Industry, Infrastructure and Services
This domain tests the classification of industries, the structure of Bihar's industrial economy, the meaning of infrastructure, and the dominance of services in output.
Classifying industry
By size: micro, small, medium and large (MSME). By ownership: public, private, joint, cooperative. By raw material: agro-based, mineral-based, forest-based. By product: consumer goods (sugar, cloth) and capital goods (machines). Bihar's mineral-heavy industry passed to Jharkhand when the state was carved out in 2000; today its strengths are food processing (rice, maize, makhana), edible oil, textiles, leather, ethanol and handicrafts - Madhubani painting, Bhagalpur silk and Sujni work.
Infrastructure
Economic infrastructure: power, roads, railways, bridges (the Mahatma Gandhi Setu, 1982), telecom and irrigation. Social infrastructure: schools, hospitals and drinking water. Bihar's per capita electricity use and road length have improved since 2005, but quality and reliability remain constraints on investment.
Services
The tertiary sector covers trade, transport, hotels, communication, banking, insurance, education, health, public administration, IT and tourism. It supplies over half of India's gross value added and the largest share of Bihar's GSDP.
Worked example
A farmer sells paddy worth ₹20,000 to a mill; the mill sells the rice for ₹26,000; a transporter charges ₹1,000 and a retailer sells to consumers for ₹29,000. Value added: primary ₹20,000, milling ₹6,000, transport plus retail ₹3,000 - total ₹29,000. Reasoning: count value added at each stage rather than adding all sale values, which would double-count the paddy.
Traps that cost marks
Putting mining or construction in the wrong sector (mining is primary, construction secondary); saying services employ most Indian workers; forgetting that infrastructure includes social infrastructure such as schools and hospitals.