Q1: Out of the following, __________ pipe is the least corrosion resistant.

ANS:C - wrought iron

Wrought iron is a type of iron alloy with a very low carbon content, typically less than 0.1%. It is characterized by its fibrous structure, which is the result of the manufacturing process used to produce it. Here's an explanation of wrought iron:

1. Manufacturing Process: Wrought iron is produced through a process called "puddling," which involves melting pig iron (crude iron) in a reverberatory furnace and stirring it to oxidize impurities like carbon, silicon, and manganese. This process removes many of the impurities and reduces the carbon content, resulting in a purer iron product. The molten iron is then worked (wrought) by forging or rolling to shape it into various forms, such as bars, sheets, or ornamental objects.
2. Properties: Wrought iron has several distinctive properties:
   • Ductility: Wrought iron is highly ductile, meaning it can be easily shaped or formed without fracturing. This property makes it suitable for forging and shaping into intricate designs.
   • Toughness: Wrought iron exhibits good toughness, allowing it to absorb shock and impact without fracturing. This property makes it suitable for structural applications where resilience is important.
   • Corrosion Resistance: While not as corrosion-resistant as stainless steel, wrought iron is more resistant to corrosion than many other types of iron and steel due to its low carbon content. It forms a protective layer of iron oxide (rust) on its surface, which helps prevent further corrosion.
3. Applications: Wrought iron has been used for centuries in various applications, including:
   • Architectural: Gates, railings, fences, and ornamental structures.
   • Structural: Beams, columns, and other structural elements in buildings and bridges.
   • Decorative: Furniture, lighting fixtures, and decorative elements.
4. Historical Significance: Wrought iron played a significant role in the development of architecture and engineering throughout history, particularly during the medieval and Renaissance periods. Its use declined with the advent of steelmaking processes that produced stronger and more cost-effective materials, but it is still appreciated for its aesthetic appeal and historical significance.