Cathodic protection is an electrical system used to prevent corrosion of metals. Which option correctly reflects this concept?

Cathodic protection is an electrical system used to prevent corrosion of metals. Which option correctly reflects this concept?

• A. Grounding
• B. Cathodic protection
• C. Anodic protection
• D. Shielding

Answer: (B)

The idea is to prevent corrosion by making the metal surface the cathode in an electrochemical cell. By connecting sacrificial anodes (like zinc or magnesium) or using an external DC current from a power source to the structure, electrons are supplied to the metal. This lowers its tendency to lose electrons (oxidize), so the corrosion reactions are greatly reduced on buried or submerged metal like pipelines or storage tanks. Grounding is about safety and fault-current paths, not specifically corrosion protection. Anodic protection is a different approach that polarizes the metal to form protective oxide films but makes the metal more anodic, not cathodic. Shielding refers to barriers or coatings that limit contact with the environment rather than using an electrical current.

The idea is to prevent corrosion by making the metal surface the cathode in an electrochemical cell. By connecting sacrificial anodes (like zinc or magnesium) or using an external DC current from a power source to the structure, electrons are supplied to the metal. This lowers its tendency to lose electrons (oxidize), so the corrosion reactions are greatly reduced on buried or submerged metal like pipelines or storage tanks. Grounding is about safety and fault-current paths, not specifically corrosion protection. Anodic protection is a different approach that polarizes the metal to form protective oxide films but makes the metal more anodic, not cathodic. Shielding refers to barriers or coatings that limit contact with the environment rather than using an electrical current.