Dear students
As it is aready informed you that Department of Youth Affairs is organizing NATIONAL YOUTH FESTIVAL 2021. The information about YUVANA is already shared among you all and now the organization is celebrating NATIONAL YOUTH DAY in virtual mode on 12 JANUARY 2021 in the Central Hall of Parliament. Honourable PM will be gracing the celebrations.
You all are requested to join the programme by the given webcast link https://webcast.gov.in/parliament/
Answer 1:
(d) According to the recommendation of United Nations (UN) minimum 50 litres of water per person per day should be provided.
Question 1:
Which of the following does not show water shortage? (1)
(a) Taps running dry
CHAPTER16 : WATER : A PRECIOUS RESOURCE
I Fill in the blanks:
1. The process of seeping of water into the ground is called ---------------
2. Water in the aquifers can be usually pumped out with help of __________ or _______________.
3. _____________ was the traditional way of collecting water.
4. Shortage of ___________ has become a matter of concern.
II Write True or False:
1. Celebration of water day is to attract the attention of everybody towards the importance of conserving water.
2. 76% of the earth’s surface is covered with water.
3. Glaciers are the solid form of water.
4. Excessive rains cause droughts whereas the absence of rains results in floods.
III Define : 1. Drip irrigation.
IV Diagram: Ground water and Water table.
SOLUTIONS
I (i) infiltration (ii) tubewells and handpumps (iii) Bawris (iv) water
II (i) T (ii) F (iii) T (iv) F
III. It is a technique of watering plants by making use of narrow tubings which deliver water directly at the base of the plant.
IV.
Q.1. Mark ‘T’ if the statement is true and ‘F’ if it is false:
(a) The freshwater stored in the ground is much more than that present in the rivers and lakes of the world. (T/F)
(b) Water shortage is a problem faced only by people living in rural areas. (T/F)
(c) Water from rivers is the only source for irrigation in the fields. (T/F)
(d) Rain is the ultimate source of water. (T/F)
Ans. (a) T (b) F (c) F (d) T
Q.2. Explain how groundwater is recharged.
Ans. The groundwater gets recharged through the process of infiltration. Infiltration means seeping of water from rivers and lakes into the empty spaces and cracks deep below the ground.
Q.3.There are ten tubewells in a lane of fifty houses. What could be the long-term impact on the water table?
Ans.If ten tubewells in a lane of fifty houses,the underground water will get used for daily domestic purposes will not effect the water table. This result in depletion of groundwater level and water table will get down.
Q.4.You have been asked to maintain a garden. How will you minimise the use of water?
Ans.To minimise the wastage of water we will use the drip irrigation which throws the water at the base of plants. We will check the leakages in the water pipes and arrange small pits for rainwater harvesting. The collected rainwater will be used later.
Q.5.Explain the factors responsible for the depletion of water table.
Ans.Various factors responsible for the depletion of water table are:
(i) Increased population: Demand of water has been increased by the increased population. As the number of humans increase, the consumption of water also increases.
(ii) Industrialization: All industries need water. As the number of human population increase, the number of industries are also increased which definitely increases the consumption of water.
(iii) Lack of water conservation techniques: Main source of water on earth and for the underground water is rain. The water of the rain, if conserved can increase the ground water level. But this is not done due to lack of water conservative techniques.
(iv) Agricultural activities: India is a country which depends on agriculture. The land used for cultivation has increased. So, the consumption of water for agriculture has increased. Irregular rainfall has increased the consumption of groundwater. This has increased the depletion of groundwater.
Q.6.Fill in the blanks with the appropriate answers: .
(a) People obtain groundwater through and .
(b) Three forms of water are solid, and .
(c) The water bearing layer of the earth is .
(d) The process of water seepage into the ground is called .
Ans.(a) wells, hand pumps
(b) liquid, gas
(c) aquifer
(d) infiltration
Q.7.Which one of the following is not responsible for water shortage?
(i) Rapid growth of industries
(ii) Increasing population
(iii) Heavy rainfall
(iv) Mismanagement of water resources
Ans.(iii) heavy rainfall
Q.8.Choose the correct option. The total water
(i) in the lakes and rivers of the world remains constant.
(ii) under the ground remains constant.
(iii) in the seas’and oceans of the world remains constant.
(iv) of the world remains constant.
Ans.(iv) of the world remains constant.
Q.9.Make a sketch showing groundwater and water table. Label it.
Multiple Choice Questions:
1. (a) always a straight line
2. (a) Plane mirror
3. (a) virtual and erect
4. (c) plane mirror and convex mirror
5. (a) Concave mirror only
6. (b) 1 m
7. (b) concave mirror or convex lens
8. (b) only a concave mirror
9. (c) both convex mirror and convex lens
10. (b) concave lens provided the image is smaller than object.
Match the following:
| Column A | Column B |
| (i) Concave lens | (g) Thinner in the middle |
| (ii) Always virtual image | (h) Concave lens |
| (iii) Changing position of image | (a) Lateral inversion |
| (iv) Wax paper | (f) Translucent |
| (v) Image obtained on screen | (e) Real image |
| (vi) Convex mirror | (b) Reflecting surface is bulged out |
| (vii) Used by dentists | (c) Concave mirror |
| (viii) White light composed | (d) Seven colours |
Fill in the blanks:
1. irregular
2. normal,plane
3. reflection
4. lateral inversion
5. concave
6. plane
7. convex
8. concave
Choose the true and false statements from the following:
1. True
2. True
3. True
4. False
5. False
6. False
7. True
