Why does copper need to be coiled in strands to be used in electric motors?
Its a compromise between voltage and current. Motors need a magnetic field to spin, which is only created by current through the wires, not voltage. The strands are actually loops of a single long wire wound many times. If you double the number of ‘strands’ (or more correctly, ‘loops’) of wire, you can get twice the magnetic field for the same current. Back at the power socket, there is a maximum amount of current available, and if you try to suck out the maximum, the power cables get warm, wasting energy. By making many loops of wire, you can lower the amount of current coming out of the socket, and still get enough magnetic field. You might ask why not make lots and lots of loops? This is where the voltage comes in. The voltage is what pushes the current around, (like water pressure in the garden tap). If there isnt enough voltage ‘presure’, the current only dribbles slowly through the super-long wire, and you end end with less than optimum magnetic field.
