Electromagnetic Induction

1. Electromagnetic Induction by Burraq January 04, 2022 Discovery of electromagnetic induction The starting point for the discovery of induction were ideas of the unity of natural forces and assumed connections between electricity and magnetism. In 1820, OERSTED noticed in an experiment that a magnetic needle near an electrical conductor was deflected when the current was switched on. Other scientists, such as AMPÈRE and FARADAY, copied OERSTED's experiments and developed them further. FARADAY discovered electromagnetic induction in 1831. Within three months he developed all the basic tests of induction and an archetype of an electric generator. The discoveries of LUIGI GALVANI (1737-1798) and ALESSANDRO VOLTA (1745 to 1827) made it possible to develop powerful electrical sources for the first time. With these electrical sources, many studies on the effects of electrical currents were carried out from 1800 onwards. At that time, ideas of the unity of the forces of nature were widespread in science. There were also suspected connections between electricity and magnetism, as there were striking analogies between electrical and magnetic phenomena, such as polarity or the attraction and repulsion between poles or electrical charges. The Danish physicist HANS CHRISTIAN OERSTED (1777-1851) believed in the connection between electricity and magnetism. He tried to prove magnetism in galvanic elements. In 1820, in a lecture to students, he wanted to make a wire glow with an electric current. When he switched on the power, he noticed a compass that happened to be nearby that the compass needle was deflected. After switching off the power, the compass needle turned back in the original north-south direction. OERSTED had discovered the magnetic effect of electric current, ie the generation of magnetism by electric current.

2. In many experiments, OERSTED examined this relationship more closely and found, among other things, that the direction of the deflection of the compass needle depends on the direction of the current. OERSTED's discoveries were taken up and further developed by other scientists. ANDRÉ MARIE AMPÈRE (1775-1836) discovered the forces between current-carrying conductors and laid the foundations for the electric motor and the ammeter. MICHAEL FARADAY also copied OERSTED's experiments. OERSTED's discovery prompted FARADAY to reverse the question, to search for the generation of electrical current through magnetism. In 1822 FARADAY wrote in his diary "Transformation of magnetism into electricity" as a task. It took FARADAY 10 years to develop electromagnetic induction in 1831discovered. FARADAY initially started from the analogy with electrical influence. Static electrical charges "generate" charge separation on neighbouring metallic bodies through influence, also known as "induction". He suspected that moving charges, ie electric current, generate induction currents through induction in neighbouring conductors. However, this was not detectable in experiments. FARADAY was able to observe that when the current is switched on or off, an induction current is generated in an adjacent coil. It is not the magnetic field of a current-carrying conductor that induces a current in the neighbouring conductor, but the change in this magnetic field. The change in the magnetic field in an induction coil can also take place through mechanical movement. Electric current can therefore be obtained from magnetism and mechanical movement. Within three months, FARADAY developed all-important basic experiments for electromagnetic induction and an archetype of an electrical generator. He discovered physical relationships that are the basis of all modern electrical engineering. In addition, FARADAY discovered the possibility of an electric motor drive during its investigations. When current flows, there is a circular magnetic field around the current-carrying conductor. If you bring a small magnet into the vessel, this magnet swims on a circular path around the wire through which it flows.

3. The basic principle of an electromagnetic drive Induction law A voltage is induced in a coil when the magnetic field enclosed by the coil changes. The induction voltage is all the greater ⦁ the faster the magnetic field encompassed by the coil changes (the faster you move the coil), ⦁ the more the magnetic field encompassed by the coil changes. The voltage induced in a coil also depends on the construction of the coil. The law of induction was discovered in 1831 by the English naturalist MICHAEL FARADAY (1791-1867). It is an important foundation for building generators and transformers. A voltage is induced in a coil when the magnetic field enclosed by the coil changes. The magnetic field can be generated by permanent magnets as well as electromagnets. The change in the magnetic field can take place through a relative movement between the coil and the magnet or through a change in the strength of the magnetic field (Fig. 2). The magnitude of the induction voltage depends on how quickly and how strongly the magnetic field encompassed by the coil changes. MICHAEL FARADAY's experimental investigations have shown that the following applies: The voltage induced in a coil is all the greater ⦁ the more the magnetic field encompassed by the coil changes,

4. ⦁ the faster the change in the magnetic field encompassed by the coil occurs. The construction of the coil also influences the amount of induction voltage. In particular, the induction voltage in a coil depends on its number of turns and on whether it has an iron core. The voltage induced in a coil is the greater, ⦁ the greater the number of turns and ⦁ are the cross-sectional area of the coil. In a coil with an iron core, the induced voltage is greater than in a coil without an iron core. All of these findings can be summarized in the law of induction. A voltage is induced in a coil when the magnetic field it encompasses changes. The induction voltage depends on the speed and strength of this change and on the construction of the coil. The current produced by an induction voltage is called the induction current. The direction of the induction current depends on the way in which the magnetic field encompassed by the coil changes. These relationships are recorded more precisely in Lenz's law. The law of induction is the physical basis for the construction and operation of transformers and generators. The law of induction is also used in the ignition coils of motor vehicles, when igniting fluorescent lamps or in modern electric cookers ( induction cookers ).

5. The law of induction was discovered in 1831 by the English naturalist MICHAEL FARADAY (1791- 1867) after intensive experimental investigations. This discovery was preceded by other important steps. The Danish physicist HANS CHRISTIAN OERSTED (1777-1851) found the magnetic effect of electric current in 1820. The French ANDRÉ MARIE AMPÈRE (1775-1836) discovered the forces between current-carrying conductors and laid the foundations for the electric motor. OERSTED's discovery prompted FARADAY to reverse the question, to search for the generation of electrical current through magnetism. With the simplest of experimental devices, he managed to find the law of induction over a period of 10 years. Induction Hardening Hardening is a frequently used metallurgical process in which the strength of a metal is increased through strong heating and sudden cooling. To avoid chemical contamination, heating methods are often chosen that avoid the use of an open flame. Induction hardening, in which iron is heated to annealing temperatures by induced eddy currents, is one of these processes. Hardening is a commonly used metallurgical process in which the strength has increased a metal by strong heating and sudden cooling. To avoid chemical contamination, heating methods are often chosen that avoid the use of an open flame. Induction hardening, in which metals are heated to annealing temperatures by induced eddy currents, is one of these processes. According to the law of induction, eddy currents arise when a conductive object is exposed to a time- varying magnetic field. For this purpose, the metal to be hardened is brought into the field of an electromagnet operated with alternating current. The field of the electromagnet induces eddy currents in the metal, which in turn give off frictional heat to the material, causing it to glow.

6. Induction hardening has a number of advantages over conventional hardening processes. In particular, the heat is supplied to the entire body relatively evenly, from all sides and also from the inside. These avoid thermal stresses, especially with larger workpieces. Tags:electrical fieldelectrical supervisorinductionmegnetic flux