About Class 7 Science NCERT Exemplar Solutions Chapter 16
Multiple Choice Questions
1. Which of the following does not show water shortage?
(a) Taps running dry.
(b) Long queues for getting water.
(c) Marches and protests for demand of water.
(d) A family gets three buckets of water per person per day.
Ans: The correct answer is option (d), a family getting three buckets of water per person per day does not show water shortage.
2. Seas and oceans are full of water on earth. However, a very small percentage of water present on earth is available for us. This percentage is roughly
(a) 0.006%.
(b) 0.06%.
(c) 0.6%.
(d) 6%.
Ans: The correct answer is option (a), 0.006%. The total amount of freshwater available for use is about 0.006% of the total water present on earth as about 97.4% of the total water on earth is in seas and ocean whereas 2% water is present in the form of glaciers and in polar ice caps.
3. Which of the following are not the liquid forms of water?
(i) Snow
(ii) Lake water
(iii) River water
(iv) Water vapour
(v) Ice
Choose the correct combination from the options below.
(a) (i), (iv) and (v)
(b) (i) and (ii)
(c) (ii) and (iii)
(d) (iv) only
Ans: The correct answer is option (a) (i), (iv) and (v). Water vapour is a gaseous form of water, whereas snow and ice are solid forms of water.
4. A man digging the ground near a water body found that the soil was moist. As he kept digging deeper and deeper he reached a level where all the spaces between particles of soil and gaps between rocks were filled with water. The upper limit of this layer is called
(a) Water level
(b) Water table
(c) Ground water
(d) Water limit
Ans: The correct answer is option (b), water table.
5. Which of the following is a way to use water economically?
(a) Construction of bawris
(b) Rainwater harvesting
(c) Drip irrigation
(d) Infiltration
Ans: The correct answer is option (c), Drip irrigation. Drip irrigation is a technique used for watering plants by using narrow tubes directly at the base of a plant near the root.
6. On which of the following day is World Water Day observed?
(a) 22 March
(b) 14 November
(c) 2 October
(d) 21 December
Ans: The correct answer is option (a), 22 March.
7. The amount of water recommended by the United Nations for drinking, washing, cooking and maintaining proper hygiene per person per day is a minimum of
(a) 5 litres
(b) 15 litres
(c) 30 litres
(d) 50 litres
Ans: The correct answer is option (d), 50 litres.
8. “Every Drop Counts” is a slogan related to
(a) Counting of drops of any liquid.
(b) Counting of water drops.
(c) Importance of water.
(d) Importance of counting.
Ans: The correct answer is option (c), Importance of water.
9. Water cycle does not involve which of the following?
(a) Evaporation
(b) Condensation
(c) Formation of clouds
(d) Rainwater harvesting
Ans: The correct answer is option (d), Rainwater harvesting. Rainwater harvesting recharges and conserves groundwater for future use.
10. Which of the following inhibits the seepage of rainwater into ground?
(a) A Pucca floor
(b) Playground
(c) Grass lawn
(d) Forest land
Ans: The correct answer is option (a), A pucca floor. In the case of pucca flooring and concrete floors, water seepage is not possible.
Very Short Answer Questions
11. State whether the following statements are True or False. If false, write the correct statement.
(a) Water vapour is the gaseous form of water.
Ans: The given statement is true.
(b) Ice is solid whereas snow is the semi-solid form of water.
Ans: The given statement is False. Snow is a solid form of water as well.
(c) Ocean water cannot be used for domestic purposes.
Ans: The given statement is true.
(d) Rapid growth of industries is one of the causes for water shortage.
Ans: The given statement is true.
12. Some definitions are given below which can be corrected by changing one word. Correct them.
(a) Aquifer is groundwater stored between layers of hard rock above the water table.
Ans: Aquifer is groundwater stored between layers of hard rock below the water table.
(b) The process of evaporation of water in the ground is called infiltration.
Ans: The process of seeping of water in the ground is called infiltration.
(c) The evaporation of water from oceans and its arrival back into oceans is called the vapour cycle.
Ans: The evaporation of water from oceans and its arrival back into oceans is called the water cycle.
13. What is the source of water in each of the following?
(a) Wells
Ans: In wells, ground water is the source of water.
(b) Ground
Ans: In the ground, rain is the source of water.
(c) Atmosphere
Ans: In the atmosphere, the source of water is evaporation.
14. State whether the following statements are True or False. If false, give the correct statement.
(a) The process of seeping water into ground is called filtration.
Ans: The given statement is False. It is called infiltration.
(b) 51% of the earth’s surface is covered with water.
Ans: The given statement is False. The surface of earth is covered with 70% water.
(c) Year 2003 was observed as the International Year of Freshwater.
Ans: The given statement is true.
(d) Snow and ice both are solid forms of water.
Ans: The given statement is true.
Short Answer Questions
15. Fill in the blanks in the given passage.
The rainwater and __________ from other sources such as rivers and ponds seeps
through the __________ and fills the empty spaces and cracks deep below the ground.
The process of seeping of water into the ground is called __________.
Ans: The 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.
16. Fill in the blanks and complete the story selecting words from the box given here.
Rajasthan is a _________ and dry place. The challenge of natural _______ of water was
met by a successful experiment. A band of social ________ had transformed a
_________ area into a green place. They have revived five dried-up ________ by
constructing water ___________ structures.
