Question

Why zinc coating is used in iron bridges?

• A. Because zinc is cheaper than iron.
• B. Because it prevents corrosion.
• C. Because zinc is better conductor of heat.
• D. Because zinc is less reactive than iron.

Answer 1

The correct option is B

Because it prevents corrosion.

Zinc forms a coating of corrosion-resistant zinc which prevents corrosive substances from reaching the more delicate part of the metal. Moreover, even if the coating is scratched, the exposed steel will still be protected by the remaining zinc.