- The analogy between electric and magnetic circuits is given in the Table 1.
- The resistivity of conductors is more or less constant but the permeability of the ferromagnetic materials varies greatly with magnetic field strength.
- Strictly speaking, flux does not actually ‘flow’ in the sense in which an electric current flows.
- In an electric circuit energy must be supplied to maintain the flow of electricity in the circuit, whereas (in a magnetic circuit) the magnetic flux once, it is set up, does not require any further supply of energy,
Example, Once the flux produced by a current in the solenoid has attained its steady value, the energy subsequently absorbed by that solenoid is all dissipated as heat due to the resistance of the winding).
- In ferromagnetic materials if the magnetic field strength is increased the flux density increases till a state of saturation is reached after which there is no increase in flux density for further increase in field strength. There is no such phenomenon in electric circuits.