Magnetism
If a substance is attracted to a magnet it is said to be magnetic.
A magnetic substance must contain iron, cobalt or nickel.
Magnets have two poles.
The north seeking pole (N) and the south seeking pole (S).
The pole of the magnet is where the magnetism is strongest.
Two poles that are different will be attracted.
(ie a North pole will be attracted to a South Pole or to another piece of iron, cobalt or nickel)
Two poles that are similar will repel each other.
(ie a north seeking pole is repelled by another north seeking pole)
|
Like poles repel |
| Lines of invisible force called magnetic field lines run from the N pole to S pole. Notice that the arrows point away from the North seeking pole, towards the South seeking pole |
Making an electromagnet
We can make an electromagnet by wrapping a coil of wire around an iron nail (or soft iron bar) and conecting the ends of the wire to a battery.
When an electric current flows through the wire there will be a magnetic field around the iron bar.
For more information see CIRCUITS
