In a galvanic couple, which material acts as the cathode, having fewer tendencies to corrode than the anode?

In a galvanic couple, which material acts as the cathode, having fewer tendencies to corrode than the anode?

• A. Anode
• B. Cathode
• C. Uniform Surface Corrosion
• D. Pitting

Answer: (B)

In a galvanic couple, two dissimilar metals in electrical contact and in an electrolyte behave like a tiny battery. The more active metal (less noble) turns into the anode and tends to oxidize, meaning it corrodes more readily. The other metal, which is more noble and less prone to corrosion, becomes the cathode and is protected to some extent because it accepts electrons rather than losing them. So the material that acts as the cathode is the less active, more noble metal in the pair, which corrodes less than the anode. For example, in saltwater, iron tends to be the anode while copper is the cathode, so iron corrodes while copper resists. The other terms describe forms of corrosion (like uniform surface attack or pitting) and don’t define the role of a metal in a galvanic couple.

In a galvanic couple, two dissimilar metals in electrical contact and in an electrolyte behave like a tiny battery. The more active metal (less noble) turns into the anode and tends to oxidize, meaning it corrodes more readily. The other metal, which is more noble and less prone to corrosion, becomes the cathode and is protected to some extent because it accepts electrons rather than losing them. So the material that acts as the cathode is the less active, more noble metal in the pair, which corrodes less than the anode. For example, in saltwater, iron tends to be the anode while copper is the cathode, so iron corrodes while copper resists. The other terms describe forms of corrosion (like uniform surface attack or pitting) and don’t define the role of a metal in a galvanic couple.