Magnetism – From the syllabus  state the properties of magnets  give an account of induced magnetism  distinguish between ferrous and nonferrous materials  describe methods of magnetisation and of demagnetisation  describe an experiment to identify the pattern of field lines round a bar magnet  distinguish between the magnetic properties of iron and steel  distinguish between the design and use of permanent magnets and electromagnets

Magnetic poles come in pairs How to make or destroy a magnet Magnetic domain theory Attraction and repulsion – the magnetic field shapes Magnetic poles can be induced ‘Hard’ and ‘soft’ magnetic materials. Magnetism You should learn:

Induced magnetism  Magnetic materials contain billions of “atomic magnets”.  Normally the atomic magnets are randomly arranged so they cancel each other out.  In a magnetic field the atomic magnets line up along the field lines so they point in the same direction.  We say magnetism has been induced in the material.  This is why magnetic materials are attracted to magnets.

Summary Like magnetic poles repel. Unlike poles attract. Strong magnets can be demagnetised by a)hammering b)heating c)using a coil with alternating current. Iron (unlike steel) is easily magnetised, easily demagnetised. Magnets can be made by a)the stroking method, or b)the electrical method (more details on page 293). Lines of flux show the direction of the field round a magnet.

1.Magnets have 2 ‘poles’, called ______ and ______. 2.We can use _____ ________ to show us the field’s ‘lines of force’. 3.The lines of force can’t _______ each other. They come out of ______ poles and go into ______ poles. 4.TWO ways that we can ruin a magnet are to: _______ it, or _______ it 5.Why do we use electromagnets on scrap yard cranes? Chapter 9.02 : Magnetism

1.Magnets have 2 ‘poles’, called ______ and ______. 2.We can use _____ ________ to show us the field’s ‘lines of force’. 3.The lines of force can’t _______ each other. They come out of ______ poles and go into ______ poles. 4.TWO ways that we can ruin a magnet are to: _______ it, or _______ it 5.Why do we use electromagnets on scrap yard cranes? Answers North South cross North South hit heat So you can put things down when you’ve finished! iron filings

Activities Lesson 1  Aims  Video starter  Experiment -Attract and repel  Notes induced magnetism  Reading  Book questions  Experiment - Making a magnet  Extension – Q1 p205  Homework – A4 poster – Uses of (permanent) magnets.

Homework assessment Content/5  1 example of uses explained briefly  3 examples of uses explained satisfactorily  5examples of uses explained in detail Communication (display)/5 Good use of (relevant) diagrams Eye-catching design Clear text Bibliography Extra effort