Trystan Casey
Electromagnetic induction, or induction, is the process of generating electrical current in a conductor by placing it in a changing magnetic field. It is the governing principle behind the operation of many electrical machines, including generators, induction motors, and transformers. The discovery of induction is generally credited to Michael Faraday, who, in 1831, demonstrated that a moving magnetic field would induce current in an electrical conductor.
| Characteristics | Values |
|---|---|
| Discovery | Michael Faraday in 1831, Joseph Henry in 1832 |
| Process | Generating electrical current in a conductor by placing the conductor in a changing magnetic field |
| Other names | Electromagnetic induction, magnetic induction |
| Applications | Electric motors, generators, transformers, rechargeable electric toothbrushes, wireless communication devices, induction cooktops, electrical components such as inductors, electric guitars, microphones |
| Units | Henries (H) |
Explore related products
What You'll Learn
Faraday's Law of Induction
Electrical induction is the process of generating electrical current in a conductor by placing it in a changing magnetic field. This phenomenon is known as electromagnetic induction.
Faraday's law can be understood through two main laws:
- First Law: Whenever a conductor is placed in a varying magnetic field, an electromotive force (EMF) is induced. If the conductor circuit is closed, a current is induced, known as an induced current. This can be achieved through various methods, such as rotating the coil relative to the magnet, moving the coil into or out of the magnetic field, changing the area of the coil within the magnetic field, or moving a magnet towards or away from the coil.
- Second Law: The induced EMF in a coil is equal to the rate of change of flux linkage. The flux linkage is calculated by multiplying the number of turns in the coil with the flux associated with the coil.
Faraday's law has been expressed mathematically in various forms, including the Maxwell-Faraday equation and the Lorentz force equation. The law is one of the four Maxwell equations that define electromagnetic theory. The German physicist Heinrich Friedrich Lenz also contributed to the understanding of Faraday's law with his rule, known as Lenz's law, which describes the direction of the induced EMF.
Electrical Plug Feels Hot: What Could Be the Cause?
You may want to see also
Explore related products
$118.76 $134.96
Electromagnetic Induction's Applications
Electromagnetic induction is a widely applied phenomenon, with applications in various devices and systems. The process involves the creation of an electromotive force (EMF) across an electrical conductor in a changing magnetic field. This force is harnessed in electrical generators, where the relative movement of a circuit and a magnetic field generates electrical energy.
Electric motors, generators, and transformers are key applications of electromagnetic induction. In transformers, the principle of inductance is used to change the voltage of electricity. Transformers consist of coils of wire, and when an AC current flows through the wire, an electromagnetic field is produced. This changing magnetic field then induces a current in another nearby wire or circuit, resulting in a voltage across the ends of the current loop.
Electromagnetic induction is also utilised in power generation and transmission. For instance, in hydroelectric power plants, the energy of falling water is used to spin permanent magnets around a fixed loop, generating AC power. Additionally, electric and hybrid vehicles benefit from electromagnetic induction, as the motor can act as a generator during braking, taking advantage of the back EMF produced.
The magnetic stripe on credit cards is another example of electromagnetic induction in everyday life. Similar to audio or video tapes, the magnetic stripe stores personal information that can be read by a playback head. Furthermore, electromagnetic induction is applied in transcranial magnetic stimulation (TMS), a diagnostic technique used to address disorders such as depression and hallucinations caused by irregular localised electrical activity in the brain.
In the realm of entertainment, rock-and-roll instruments like electric guitars use electromagnetic induction to create their distinctive beats. Additionally, Faraday's disc, which involves rotating a copper disk near a bar magnet, is another illustration of electromagnetic induction in action.
Understanding Electric Fence Chargers Through Joules
You may want to see also
Explore related products
$38.52 $40.49
Induction and Inductance
The discovery of electromagnetic induction is generally credited to Michael Faraday, who published his findings in 1831. Independently, Joseph Henry also discovered it in 1832. Faraday's law of induction, as it came to be known, states that an electromotive force (emf) is created when a permanent magnet is moved relative to a conductor, or vice versa. This force is given in volts, with N being the number of turns of wire and Wb the magnetic flux in Webers.
Electromagnetic induction is the process of generating electrical current in a conductor by placing it in a changing magnetic field. This process is also called induction, because the current is said to be induced in the conductor by the magnetic field. Induction is measured in units of Henries (H). When induction occurs in an electrical circuit and affects the flow of electricity, it is called inductance (L).
