I have a physics assignment (due tomorrow!) where I need to construct a DC motor that has to run for at least 20 seconds. I'm almost finished, but I've hit a roadblock. The coil won't magnetise and form an electromagnet and I'm stumped as to why. There is a current running through the coil, the commutator sparks when I connect the power, but it doesn't magnetise properly. Both a north and south pole attract each ends. Any answers?
