Magnetism

• Two 'like' magnetic poles repel and 'unlike' magnetic poles attract
• The ends of a magnetic field are north-seeking (N) and south-seeking poles (S)
• Magnetic materials, electromagnets and the Earth create magnetic fields which can be described by drawing field lines to show strength and direction
• The stronger the magnet, and the smaller the distance from it, the greater the force of attraction
• Field lines flow from the north-seeking pole to the south-seeking pole
• An electromagnet uses the principle that a current through a wire generates an electromagnetic field
• An electromagnet is basically a wire coiled around a magnetic metal core. A cell/battery is used to generate a current that passes through the metal
• The strength depends on the current, the core and the number of coils of the solenoid
• The magnetic field of an electromagnet decreases in strength with distance
• Core is the soft iron metal which the solenoid is wrapped around
• Magnetic force is the non-contact force from a magnet on a magnetic material
• Solenoid is the wire wound in a tight coil, part of an electromagnet
• Electromagnet is a non-permanent magnet turned on and off by controlling the current through it