Electrode Whewell at Faraday's request). The anode is now defined as the electrode at which electrons leave the cell and oxidation occurs (indicated by a minus symbol, "−"), and the cathode as the electrode at which electrons enter the cell and reduction occurs (indicated by a plus symbol, "+"). Each electrode may become either the anode or the cathode depending on the direction of current through the cell. A bipolar electrode is an electrode that functions as the anode of one cell and the cathode of another cell. A primary cell is a special type of electrochemical cell in which the
Aluminum electrolytic capacitor as "Z". In this sense the impedance is a measure of the capacitor's ability to pass alternating currents. Impedance can be calculated using the idealized components of a capacitor's series-equivalent circuit, including an ideal capacitor formula_4, a resistor formula_5, and an inductance formula_6. In this case the impedance at the angular frequency formula_7 is therefore given by the geometric (complex) addition of ESR, by a capacitive reactance (Capacitance) and by an inductive reactance (Inductance) Then formula_10 is given by Aluminum electrolytic capacitor Aluminum electrolytic capacitors are polarized electrolytic capacitors whose anode electrode (+) is made of a pure aluminum foil