Faraday’s Motor and Electromagnetism

Abstract

Michael Faraday’s apparatus was a feat in engineering, and he applied the new learning of electromagnetism and connected it to motion. This discovery revolutionized transportation, providing a basis for the sophisticated motors we have today.This invention was generated shortly after the discovery of electromagnetism, being heavily related to those revelations. Hans Christian Ørsted discovered that the addition of electric current flowing through wire, would produce magnetism. Later, André-Marie Ampère expanded on this discovery to state that said magnetism would produce a circular magnetic force, developing a cylinder around the wire. Isolating the magnetic pole would cause the electrically-charged wire to move in a constant, circular motion. Faraday used this knowledge to develop the first electric motor, created in 1821, just a year after electromagnetism was discovered.The original motor was composed of a copper wire hanging inside a glass vessel, with an electrified mercury pool and a secured permanent magnet at the bottom but not submerged. The entire apparatus would be connected to a battery, and caused the wire to spin clockwise around the battery.Homopolar motors can be assembled easily, while demonstrating the principles of Faraday’s motor. One method is to connect a loosely coiled 18-gauge wire to the positive terminal of a AA battery, which is atop two neodymium magnets. The wire should also touch the bottom magnet, causing the coil to orbit it.Another method of constructing a homopolar involves connecting a neodymium magnet to the negative terminal of a D-cell battery. The flat-head of a screw is attached to another small, strong magnet of the same kind. The pointed-end of the screw hangs from the positive terminal of the battery, suspended through the magnetic attraction from either side.The rotational movement of the copper wire is due to the Lorentz force - the effect of the electromagnetic fields produced through the battery and magnets. Current passes through the positive terminal into the copper wire, which transfers it to the magnet and back to the battery, and thus, the circuit is complete. When the magnetic field is perpendicular to the current from the copper wire, the Lorentz force is generated, prompting the circular motion of the coil. During my presentation, I will demonstrate how homopolar motors can be built using just a few readily available materials to demonstrate electromagnetism to students of different age ranges.The principles of Faraday’s motor are found in a myriad of modern technology, transforming several aspects of engineering. Faraday utilized the principles of electromagnetism to generate an invention that would be applicable in everyday use. Motors have come a long way since Faraday’s day, but those for cars, boats, and other forms of transportation are all based on his findings. Without Faraday, the modern day would not look as it does, and surely the future will also be heavily impacted by his discovery.