The simple experiment to show that like poles repel while unlike poles attract each other is: Suspend a bar magnet and allow it to freely rotate. When it will come to rest, it will point towards the north-south direction. Now, bring the N pole of the second magnet near the North pole of the suspended magnet, we will see repulsion between the two magnets. But, if we bring south pole of the second magnet near the north pole of a suspended magnet then we will observe attraction. So, we can say like poles repel while unlike poles attract.