Some important MCQs with explanations related to Economic Geology for the Jharkhand Academic Council (JAC) 12th Exam -2

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11. Which is the chief ore of copper?

A. Chalcopyrite
B. Malachite
C. Azurite
D. Bornite

Correct Answer: A. Chalcopyrite
Explanation:
Chalcopyrite (CuFeS₂) is the primary ore of copper, widely used in copper extraction.

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12. Which mineral is known as the “ore of zinc”?

A. Galena
B. Sphalerite
C. Cassiterite
D. Bauxite

Correct Answer: B. Sphalerite
Explanation:
Sphalerite (ZnS) is the most important ore of zinc, commonly found in sedimentary and hydrothermal deposits.
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13. Which rock type is associated with coal formation?

A. Igneous rock
B. Metamorphic rock
C. Sedimentary rock
D. Volcanic rock

Correct Answer: C. Sedimentary rock
Explanation:
Coal is formed from plant remains through compaction and is typically found in sedimentary rocks.

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14. What is the most abundant fossil fuel found in Jharkhand?

A. Petroleum
B. Natural Gas
C. Coal
D. Uranium

Correct Answer: C. Coal
Explanation:
Jharkhand is rich in coal reserves, with major coalfields like Jharia and Bokaro.

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15. Which is the largest manganese-producing state in India?

A. Odisha
B. Karnataka
C. Madhya Pradesh
D. Jharkhand

Correct Answer: A. Odisha
Explanation:
Odisha is the largest producer of manganese in India, used in steelmaking and other industries.

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16. What is the primary use of bauxite?

A. Cement production
B. Aluminum extraction
C. Steel production
D. Fertilizer manufacturing

Correct Answer: B. Aluminum extraction
Explanation:
Bauxite is the chief ore of aluminum and is processed to extract aluminum metal.

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17. What is the process of separating gangue from ore called?

A. Refining
B. Beneficiation
C. Smelting
D. Roasting

Correct Answer: B. Beneficiation
Explanation:
Beneficiation is the process of separating valuable minerals from the gangue to enhance the quality of the ore.

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18. Which mineral is commonly referred to as “black gold”?

A. Coal
B. Petroleum
C. Graphite
D. Obsidian

Correct Answer: A. Coal
Explanation:
Coal is called "black gold" due to its importance as a valuable energy resource.

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19. What is the term for naturally occurring substances with economic value extracted from the earth?

A. Rocks
B. Minerals
C. Ores
D. Deposits

Correct Answer: B. Minerals
Explanation:
Minerals are naturally occurring substances with a definite chemical composition and economic importance.

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20. Which of the following processes is used for gold extraction?

A. Leaching
B. Smelting
C. Froth flotation
D. Roasting

Correct Answer: A. Leaching
Explanation:
Leaching, often with cyanide, is a common process used for gold extraction from its ores.

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