Making an electromagnet is one of the most curious things that can be done. It is usually a typical job in the ESO technology subject and it is usually one of the ones that gives you the most marks to do it correctly.
The characteristics of an electromagnet is that it will only work as such when we have connected it to the battery, which differentiates it from a normal magnet, which is always magnetized and can be uncomfortable for us.
We are going to do it with a battery from a hip flask, a screw, a couple of copper wires, three cables, a piece of cardboard, a clip that will serve as a switch (it will be what joins the terminals) and some other little things.
Instead, with our electromagnet, we can only have a magnet whenever we want, which is interesting and may impress our teacher. In addition, many of them will assign it to you as essential work to pass the subject, so it may be necessary to learn how to do it to ensure your child’s academic future.
This is produced by an effect in which the current that comes out of the flask battery passes towards the metal that we want to magnetize. Basically without current it is not possible to have a magnet, immediately losing its properties.
What do you need to make an electromagnet?
- A 5 volt flask battery.
- A big screw.
- A carton.
- Two small nails.
- A large bare copper wire.
- Three normal wires.
- Scissors.
- Insulating tape.
- A clip.
Instructions to make an electromagnet
- Strip the end of the cables: The first thing to do is strip both ends of the cables, since they must make contact with both the battery pack and the screw, since it will be the energy from the battery that will carry the force to the screw and if the wires are not bare it will not make contact. We are going to take the scissors and cut the lining that covers the cable, then we are going to push down in such a way that the tip is bare and the copper is visible. We are going to do it both on one side and on the other and we are going to hook one end of each cable to each side of the pile to leave it already done. We will leave the excess cable for later.
- Winding the screw: Now we are going to magnetize our screw, in this way we will be able to carry out the experiment. We are going to wrap the bare copper wire around our screw, completely wrapping it so that it covers everything except the tip, which is what will serve as a magnet. Once we have it rolled up, we are going to move on to the next step.
- Join the first cable to the screw: Now we must make the battery make contact with the screw, since this is how we are going to get the energy to pass through the screw. This will not be enough since later we will have to do more things that we will see later. First, we are going to attach the bare end of the second wire to the copper of the screw, using masking tape to keep it attached so that there are no shorts. Now we are going to join the cable that we had reserved to the screw on the other side also with insulating tape and at the bare end, since in this way the first cable and the second will be connected. Now let’s move on to the switch.
- Connection with the switch: Now we are going to connect everything to the homemade switch. We are going to join each wire (the second and the third) to the nails, one each using adhesive tape and by the tips as usual. Now we are going to drive the nails into the cardboard, leaving just enough space for our clip to fit and it can stay attached to the cardboard without coming off unless we want it to come off.
- Operation: We already have our electromagnet ready, which works in this way. When the clip touches the two nails of the switch, the magnet will be turned on, so we can use the screw to attract metals towards it, check it out. If we want to turn it off, we will simply remove the clip from one of the nails, since this way we will close the electrical circuit and no electrical current will be transmitted.
Tips for making an electromagnet
- It doesn’t work: If it doesn’t work, you should check a few things to find out what happened or what you did wrong.
- The battery does not work: It may be that you have picked up a battery that is in poor condition, worn out or that it has a faulty contact.
- The tape has been released: One of the cables has released its insulating tape, therefore the circuit is going to close.
- The clip does not make good contact: If it does not make good contact with the nails, the clip will not work correctly and it will never be able to work.
- The cable is wrong: One of the cables may not be right and for this reason, it cannot pass the current well.