3-ELE-08

Outcomes

• Pupils understand that magnets exert forces on each other and other magentic materials. These forces can be magnetic attraction or repulsion.
• Pupils can plot a magnetic field around one bar magnet, two bar magnets (attracting and repelling) and predict the shape of magnetic fields resulting from various arrangements of magnets.
• Pupils can recall that certain elements can be magnetised when in a magnetic field.
• Pupils understand that a domain is a small region of a ferromagnetic material that has its own magnetic field, which can be aligned.
• Pupils understand that the direction of a magnetic field line indicates the direction of the force on a test north pole placed in the field at that point.
• Pupils can see that a uniform field can be created between to attracting bar magnets.

Specification References

6.2 recall that magnets repel and atract other magnets, and attract magnetic substances.

6.4 understand the term 'magnetic field line'

6.5 understand that magnetism is induced in some materials when they are placed in a magnetic field.

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

6.7 know how to use two permanent magents to produce a unifrom magnetic field.

Starter

Using the mini white boards, ask the pupils to draw a magnetic field around a bar magnet. Identify the two main points about drawing a magnetic field- the lines are continuous, they do not cross and they have arrows. Develop into a discussion about the direction of the arrows and what causes a magnet to have a magnetic field.

Demo the domains under a microscope and allow the pupils to make a note about the structure of a ferromagnet.

Main Body of Lesson

• Knowing of the structure of a magnetic field around a bar magnet, the pupils predict and then create the magnetic field around arrangements of bar magnets using this worksheet. Identify neutral points on diagrams.

• Use mini turntables or upturned watchglasses to show that N and N repel, S and S repel but N and S attract.

• Discuss the general shape of the Earth's magnetic field and what other elements found in the Earth are ferromagnetic.

Homework

Research into where magnets are uses in everyday life. 3 examples with explanations.

Additional Information

Resources Required

bar magnets plotting compasses small frictionless tunrtables or upturned watchglasses

Skills Addressed

Prediction of experimental outcome.

Notes

Students find understanding magnetic fields easy if the idea about direction of field lines is fullu understood. Therefore key point of lesson is:

• Pupils understand that the direction of a magnetic field line indicates the direction of the force on a tiny north pole magnet placed in the field at that point.