1. What is a sacrificial anode?
- A. A dielectric fitting installed to electrically insulate two dissimilar metals from one another.
- B. A more anodic metal bonded to the protected component so it corrodes preferentially and is replaced periodically.
- C. A pre-weighed metal strip immersed in the fluid to estimate the average corrosion rate over time.
- D. A noble metal coupled to the system so that it resists corrosion and shields the anodic parts.
Show the answer and explanation
Answer: B. A sacrificial anode is a more active metal, such as zinc, magnesium, or aluminum, fastened mechanically and electrically to the part you want to keep. It corrodes instead of that part and is replaced when it is used up. A coupon is a weighed strip used to measure a corrosion rate, not to protect the metal. A dielectric fitting insulates two metals from each other. A noble metal does not sacrifice itself for a more active one; that pairing runs the wrong way.