Electric circuit and Magnetic circuit: Similarities and Dissimilarities

In this article, we are going to discuss differences and similarities between electric circuit and magnetic circuit. The electric circuit is known as the path traced by the current. The magnetic circuit is known as the path traced by the magnetic flux. Let’s discuss similarities and dissimilarities of Electric circuit and Magnetic circuit.


Similarities between electrical and magnetic circuits are given below.

Magnetic circuit

Electric circuit

The close path for the magnetic flux is called magnetic circuit. The close path for the electric current is called electric circuit.
The number of magnetic lines of force decide the magnetic flux. Flow of electron decide the current passing through the conductor.
Flux (ф) = MMF/Reluctance Current (I) = EMF/Resistance
MMF is the driving force in the magnetic circuit. The unit of MMF is ampere-turns (AT). EMF is the driving force in the electric circuit. The unit of EMF is volts (V).
Reluctance (S) opposed by the magnetic path to the flux. The unit of reluctance is AT/wb. Resistance (R) oppose the flow of current. The unit of resistance is ohm (Ω).
Flux (ф) measured in weber (Wb). Current (I) measured in Ampere (A).
MMF measured in Amp Turns (AT). EMF measured in Volts (V).

    \[ S = \frac{1}{\mu_0 \; \mu_r \; A} \]

    \[ R = \rho \frac{L}{A} \]

Permanence = 1/Reluctance = 1/S Conductance = 1/Resistance = 1/R
Permeability (μ) Conductivity (σ)
Reluctivity Resistivity
Flux Density (B) = ф/A (Wb/m2) Current Density (J) = I / A (A/m2)
Magnetic Intensity (H) = NI/L (AT/m) Electric Intensity (E) = V/d (V/m)
Kirchhoff MMF Law and Flux Law is applicable to the Magnetic Flux. Kirchhoff Current Law (KCL) and Kirchhoff Voltage Law (KVL) is applicable to the electrical circuit.
Similarities and Difference Electrical Circuit and Magnetic Circuit
Similarities and Difference Electrical Circuit and Magnetic Circuit


There are few dissimilarities between the two circuits which are listed below:

Magnetic circuit

Electric circuit

There is no magnetic insulator as flux can pass through all the materials, even through the air as well.

For magnetic flux there is no perfect insulators.

There are many materials which used as insulators. From which current cannot pass.

i.e. air, PVC, glass, synthetic resin etc.

Magnetic flux does not flow but it set up in the magnetic circuit. The electric current actually flows in an electric circuit.
At constant temperature, the reluctance (S) of a magnetic circuit is not constant but varies with μr. At constant temperature, the resistance of an electric circuit is constant as its value depends on resistivity which is almost constant.
Once magnetic flux is setup in a magnetic circuit, no energy needed. Energy needed as long as current flows through electric circuit.


Coulomb’s Law: Statement, Vector form, Nature of force and Limitation

 8,780 total views,  3 views today


Leave a Reply

Your email address will not be published. Required fields are marked *