Please enable JavaScript.
Coggle requires JavaScript to display documents.
Magnetism and Electromagnetism - Coggle Diagram
Magnetism and Electromagnetism
Magnets
The 2 poles are called North and South
2 poles the same will repel (N+N or S+S)
Opposite poles will attract (N+S)
Permanent magnets are always magnetic and always have poles
Induced magnets are materials that do not have fixed poles, but become magnetic when placed in a magnetic field
The 4 magnetic materials are iron, steel, nickel and cobalt
The Earths Core
The Earths Core is magnetic and creates a large magnetic field around the Earth
If the compass doesn't point to the Geographic North Pole, it is over North Canada. The Earth's magnetic pole above Canada is magnetic South Pole
We know this because a freely suspended magnetic compass will align itself with the earths field lines and point North
Magnetic fields
The field lines always point from north to south
Strength of the field decreases as the distance from the magnet increases
Direction always points to south pole and away from north pole, at any point
Can be drawn using a plotting compass (a small compass that contains a bar magnet inside). They show the direction of the magnetic field at a certain point
Current
Produces a magnetic field around the wire
The direction is dictated by the "right hand grip rule"
When a current flows in a wire, it creates a circular magnetic field around the wire. This magnetic field can deflect the needle of a magnetic compass. The strength of the magnetic field is greater when its closer to the wire, and decreases if the current increases
greater current = greater magnetic field
greater distance from wire = weaker magnetic field
Solenoids
A solenoid consists of a wire coiled up into a spiral shape
