Correct Answer:
A. An impressed current system uses an external power source to apply a direct current to the hull fittings, making the fittings the anode in the electrochemical cell, which prevents their corrosion.
Explanation:
- A. Correct: An impressed current system works by using an external power source (like a rectifier) to provide a continuous direct current to the hull fittings. This current forces the fittings to act as the anode, thereby preventing their corrosion by controlling the electrochemical reactions on the metal surface.
- B. Incorrect: This describes a natural galvanic or sacrificial anode system, not an impressed current system. Impressed current systems rely on external power rather than natural electrical potential differences.
- C. Incorrect: This describes a sacrificial anode system, not an impressed current system. Sacrificial anodes provide protection through galvanic corrosion, not impressed current.
- D. Incorrect: This describes the use of chemical coatings, which are not part of an impressed current system. Impressed current systems rely on an external electrical current rather than physical barriers.
Correct Answer:
A. An impressed current system uses an external power source to apply a direct current to the hull fittings, making the fittings the anode in the electrochemical cell, which prevents their corrosion.
Explanation:
- A. Correct: An impressed current system works by using an external power source (like a rectifier) to provide a continuous direct current to the hull fittings. This current forces the fittings to act as the anode, thereby preventing their corrosion by controlling the electrochemical reactions on the metal surface.
- B. Incorrect: This describes a natural galvanic or sacrificial anode system, not an impressed current system. Impressed current systems rely on external power rather than natural electrical potential differences.
- C. Incorrect: This describes a sacrificial anode system, not an impressed current system. Sacrificial anodes provide protection through galvanic corrosion, not impressed current.
- D. Incorrect: This describes the use of chemical coatings, which are not part of an impressed current system. Impressed current systems rely on an external electrical current rather than physical barriers.