You were also supposed to show us the circuit diagram. Without the picture, most of us have no way to know what any of this is about.
My guess is:
It's an electromagnet. A long piece of wire is coiled around an iron core. Then, when the ends of the wire are connected to the terminals of the battery, electric current flows through the wire, and the magnetic field around the wire makes the iron core a magnet.
==> The more times the wire is coiled around the core, the stronger the magnet is when it's turned on, and the more paper clips it can pick up.