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From Kirchhoff ’ s loop rule
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Where C is the constant of integration . This integration constant has dimensions of current and is independent of time . Since source has an emf which oscillates symmetrically about zero , the current it sustain also oscillates symmetrically about zero , so there is no time independent component of current that exists . Thus constant C = 0 So we have
� From instantaneous values of current and voltage ( equation 11 and 10 ) we see that in pure inductive circuit the current lags behind emf by a phase angle of π / 2
� This phase relationship is graphically shown below in the figure