What is the difference between impedance and reactance?

Answer 1

Impedance is related to alternating current Circuits.
Resistance is related to direct curent circuits. It has the Unit of inverse velocity. hence resists the motion of electrons in a conductor and as a result dissipates heat energy.Hence it is considered as a heat dissipating device..

Reactance is an energy storing device and is associated with coils which are magnetic energy producing device.

Hence a reactance stores energy and then gives it back .

Impedeance is the sum of resistance plus reactance but reactance is 90 degrees out of phase. Hence reactance is
described as imaginary quantity where resistance is real quantity.
Resistance is real because it dissipates energy and reactance is imaginary be cause it stores energy as magnetic and does not dissipate as heat energy.
Impedeance in a circuit folows the same circuit rules as resistance.

Answer 2

Reactance is the imaginary part of impedance.

It is only meaningful for AC. When an alternating current is applied to a circuit that contains capacitance or inductance, the impedance will have a part that is purely down to the resistance of components and a part that is due to the behaviour of the capacitors and resistors.

Mathematically this is handled using complex numbers, and the reactance is the imaginary part of the complex number describing the impedance.

Answer 3

Impedance is based on the flow of real power, and reactance includes reactive power. If you need real and reactive power explained, that's a much longer answer.

Answer 4

In ac circuit z=sqrt(R^2+(xl-xc)^2)
z=impedence
xl-xc=reactance