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Updated on 11th July, 2023 , 6 min read
Faraday's law of induction, in physics, is a quantitative connection indicating that a changing magnetic field generates a voltage in a circuit, discovered in 1831 by the English scientist Michael Faraday on the basis of experimental data. Faraday's law of electromagnetic induction, usually known as Faraday's law, is a fundamental rule of electromagnetism that explains how a magnetic field interacts with an electric circuit to create an electromotive force (EMF). This is referred to as electromagnetic induction. To uncover the phenomenon of electromagnetic induction, he conducted three major experiments.
Faraday's law of induction (abbreviated Faraday's law) is an electromagnetism fundamental law that predicts how a magnetic field would interact with an electric circuit to create an electromotive force (emf)—a phenomenon known as electromagnetic induction. It is the basic concept of transformers, inductors, and many other electrical motors, generators, and solenoids. The Maxwell-Faraday equation (listed as one of Maxwell's equations) states that a spatially varying (and possibly time-varying, depending on how a magnetic field varies in time) electric field always accompanies a time-varying magnetic field, whereas Faraday's law states that there is emf (electromotive force, defined as electromagnetic work done on a unit charge after it has traveled one round of a conductive loop).
Faraday's law may be deduced from the Maxwell-Faraday equation (which describes transformer emf) and the Lorentz force (describing motional emf). The integral version of the Maxwell-Faraday equation only represents the transformer emf, whereas Faraday's law equation describes both the transformer and motional emf.
The following are some examples of Faraday's Law of Electromagnetic Induction-
Faraday and Henry conducted a long series of experiments that led to the discovery and understanding of electromagnetic induction. Faraday deduced from his experimental findings that an emf is produced when the magnetic flux across the coil varies over time.
An electromotive force is produced whenever a conductor is put in a changing magnetic field. When the conductor circuit is closed, a current, known as induced current, is induced. Any change in the magnetic field of a wire coil will produce an emf in the coil. This induced emf is known as induced emf, and if the conductor circuit is closed, current will circulate through the circuit as well, and this current is known as induced current.
The following are some of the methods for modifying the magnetic field-
It indicates that the magnitude of the induced emf in the coil equals the rate of change of the flux that links with the coil. The coil's flux linkage is the product of the number of turns in the coil and the flux associated with the coil. Faraday's law is expressed as follows-
ε= -N 𝜟Φ/𝜟t |
where E is the electromotive force, N is the number of rotations, and t is the magnetic flux.
The following are some of the ways to boost induced EMF by a coil-
Consider a magnet coming up to a coil. Consider the following two-time instances- T₁and T₂.
NΦ₁represents the flux connection with the coil at moment T₁.
NΦ₂represents the flux connection with the coil at moment T₂.
The flux linkage changes as a result of,
N(Φ₂– Φ₁)
Consider this shift in flux connection as,
Φ = Φ₂– Φ₁
As a result, the flux linkage change is given by NΦ.
The flux linkage rate of change is given by NΦ/t.
Taking the derivative of the above equation, we obtain, N dΦ/dt
The induced emf in a coil is equal to the rate of change of the flux linkage, according to Faraday's second law of electromagnetic induction. Therefore,
E = N dΦ/dt |
Considering Lenz's law,
E = -N dΦ/dt |
The following details are deduced from the preceding equation-
The following gives information about the link between the location of the magnet and the deflection in the Galvanometer by summarising the above points in a table-
Position of Magnet | Deflection in Galvanometer |
Magnet at Rest | No deflection in the galvanometer. |
The magnet is kept in the same location (near the coil). | No deflection galvanometer. |
The magnet is drawn to the coil. | The galvanometer deflects in one direction. |
The magnet begins to travel away from the coil. | The galvanometer deflects in the opposite direction. |
The magnet remained in the same place (away from the coil). | No deflection in the galvanometer. |
Faraday's law has applications in the following fields-
Faraday eventually established that if there was relative motion between a conductor and a magnetic field, the flux connection with a coil changed, and this change in flux created a voltage across a coil. Faraday's law states that "the electromotive force is created when the magnetic flux or magnetic field varies with time." In addition, based on the foregoing tests, Michael Faraday developed two laws.
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By - Nikita Parmar 2024-09-06 10:59:22 , 6 min readAns. Faraday law outlines how magnetic fields change and cause current to flow in wires.
Ans. The energy that causes current to flow through a circuit is measured as electromotive force or emf.
Ans. "Whenever a conductor is put in a fluctuating magnetic field, an electromotive force is produced," asserts Faraday’s first law of electromagnetic induction. Similarly, when the conductor circuit is closed, a current is induced, which is referred to as an "induced current."
Ans. The negative sign shows that the direction of the induced emf and the change in magnetic field direction have opposing signs.
Ans. According to Faraday’s first-second law of electromagnetic induction, the induced emf in a coil equals the rate of change of the flux linkage.