ANS:B - galvanising

Galvanizing is a process used to protect steel or iron from corrosion by coating it with a layer of zinc. This process involves immersing the steel or iron in a bath of molten zinc or applying zinc coatings through electroplating. The zinc forms a protective barrier over the surface of the metal, providing excellent corrosion resistance. There are two primary methods of galvanizing:

1. Hot-dip Galvanizing: In this method, the steel or iron is immersed in a bath of molten zinc, which adheres to the surface of the metal, forming a zinc-iron alloy layer. Hot-dip galvanizing is widely used for large structures, such as structural steel beams, poles, and fencing.
2. Electro-galvanizing: Also known as zinc electroplating, this method involves passing an electric current through a zinc solution while the steel or iron object serves as the cathode. Zinc ions from the solution are deposited onto the surface of the metal, creating a thin layer of zinc coating. Electro-galvanizing is often used for smaller, more intricate parts and components.

The zinc coating acts as a sacrificial anode, corroding preferentially to protect the underlying steel or iron from oxidation. Galvanized steel is durable, long-lasting, and requires minimal maintenance, making it suitable for various applications, including construction, automotive manufacturing, and industrial equipment.