Cathodic Protection Tester Practice Exam

In a corrosion cell, electrons flow in which direction?

1. Cathode to anode through the metallic path

2. Anode to cathode through the metallic path

3. Cathode to anode through the electrolyte

4. Anode to cathode through the electrolyte

The correct answer is: Anode to cathode through the metallic path

In a corrosion cell, the flow of electrons occurs from the anode to the cathode through the metallic path. This movement of electrons is a fundamental principle of electrochemistry and is essential to understanding how corrosion processes take place. At the anode, oxidation reactions occur, which result in the loss of electrons. These electrons are then transferred through the metallic path to the cathode, where reduction reactions take place. This flow is driven by the difference in electrochemical potential between the two electrodes. In a typical scenario, metals will corrode if they provide electrons to a more noble (less easily oxidized) material, establishing a current that can facilitate the corrosion process. Understanding this electron flow is critical when discussing cathodic protection systems, as these systems often use a source of electrons to mitigate corrosion by effectively reversing the natural current flow that leads to deterioration of the metal.