The correct option is (b) 2 only.
Explanation
Industries are classified based on the source of raw materials into agro-based, mineral-based, marine-based, and forest-based industries. Mineral-based industries are primary manufacturing units that use mineral ores as their raw materials. The products of these industries feed other industries.
Statement-wise Analysis
- Statement 1 is Incorrect. Industries, including mineral-based ones, involve the processing of raw materials into finished goods. This falls under Secondary activities (manufacturing sector). Tertiary activities refer to the service sector (transport, trade, banking, etc.), which supports the industrial process but does not include the manufacturing units themselves.
- Statement 2 is Correct. The output of mineral-based industries often serves as the input for other industries. For example, the Iron and Steel industry produces steel, which is a basic raw material used for manufacturing heavy machinery, building materials, and consumer goods.
- Statement 3 is Incorrect. Products of mineral-based industries are fundamental to infrastructure development. Railway tracks, rolling stock (engines and coaches), and station infrastructure heavily rely on iron, steel, and cement. Therefore, it is factually incorrect to state that these products are never used for infrastructure like railways.
Key Takeaway: Mineral-based industries are secondary sector activities that process mineral ores (e.g., iron ore, limestone) into products (e.g., steel, cement) essential for industrial machinery and infrastructure.