6.7

6.7 starter

Tell the person next to you…
1. If the field lines are close together, what does this tell you about the field?
2. If the field lines are widely spaced, what does this tell you about the field?
3. If the magnetic field lines are parallel to each other, what does this tell you about the field?

Answers
1. The field is strong
2. The field is weak
3. The field is of a constant strength - a "uniform" field

6.7

· 6.7 know how to use two permanent magnets to produce a uniform magnetic field pattern

· When the field lines are parallel, the field will be uniform (constant field strength)

See the full gallery on Posterous

6.6

6.6

· 6.6 sketch and recognise the magnetic field pattern for a permanent bar magnet and that between two bar magnets

6.4

Plenary questions and the Earth's Magnetic field.ppt Download this file

6.4

• 6.4 understand the term ‘magnetic field line’

Observing the magnetic field around a bar magnet and a wire

magnetic field around a bar magnet and wirehttp://www.youtube.com/watch?v=pjJSa148CKI

· Use iron filings to observe the magnetic field around a bar magnet
· Use plotting compasses to observe the field
· Use the 3D field demonstrator to observe field

6.4 Field around bar magnet simulation

Website:

http://www.walter-fendt.de/ph14e/mfbar.htm

6.4 plenary questions and Earth's Magnetic Field

6.4 plenary 2

· Can you stop a magnetic field?
· Watch the incredible flying paperclip demo to find out!
· Now you can try with your hand...

6.5 and 6.3

6.5 starter

Demo
· How I turned a needle into a compass to find my way out of the jungle...

6.5 and 6.3

· 6.5 understand that magnetism is induced in some materials when they are placed in a magnetic field
· 6.3 recall the properties of magnetically hard and soft materials

Practical
1. Stroke a magnet along a steel bar and an iron bar
2. Try picking up some bar clips
3. Bang both bars on the desk
4. Now try picking up the paperclips again
5. Repeat the experiment but this time put the bars inside an electromagnet instead of stroking them

Explanation
· Steel is a magnetically hard material. It retains its magnetism when magnetised
· Iron is a magnetically soft material. It can be magnetised, but easily loses its magnetism

6.2

6.2 Starter

Neodymium magnets are strong…

6.2 starter 2

· Magnetic materials are attracted by magnets.
· Can you list the 5 magnetic materials?

(3 elements, 2 compounds)

Answer

3 elements
1. Fe (iron)
2. Co (cobalt)
3. Ni (nickel)

2 compounds
1. Steel (an alloy of iron)
2. Fe3O4 (magnetite (lodestone), one of the oxides of iron)

And the exceptions that prove the rule… ?
· Magnet moves water - diamagnetism

· Levitating frog...

· Ferrofluids…

6.2

· 6.2 recall that magnets repel and attract other magnets, and attract magnetic substances

Question

You have 3 bars that all look the exactly the same but they are made from:
1. a magnet
2. steel
3. aluminium

You are given a horseshoe magnet. How can you use this to tell which bar is which?

Answer
1. The bar magnet will be attracted to one pole of the horseshoe magnet and repelled by the other
2. The steel bar will be attracted to both poles of the horseshoe magnet
3. The aluminium bar will be attracted to neither pole of the horseshoe magnet

6.2 Plenary - Multichoice questions

Attraction and repulsion quiz.swf Download this file

6b Plenary Multichoice questions.pptx Download this file

P6 student objectives sheet

P6 IGCSE Physics Student Objectives.doc Download this file