Around a magnet, there are invisible magnetic field lines which show the magnetic field.
These magnetic field lines always come out of the north pole and go towards the south pole. This is shown by the direction of the arrows.
Make sure to include arrowheads as it shows the direction of the field lines. The magnetic fields are strongest at the north and south poles, which is shown by the line concentration.
The distances between the field lines show how strong the magnetic field is.
Two ways that magnetic field lines can be shown are:
Plotting compasses is one way to show magnetic field lines.
Here we have many small compasses surrounding the bar magnet. As you can see, the north pole is pointing towards the south pole at all times. if you extend the lines, it will start to look like the original magnetic field diagram, going out of the north pole and into the south pole.
To show magnetic field lines, we can also place a bar magnet in a pile of iron fillings. The iron fillings will sort themselves along the magnetic field lines.
Here we can see the iron fillings showing the magnetic field around the bar magnet.
We can use the magnetic field lines of two magnets to show how opposite poles attract.
Here we can see the field lines of the two magnets interacting. As we know that field lines travel from north to south, it is easy to see why there is an attraction between opposite poles.
Now let’s look at like poles. For example, two north poles next to each other.
As the magnetic field lines are trying to go from north to south, the magnets will repel each other. The magnetic field lines of the magnets are not touching because the magnetic field lines are trying to reach the south pole.
This means that when like poles are placed near each other, there is a repulsion.