{"id":24512,"date":"2021-06-18T13:03:50","date_gmt":"2021-06-18T07:33:50","guid":{"rendered":"https:\/\/mcq-questions.com\/?p=24512"},"modified":"2022-03-02T10:38:18","modified_gmt":"2022-03-02T05:08:18","slug":"ncert-solutions-for-class-7-science-chapter-16","status":"publish","type":"post","link":"https:\/\/mcq-questions.com\/ncert-solutions-for-class-7-science-chapter-16\/","title":{"rendered":"NCERT Solutions for Class 7 Science Chapter 16 Water: A Precious Resource"},"content":{"rendered":"
These NCERT Solutions for Class 7 Science<\/a> Chapter 16 Water: A Precious Resource Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.<\/p>\n Question 1. Question 2. Question 3. Question 4. <\/p>\n Question 5. b. Increasing industries: The number of industries is on the rise ever since the human population began multiplying exponentially. These industries need water for various processes.<\/p>\n c. Lack of water conservation techniques: Rain is the main source of water for both the surface and the underground water bodies. Upon proper conservation, the ground water can be increased. This has not yet been achieved due to lack of implementation of such water conservative techniques.<\/p>\n d. Agricultural activities: Our country depends vastly on its agricultural roots and the land that is used for the cultivation has increased. Hence, water consumption has also increased. Groundwater is exploited as there is an irregularity in the rainfall. This results in the depletion of groundwater.<\/p>\n Question 6. Question 7. Question 8. Question 9. NCERT Extended Learning Activities and Projects<\/span><\/p>\n Question 1. <\/p>\n Question 2. Question 3. Question 4. Question 5. Activity 1<\/span><\/p>\n Objective: To collect information (articles and pictures) on water shortage from the newspapers and magazines. Observation: Forms of Water: in nature, water exists in three forms:<\/p>\n Water Cycle: The water cycle is a natural process that continuously happens on earth. The water cycle maintains the amount of water on the earth. It can be divided into four phases: <\/p>\n Depletion of Water Table: As long as the water drawn from the ground is replenished by seepage of rain water, the water table remains unaffected. The problem starts when we take more water from the ground than is replenished by natural means. Then the water table goes down and it is said to have been depleted.<\/p>\n Reasons for the depletion of water table: <\/p>\n Water Management: It is the continuous matching of water resources with the water requirements of a place. Water management essentially involves activities that identify sources of water, prevent wastage of water, and implement recycling of water. It may also include treatment of water to make it suitable for human consumption. It may include the following exercises:<\/p>\n Rainwater Harvesting: Instead of letting rainwater runoff into the sea, it can b>e used to recharge groundwater. This is known as rainwater harvesting. Rainwater harvesting can be used to raise the water table in arid areas. It can also be used to create water storage areas. Bawris: This is an old method of rainwater storage and recharge. In olden days people built deep step wells into the ground. These deep step wells are called bawris. During rainy season these wells are filled with water. The water is stored in these wells for longer time because they are very deep and the evaporation of water is less. During shortage, people use this water.<\/p>\n Drip irrigation: It can be used by farmers to save water. It is a technique of watering plants by making use of narrow tubing, which delivers water directly at the base of plant. Effects of Water Scarcity on Plants: Plants need water to absorb nutrients from the soil and make their food. Without water, plants would die and greenery would be lost. This, in turn, would mean the end of all life on the earth. Because without plants, there would have no food, oxygen or rainfall. There would also be many other problems.<\/p>\n Every individual should use water judiciously. Overdrawing of underground water should be avoided and efforts should be made to recharge underground water. To avoid wastage of water in the fields, drip irrigation may be adopted for watering the plants. One should also promote afforestation.<\/p>\n Very Short Answer Type Questions<\/span><\/p>\n Question 1. <\/p>\n Question 2. Question 3. Question 4. Question 5. <\/p>\n Question 6. Question 7. Question 8. Question 9. Question 10. Question 11. Question 12. Question 13. <\/p>\n Question 14. Question 15. Short Answer Type Questions<\/span><\/p>\n Question 1. Question 2. Question 3. <\/p>\n Question 4. Question 5. Question 6. Question 7. Question 8. <\/p>\n Question 9. Long Answer Type Questions<\/span><\/p>\n Question 1. Question 2. This cycle is not as straight forward and simple as the statement seems to imply. All of the water that falls on the land does not immediately flow back into the sea. Some of it seeps into the soil and becomes part of the underground reservoir of freshwater. Some of this underground water finds its way to the surface through springs. We bring it back to the surface for our use through wells or tube-wells. Water is also used by terrestrial animals and plants for various life-processes.<\/p>\n <\/p>\n Question 3. Question 4. Picture-Based Questions<\/span><\/p>\n Question 1. <\/p>\n Question 2. These NCERT Solutions for Class 7 Science Chapter 16 Water: A Precious Resource Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams. Water: A Precious Resource NCERT Solutions for Class 7 Science Chapter 16 Class 7 Science Chapter 16 Water: A Precious Resource Textbook Exercise …<\/p>\nWater: A Precious Resource NCERT Solutions for Class 7 Science Chapter 16<\/h2>\n
Class 7 Science Chapter 16 Water: A Precious Resource Textbook Exercise Questions and Answers<\/h3>\n
\nMark \u2018T\u2019 if the statement is true and \u2018F\u2019 if it is false:
\na. The freshwater stored in the ground is much more than that present in the rivers and lakes of the world.
