About This Section
This section collects previous-year Board examination questions (CBSE and State Boards) from Chapter 5, with model answers, to show the pattern and depth expected in the exam.
Board PYQ — Very Short Answer (1 mark)
Q1. Which mineral is contained in monazite sand? Ans. Thorium.
Q2. Name the finest quality of iron ore. Ans. Magnetite.
Q3. Name one non-conventional source of energy. Ans. Solar energy (also wind, tidal, geothermal, biogas, nuclear).
Board PYQ — Short Answer (3 marks)
Q4. Why are minerals a finite resource that must be conserved? Ans. Minerals form through very slow geological processes over millions of years, so their rate of formation is far slower than the rate of use. They are non-renewable and finite, and as rich ores are used up, extraction becomes costlier. Hence they must be conserved through recycling, substitutes and planned use.
Q5. Distinguish between ferrous and non-ferrous minerals. Ans. Ferrous minerals contain iron (e.g. iron ore, manganese) and form the base of metallurgical industries. Non-ferrous minerals do not contain iron (e.g. copper, bauxite, gold) and are used in electrical and engineering industries.
Board PYQ — Short Answer (3 marks)
Q6. Explain the mode of occurrence of minerals in placer deposits and ocean waters. Ans. Placer deposits occur as alluvial deposits in the sands of valley floors and the base of hills; being non-corrodible, they include gold, silver, tin and platinum. Ocean waters contain minerals like common salt, magnesium and bromine, and the ocean beds hold manganese nodules.
Q7. Why are heavy industries located near coalfields? Ans. Coal is a bulky material that loses weight on use (turning to ash) and is expensive to transport far. So heavy industries and thermal power stations are located on or near the coalfields to reduce transport costs.
Board PYQ — Long Answer (5 marks)
Q8. Describe the distribution of any two non-ferrous minerals in India. Ans. Copper — India is deficient in copper; leading producers are the Balaghat mines (MP), Khetri mines (Rajasthan) and Singhbhum (Jharkhand). Bauxite — the ore of aluminium, found in the Amarkantak plateau, Maikal hills and Bilaspur-Katni; Odisha is the largest producer (Panchpatmali, Koraput).
Q9. Explain the conventional sources of energy in India. Ans. Conventional sources include firewood and cattle-dung cake (rural), coal (most abundant; Gondwana and tertiary fields), petroleum (Mumbai High, Gujarat, Assam), natural gas (Krishna-Godavari basin), and electricity from hydel (running water) and thermal (coal, oil, gas) sources.