To find out about laws of magnetism you can perform the following simple experiment.
Suspend a bar magnet as shown in figure, so that it can freely rotate. Allow it to come to rest. You will notice that it remains in north-south direction.
Now bring N pole of second bar magnet near N pole of the suspended bar magnet. What do you observe?
Now take the same pole near the south pole of the suspended magnet. What do you observe?
You will notice in each case that when like poles are near each other, there is repulsion and when there are unlike poles near each other there is attraction. From this experiment, we can conclude that:
