Figure 1-7B.Linear impedance circuit.
Figure 1-7C.Linear impedance circuit
The battery in view (A) could be replaced with an ac generator, as shown in view (B), to plot the
characteristic chart. The same linear voltage-current chart would result. Current flow in either direction is
directly proportional to the change in voltage.
In conclusion, when dc or sine-wave voltages are applied to a linear impedance, the current through
the impedance will vary directly with a change in the voltage. The device could be a resistor, an air-core
inductor, a capacitor, or any other linear device. In other words, if a sine-wave generator output is applied
to a combination of linear impedances, the resultant current will be a sine wave which is directly
proportional to the change in voltage of the generator. The linear impedances do not alter the waveform of
the sine wave. The amplitude of the voltage developed across each linear component may vary, or the
phase of the wave may shift, but the shape of the wave will remain the same.