Q1: __________ pipe is the most suitable for carrying sanitary drainage.

ANS:C - Cast iron

Cast iron is a ferrous alloy containing a high proportion of carbon (typically 2% to 4%), along with silicon, manganese, sulfur, and phosphorus. It is produced by melting pig iron (iron obtained from smelting iron ore with coke) and then casting it into molds to form various shapes and sizes. Here's an explanation of cast iron:

1. Composition: Cast iron primarily consists of iron (Fe) and carbon (C), with carbon content typically ranging from 2% to 4%. The high carbon content distinguishes cast iron from other types of iron and steel alloys. Other alloying elements, such as silicon (Si), manganese (Mn), sulfur (S), and phosphorus (P), are also present in smaller amounts, influencing the properties of the cast iron.
2. Types: There are several types of cast iron, including:
   • Gray Cast Iron: The most common type of cast iron, characterized by its gray color and flake graphite microstructure. Gray cast iron exhibits good machinability and damping capacity but is relatively brittle.
   • White Cast Iron: Contains carbide impurities and has a white crystalline fracture surface. White cast iron is hard and wear-resistant but brittle and difficult to machine.
   • Ductile or Nodular Cast Iron: Contains nodules of graphite in its microstructure, imparting ductility and toughness to the material. Ductile cast iron offers improved mechanical properties compared to gray and white cast iron.
   • Malleable Cast Iron: Heat-treated to convert the carbon in the form of graphite into irregularly shaped nodules, resulting in improved ductility and toughness.
3. Properties:
   • High Compressive Strength: Cast iron has excellent compressive strength, making it suitable for applications where components experience compressive loading.
   • Good Wear Resistance: Cast iron exhibits good wear resistance, making it suitable for components subjected to abrasive wear, such as engine cylinder liners and brake discs.
   • Brittle: While cast iron has good compressive strength and wear resistance, it is relatively brittle and prone to fracture under tensile loading.
   • Damping Capacity: Cast iron has excellent damping capacity, absorbing and dissipating vibrations and noise, making it suitable for applications requiring vibration damping, such as machine tool beds and engine blocks.
4. Applications:
   • Automotive: Engine blocks, cylinder heads, brake discs, and brake drums.
   • Construction: Drainage pipes, manhole covers, and architectural elements.
   • Machinery: Machine tool beds, gears, pulleys, and flywheels.
   • Cookware: Skillets, pans, and Dutch ovens.

In summary, cast iron is a versatile ferrous alloy known for its high compressive strength, wear resistance, and damping capacity. It finds applications in a wide range of industries, including automotive, construction, machinery, and cookware. However, its brittleness and susceptibility to cracking under tensile loading must be considered in engineering design and applications.