Faraday’s Laws of Electromagnetic Induction

Posted on By
Spread the love

Faraday’s Laws of Electromagnetic Induction

 

Faraday’s Laws of Electromagnetic Induction :- After performing a series of experiments (Faraday’s Experiment) on magnetic fields and electric currents, Michael Faraday summarized his observations in the form of two fundamental laws known as Faraday’s Laws of Electromagnetic Induction. These laws explain how an electromotive force (emf) and current are induced in a closed circuit due to a changing magnetic field.

Faraday’s First Law

(Faraday’s Laws of Electromagnetic Induction)

  • Whenever the magnetic flux linked with a circuit changes, an electromotive force (emf) is induced in the circuit.

If the circuit is closed, this induced emf causes an induced current to flow through it.

The magnetic flux can change in any of the following ways :

  1. By changing the strength of the magnetic field (B).
  2. By changing the area (A) of the coil or loop.
  3. By changing the angle (θ) between the magnetic field and the normal to the coil.
  4. By moving the magnet or the coil relative to each other.

Thus, a change in magnetic flux is the main cause of electromagnetic induction.

Faraday’s Second Law

(Faraday’s Laws of Electromagnetic Induction)

  • The magnitude of the induced emf is directly proportional to the rate of change of magnetic flux linked with the circuit.

Mathematically,

\displaystyle e=-\frac{d\phi }{dt}

where

  • e = induced emf,
  • Φ = magnetic flux,
  • dΦ/dt = rate of change of magnetic flux,
  • the negative sign indicates the direction of the induced emf as given by Lenz’s Law.

If the coil has N number of turns and Φ is the magnetic flux linked with each turn of the coil then, the total magnetic flux linked with the coil at any time = NΦ. So induced emf,

\displaystyle e=-\frac{d}{dt}(N\phi )=-N\frac{d\phi }{dt}=-\frac{N({{\phi }_{2}}-{{\phi }_{1}})}{t}

Faraday’s laws of electromagnetic induction form the foundation of modern electrical technology. They explain the generation of electricity from motion and magnetic fields—principles that power electric generators, transformers, and numerous everyday electrical devices. Faraday’s discovery remains one of the greatest contributions to the development of electromagnetism and electrical engineering.

 

Class 12th NCERT
error: Content is protected !!