Ans: Rajasthan is a hot and dry place. The challenge of natural scarcity of water was met by a successful experiment. A band of social workers had transformed a dry area into a green place. They have revived five dried-up rivers by constructing water harvesting structures.
17. Place the following statements in a proper order to form a meaningful paragraph.
(a) Which in turn decreases the seepage of rain water into the ground.
(b) This decreases the open areas like park, and playgrounds.
(c) Increasing population create demand for construction of houses, shops, offices, roads and pavements.
(d) This results in depletion of water table and creates scarcity of more water.
Ans: The correct sequence is-
(c) Increasing population creates demand for construction of houses, shops, offices, roads and pavements.
(b) This decreases the open areas like park, and playgrounds.
(a) Which in turn decreases the seepage of rain water into the ground.
(d) This results in depletion of water table and creates scarcity of more water.
18. How can you observe the three forms of water in (i) nature and (ii) At home?
Ans: Three forms of water in
i) Nature-
Snow – solid form
Water – liquid form
Vapours – Gaseous form
ii) At home-
Ice – solid form
Water – liquid form
Steam – gaseous form.
19. Complete the given table
Ans: The complete table is given below
20. Match Column I with Column II
Ans: The match is
21. A list of jumbled words is given here. Write the correct form of each word.
a) WASHFERRET
Ans: Freshwater
b) CHARREGE
Ans: Recharge
c) QUIFERA
Ans: Aquifer
d) WOSN
Ans: Snow
22. From where do the following usually get water? In which form is water present in them?
a) Clouds
b) Plants
c) Mountain tops
d) Aquifer
e) Animals
Ans: The following get their water from these sources
Long Answer Questions
23. Complete the following chart by writing appropriate words in the boxes marked (a) to (e).
Ans: The missing words are
a) Solid
b) Gas
c) Lake water
d) Underground water
e) Ice
24. What is groundwater? What are the sources of water which are fed by groundwater?
Ans: The water found beneath in the gaps and spaces in soil, sand, and rock is known as groundwater. It is stored in and slowly travels through aquifers, which are natural formations of soil, sand, and rocks. The availability and level of ground water varies depending on where you live. Wetlands, rivers, and lakes are all sources of groundwater, which are also nourished by it.
25. Water is very precious for all living beings. What will happen in future if we do not save water now?
Ans: We shall suffer greatly if there is no water in the future, as water is said to be the elixir of life. Every organism requires it in order to survive and live a normal existence.
i. Our personal hygiene will be disrupted, such as brushing our teeth, washing our clothes, and bathing.
ii. Construction will be halted due to the large volume of water required.
iii. Farmers will be affected as well. Water is extremely important in agriculture. The crops will become parched.
iv. There will be a drought situation.
Water - A Precious Resource, Class 7 Science Chapter 16
This chapter intends to spread Environmental awareness about the dangerous mismanagement of water resources, which is giving rise to water scarcity. Water is precious for humanity’s survival, we need to conserve it for the future generation.
FAQs on NCERT Exemplar for Class 7 Science Solutions Chapter 16 Water : A Precious Resource
1. Why is Water a precious resource?
The whole NCERT exemplar for Class 7 Science Chapter 16 (Water - A precious resource), has emphasized enough the grave importance of water. Water is one of the most important natural resources for the survival of humanity on the planet earth. Not only humanity but water is required by every living organism to survive. Water is the basis of the existence of all life on earth. Without it plants will wilt, animals will die to the point where no life will exist.
2. List two ways why Humans are responsible for Water Depletion?
Humans are a major factor in Water Depletion on the Earth. These are two major ways human contributes to water depletion:
Agricultural activities: Agriculture is the biggest reason for the constant reduction in the available groundwater. Due to irregular rainfall, farmers have no other option but to depend on Groundwater. Hence the reduction.
Increasing industries: Human population is increasing, so the increase in the number of industries to fulfil the demands of the increasing population. And these industries directly or indirectly require water to run. Hence increasing the burden on current water resources.
3. How does Groundwater get recharged?
Groundwater is recharged through the process of Infiltration. When rain falls, the water from various sources (River, lakes and ponds), with rainwater seeps into the ground, via soil and cracks in the ground. Infiltration is the name given to this process of water getting into the ground. But nowadays, Groundwater available is reducing day by day, due to the over-exploitation of it, done by human beings. Humans are consuming groundwater more than nature can recharge it. Hence, steps are needed to preserve it.
4. Why is Water Day Celebrated each Year?
The World Water Day is held each year on the date of 22 march. This day is celebrated to spread environmental awareness about the concerning trends of exploitation of water resources. Every year, water day is celebrated to attract the attention of people towards these trends, to educate the people about the importance of water conservation and about the dangerous consequences of not preserving water. The United Nations is the organization, which marks 22 March as World Water Day.
5. What is Water Table?
The Water Table is the uppermost limit of the layer, under which the space between particles of soil and gaps between the rocks is completely saturated with water. Water found below the water table is known as Ground Water.
The levels of the water table fluctuate a lot, depending upon the pace and time of measurements taken. But in general, the water table is continuously decreasing every day, due to the over usage of groundwater, throughout the world.
