A magnetic coil is made using a conductor, generally an insulated copper wire, and winding it around a core to produce an inductor, or a magnet. Basically, a wire that has electricity running through it produces a magnetic field. However, using a single wire would only generate a very faint field. Consisting of more than one turn, or a loop of wire, a magnetic coil focuses the magnetic field, with every coil of wire supplying a small amount of magnetic field. Adding up all those magnetic fields together creates a stronger vector field that properly functions as a magnet. A simple magnetic coil is very easy to make, provided you have the necessary items for it.
Most of the items above can be easily found in your home, except for the magnet wire and the battery, which you can readily get from any hardware store. For safety purposes, make sure that you have a proper location where you can build your magnetic coil, preferably in a workshop, garage, or basement.
Step 1 - Select a Magnetic Core
First, you need to have a magnet core. The iron nail, or any cylindrical piece of iron that you choose to use, will serve as the base from where the magnetic field will converge and eventually amplify. There are other kinds of coils that make use of air as its core by either wrapping the copper wire around a thin cylindrical paper or winding the wire into a coil by itself, having no core at all in the middle. However, this is not advisable to do if you really want your magnetic coil to function strongly.
Step 2 - Wrap the Core
Next, after selecting your core, wrap a strand of magnet wire around it. Remember that the more the coil is tightly spaced together, the better and stronger its magnetic force will be. Then set aside approximately 6 to 7 inches of wire dangling at the end of the core. Proceed to wrap all the way to the other side of the core.
Step 3 - Adhere the Coil to the Core
Using glue or tape, adhere the coil to the core. Leave another 6 to 7 inches of allowance, and trim the rest of the wire off from its roll. This means that you now have two extra strands of wire at the opposite ends of the core that you will need.
Step 4 - Bare the Wire
Now, strip off the enamel coat from the two end wires by burning an inch of the enamel using a lighter or a match. Let it cool off for a few seconds before wiping it off with a clean cloth. Make sure that both end wires are now bare and devoid of the enamel. You now have your very own magnetic coil.
Step 5 - Use the Magnetic Coil
To use your magnetic coil, connect the coil to an electric power source. Keep in mind though that the length of wire used to build the coil determines the resistance or impedance of the coil, and so will determine how much current will flow through it at a specific voltage. Using the lantern battery as a source, attach the two end wires beneath the coils protruding out of the battery. It is then ready for use, and you can test it by trying to pick up items like nails, paper clips, coins, and other small metal objects.