Cathodic Protection Tester Practice Exam

As polarization increases in an electrochemical corrosion cell, what happens to the current?

1. It remains constant

2. It increases

3. It decreases

4. It becomes negligible

The correct answer is: It decreases

In an electrochemical corrosion cell, polarization refers to the changes in the electrochemical potential of the anode and cathode as a result of current flow. As polarization increases, the potential difference between the anode and cathode becomes larger due to various reactions occurring at the surface of the electrodes. When polarization occurs, the energy barrier for electron transfer at the electrodes becomes higher, which generally leads to a reduction in the available current. This is because increased polarization means that more voltage is required to drive the same amount of current through the system. Therefore, as polarization increases, the actual current diminishes, explaining why it decreases in this scenario. Overall, understanding this relationship is crucial in cathodic protection as managing polarization is essential for effective corrosion prevention.