Q1: Hot extrusion process is not used for making

ANS:A - cast iron pipe for domestic water supply.

Hot extrusion process is not typically used for making cast iron pipe for domestic water supply. Explanation:

1. Aluminium curtain rods: The hot extrusion process is commonly used for shaping aluminum and its alloys into various profiles, including curtain rods. In hot extrusion, the material is heated above its recrystallization temperature and forced through a die to produce the desired shape. Aluminum and its alloys have suitable properties for hot extrusion, making this process well-suited for manufacturing curtain rods and similar products.
2. Stainless steel tubes used in furniture: Stainless steel can be hot extruded to produce tubes and profiles used in furniture manufacturing. The hot extrusion process allows for the production of stainless steel tubes with complex cross-sectional shapes and uniform dimensions. This method is commonly employed in the production of furniture components where strength, corrosion resistance, and aesthetic appeal are important.
3. Cast iron pipe for domestic water supply: Cast iron pipes for domestic water supply are typically manufactured using other methods such as centrifugal casting or sand casting. While hot extrusion can theoretically be used to shape cast iron, it is not commonly employed for producing cast iron pipes due to the nature of the material and the requirements of the application. Cast iron is more commonly used in applications such as drainage systems, sewer lines, and soil pipes where its corrosion resistance and durability are valued.