Electromagnetic Induction and Laws

The scientist Michael Faraday was discovered and published the Electromagnetic induction in the year 1831. In the year 1832, the American scientist Joseph Henry was independently discovered. The basic concept of electromagnetic induction has taken from the idea of lines of force. Although at the time of discovering, scientists simply discarded his ideas, because they were not created mathematically. James Clerk Maxwell has utilized the ideas of Faraday as the basis of his quantitative electromagnetic theory. In the year 1834, Heinrich Lenz has invented the law to explain the flux throughout the circuit. The induced e.m.f direction can be received from the Lenz’s law & the current results from the electromagnetic induction.

What is Electromagnetic Induction?

The definition of electromagnetic induction is the creation of voltage or an electromotive force across a conductor within a varying magnetic field. Generally, Michael Faraday is recognized with the innovation of induction in the year 1831. James Clerk Maxwell has described scientifically it while Faraday’s law of induction. The induced field direction can be discovered through Lenz’s law. Afterward, Faraday’s law was generalized the equation of Maxwell-Faraday. The applications of Electromagnetic induction include electrical components like transformers, inductors, as well as devices like generators and motors.

Faraday’s Law of Induction and Lenz’s law

Faraday’s law of induction uses the ΦB-magnetic flux throughout an area of space surrounded by a wire loop. Here the flux can be described by a surface integral.

magnetic flux

Where ‘dA’ is a surface element
‘Σ’ is enclosed with the wire loop
‘B’ is the magnetic field.
‘B•dA’ is a dot product which communicates with the amount of magnetic flux.

The magnetic flux throughout the wire loop can be proportional to the no. of magnetic flux lines that exceed throughout the loop.

Whenever the flux during the surface alters, Faraday’s law states that the wire loop obtains an EMF (electromotive force). The most prevalent law states that the induced EMF within any closed circuit can be equivalent to the rate of change of the magnetic flux included by the circuit.

Where ‘ε’ is the EMF & ‘ΦB’ is the magnetic flux. The electromotive force direction can be given by Lenz’s law, and this law states that an induced current which will flow within the way that will resist the transform which generated it. This is because of the negative signal within the earlier equation.

To raise the electromagnetic force which is generated, an ordinary approach is to develop flux connection by making a tightly wound loop of wire collected with N equal twists, each one with the similar magnetic flux going through them. Then the resulting EMF will be N times that of 1-single wire.

ε = -N δΦB/ ∂t

An EMF can be generated through a deviation of the magnetic flux throughout the wire-loop surface can be obtained in numerous ways.

  • The magnetic field (B) changes
  • The loop of wire can be distorted as well as the surface (Σ) will be changed.
  • The direction of the surface (dA) changes & any above combination

Lenz’s Law Electromagnetic Induction

Lenz’s law electromagnetic induction states that whenever an electromagnetic force is produced by adjusting magnetic flux based on Faraday’s Law, then the induced emf polarity generates a current & magnetic field resists the change which generates it.

ε = -N δΦB/ ∂t

In the above electromagnetic induction equation, the negative signal indicates the induced emf, as well as the, modify within magnetic flux (δΦB),  have reverse signals.


Ε is an Induced emf

δΦB is modified in magnetic flux

N is no. of twists within the coil

Maxwell-Faraday Equation

Generally, the relation between the electromagnetic force which is known as ε within a wire loop about a surface like Σ, as well as the electric field (E) within the wire can be given by

electric-field-in-the maxwell
electric-field-in-the maxwell

In the above equation, ‘dℓ’ is a curve element of the surface which is known as ‘Σ’, uniting this with the flux definition.
The Maxwell-Faraday equation’s integral form can be written as

magnetic flux

The above equation is one of the Maxwell equations from the four equations and hence plays an essential role within the classical electromagnetism theory.


Faraday’s Law & Relativity

Faraday’s law states two different facts. One is the electromagnetic force can be generated through a magnetic force over a moving wire, as well as the EMF of the transformer EMF can be generated with an electric force because of a magnetic field change.

In the year 1861, James Clerk Maxwell drew notice for the separate physical observable fact. This can be considered to be an exclusive example in physics concepts wherever such a basic law is raised to make clear two such dissimilar facts.

Albert Einstein was observed that the two conditions both communicated toward a comparative movement among a magnet & a conductor, and the result was unchanged by which one was traveling. This was one of the main lanes that led him to expand particular relativity.

Electromagnetic Induction Experiment

We know that electricity can be carried by the flow of electrons otherwise current. One of the main and very useful features of current is that it makes its own magnetic field which is applicable in several types of motors as well as appliances. Here we are going to give an idea about this concept by explaining electromagnetic induction experiment.


The required materials of this experiment mainly include thin copper wire, 12V lantern battery, long metal nail, 9V battery, toggle switch, wire cutters, electrical tape, and paper clips.

  • Connections and It’s Working
  • Take a long length of wire and connect to positive o/p of the toggle switch.
  • Turn the wire as a minimum of 50 times around the metal nail to make a solenoid.
  • Once the twisting of the wire has done, connect the wire to the battery’s negative terminal.
  • Take a wire piece and connect this to the battery’s positive terminal and toggle switch negative terminal.
  • Activate the switch.
  • Place the paper clips near to the metal nail.

The flow of current within the circuit will make the metal nail to be magnetic as well as it will magnetize paper clips. Here a 12V battery will generate a stronger magnet compare with the 9V battery.


The electromagnetic induction principles can be applied in numerous devices as well as systems. Some of the electromagnetic induction examples include the following.

  • Transformers
  • Induction motors
  • Electric generators
  • Electromagnetic forming
  • Hall Effect meters
  • Current Clamp
  • Induction cooking
  • Magnetic flow meters
  • Graphics tablet
  • Induction welding
  • Inductive charging
  • Inductors
  • A flashlight which is Powered Mechanically
  • Rowland ring
  • Pickups
  • Transcranial magnetic stimulation
  • Wireless energy transfer
  • Induction Sealing

Thus, this is all about Electromagnetic induction. It is a method where a conductor is located within a varying magnetic field which will cause the invention of a voltage across the conductor. This will cause an electrical current. The principle of electromagnetic induction can be applied in different applications like transformers, inductors, etc. This is the foundation of all kinds of electric motors and generators which can be used for generating electricity from electricity motion. Here is a question for you, who discovered electromagnetic induction?


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