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Combining an electrical phenomenon with a field of force is known as electromagnetic induction. When a flux and an electrical conductor, like a coil of a wire, are moved near each other, this phenomenon occurs. Current will flow through the conductor whenever it crosses lines of force within the force field as long as it is a loop component. Michael Faraday, a chemist, discovered electromagnetic induction in the 1830s. When Faraday moved a magnet in and out of a coil or one loop of a wire, he found that an emf or voltage was induced, thereby producing an electric current. So physicists developed a method to generate an electrical current in an exceeding circuit utilising a magnetic force field instead of batteries. As a result, a vital law relating to electricity and magnetism was developed.
Magnetic flux:
Changing the amplitude of the force field in an exceedingly loop or changing the loop’s area can both modify the field of force. Magnetic flux is defined as Φ = BAcos𝜃, where 𝜃 is the angle between B and the direction of the loop’s area A (along the axis of the loop).
Faraday law:
A current is induced by changing the magnetic flux through a wire loop. According to Faraday’s Law, the induced emf in a wire is proportional to the flux speed through the loop. E = -N dΦ/dt
The above equation is easy to use when an electromagnet generates the flux. The induced emf is adequate for the number of spins within the loop times the speed of flux changes when the electromagnet is turned on or off. The flux also can be altered by increasing or decreasing the scale of a loop.
Lenz’s law:
Lenz’s Law states that the field of force formed by the induced emf produces a current whose force field opposes the initial change in flux through the wire loop; therefore, the direction of the induced current is often determined.
Ways of producing induced emf:
- Changing the magnetic field around the coil/loop/circuit
- Altering the coil’s area A within the magnetic field
- Altering the angle between B and A.
How does electromagnetic induction work?
Electric generators and electric transformers are two major devices that run on the principle of electromagnetic induction. Both devices are necessary to produce and manage the electric current we use on a daily basis. Electromagnetic induction is used in electric generators to convert kinetic energy into electrical energy. In power plants, they generate electricity. To modify the voltage of an electric current, electric transformers employ electromagnetic induction. Some transformers raise voltage, whereas others lower it.
Mutual inductance and self-inductance
When two circuits are connected so that a change in the current of one generates an emf in the other, mutual inductance arises.
Consider a switch, a coil, and a battery in a basic circuit. The current through the coil generates a magnetic field when the switch is closed. The magnetic flux through the coil changes as the current is increased. The emf generated by the changing magnetic flux opposes the emf generated by the battery. This effect occurs only when the current is approaching its steady-state value immediately after the switch is closed or reduced to zero when the switch is opened. Self-inductance is the term for this phenomenon.
Application of electromagnetic induction
- Magnetic induction is used to read and write data on hard drives.
- Graphics tablets, electric and hybrid automobiles, and transcranial magnetic stimulation are all examples of magnetic induction applications.
- The fastest way to cook is with an induction cooker. It also works on the mutual induction principle. A fluctuating magnetic field occurs when current passes through a copper wire coil positioned beneath a cooking container. This alternating or changing magnetic field induces emf, thereby inducing a current in the conductive container, and we know that current flow always generates heat.
- According to Faraday’s Law, an emf is generated in an electrically isolated conduit in which conducting fluids flow when a magnetic field is applied. This induced emf is related to the fluid flow velocity. The velocity of certain fluids is measured using an electromagnetic flow metre.
Conclusions:
- Electromagnetic induction generates a current or an emf by changing the magnetic flux.
- Change in magnetic flux can only produce induced emf.
- DC cannot produce induced emf.
- Lenz’s Law tells about the direction of induced emf.
- Mutual induction is the phenomenon for two coils, whereas self-inductance is for only a single coil.
- Transformers, generators work on the principle of electromagnetic induction.
