Water Resources – important questions for Boards 2027

CBSE Class 10 Social Science

1. MCQ · 1 mark

   Which statement correctly describes a dam and its spillway or weir? Choose the correct option. (A) A dam is a barrier across flowing water; a spillway or weir allows water to pass over or through it. (B) A dam is a pipe used only to carry drinking water; a spillway prevents all water flow. (C) A dam is a field-storage tank; a spillway is a type of crop. (D) A dam is a river’s floodplain; a spillway is a forest channel.

   Answer

   (A) A dam is a barrier across flowing water; a spillway or weir allows water to pass over or through it — Most dams have a section called a spillway or weir over which or through which it is intended that water will flow.

2. SA · 2 marks

   Give one example each of how the Bhakra–Nangal and Hirakud projects combine different uses of water.

   Answer

   In the Sutluj-Beas river basin, the Bhakra–Nangal project water is being used both for hydel power production and irrigation. The Hirakud project in the Mahanadi basin integrates conservation of water with flood control.

3. LA · 4 marks

   Dams were traditionally built to store water for irrigation, while modern dams serve several additional purposes. Explain this change and identify four purposes served by modern dams. (4 marks)

   Answer

   Dams have changed from irrigation structures into multi-purpose projects integrating several uses of impounded water. 1. Traditionally, dams impounded rivers and rainwater for later use in irrigating agricultural fields, particularly when crops needed water. 2. Modern dams generate electricity through hydel power production, supporting energy needs alongside water storage. 3. Modern dams supply water for domestic and industrial uses, serving households and economic activities. 4. Dams also help control floods and provide water for recreation, inland navigation and fish breeding. The Hirakud project in the Mahanadi basin integrates water conservation with flood control. Modern dams therefore serve several connected purposes beyond the traditional storage of water for irrigation.

4. LA · 5 marks

   Describe the aims of the Pradhan Mantri Krishi Sinchayee Yojana and the purpose and state coverage of the Sardar Sarovar Project. How can an upstream water diversion create an interstate dispute?

   Answer

   The Pradhan Mantri Krishi Sinchayee Yojana promotes improved irrigation and sustainable water conservation, while the Sardar Sarovar Project supplies water across several states. 1. The Pradhan Mantri Krishi Sinchayee Yojana aims to increase water availability in both duration and extent and improve irrigation. 2. The scheme also promotes water-saving technologies under the principle of “per drop more crop” and introduces sustainable water conservation practices. 3. Built over the Narmada River in Gujarat, the Sardar Sarovar Project covers Gujarat, Madhya Pradesh, Maharashtra and Rajasthan. It is intended to meet water requirements in drought-prone and desert areas, including providing irrigation to 18.45 lakh hectares in Rajasthan. 4. An upstream diversion can reduce the water flowing downstream. The proposed diversion at Koyna by Maharashtra for a multipurpose project led Karnataka and Andhra Pradesh to object because reduced downstream flow could harm agriculture and industry. These examples show why water projects require attention to both regional needs and downstream effects.

5. VSA · 1 mark

   Name the three dam types classified by structure and materials, and state the three height categories of dams.

   Answer

   Dams are classified as timber dams, embankment dams or masonry dams; they are categorised as low dams, medium height dams and high dams.

6. SA · 2 marks

   State two environmental or health impacts of dams described in the textbook, apart from their effects on river habitats.

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7. LA · 4 marks

   Explain why multipurpose projects were promoted after Independence as part of national development. Include Nehru’s description of dams as the ‘temples of modern India’. (4 marks)

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8. LA · 5 marks

   Explain why the fact that Earth’s surface is covered with water does not mean that usable water is plentiful. Discuss why conserving the available water is important. (5 marks)

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9. MCQ · 1 mark

   Which effect of dams can obstruct aquatic animals’ migration and spawning? Choose the correct option. (A) Fragmentation of rivers by dams. (B) Increased movement of sediment downstream. (C) Removal of all reservoirs. (D) Unrestricted passage between river stretches.

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10. SA · 2 marks

    The textbook notes that much of Earth’s surface is covered with water, but only a limited share is available for human use. Explain why this distinction matters when considering water scarcity.

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