Faraday's Law

Faraday's Law: Faraday’s law also referred to as Faraday's Law of electromagnetic induction. This is the basic law of electromagnetism that anticipate how a magnetic field would interact with an electric circuit to produce an electromotive force (EMF). This phenomenon is commonly called electromagnetic induction. Faraday's Law was proposed by  Michael Faraday in the year 1831. Faraday performed three main experiments for the discovery of electromagnetic induction. Faraday proposed two laws-

  1. First Law of Faraday of Electromagnetic Induction
  2. Second Law of Faraday of Electromagnetic Induction

Faraday's First Law of Electromagnetic Induction

Whenever a conductor is placed in a magnetic field which varies and an EMF gets induced across the conductor (called induced emf), and if the conductor is a closed circuit then the induced current flows through it. The magnetic field can be varied by various methods  such as-

  • By allowing the magnet to move.
  • By allowing the coil to move.
  • By rotating the coil that is relative to the magnetic field.

Faraday's Second Law of Electromagnetic Induction

According to Faraday's second law of electromagnetic induction, “the magnitude of induced EMF is equal to the rate of change of flux linkages with the coil. The flux linkages are the product of the number of turns and the flux that is associated with the coil”.

Faraday Law Formula

Suppose a magnet approaches a coil. Consider t1 and t2 as the times taken by the magnet approaching the coil.

The Flux linkage with the coil at time t1 is NΦ1.

The Flux linkage with the coil at time t2 is NΦ2

The change in the flux linkage is N(Φ2 – Φ1)

Assume the change in the flux linkage as, ΔΦ = Φ2 – Φ1

Therefore, the change in flux linkage is NΔΦ

Hence, the rate of change of flux linkage is NΔΦ/t

Taking the derivative of the above equation as, N dΦ/dt

According to Faraday’s second law of electromagnetic induction, induced emf in a coil is equal to the rate of change of flux linkage. Therefore,

EMF = N(ΔΦ/Δt)

According to Lenz’s law,

EMF = -N(ΔΦ/Δt)

Applications of Faraday’s Law

Some of the application of Faraday's Law is-

  • Transformers
  • Induction cooker
  • Electromagnetic flowmeter
  • Electric guitar and electric violin
  • Maxwell’s equation has its basis in the converse of Faraday’s laws
Related Links-
Newton's Law of MotionBoyles's Law
Newton's First Law of MotionCharles Law
Newton's Second Law of MotionHooke's Law
Newton's Third Law of MotionLaws of Thermodynamics
Pascal LawOhm's Law
Zeroth Law of ThermodynamicsLenz's Law
Faraday's Law- FAQs

Ans. Faraday’s law also referred to as Faraday's Law of electromagnetic induction. This is the basic law of electromagnetism that anticipate how a magnetic field would interact with an electric circuit to produce an electromotive force (EMF).

Ans. Whenever a conductor is placed in a magnetic field which varies and an EMF gets induced across the conductor (called induced emf), and if the conductor is a closed circuit then the induced current flows through it.

Ans. Faraday's second law of electromagnetic induction states that the magnitude of induced EMF is equal to the rate of change of flux linkages with the coil. The flux linkages are the product of the number of turns and the flux that is associated with the coil.

Ans. According to Faraday’s second law of electromagnetic induction, induced emf in a coil is equal to the rate of change of flux linkage. Therefore, EMF = N(ΔΦ/Δt)

Ans. Some of the application of Faraday's Law is- Transformers, Induction cooker, Electromagnetic flowmeter, Electric guitar and electric violin, Maxwell’s equation has its basis in the converse of Faraday’s laws.

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