AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
Iron ore, coal, and limestone are required in a 4:2:1 ratio — all heavy and bulky — making transportation costs very high, so plants must locate near raw material sources to minimise costs.
The key phrase from the textbook is: "Iron and steel is a heavy industry because all the raw materials as well as finished goods are heavy and bulky entailing heavy transportation costs." For 1 mark, just link the heavy/bulky nature of inputs (and the 4:2:1 ratio) directly to high transport costs and proximity to sources. No elaboration needed.