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R, C & L in A.C. Circuits

Here are some general formulae for working out values in an A.C. circuit:


Resistors are exactly the same as in D.C. circuits

I = V / R           P = I2R


I = V / XC

XC is the capacitive reactance = 1 / (2pfC)

f is the frequency, C is the capacitance

(Remember Voltage lags Current by 90o)


I = V / XL

XL is the inductive reactance = 2pfL

f is the frequency, L is the inductance

(Remember Voltage leads Current by 90o)

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