The electromagnet is a classic scientific experiment, often carried out in the school environment. The idea is to turn an iron nail into a magnet using a copper coil and a battery. The principle of operation of an electromagnet is based on the transfer of electrons, subatomic particles that carry a negative charge, from the battery into the coil. This movement of electrons generates a magnetic field around the nail, which allows the nail itself to function as a magnet, thus being able to attract small metal objects such as a paper clip. With a little effort and patience you can make an electromagnetic charge yourself.
Steps
Part 1 of 3: Prepare the Thread for the Bobbin
Step 1. Gather the necessary materials
In order to make an electromagnet, you will need the following:
- An iron nail about 15 cm long.
- Three meters of.22 mm thick insulated copper wire.
- At least one battery (Dcell).
- A cable stripper, which you can also find in hardware stores.
- A rubber band.
Step 2. Remove the insulation from the copper wire
The copper wire is usually covered with a plastic sheath or a layer of insulating material, to prevent short circuits or even to protect against any shocks. In any case, the battery cannot transfer electrons through the sheath and must therefore be removed.
- Remove a few inches of the sheathing from both ends of the copper wire using the stripping pliers.
- A wire stripper looks like a pair of scissors with a hole in the center. You pass the cable through the hole, then tighten the sheath to cut it and pull it off. You should get one that fits the specific cable. Some of these tools have multiple holes of different sizes based on the section of the wire.
Step 3. Wrap the copper wire around the nail
Once the wire is prepared you can start building the battery. To start, create neat coils around the nail. The tighter the windings, the greater the charge. Leave enough loose thread on both ends. They will be connected to the battery, so it's a good idea to leave about 20cm per side of wire free.
- The thread should be wound in one direction. This allows electrons to flow through the wire in order to generate a magnetic field.
- Otherwise the magnetic fields generated by opposite coils will end up canceling each other out.
Part 2 of 3: Connect the Battery
Step 1. Connect the battery
Once you are done with the coil, connect the ends of the wire to the battery. Connect one to the positive terminal and the other to the negative. Make sure that the stripped portions of the wire actually make contact with the battery terminals. Wrap the elastic around the battery from end to end to secure the connections.
- Polarity doesn't matter. It will work both one way and the other.
- If you can't secure the connections with the rubber band you can try using two pieces of electrical tape.
Step 2. Give it a try
You should have successfully created an electromagnet. To test if the magnet works, bring it close to a metal object, such as the paper clip - it should rise and stick to the magnet. You just created a magnetic charge with wire, nail and battery.
If you want to increase the strength of the magnet, increase the number of turns around the nail. This will allow the electromagnet to attract more objects
Step 3. Resolve possible problems
If the magnet doesn't work, check the battery. If it isn't charged enough, it may not be enough to make the electromagnet. If the battery is okay, go through the whole process again. You may not have wound the coil properly, negatively affecting the flow of electrons. You may also have forgotten to remove the wire insulation efficiently.
Part 3 of 3: Safety Precautions
Step 1. Use gloves to handle the magnet
Always use them in experimentation. The threads can get very hot when fed and there is no need to burn your hands. This is especially true if you want to increase the power of the magnet: the higher the power, the more heat increases.
Step 2. Pay attention to the heat
As previously mentioned, an electromagnet overheats as its power increases, creating denser windings. If it gets hot, unplug the terminals to deactivate the magnet for a while. Excessive heat can cause burns or, in rare cases, a fire.
Step 3. Disconnect the wires once the experiment is finished
You should avoid leaving the electromagnet connected when it is not in use. First of all, you would drain the battery; moreover, heat can become a danger. Disassemble the electromagnet as soon as you are done playing with it.
