When he placed a thin card covered with iron filings on a magnet, he could see the filings form chains from one end of the magnet to the other. He visualized that magnets, electric charges, and electric currents produce lines of force. As the wire lead was pulled away from the battery, the current continued to flow for a short time in the form of a bright arc between the battery terminal and the wire.įaraday’s thinking was permeated by the concept of electric and magnetic lines of force. When he had opened the circuit, the rapid decrease in the current had caused a large voltage between the battery terminal and the wire. He had produced large electric arcs from a long helical conductor when it was disconnected from a battery. In his paper of July 1832, Henry reported and correctly interpreted self-induction. Henry had discovered electric induction quite independently in 1830, but his results were not published until after he had received news of Faraday’s 1831 work, nor did he develop the discovery as fully as Faraday. When the switch S is closed in the primary circuit, a momentary current flows in the secondary circuit, giving a transient deflection of the compass needle M. Within a few months, Faraday built the first, albeit primitive, electric generator.įigure 7: Faraday's magnetic induction experiment. He also demonstrated that an electric current can be induced by moving a magnet, by turning an electromagnet on and off, and even by moving an electric wire in Earth’s magnetic field. Building on this observation in other experiments, Faraday showed that changes in the magnetic field around the first coil are responsible for inducing the current in the second coil. When the primary current was switched off, a similar deflection of the compass needle occurred but in the opposite direction.
When the first circuit was turned on, Faraday observed a momentary deflection of the compass needle and its immediate return to its original position. A wire from the second coil was extended to a compass needle a metre away, far enough so that it was not affected directly by any current in the first circuit. The first coil was attached to a battery when a current passed through the coil, the iron ring became magnetized. In 1831 he finally succeeded by using two coils of wire wound around opposite sides of a ring of soft iron ( Figure 7).
#DISCOVERY CHANNEL IRON WARS HOW TO#
COVID-19 Portal While this global health crisis continues to evolve, it can be useful to look to past pandemics to better understand how to respond today.Student Portal Britannica is the ultimate student resource for key school subjects like history, government, literature, and more.From tech to household and wellness products. This Time in History In these videos, find out what happened this month (or any month!) in history.#WTFact Videos In #WTFact Britannica shares some of the most bizarre facts we can find.Demystified Videos In Demystified, Britannica has all the answers to your burning questions.Britannica Explains In these videos, Britannica explains a variety of topics and answers frequently asked questions.Britannica Classics Check out these retro videos from Encyclopedia Britannica’s archives.
0 kommentar(er)