Self-inductance, or simply inductance, is the property of a circuit whereby a change in current causes a change in voltage in the same circuit. When one circuit induces current flow in a second nearby circuit, it is known as mutual-inductance. An electrical transformer uses inductance to change the voltage of electricity into a different voltage level.
Electromagnetic induction has many applications, including electrical components such as inductors and transformers, and devices such as electric motors and generators.
Understanding the Significance of 225 on Buick Electra Models
You may want to see also
Explore related products
How Induction Works
The process of electromagnetic induction involves generating an electric current in a conductor by placing it in a changing magnetic field. This phenomenon is the underlying principle behind many devices, including electric generators, microphones, electric guitars, and transformers.
Electromagnetic induction was discovered by Michael Faraday in 1831, and he is credited with being the first scientist to document his findings. Faraday's experiments involved wrapping a coil around an iron ring and observing the effects of connecting and disconnecting a battery to one of the wires. He noticed that a transient current, or a "wave of electricity", was created when the battery was connected and disconnected. This was due to the change in magnetic flux caused by the battery's connection and disconnection.
Faraday's discovery led to the formulation of Faraday's Law of Electromagnetic Induction, which states that an induced electromotive force (emf) in a closed circuit is equal to the time rate of change of the magnetic flux through the circuit. In simpler terms, this means that an electric current can be induced in a conductor by either passing it through a magnetic field or by moving the magnetic field past the conductor. If the conductor is part of a closed circuit, an electric current will flow.
The magnitude of electromagnetic induction is influenced by factors such as flux density, the number of loops in the conductor, the length of the conductor, and the rate at which the magnetic field changes within the conductor. The direction of the induced emf is described by Lenz's Law, which states that the induced emf acts in a direction that opposes the change in magnetic flux that produced it.
Harley-Davidson's Electric Future: What's the Plan?
You may want to see also
Explore related products
History of Electrical Induction
The history of electrical induction is closely tied to the history of electromagnetism more broadly. The ancients observed electric charge or static electricity (by rubbing silk on amber), electric current (lightning), and magnetic attraction (lodestone). In 1824, Hans Christian Ørsted discovered that an electric current passing through a coil creates a magnetic field capable of shifting a compass needle.
In 1831, Michael Faraday discovered electromagnetic induction. In his first experimental demonstration, on August 29, 1831, Faraday wrapped two wires around opposite sides of an iron ring or "torus". He expected that when the current started to flow in one wire, a sort of wave would travel through the ring and cause some electrical effect on the opposite side. Using a galvanometer, he observed a transient current flow in the second coil of wire each time a battery was connected or disconnected from the first coil. This current was induced by the change in magnetic flux that occurred when the battery was connected and disconnected.
Faraday mathematically described his discovery as Faraday's law of induction, which states that where the electromotive force (emf) is in volts, N is the number of turns of wire, and Wb is the magnetic flux in Webers. Faraday's law was later generalized to become the Maxwell–Faraday equation, one of the four equations in James Clerk Maxwell's theory of electromagnetism.
Faraday also found several other manifestations of electromagnetic induction. For example, he saw transient currents when he quickly slid a bar magnet in and out of a coil of wires, and he generated a steady (DC) current by rotating a copper disk (now known as "Faraday's disk") near a bar magnet with a sliding electrical lead.
Joseph Henry also discovered electric induction independently in 1830, but his results were not published until after Faraday's work in 1831. In 1834, Heinrich Lenz formulated Lenz's law to describe the "flux through the circuit", which gives the direction of the induced electromotive force.
Understanding Electrical Ratings: 50A Current Capacity Explained
You may want to see also
Frequently asked questions
Electrical induction, or electromagnetic induction, is the principle that explains how electric generators, microphones, electric guitars, and transformers operate. It occurs when a circuit with an alternating current generates a current in another circuit by simply being placed nearby.
Electrical induction occurs when a current is passed through a coil, creating a magnetic field capable of shifting a compass needle. A moving or changing magnetic field produces a current in a current loop or a voltage across the ends of a current loop. This is called electromagnetic induction and the current or voltage is called an induced current or an induced voltage.
Electrical induction was first discovered by Michael Faraday in 1831 and was discovered independently by Joseph Henry in 1832. Faraday's law of electromagnetic induction states that the induced electromotive force in a closed circuit is equal to the time rate of change of the magnetic flux through the circuit.
