WHAT IS A MAGNETIC CIRCUIT?

A magnetic circuit is a complete closed path followed by the magnetic flux lines. The magnetic flux lines begin from a magnet or electromagnet and return to it, thus forming a closed loop. The magnetic flux lines or lines of magnetic force represent the magnetic field virtually. This provides a conceptual answer to the question of what is a magnetic circuit?

WHAT IS A MAGNETIC CIRCUIT?

ANALOGY OF A MAGNETIC CIRCUIT AND AN ELECTRIC CIRCUIT

• Analogous to a magnetic circuit, which consists of magnetic flux and completes its path consisting of magnetic lines of force, an electric circuit comprises electric current flowing through the conductors in a closed path. 

  
  

• As in an electric circuit, the resistance opposes the flow of electric current, likewise, in a magnetic circuit, the magnetic reluctance opposes the flow of magnetic flux. 

  
  

• The voltage (EMF or electromotive force) in an electric circuit is analogous to the MMF (or magnetomotive force) in a magnetic circuit.

• Ohm’s law

Ohm’s law for an electric circuit states that the current flowing through a conductor is directly proportional to the voltage across the conductor, and is inversely proportional to the resistance across the circuit.  

V=IR

Where V is the voltage,

I is the current, and

R is the resistance.

Ohm’s law for a magnetic circuit or Rowland’s law states that the number of magnetic lines of force (𝞍) is directly proportional to the magnetomotive force (MMF) and inversely proportional to the reluctance (R).

𝞍=MMF/R

Where, 𝞍 is the magnetic flux,

MMF is the magnetomotive force, and

R is the reluctance.

• The flow of electrons in an electric circuit determines the flow of electric current in the conductor. The magnetic lines of force determine the flux in the core of a magnetic circuit.

WHAT IS A MAGNETIC CIRCUIT?

A magnetic circuit consists of magnetic materials (consisting of high permeability), which provide a low reluctance path for the magnetic flux to flow in a magnetic field. 

ADVANTAGES OF MAGNETIC CIRCUITS

• The magnetic circuits manage the performance of the circuit by providing it direct access to the magnetic properties of the circuit, like magnetic flux. 

  
  

•  The magnetic circuits are more efficient in transferring energy between the components of the circuit. Magnetic circuits are there in transformers to provide good power transfer. They provide direct control over the power supply in a transformer. These circuits improve efficiency by using magnetic cores with high permeability. 

  
  

• The electrical isolation and voltage management are also possible in electrical machines consisting of magnetic circuits. 

PARAMETERS OF A MAGNETIC CIRCUIT

MAGNETIC FLUX

Magnetic flux is defined as the number of magnetic field lines through a given surface area in a magnetic circuit.

𝞍=B.A.cosƟ

Where, 𝞍 is the magnetic flux (in Weber),

 B is the magnetic field strength (in Tesla),

A is the area of magnetic field lines (in square meters),

Ɵ is the angle between the magnetic field lines and the normal to the surface.

MAGNETOMOTIVE FORCE (MMF)

Magnetomotive force (MMF) is defined as the ratio of the product of the current and the number of turns of a coil in a magnetic circuit. 

MMF=NI

Where MMF is the magnetomotive force (in Ampere Turn or AT),

N is the number of turns in the coil,

I is the current flowing through the coil.

ELECTROMOTIVE FORCE (EMF)

Electromotive force (EMF) is defined as the energy per unit charge provided by a source like a battery for moving the charges and thus assisting the electric current to flow in the electric circuit.

RELUCTANCE

Reluctance is a measure of the opposition provided by a magnetic circuit to the setting up of the magnetic flux. It is the ratio of the magnetomotive force to the magnetic flux.

R=MMF/ 𝞍,

Where MMF is the magnetomotive force,

R is the reluctance, and

𝞍 is the magnetic flux.

CONCLUSION

This article provides the answer to your question, What is a magnetic circuit? The analogy between an electric circuit and a magnetic circuit is also there. There is also a clarification about the parameters of a magnetic circuit. Magnetic circuits are used in many electrical machines like motors, transformers, electromagnets, etc. Continue visiting our website to learn more about many topics of electrical engineering. This article will provide you with knowledge about what are the types of sources in an electric circuit.