How to Determine the Negative Pole of a Magnet
- 1). If you do not have access to a magnetometer, get your hands on a compass or second magnet to check the polarity of the magnet in question.
- 2). Place the second magnet or compass close to the first magnet and see what happens.
- 3). The red end of the compass needle with repel your magnet's north pole and attract your magnet's south pole. The same idea applies when using a second magnet -- the second magnet willl attract opposite poles and resist like ones.
Source...