Transcript Date Magnets and their Properties – Part 2 Lesson Outcomes Task 1: Use abstract ideas to demonstrate interactions between poles using field lines Level 5 Task 2: Explain.

Date
Magnets and their Properties – Part 2
Lesson Outcomes
Task 1: Use abstract ideas to
demonstrate interactions
between poles using field lines
Level 5
Task 2:
Explain how it is possible to
make a magnet
Level 6
Task 3:
Use scientific ideas or abstract
ideas to explain what happens
to metal atoms when you
make a magnet
How I did Targets
Connector:
(Level 4)
What is a
magnetic
field? Answer
in your own
words
BIG picture
• What skills will you be developing this lesson?
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Literacy
Team work
Self management
Creative thinking
Independent enquiry
Participation
Reflection
• How is this lesson relevant to every day life?
(WRL/CIT)
Magnets and Magnetic Fields
The region around a magnet where it has a magnetic effect
is called its magnetic field.
When a magnetic material is placed in a magnetic field it will
experience a force.
S
N
The iron filings feel the effect of the magnetic field and
show the direction of the forces in this region.
Shape of a Magnetic Field
What is the shape and direction of the lines of force in the
magnetic field around a bar magnet?
strongest
field
at poles
N
S
weakest field further
away from poles
Where is the magnetic field strongest?
strongest
field
at poles
Strength of Magnetic Field
Well, we can’t see it for a start, but...
However, iron filings are pushed into patterns by a
magnetic field. If we sprinkle iron filings on a piece of
paper over a magnet we can see...
The lines of force are very
close together here – the field
is very strong.
The lines of force are further
apart here – the field is weaker.
A line of force links one pole of a magnet to the other pole.
Magnetic fields
N
S
New Information for Task 1
Viewing magnetic fields: N poles
together
S
N
N
S
Bring the two north poles as close to each other as
possible and place a piece of paper on top of the
magnets.
Carefully scatter iron filings onto the paper.
Draw the pattern created by the iron filings.
Q1
What do you notice about the pattern of the lines of
force in the region between the two north poles?
S
N
Viewing magnetic fields: N and S poles
together
Bring the north and south poles of two bar magnets together.
S
N
S
N
What happens to the magnets?
Next, put the north and south poles close to each other,
without letting them touch, and place a piece of paper on top.
Carefully scatter iron filings onto the paper.
Draw the pattern created by the iron filings.
Q2
What do you notice about the pattern of the lines of force
in the region between the north and south poles?
S
N
S
N
Q3
How does this pattern compare with the pattern between
the two north poles?
Task 1: Answers
Attracting
Task 1: Answers
Repelling
Task 1: Answers
Attracting
Repelling
Task 1: Review
Go back to your lesson outcome grid and fill out
the ‘How I did’ and the ‘Targets’ column.
Lesson Outcomes
Task 1:
Level 5
How I did
Met?
Partly met?
Not met?
Targets
How can I improve
on task 2?
New Information for Task 2
Making a magnet
A magnet can be made by magnetizing a material which is
attracted to a magnet, e.g. a paper clip.
There are three methods that can be used to make a magnet:
 Stroke a magnet along the paperclip from one end to the
other and then starting from the same place, repeat the
movement. The more times this is done, the more
magnetic the clip becomes.
 Hold a nail in a magnetic field and hit it with a hammer.
 Put a magnetic material in a strong magnetic field.
Task 2
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For this experiment write the IV, DV, CV
How will you make it safe?
What apparatus will you use?
Draw a results table
Experiment
Making a magnet
• Does an iron nail attract a paper clip?
Groups
‘A’
Bang the iron nail with a hammer 50 times
and try again , how many paper clips it
can attract now ?
Groups
‘B’
Rub the iron nail with a bar magnet for a few
minutes. Does it attract the paper clip? How
many ?
Task 2: (level 6)
•
Task 2: Answer the following questions:
1.
Which materials can be turned into magnets?
2.
What are the three ways in which magnets can be
formed?
3.
From what have you seen, which method was the best
at making a magnet? What is your evidence for this?
Task 2: Review
Go back to your lesson outcome grid and fill out
the ‘How I did’ and the ‘Targets’ column.
Lesson Outcomes
Task 1:
Level 5
How I did
Met?
Partly met?
Not met?
Targets
How can I improve
on task 2?
New Information for Task 3
What causes magnetism ?
• Some metals can become magnetic.
• They contain ‘domains’ which are like small
magnets each with a N and S pole.
• Normally these are all pointing in a random way,
so the magnetic effect of each domain is
cancelled out.
• To magnetise a material these domains must
point in one direction.
Hammering an iron nail can also align the
magnetic domains.
Task 3: (Level 7)
• Task 3:
• Read through the worksheet called ‘8Ja3 What is a
Magnet’
• Stick into your books.
• Answer all questions in your books.
Task 3: Review
Go back to your lesson outcome grid and fill out
the ‘How I did’ and the ‘Targets’ column.
Lesson Outcomes
Task 3:
Level 7
How I did
Met?
Partly met?
Not met?
Targets
How can I improve
on task 3?
Homework
• Homework task:
• Due date:
• Criteria for level 5:
• Criteria for level 6:
• Criteria for level 7: