Electromagnetism
You might be familiar with magnets which are used to hang notes and pictures on fridges, these magnets are called permanent magnets because their magnetic field is always on. Did you know that it is possible to turn magnets on and off? Electromagnets behave like permanent magnets when they are turned on, but they lose their magnetic properties if you turn them off. Magnetic fields and electric fields are identical and can communicate with each other; this is called electromagnetism. This field is particularly important for electronics since an electrical current causes a magnetic field. Magnetism was investigated experimentally as early as the 13th century. As soon as affordable electricity sources became available, scientists were able to gather lots of experimental evidence. Electromagnets have been used to build gas turbines, engines, MRI machines, levitating toys, and several other useful gadgets that you depend on in daily life. There are nearly unlimited applications for electromagnets, powering everything from consumer devices and heavy machinery to mass transportation. They may also be responsible for space exploration in the future, where magnetic fields are used by ion propulsion devices to accelerate charged particles. For our experiment we will demonstrate how an electromagnets strength is affected based upon the number of wires coiled around it. We predict increasing the number of coils will result in the electromagnet being stronger. The materials being used are copper wires, iron bolts, a compass, tape, a 6-volt battery, alligator clips, sandpaper, and paper clips. To start, we have pulled the wire and rotated it around the iron bolt to the number we have desired. We made sure that we left some extra wire hanging so it would be easier to attach the battery later. To keep the wire from unravelling, we had gotten some masking tape and taped it to the iron bolt. We then used a small piece of fine-grit sandpaper to gently remove the insulation from the ends of the wires. Then, we connected the alligator clips to the end of the battery and the copper wire. This produces a magnetic field as the electric current passes through the electromagnet. You should be able to pick up paper clips. 50 coiled iron bolt picks up less paper clips than the 200 coiled iron bolts. This is because the increasing number of coils adds more field lines to the electromagnet making it much stronger. In addition, the electrons flow from the negative end of the battery to the positive end of the battery, and the conventional current passes through the positive end of the battery to the negative end of the battery. If we reverse the direction of the alligator clips the direction of the magnetic field will also change which you can see on a compass. As a final observation, our hypothesis was correct. The more coils that were wrapped around the electromagnet the stronger it was.
