**Introduction Electrical Impedance**:

**In electrical engineering life**, electrical resistance is a measure of the resistance that a circuit offers to current when a voltage is applied.And the Impedance enlarge the minded of (resistance) P to alternating current (AC) circuits. Impedance)be the owner of both magnitude and phase, different from resistance, which has only magnitude.dissimilar to from electrical resistance, electrical impedance’s opposition to current depends on the frequency of the circuit. Resistance can be line of thinking of as impedance with a phase geometrical relation of zero.

**As you know** the circuit where the current lags 90° (electrical) in high regard of the applied voltage in a clearly inductive circuit. A circuit where current leads 90° (electrical) in respect of the applied voltage in a clearly capacitive circuit. A circuit where the current does not fall behindnor lead in respect to the applied voltage in a completely resistive circuit.

As you know the circuit where the current lags 90° (electrical) in high regard of the applied voltage in a clearly inductive circuit. A circuit where current leads 90° (electrical) in respect of the applied voltage in a clearly capacitive circuit. A circuit where the current does not fall behindnor lead in respect to the applied voltage in a completely resistive circuit. When a circuit is driven with direct current (DC), there is no contrast between impedance and resistance.

presents ahead with resistance, As a result there will be leading or lagging effect on the current of the circuit effecting life rules on the value of reactance and resistance of the circuit.

In the AC circuit, the growing effect of reactance and resistance is entitle as impedance. The impedance is usually denoted by English letter Z. The value of impedance is represented as

In this you know that Where R is the value of circuit resistance and X is the value of circuit reactance.And the The angle between applied voltage and current is

Inductive reactance is taken as positive and Capacitive reactance is taken as negative.and is the angle between the applied voltage and current.

The Impedance can be represented in complex form.

**The Impedance of a Series RL Circuit:**

Let us start the life of the series RL circuit to get the expression for its impedance. Here the value of resistance R and inductance UseL are connected in series. The reactance of the inductor is ωL. So the complex form is an expression of constraint.

**The Impedance of a Series RC Circuit:**

Let us connect a resistance of value R ohm in series with a capacitor of capacitance C farad. The reactance of a capacitor is 1/ωC. The resistance R and reactance of the capacitor are in series.The impedance expression can be written as.

**The Impedance of a Parallel RL Circuit:**

Here resistance and inductor are connected in parallel. Here the impedance of the circuit is the sum of the impedance and the reactance.

**The Impedance of a Parallel RC Circuit:**

Here, since the capacitor and resistor are connected in parallel, the impedance of the circuit is the sum of the mutual resistance and the reactance of the capacitor.

**The Impedance of a Series RLC Circuit:**

Here resistors, capacitors, and inductors are connected in series. The total reactance of the circuit is the sum of the reactances of the inductors and capacitors. Reactance of capacitors is taken as negative. The impedance of a series RLC circuit is expressed.

**The Polar Representation of Impedance:**