Impedance
Related wiki pages: Electronic Theory, Capacitors, Inductors, Ohm's Law
Impedance is a property of electrical circuits that "impedes" current from flowing. Fundamentally, there are two types of impedance: Resistance and Reactance.
The magnitude of impedance (represented by <math>Z\,</math>) of a circuit or component can be computed by taking the sum of the squares of the resistance (represented by <math>R\,</math>) and reactance (represented by <math>X\,</math>).
<math>Z = \sqrt{R^2 + X^2}\,</math>
However, it is more useful to represent impedance as a complex number and use it in phasor analysis.
Impedance can be used in the normal Ohm's Law equation:
<math>V = IZ\,</math>
where V is voltage and I is current. For working with alternating current, this is more correct than the usual direct current equation <math>V = IR\,</math>.
Electronic Theory  
Physical quantities  Current * Gain * Impedance * Power * Q of a circuit * Radiated Power Measurement * Reactance* Resistivity * Resonance * Voltage 
Components  Baluns * BipolarJunction Transistors * Capacitors * Diodes * Inductors* Lasers * Microphones * Resistors * Transformers * Wire 
Circuits  Attenuators * Digital Signal Processing (DSP) * Dummy load * Filters * LC filters * Power Supply Design * Rectifier Circuits 
Design  Amplifier Design * Oscillator Design 
Electromagnetic Waves  Relative power (Decibels) * Harmonics * Interference and BPL 
