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Question:

Published on: 21 June, 2022

Compare electric and magnetic circuits with respect to their similarity and dissimilarities.

Answer:

The similarity between electric and magnetic circuit is given in table 1

Table 1

SL No.	Electric Circuit	Magnetic Circuit
1	Conductivity \(\sigma\)	Permeability \(\mu\)
2	Intensity of electric field E	Intensity of magnetic field H
3	Electro motive force (emf) potential difference or voltage	Magneto motive force (mmf) magnetic voltage
4	Current \(I=\int{\vec{J.}\vec{ds}}\)	Magnetic flux \(\mathrm{\Phi}=\int{\vec{B.}\vec{ds}}\)
5	Current density J \(J=\frac{1}{S}=\sigma E\)	Flux density \(B=\frac{\mathrm{\Phi}}{S}=\mu H\)
6	Resistance	Reluctance
7	Conductance	Permeance
8	Ohm’s law \(R=\frac{V}{I}=\frac{1}{\sigma S}\)	Ohm’s law \(Ӄ=l\mu S\)
9	Kirchhoff’s laws \(\sum I=0\) and \(\sum V-\sum I R=0\)	Kirchhoff’s laws \(\sum\mathrm{\Phi}=0\) and \(Ӄ-ӃΦ=0\)

Some dissimilarity between electric and magnetic circuits are given below:

Unlike an electric circuit when current actually flows an electrical conductor, magnetic flux in a magnetic circuit does not flow through a magnetic material.
In an electric circuit energy must the supplied to maintain the flow of current and this energy is dissipated as heat produced in the resistance of the circuit. In a magnetic circuit once the magnetic flux leakage is set up, it does not require further supply of flux to maintain the same since energy is stored in the magnetic field.
Conductivity \sigma is independent on the current density J in an electric circuit where as permeability \mu depends on flux density B in a magnetic circuit. This is due to the fact that ferromagnetic materials are nonlinear and these are mostly used in most practical magnetic circuits.
Magnetic flux can flow through a small cut in an iron ring i.e., the flux flows through air gap. In case of electric circuit, current cannot flow through any air gap or through discontinuity of a conductor.

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Power Electronics Radio Frequency and Microwave Engineering Basic Electrical Engineering Analog Communication Electrical Engineering Management

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