A magnet pulls a steel thumbtack across a shelf. Which field is responsible?
Every drawing of a bar magnet's field shows the same loops, from one end of the magnet around to the other. The arrows on those loops always run the same way, and the poles decide it.
A magnet has a north pole and a south pole, and the drawing tells them apart by direction.
Here is the bar magnet's field.
Follow any line outside the magnet the way its arrow points. The line does three things. It leaves the magnet at the north pole. It curves around through the space beside the magnet. And it enters the magnet again at the south pole.
Outside a bar magnet, do the field lines run from north to south, or from south to north?
So the arrows alone tell you which end is which: lines out at the north pole, lines in at the south pole.
A fridge magnet's field lines, outside the magnet, enter it at one pole. Which pole?
The field lines outside a door-latch magnet leave it at one pole. Which pole?
Outside a bar magnet, which statement about its field lines is correct?
The arrows are marked on the drawn loops. Which pole do the arrows lead away from?
One loop in the drawing is followed, outside the magnet, the way its arrows point. Where does the followed loop finish?