Cathodic Protection Tester Practice Exam

Which part of a corrosion cell is generally positive?

1. Electrolyte

2. Anode

3. Cathode

4. External circuit

The correct answer is: Anode

The correct answer is B, the anode. In a corrosion cell, the anode is the electrode where oxidation occurs, which is a process that releases electrons. Because the anode is losing electrons, it is considered to have a higher positive electrical potential relative to the cathode, where reduction takes place (the gain of electrons). Understanding the roles of the anode and cathode is crucial in cathodic protection systems. The anode is where metal reacts with the electrolyte (like water or soil), causing the metal to corrode. This process creates a flow of electrons through the external circuit towards the cathode, which is often the metal structure that needs protection. The electrolyte serves as a medium for ion transport in the corrosion process but does not have a defined positive or negative charge in the same way that the anode and cathode do. The external circuit connects the anode and cathode but does not itself serve as a site for electrochemical reactions. Therefore, the anode is the only part of the corrosion cell that is characterized as generally positive due to its role in the oxidation reaction, further emphasizing its importance in understanding cathodic protection principles.