Iron is magnetically soft – it can be easily magnetised and demagnetised. Magnetic fields lines are invisible but they fill the space around a magnet where the magnetic forces work on magnetic ...

Bar magnets and horseshoe magnets are two of the most common shapes of magnet. The magnetic field is shown by lines with arrows that point from north to south. You can tell how old some coins are ...

Earth's main magnetic field is generated in the planet's outer core, a layer of molten iron 2,2001,800-3,100 miles ... the planet's surface and where all lines of longitude converge.