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

Find the resonant frequency arallel resonance

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

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

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

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

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

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

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

The forced response The steady state responseThe(t) has been switched into the circuit at some remote U.=V. cos ot time in the past, and the natural response has died-out completely. The forced response(steady state response)must satisfy the differential equation