Magnet
Magnetic material
Characteristics of magnetis
Characteristics of magnets
Making a magnet from magnetic materials
Type of magnets
The attraction of a magnet is called magnetism
Lodestones and magnets that exist naturally and nature other magnets can be man-made magnetic material
A magnet is able to attract a magnetic material
Magnetic Materials
Nickel
Cobalt
Iron
Steel
Non-magnetic materials
Metal
Non-metal
Glass
Wood
Aluminium
Zinc
Copper
Different shape
Different sizes
All magnets have 2 poles
The magnetism of a magnet is the strongest at these 2 poles.
The magnetic strength becomes weaker further away from the poles
When a magnet is suspended freely it always comes to a rest in a North South direction
North
South
North seeking pole
South seeking pole
The poles can exert a magnetic force
On other magnets
On magnetic materials
Attraction
Repulsion
Attraction
The like poles of 2 magnets facing each other
The unlike poles of 2 magnets facing each other
Temporary
Permanent
Electromagnet
Magnetism can pass through a non-magnetic material to attract a magnetic material
Magnetism cannot pass through a magnetic material to attract a magnetic material
The iron sheet can block the magnetism of the magnet from attracting the magnetic material
Strength of a magnet
Affected by
Distance
Not affected by
Size
Applications
Applications
television or loud speakers
A magnetic door
Rerfrigerators
Compass
Fire alarms
electric bells
scrap yards
Methods
Stroking
electricity
Stroke with same stroking pole all the time
Stroke in one direction
If the permanent magnet strokes the magnetic material back and forth or changing the directions constantly, it will not be magnetised
If the stroking pole keeps changing, it will not be magnetised
Using 2 permanent magnets to stroke
The stroking pole used in each magnet must be opposite
Stroke the magnetic material in opposite directions
An iron nail is coiled around by electrical wire
Must be connected to an electrical supply such as a battery to work
Iron nail will become a magnet when electricity is turned on. The magnet is them called an electromagnet
Increasing strength
Coil more coils of wire around the iron nail
Amount of electricity= using battries
Is a temporary magnet and once electricity is turned off it loses magnitism and cannot attract magnetic object anymore
How to demagnetise a magnet
Heating
Dropping
Hammering
Test for magnets, magnetic materials and non-magnetic materials
Magnetic material got no fixed S-pole and N-pole
Non-magnetic material has no poles
Has fixed S-pole and N-pole at its end
An object is only a magnetic material if it does not repel a magnet but will always be attracted to the magnet
AN object is a non-magnetic material if it cannot repel or attract a magnet in any ways
The more strokes, the stronger the magnet