Question

4. Given the strength of the battery and the size of the coil, there are an ideal number of coil turns that make a motor spin at high speeds without being unstable. Critique a motor design constructed with a coil of 50 coils of wire instead of 15 coils.

Answer 1

The Strength of the electromagnet depends on how many coils you wrap around and how high the voltage is applied. The coil of wire acts as an electromagnet. Magnets like to align themselves in parallel, so when the electromagnet is on, there is a torque on it due to the permanent magnet. The torque is clockwise or counterclockwise, depending on which way the electromagnet (coil) has to rotate to align itself with the permanent magnet. Say you completely stripped the insulation off of the coil wire where it touches the battery connectors. As you rotate the coil though one revolution, the torque is clockwise half the time and counterclockwise the other half.