In an impressed current system, the rectifier positive terminal is connected to:

In an impressed current cathodic protection system, the rectifier is a crucial component that converts alternating current (AC) from the power supply to direct current (DC), which is then used to protect metal structures from corrosion. The positive terminal of the rectifier is connected to the structure that requires protection.

The reason for this connection is that in cathodic protection systems, the structure (such as a pipeline or tank) needs to be polarized negatively to mitigate corrosion. By connecting the positive terminal of the rectifier to the structure, the system introduces the necessary current to counteract corrosion by creating a protective cathodic environment.

In this setup, the negative terminal of the rectifier would be connected to the anodes, which are designed to release electrons into the electrolyte (in most cases soil or water). This electron flow from the anodes to the structure prevents corrosion by ensuring that the structure is maintained at a potential lower than that of the surrounding electrolyte.

Understanding this connection is vital as it highlights the working principle of impressed current systems in cathodic protection, emphasizing the roles of the rectifier, the structure being protected, and how the flow of current contributes to corrosion prevention.