenger sites as well as the treasure hunt site is located on the
                             filamentality website.
         Additional Online Resources
•   Magnet Song
•   http://www.youtube.com/watch?v=G-nkIECIBWM
•   How does electricity create a magnet?
•   http://www.youtube.com/watch?v=emlzh9XXWgQ
•   Cartoons
•   http://www.youtube.com/watch?v=2vqgXRKHI-s
•   http://www.youtube.com/watch?v=I6VrCJRssKc
•   Mutual Distraction (Cartoon)
•   http://www.youtube.com/watch?v=4_5cztU9hVk
•   Underdog Cartoon
•   http://www.youtube.com/watch?v=jjX9vgT1rWw
•   http://www.youtube.com/watch?v=KFVhJX9RsGQ
•   http://www.youtube.com/watch?v=kQvv1V9z8uU
•   Magnet Quiz
•   http://library.thinkquest.org/06aug/02337/quiz.htm
•   Teaching magnets to students
•   http://www.youtube.com/watch?v=oypDGvBoKl0
Can you name something that is
        huge and has
    North and South Pole?
• If you answered “The Earth”, you were right!

• The Earth is a giant magnet. It has two magnetic
  poles and it is also surrounded by a magnetic

• This magnetic field is what causes the needle of a
  compass to point in different directions and the
  poles of a magnet to point either north or south.
The earth is like a giant magnet!
The nickel iron core of the earth gives the earth a
magnetic field much like a bar magnet.
What are magnets used for?
    Why do we need to
    learn about them?
   Do you like roller coasters or
   other amusement park rides?
• If you answered yes, then you should know that a roller coaster
  mainly uses magnets to achieve quick acceleration at the
  beginning of the roller coaster ride. The type of magnets used
  in a roller coaster may vary, but the roller coaster depends
  upon both the negative and positive abilities of magnets.
Computers use magnets on all of
         these parts:
                    Cooling fans
                  Floppy disk spinner
                     CD spinner
                    DVD spinner
                  Hard disk spinner
                   Never put a magnet near a
                computer or it will cause the magnets
                 inside the computer to mess up.
  Magnets are used in factories
• Magna-Rails
  Positioned under conveyor belts, Magna-Rails hold parts firmly
  to the belt even at high speeds and on up or down inclines as
  steep as 90 degrees.

                        Places, such as car manufactures, also
                        use magnets to carry heavy metal from
                        place to place.
  What else are magnets used for?
The Refrigerator
Uses magnets in its compressor
and ice maker dumper. It also
uses magnets in the strip
around the door to hold the
refrigerator door closed.

 The clothes washer
 Uses magnets in its pump and
 agitator timer.

 The clothes dryer
 Uses magnets in its timer
 and drum turner
 What else uses magnets?
A CD spinner, DVD spinner, and head positioner all
uses magnets. A Television has lots of magnets in it
along with a stereo system and speakers. These all
work by using magnets.
Without magnets, you would not
         be able to….
• Use the microwave
• Have a dishwasher
• Have a furnace
• Use a credit card
• Hear the phone ring
• Or hear the door bell ring
All of these things use magnets to work!
  Without magnets, you would not
           be able to….
• Post up your sports schedules on the
• Turn on the ceiling fan
• Use the electrical can opener
• Ride in a moving cars
(that’s right, cars have LOTS of
magnets inside to make them work!)
Magnets are all around us. Chances
are, if something moves with electrical
power, then it has a magnet in it
somewhere. How do magnets work
you might want to know? That is what
you are going to begin to learn about in
our magnet unit.

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