An electromagnet will maintain a charge as long as current continues to flow through it. Strengthening the charge is a matter of changing, or adjusting the components that enable the charge to flow. There are many ingredients that affect electromagnet strength. The length and width of the magnetic field, the amount of resistance the current encounters, the pulling power of the magnet itself, all determine how strong your electromagnet will be.
Prepare the wire for a good connection. Using the wire strippers, sheer off an inch or two of the insulating material at the ends of the wire. This will allow for a clean connection to the battery terminals
Wrap the wire around the nail. Once the current is running through the wire, a magnetic field is generated through the wire. This is because once electrons are excited, they tend to excite each other in the process which is what causes the current to flow. By wrapping the wire around the nail, the magnetic field in the wire is strengthened. Wrapping the wire pushes the electrons closer together. The closer the electrons are to each other, the more excited they get. The magnetic field increases. In technical terms, this is called the magnetic flux density of the magnet.
Connect the wire to the battery. Connect one end of the wire to the positive battery terminal, and the other to the negative battery terminal. If all is in place, a current should be moving through your wire.
Adjust wire position. You can adjust the wire position, or increase the thickness, or size of the wire to add additional strength to your electromagnet. The more coils in the wire, the stronger the magnetic field will be. The length of the coil also affects it’s strength, meaning the longer the wire, the more coils can be wound around the nail. The thickness of the wire determines how easily electric current can pass through. A thin wire provides less space for the current to move through, thereby lessening the strength of the current’s flow. Using a thicker wire will increase the strength of your electromagnet.
Add another layer of wire. One additional step you can take to increase your electromagnet’s strength is to wrap an additional layer of wire on top of the layer in place.
Enamel coated wire acts as a better conductor than plastic coated wire. The longer the nail, the longer the wire, the stronger your electromagnet will be.
Be careful not to generate too much heat as the strength of your electromagnet increases. Electrons tend to release heat as energy when their magnetic field is increased. Wrapping a second layer of wire will increase the strength of your electromagnet, but the distance of this second layer from the core means it’s magnetic field won’t be as strong as the first layer’s field.