What is Pure Inductor Definition, Self Inductance and Mutual Inductance


Inductor store energy in terms of magnetic field. It is a two terminal device, which is consisting of a coil wound around a core. Refer the diagram an inductor is having a coil with N number of turns. An Ideal inductor, the internal resistance of the coils is zero. But all inductors have its own property of opposing the flow of current. which is called as inductance reactance. Inductor works only, in an Alternating Current circuit. In Direct Current circuits inductor acts as a short circuit path to the current. Due to this property, the transformer should not charge with DC Power supply. Also, another one important property of inductor (current through an inductor cannot be changed instantly) uses in VFD, a Filter circuit, SMPS, UPS, battery charges, Electric motor, and inductor is everywhere in the world etc.

Let us consider a closed circuit, in an inductor, I is the current (flow of electron or charges), the inductor produces the flux pi, the inductor wound with N number of turns If the coil has N number of turns, then the total flux linked by N turns is equal to..

Hence the total flux linkages in an inductor is directly proportional to the current I, that is,

Here the proportional constant L is the inductance of the coil. The SI unit of inductance is Henry.

Difference between inductor and inductance:

Inductor is the material which is used to establish the theoretically calculated value of inductance of the coils to the practical world, where the inductance is the value of the inductor.


Inductor: Material

Inductance: Property of inductor, the value use to design a specific inductor.


The inductance was discovered by an American physicist, Joseph Henry in 1830 and Michal Faraday in separate continents, Actually, the first inductor was discovered by Michal Faraday. The symbol L for inductance, in honor of the physicist Heinrich Lenz. In the SI system, the measurement unit for inductance is the Henry, with the unit symbol H, named in honor of Joseph Henry, who discovered inductance independently of, but not before, Faraday.

Also see:History of Electrical Engineering


The unit of inductance is Henry, unit of current is Ampere, unit of flux is Weber.

Definition of one Henry:

An inductor produces 1 Weber for one ampere means the inductance value is one Henry.

Suppose the varies with respect to time, then the magnitude of the magnetic flux also varies with respect to time. As per Faraday’s law of electromagnetic induction, the time-varying magnetic flux creates an induced voltage in each turn is equal to the derivative of the flux, hence the voltage V across N turns is,

Hence, a coil has an inductance of 1 Henry, if an emf of I volt is induced in the coil when the current varies uniformly at the rate of 1 amp/sec.

The voltage V appears across the terminals of the coil, and it tends to oppose the current entering the coil.

From the two voltage…

The flux is directly proportional to the current flowing across the conductor.

Also, the energy stored in an inductor is equal to..

Series and Parallel connection of an inductor:

Parallel connection:

Inductors in a parallel configuration each have the same potential difference (voltage). To find their total equivalent inductance (Leq):

Series connection:

The current through inductors in series stays the same, but the voltage across each inductor can be different. The sum of the potential differences (voltage) is equal to the total voltage. To find their total inductance:

Types of Inductor:

  • Air-core inductor
  • Ferromagnetic-core inductor
  • Variable inductor

Also see:

Key points:

  • The inductance value or the rate of change of current doubled the induced emf also doubled
  • Inductor works under the faraday’s law of electromagnetic induction.
  • Inductor do not allow the instant current changes.
  • Inductance is the property of inductor to oppose the flow of current.
  • The flux is produced in the inductor is directly proportional to current flow through it.
  • Inductor works under AC power source; it creates short circuit path to the DC power source. Hence the inductor cannot be used in DC circuit.

Also seeWhat is Meant by Open Circuit

Self Inductance Vs Mutual Inductance:

Self Inductance is defined as the property of inductor which induces the emf in the same circuit due to changes in the current. example: torrid coil

Where mutual Inductance is defined as the emf induced in the other circuit by change in the current in the other circuit. Example: Transformer

Also see:



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