\nb. Water shortage is a problem faced only by people living in rural areas.
\nc. Water from rivers is the only source for irrigation in the fields.
\nd. Rain is the ultimate source of water.
\nAnswer:
\na. T
\nb. F
\nc. F
\nd. T<\/p>\n
\nExplain how groundwater is recharged?
\nAnswer:
\nThe rainwater and water from other sources, such as rivers and ponds, seeps through the soil and fills the empty spaces and cracks deep below the ground. The process of seeping of water into the ground is called infiltration. The groundwater thus gets recharged by this process.<\/p>\n
\nThere are ten tube wells in a lane of fifty houses. What could be the long term impact on the water table?
\nAnswer:
\nTen tube-wells in a lane of fifty houses can lead people to mindlessly exploit the groundwater. This can lead to depletion of the water table in the long run.<\/p>\n
\nYou have been asked to maintain a garden. How will you minimise the use of water?
\nAnswer:
\nDrip irrigation can be implemented to reduce the wastage of water. By this process, water is delivered to the base of the plants directly. Pipes should be checked for leaks. Arrangements should be made for collecting rainwater in small pits. This water can be used later for various purposes.<\/p>\n
\nExplain the factors responsible for the depletion of water table.
\nAnswer:
\nHere are a few factors which are responsible for the depletion of water table:
\na. Increased population: As our population increases, correspondingly the demand for water also increases.<\/p>\n
\nFill in the blanks with the appropriate answers:
\na. People obtain groundwater through ……………….. and ………………..
\nb. Three forms of water are ……………….., ……………….. and ………………..
\nc. The water bearing layer of the earth is ………………..
\nd. The process of water seepage into the ground is called ………………..
\nAnswer:
\na. wells and tube-wells, b. solid, liquid and gas, c. aquifer, d. infiltration<\/p>\n
\nWhich one of the following is not responsible for water shortage?
\na. Rapid growth of industries
\nb. Increasing population
\nc. Heavy rainfall
\nd. Mismanagement of water resources
\nAnswer:
\nc. Heavy rainfall<\/p>\n
\nChoose the correct option. The total water
\na. in the lakes and rivers of the world remains constant.
\nb. under the ground remains constant.
\nc. in the seas and oceans of the world remains constant.
\nd. of the world remains constant,
\nAnswer:
\nd. of the world remains constant.<\/p>\n
\nMake a sketch showing ground-water and water table. Label it.
\nAnswer:
\n<\/p>\n
\nRole play: You are a water detective in your school. You have a team of six members. Survey the campus and make a note of the following.
\na. Total number of taps
\nb. Number of taps leaking
\nc. Amount of water wasted due to leaking
\nd. Reasons of leakage
\ne. Corrective measures taken
\nHint:
\nDo it yourself.<\/p>\n
\nGroundwater pumped out: Try to find out if there are any hand pumps in your neighbourhood. Go to the owner or the users of a few of these and find out the depth at which they struck water. If there are any differences, think of the probable reason. Write a brief report and discuss it in your class. If possible, visit a place where boring is going on to install a hand pump. Watch the process carefully and find out the depth of the water table at that place.
\nHint:
\nThere is a difference in depth of water table in difference places. According to the depth of the water table, the pumps are bored to different, depths at different places.<\/p>\n
\nCatching rainwater-Traditional methods: Form groups of 4 to 5 students in the class and prepare a report on the various traditional ways of water harvesting. If possible, use the following web link: www.rainwaterharvesting.org.
