Electrical Engineering ⇒ Topic : Current-frequency curve

Current-frequency curve. Fig. (b) shows the current-frequency curve of the parallel circuit shown in Fig. a (i). Note that value of line current is minimum at resonance (I_r = V/Z_R). As the frequency changes from resonance, the line current increases rapidly. This action can be explained as follows. For frequencies other than the resonance, the reactive currents in the two branches of the circuit are not equal. The resultant reactive current must be supplied by the line.As the difference of the reactive currents in the two branches increases with the amount of deviation from the resonant frequency, the line current will increase in the same manner.

                                                                       figure (a)

                                         figure (b)