Galvanised iron sheets are protected from rusting due to the presence of a layer of

Galvanised iron sheets are protected from rusting because they are coated with a thin layer of zinc. Galvanisation specifically involves applying a zinc metal coating onto iron or steel; this zinc layer acts as a physical barrier and also provides sacrificial (anodic) protection to the underlying iron so that the iron does not corrode even if small parts of the coating are damaged [1]. Texts for students explicitly state that galvanisation protects steel and iron by coating them with a thin layer of zinc and note that the galvanised article remains protected against rusting even when the zinc coating is broken [2].

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 3: Metals and Non-metals > 3.5.1 Prevention of Corrosion > p. 54
2. [2] Science-Class VII . NCERT(Revised ed 2025) > Chapter 4: The World of Metals and Non-metals > Activity 4.5: Let us experiment > p. 50