\nHint:
\nDo it yourself.<\/p>\n
\nConservation of water: Carry out a campaign to conserve water at home and in the school. Design posters to remind others of the importance of water resources.
\nHint:
\nDo it yourself.<\/p>\n
\nCreate a Logo: Hold a competition to create a logo or a symbol depicting water scarcity.
\nHint:
\nDo it yourself.<\/p>\n
\nMaterials Required: Old newspapers and magazines, scrap book.
\nProcedure:<\/p>\n\n
\nPreserve water bodies in the country
\n
\nConclusion: The water is very precious for every living being but nowadays there is a shortage of water everywhere around the world.<\/p>\n\n
\ni. Evaporation: It is a process when the water from the earth\u2019s surface gets converted into water vapour due to the heat of the sun. The water vapour then goes into the air.
\nii. Condensation: The water vapour rises up in the atmosphere and gets accumulated above, condenses and forms water droplets. These droplets collect together and form clouds.
\niii. Precipitation: When the volume of droplets increases in the atmosphere, they fall on the earth as rainfall, also called as precipitation. Sometimes it also occurs as snowfall in some areas.
\n
\niv. Collection: As the water falls back on the earth, it travels along the surface and gets accumulated at different places like lakes, rivers, seas, oceans and under the ground. That\u2019s how the amount of water is regulated on the earth.<\/p>\n\n
\nThe depletion of water table is taking place due to some causes. These causes are:<\/p>\n\n
\n
\n<\/p>\n
\n<\/p>\nClass 7 Science Chapter 16 Water: A Precious Resource Additional Important Questions and Answers<\/h3>\n
\nWhich day is celebrated as the world water day?
\nAnswer:
\n22 March is celebrated as the world water day.<\/p>\n
\nWhat is groundwater?
\nAnswer:
\nThe water found below the water table is called groundwater.<\/p>\n
\nWhat is water table?
\nAnswer:
\nThe upper limit of underground water where all the space between the particles of soil and gaps between rocks are filled with water is called water table.<\/p>\n
\nWhat are the three forms of water?
\nAnswer:<\/p>\n\n
\nDefine aquifer.
\nAnswer:
\nThe groundwater stored between the layers of hard rocks below the water table is known as an aquifer.<\/p>\n
\nWhat is infiltration?
\nAnswer:
\nThe process of seeping of water into the ground is called infiltration.<\/p>\n
\nWhy is water cycle important?
\nAnswer:
\nThe water cycle is important because this process provides the earth with the natural, continual water supply that all living things need in order to survive.<\/p>\n
\nWhat is the source of groundwater?
\nAnswer:
\nThe rainwater and water from other sources, such as rivers and ponds, seeps through the soil and fills the empty spaces and cracks deep below the ground.<\/p>\n
\nWhat percentage of earth\u2019s surface is covered with water?
\nAnswer:
\n71%.<\/p>\n
\nWhy do certain regions on the earth become desert?
\nAnswer:
\nCertain regions on the earth become desert because they get very little rain.<\/p>\n
\nName the available water resource on the earth.
\nAnswer:
\nOceans, seas, lakes, rivers, ice, groundwater and moisture in the air.<\/p>\n
\nWhat is water management?
\nAnswer:
\nWater management refers to the activities that ensure the continuous matching of water resources with the water requirements of a place.<\/p>\n
\nWhat do you mean by rainwater harvesting?
\nAnswer:
\nInstead of letting rain water run-off into the sea, it can be used to recharge groundwater. This is known as rainwater harvesting.<\/p>\n
\nHow water in an aquifer can be pumped out?
\nAnswer:
\nWith the help of tube wells or hand pumps.<\/p>\n
\nIn which state can the water be found when it circulates through the water cycle?
\nAnswer:
\nWhen water circulates through the water cycle it can be found in all the three forms, i.e., solid, liquid and gas (vapour).<\/p>\n
\nState various uses of water?
\nAnswer:
\nWater is used for various activities such as agriculture, industries, cooking, cleaning utensils, bathing, washing clothes and most importantly for drinking.<\/p>\n
\nWhy do we need water cycle?
\nAnswer:
\nThe earth is covered by water, however, almost 97% is salt water found in the oceans. We cannot drink salt water or use it for crops because of the salt content. We can remove salt from ocean water but the process is very expensive. Hence, water cycle is required to maintain the flow of fresh usable water on the earth.<\/p>\n
\nWhat do you mean by drip irrigation?
