Z = SQR (R² + XL²) Where: Z = Impedance (ohm) R = Resistance (ohm) XL= Inductance Reactance (ohm)
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Nominal impedance is exactly that, nominalin other words, supposed or theoreticaland varies with a number of factors, including frequency and relative humidity. The International
http://www.ehow.com/facts_6948065_nominalimpedanc...

Electrical impedance. is the. complex. ratio of the voltage to the current in an. alternating current. (AC) circuit. Impedance extends the concept of. resistance. to AC circuits,
http://www.quora.com/ElectricalEngineering/Whati...

The resonant frequency f = 1/SQRT(L *C) For a parallel LC circuit, the equivalent total Reactance is. Xt = 1 / (1/jXC) + (1/jXL) which in turn is. Xt = (jXL * jXC) / (jXL + jXC)
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