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Social Science (087) — AI-generated practice question

AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.

Q1. [1] straightforward initial-understanding
Which one of the following correctly explains how bauxite is formed? (A) It crystallises from molten magma forced into cracks in igneous rocks. (B) It is deposited in horizontal layers due to evaporation in arid regions. (C) It is left behind as a residual mass after surface rocks decompose and soluble material is washed away. (D) It accumulates in river and valley sands as a placer deposit.
  1. A It crystallises from molten magma forced into cracks in igneous rocks.
  2. B It is deposited in horizontal layers due to evaporation in arid regions.
  3. C It is left behind as a residual mass after surface rocks decompose and soluble material is washed away.
  4. D It accumulates in river and valley sands as a placer deposit.
Generated by claude-sonnet-4-6 · 2026-06-26 13:30 · grounding rag
Model Answer

(C) It is left behind as a residual mass after surface rocks decompose and soluble material is washed away.

Explanation

The textbook (Chapter 5, Mode of Occurrence of Minerals) explicitly states: "Another mode of formation involves the decomposition of surface rocks, and the removal of soluble constituents, leaving a residual mass of weathered material containing ores. Bauxite is formed this way." Options A, B, and D describe veins/lodes, evaporite sedimentary minerals, and placer deposits respectively — none of which apply to bauxite.

Previous-year CBSE Grade 10 board exam questions, organised by subject and chapter, each with a model answer — free to read and print.