When an electromagnet is placed next to another magnet, the attraction and repulsion between the two can cause movement or vibrations. In this activity, students will learn how an electromagnet works ...

The Hendo hoverboard probably uses electromagnetic repulsion for lift off. ... If I replace the magnet in the diagram with a coil of wire, I can change the magnetic field without even moving coil.

Independent variable is the current in the coil. Dependent variable is the strength of the electromagnet, indicated by the number of paper clips that the electromagnet can hold.

The diagram shows four different positions of the coil in an alternator, and the corresponding potential difference produced. Figure caption, The potential difference-time graph for an alternator ...