How to Identify a Magnet's North and South Poles
It doesn't matter if you have neodymium magnets or samarium cobalt magnets, every magnet has a North and South Pole. Sometimes a magnet's poles are identified directly on the magnet, but most of the time it is not. One way you can determine the North and South Pole of a magnet is with a compass. Interestingly, the geographical North Pole is a magnet's South Pole. Therefore, when you place a magnet, such as a bar or disc magnet, next to a compass, the North pole of the magnet will point toward the South Pole of the compass and vice versa.
While you can use a compass to determine the North and South Pole of a magnet, there's an easier way: a magnetic pole identifier. This handheld device is easy to operate — all you have to do is press and hold a button and place the tip of the identifier against one side of a magnet. If the red light on the device goes on, you're dealing with the magnet's North Pole. Green means South Pole. You can also move the pole identifier along the side of a magnet to see where the poles switch as one light goes dark and the other switches on.