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Effective Resistance and QFactor
R_{eff} expresses the ac resistance, which is generally greater than the dc resistance. This is particularly true when the cross section of the wire in the winding of the selfinductance is large, or when, as in the case of some devices, such as motors and generators, the wire is embedded in slots. The leakage fluxes in transformers and stray fluxes in reactors and choke coils produce losses in the metal tanks or cases that enclose the core and windings. Such losses are reflected into the effective resistance values. The quality factor, QF, or simply Q^{1}, of a coil is the ratio of reactive power to real power. Hence
Other definitions are
Equations 4109, 4110, and 4111 are equivalent. The term, energy lost per cycle, represents the irreversible energy, i.e., the energy that is converted into heat and the energy stored in the circuit represents the reversible energy.


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