A real, an imaginary, or a complex forcing function will produce a real, an imaginary, or complex response, respectively. Instead of applying a real forcing function to obtain the desired real response, we apply a complex forcing function whose real part is the given real forcing function; we obtain a complex response whose real part is the desired real response

《电路》（英文版）7-6 Phasor relationships for、and R:

8-1 Nodal, mesh and loop analysis Nodal analysis:

The phasor diagram is a name given to a sketch in the complex plane of the phasor voltages and currents throughout a specific circuit

Example 1: If 0=4v2 cos\tV, Z=2/600Q2 Find p(t)and P. Solution:

sinusoidal voltage: V =V29 A sinusoidal current: I= We define the complex powerS=vi=V∠9,I∠-9 =V∠,-=V∠=+ jVI sin=P+j P=VIcos 9 --active(average) power

Let us now define resonance. In a two-terminal electrical network containing at least one inductor and one capacitor, resonance is the condition which exists when the input impedance of the network is purely resistive

Find the resonant frequency arallel resonance

Example 2: Find the three inductance appearing in the T equivalent of the transformer shown in Fig., if L2=4H and the input inductance at A-B is 6H with C-D open-circuited, and 2H with C-D short-circuited

《电路》（英文版）12-1 Three-phase voltages