# Compare electric and magnetic circuit.

Compare electric and magnetic circuit.
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 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. Magnetic intensity (H) = NI/l ampere turns per metre. Electric intensity (E) = V/d volts per metre.

 Electric circuit Magnetic circuit Path traced by the current is known as electric current. The magnetic circuit in which magnetic flux flow EMF is the driving force in the electric circuit. The unit is Volts. MMF is the driving force in the magnetic circuit. The unit is ampere turns There is a current I in the electric circuit which is measured in amperes. There is flux φ in the magnetic circuit which is measured in the weber. The flow of electrons decides the current in conductor. The number of magnetic lines of force decides the flux. Resistance (R) oppose the flow of the current. The unit is Ohm Reluctance (S) is opposed by magnetic path to the flux. The Unit is ampere turn/weber R = ρ. l/a. Directly proportional to l. Inversely proportional to a. Depends on nature of material S = l/ (µ0µra). Directly proportional to l. Inversely proportional to µ = µ0µr . Inversely proportional to a The current I = EMF/ Resistance The Flux = MMF/ Reluctance The current density The flux density Kirchhoff current law and voltage law is applicable to the electric circuit. Kirchhoff mmf law and flux law is applicable to the magnetic flux.

Dissimilarities between Electric and Magnetic Circuits:

 Electric circuit Magnetic circuit Electric current flows Flux does not actually flow (it only gets established or set up) Energy is needed continuously for the flow of current. Energy is only needed for establishment of field (flux). Current cannot pass through the insulators. Flux can pass through almost all things including air. Electrical Insulator is available Magnetic Insulator does not exist.

 Sr. No Electric circuit Magnetic circuit 1. Current: Flow of electrons through conductor is current. It is measured in ampere. Flux: lines of force through medium from N pole to S pole form flux. It is measured in weber. 2. EMF: It is driving force for current, measured in volt. MMF: It is driving force for flux, measured in A-T. 3. Resistance: It is opposition of conductor to current, measured in ohms. Reluctance: It is opposition offered by magnetic path to flux, measured in A-T/Wb. 4. Resistance is directly proportional to length of conductor Reluctance is directly proportional to length of magnetic path. 5. For electric circuit we define the conductivity. For magnetic circuit we define permeability. 6. Electric circuit is closed path for current. Magnetic circuit is closed path for magnetic flux. 7. For electric circuit, I = EMF/Resistance For magnetic circuit phi = MMF/Reluctance. 8. Voltage = IR MMF= phi * S 9. Resistivity Reluctivity 10.

Comparison between Magnetic and Electric Circuits