Normally, oxidation reactions are taking place on the anode. So when anions come into the anode in the solution, they undergo oxidation and release electrons. Therefore, there is electron abundance on the anode compared to the cathode. Because of this, electrons flow to cathode from the anode. Since current flow is in the opposite direction of the electron flow, we see it as current flowing into anode.Ĭommon anode is used in the seven-segment displays. This is an electronic display device which shows decimal numerals. They are widely used in digital clocks and meters, etc. In these displays, all the anodes are connected to one point, and it becomes a common anode. Therefore, instead of seven anodes, there is only one common anode. Power supply’s positive end is connected to the anode. However, power will be supplied to all the seven segments.Ĭathode is the electrode where the positive current flows out of the system. In an electrochemical cell, inside the solution, the cations are attracted to the cathode. Reduction reaction takes place on the cathode therefore, there should be electrons. Since current is flowing out of the electrode, electrons are flowing in. As these electrons are used up to the reduction reactions, there will be more electron deficiencies. This allows more electrons to come into the cathode from the anode. When all the seven cathodes of a 7-segment display are connected together, it becomes common cathode.

Led cathode anode