Compare electric and magnetic circuit.
Electric circuit | Magnetic circuit |
The circuit which contain EMF, current and resistance is called as electric circuit. | The circuit which contain MMF, flux and reluctance is called as magnetic circuit. |
EMF is the driving force for flow of electrons. The unit of EMF is volts. | MMF is the driving force for flow of flux. The unit of MMF is ampere turns. |
In electrical circuit, there is a flow of electric current (I) it's unit is ampere. | In magnetic circuit, there is a flow of magnetic flux (Φ) its unit is Weber. |
Opposition to the flow of current is called as resistance (R). Its unit is Ohm. | Opposition to the flow of flux is called as reluctance (S). Its unit is ampere per weber. |
Voltage = current × resistance | MMF = flux × reluctance |
Ohm's law for electric circuit is applicable. | Ohm's law for magnetic circuit is applicable. |
Conductivity | Permeability |
Resistivity | Reluctivity |
Kirchoff's current and voltage law is applicable. | Kirchoff's flux and MMF law is applicable. |
The electric current density (J) = I/a ampere per metre square. | The magnetic flux density (B) = Φ/a Weber per metre square. |
Electric intensity (E) = V/d volts per metre.
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Magnetic intensity (H) = NI/l ampere turns per metre.
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Electric circuit
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Magnetic circuit
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Path traced by the current is known as electric current.
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The magnetic circuit in which magnetic flux flow
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EMF is the driving force in the electric circuit. The unit is Volts.
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MMF is the driving force in the magnetic circuit. The unit is ampere turns
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There is a current I in the electric circuit which is measured in amperes.
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There is flux φ in the magnetic circuit which is measured in the weber.
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The flow of electrons decides the current in conductor.
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The number of magnetic lines of force decides the flux.
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Resistance (R) oppose the flow of the current. The unit is Ohm
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Reluctance (S) is opposed by magnetic path to the flux. The Unit is ampere turn/weber
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R = ρ. l/a. Directly proportional to l. Inversely proportional to a. Depends on nature of material
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S = l/ (µ0µra). Directly proportional to l. Inversely proportional to µ = µ0µr . Inversely proportional to a
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The current I = EMF/ Resistance
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The Flux = MMF/ Reluctance
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The current density
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The flux density
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Kirchhoff current law and voltage law is applicable to the electric circuit.
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Kirchhoff mmf law and flux law is applicable to the magnetic flux.
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Dissimilarities between Electric and Magnetic Circuits:
Electric circuit
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Magnetic circuit
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Electric current flows
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Flux does not actually flow (it only gets established or set up)
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Energy is needed continuously for the flow of current.
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Energy is only needed for establishment of field (flux).
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Current cannot pass through the insulators.
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Flux can pass through almost all things including air.
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Electrical Insulator is available
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Magnetic Insulator does not exist.
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Sr. No
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Electric circuit
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Magnetic circuit
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1. |
Current: Flow of electrons through conductor is current. It is measured in ampere.
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Flux: lines of force through medium from N pole to S pole form flux. It is measured in weber.
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2. |
EMF: It is driving force for current, measured in volt.
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MMF: It is driving force for flux, measured in A-T.
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3. |
Resistance: It is opposition of conductor to current, measured in ohms.
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Reluctance: It is opposition offered by magnetic path to flux, measured in A-T/Wb.
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4. |
Resistance is directly proportional to length of conductor
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Reluctance is directly proportional to length of magnetic path.
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5. |
For electric circuit we define the conductivity.
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For magnetic circuit we define permeability.
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6. |
Electric circuit is closed path for current.
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Magnetic circuit is closed path for magnetic flux.
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7. |
For electric circuit, I = EMF/Resistance
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For magnetic circuit phi = MMF/Reluctance.
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8. |
Voltage = IR
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MMF= phi * S
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9. |
Resistivity
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Reluctivity
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10. |
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