A small anode and a large cathode configuration is considered:

In corrosion protection systems, the configuration of anodes and cathodes significantly influences the effectiveness of the cathodic protection method. A small anode paired with a large cathode creates an imbalance in the electrochemical reactions occurring in the system, leading to inefficient protection.

When a small anode is connected to a large cathode, the anode has a limited capacity to provide the necessary protective current to the much larger cathode surface. This results in insufficient cathodic protection, which can lead to localized corrosion or failure in protecting the system.

Moreover, a small anode can become quickly depleted or consumed due to the high current demand from the large cathode, further diminishing the protective effect. In the context of cathodic protection, achieving a more balanced configuration, where the anode size is appropriate in relation to the cathode size, is generally preferred for long-term corrosion management. Thus, this configuration is considered undesirable.