To determine the polarity of a magnet, you can use a compass. The end of the magnet that attracts the north pole of the compass is the magnet's north pole, and the end that attracts the south pole of the compass is the magnet's south pole.
Reverse the polarity of the magnet.
Use a compass. It will always point to a magnet's south pole.
You can identify the polarities of a round magnet using a compass. The end of the magnet that points north on the compass is the north pole of the magnet, while the end that points south on the compass is the south pole of the magnet.
To determine the polarity of a magnet without a compass, you can use the "hanging method." Hang the magnet from a string and observe how it aligns itself. The end that points north is the north pole, and the opposite end is the south pole.
Reverse the polarity of armature windings of the motor.
To reverse the polarity of a compass that is 180 degrees off, you can simply flip the compass needle in the opposite direction. This will align the compass needle correctly with the Earth's magnetic field and reverse the polarity.
Permanent magnet field motors. With a these motors, a permanent magnet is used to replace the field coil. DC power is connected via the brushes, to the armature only. Reversing the polarity, will cause the motor to reverse its direction of rotation. It is very common to use a switch to intentionally reverse to the polarity, to allow reversal of the motor if desired.
About 0.15% chance to happen within a time period of a year.
Demagnetize it, then remagnetize it the opposite direction. It's a lot of work and it would undoubtedly be easier just to repaint it and claim you reversed the polarity.
The polarity of both ends of a magnet is different. The positive and negative polarity exist for a magnet.
The polarity of a compass needle must be oriented such that the north-seeking end of the needle points towards the Earth's geographic North Pole. This is due to the magnetic field of the Earth, which causes the compass needle to align in a north-south direction.