\nAnswer:
\nDrip irrigation is a method through which maximum number of plants can be irrigated with minimum use of water. For this, pipelines are laid throughout the rows of plants. Pipes are pierced at strategic points to release water in droplets. This helps in saving the water which is an important but scarce resource.<\/p>\n
\nWhat is rainwater harvesting?
\nAnswer:
\nCollecting and conserving the rainwater from the rooftops of the buildings is called rainwater harvesting. In this technique water from the rooftops of the houses, industries, etc., is collected. It is used directly or allowed to seep into the soil instead of allowing it to flow down. It helps in raising the water table.<\/p>\n
\nWhat are bawris?
\nAnswer:
\nBawris was the traditional way of collecting rainwater. Bawris were recharged time to time. With time, they fell into discuss and garbage started piling in these reservoirs. Nowadays, the bawris are being revived.<\/p>\n
\nWhat will be the consequences if water is not available to the plants?
\nAnswer:
\nPlants need water to get nutrients from the soil to prepare their food. If water is not available to plants, the green character of the planet shall be lost. This may mean the end of all life, for a world without plants shall mean no food, no oxygen, not enough rain and innumerable other problems.<\/p>\n
\nHow increasing industries are responsible for depletion of water table?
\nAnswer:
\nWater is used by all the industries. Almost everything that we use needs water somewhere in its production process. The number of industries is increasing continuously. Water used by most of the industries is drawn from the ground.<\/p>\n
\nWhy is distribution of water uneven in our country?
\nAnswer:
\nIndia is a vast country and the rainfall is not the same everywhere. Some regions have excessive rains while some others have very little rainfall. Excessive rains cause floods, whereas the absence of rains results in droughts. Therefore, some regions in our country may have floods while others may suffer from droughts at the same time.<\/p>\n
\nDefine water management.
\nAnswer:
\nPreventing the wastage of precious water is called water management. A couple of techniques can be employed to save precious water.<\/p>\n\n
\nHow is increasing population responsible for depletion of water table?
\nAnswer:
\nIncreasing population creates demand for construction of houses, shops, offices, roads and pavements. This decreases the open areas like parks and playgrounds. This, in turn, decreases the seepage of rainwater into the ground. Moreover, a huge amount of water is required for construction work. Often, groundwater is used for this purpose. So, on one hand we are consuming more groundwater and on the other hand we are allowing lesser water to seep into the ground. This results in the depletion of water table.<\/p>\n
\nWhat is meant by the water cycle? How water cycles in the nature? Why this cycle is not as straight forward and simple as we discuss in the definition?
\nAnswer:
\nThe whole process in which water evaporates and falls back on the land as rain and later flows back into the sea via rivers is known as the water cycle. It is the circulation of water between the atmosphere and the surface water.
\n
\nWater evaporates continuously from the surface of seas, rivers, lakes, oceans and vegetation on land into the atmosphere due to the heat of the sun. Water vapours, being lighter, rise upwards and join clouds in the sky. The clouds are carried in the air through long distances. When cooled sufficiently, water vapours condense into water droplets which come down as rain, snow or hail. The rain water finds its way back into the rivers and sea thereby completing the water cycle.<\/p>\n
\nDiscuss some of the steps involved in the conservation of water.
\nAnswer:
\nThe steps involved in the conservation of water are:<\/p>\n\n
\nWater is very precious for all living organisms. What will happen in future, if we do not save water now?
\nAnswer:
\nWater is needed for various life activities. If we continue the misuse and wastage of water and do not conserve it, the life on the earth will get affected. This may lead to consequences such as:<\/p>\n\n
\na. Observe the picture shown below and identify it.
\n
\nb. Identify all the processes numbered 1-7.
\nAnswer:
\na. It shows water cycle.
\nb.<\/p>\n\n
\nObserve the given picture and identify it. What is the importance of this process?
\n
\nAnswer:
\nThe given picture shows the drip irrigation. It is an allocation technique used by farmers to water their fields. In this, water is allowed to slowly drip into the plants so that the water directly gets into the roots of the plants. This minimises evaporation, saves water and allows the nutrients to reach the plants easily. Narrow tubes are used to make water reach the roots of the plants in drip irrigation.<\/p>\nNCERT Solutions for Class 7 Science<\/strong><\/h4>\n
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