Magnetism

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Magnetism
A Teaching Perspective
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Introduction

• What is Magnetism???
• A powerful force that causes some metals to
  attract or repel
• A magnet has two poles N S
• Only iron, nickel, cobalt and gadolinium have
  strong magnetic effects

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Key points

• Understanding the principle of attraction and
  repulsion
• Understanding the relationship between north and
  south poles
• How magnetism is used in and relates to everyday
  life.

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Attraction Repulsion
N S
N S
S N
N S
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What happens when you break a magnet???
N S
N S
N S
This is called a magnetic dipole.
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What is a magnet made of?
Individual domains cancel out - UNMAGNETIZED
Individual domains combine - MAGNETIZED
Domains tiny regions (max 1mm length or width)
which behave like a tiny magnet
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How to introduce magnetism

• Computer workshop
• Magnetic Field Lines Practical
• Bookwork
• Chalk and Talk
• What is Magnetic practical
• Whatever you feel is comfortable?

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Physical Impact Activity 2
Possible Aims

• Why we dont drop magnets
• How atomic magnets align themselves
• An introduction into a discussion on compasss
  and how they work

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Physical Impact Step 1

• What you will need

• 1 Hammer
• 1 Nail
• 1 Compass
• 1 Board/block of wood

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Physical Impact Step 2

• Using your Compass find true north.
• Align your nail in a north-south direction
• Check your nail with the compass
• Hit your nail while in this direction 50 times
  (only little taps are needed)
• Using your compass, do you notice anything about
  the nail?

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Physical Impact Step 3

• Reverse the direction of your nail and hit it
  with a hammer 50 times.
• What do you think will happen?
• Using your compass, check the nail to see if it
  is magnetised?
• Did you think this would happen?

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Physical Impact Step 4

• Now align your nail in an east/west direction
• Hit it 50 times with a hammer again.
• Why is it different this time?

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Physical Impact Conclusion

• Advantages
• Low resource requirements
• Easy Instructions to follow
• Shows why students shouldnt drop or hammer their
  magnets

• Disadvantages
• Loud
• The students are armed!
• May not work for all students

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Magnetic Teaching Tools
http//teachers.teach-nology.com/themes/science/ma
gnets/
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Magnetic Teaching Tools
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Magnetism Conclusion

• SACSA covered mainly by Energy Systems strand
  (4.3, 4.4, 5.3 5.4) with some relation to
  Matter (chemistry) and Earth Space
• Magnetism can lead into other areas of science
• Allows students to think about and explore
  abstract notions

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Magnetism Conclusion

• Magnetism is an important real world science and
  is a basis for prospective physics students