The Operation of Electric Motors :: essays research papers

I have written this science research paper to help people understand more about the electric motors and their operation. The electric motor transforms electrical energy into mechanical energy, which in turn makes motion possible. To better understand electric motors, one should first understand the basics of electric motors operation, electromagnetics. One can create an electromagnet by running an electric current through a wire which in turn will create a magnetic field. An electromagnet may only be a temporary magnet but it has the same magnetic properties as a permanent magnet. Any magnet creates a magnetic field and this magnetic field will contain two ends or polls, one North and one South. The fundamental law of magnets states that ?Opposites attract and likes repel? and the same holds true with an electromagnet. A simple electromagnet can be created by the use of a power source and a piece of wire as shown in Figure 1. The magnetic field created will be stronger then the magnetic field of the earth, effecting the compass and will cause the needle to move in the direction of this newly created magnetic field. As current flows through the wire, a magnetic field is created around the wire. Figure 2 shows the circular shape of the magnetic field around the wire as if you were able to look down the end of the wire. The magnetic field itself is invisible, but the magnetic field strength can be measured through the use of special equipment. The magnetic field weakens the further you move away from the wire and will always be perpendicular to the wire and the fields direction depends on the which direction the current if flowing. Since the magnetic field is always circular and perpendicular to the wire, the magnetic field can be increased simply by creating a coil of wire. Figure 3 shows an example of a simple electromagnet by coiling a wire around a nail and connecting it to a power source. The magnetic field is amplified by each loop of wire around the nail. An electric motor depends upon magnetism to function, to be more specific, electromagnetism. By continuously changing the direction of the electromagnetic field in a motor, we take advantage of the basic magnet principle that ?Opposites attract and likes repel?. This allows an electric motor to rotate.