only magnets can repel
magnetic materials & magnets can attract
shapes: rod, button, bar, ring, u-shaped, horseshoe
magnetic materials (I see naughty cats):
freely suspended magnet → NS direction
lose strength: hammer, heat, drop
stroking more times
electromagnet
more no of turns of wire, more batteries
scrapyard → able to pick up magnetic materials + demagnetise: able to be reused