CBSE Class 7 Science Water A Precious Resource VBQs

Choose One Option For The Follwing.

Question. The Punjab preservation of subsoil water act was passed in the year:
a) 2009
b) 2010
c) 200l
d) 2015
Answer : A

Question. We should not keep taps running while:
a) Brushing
b) Shaving
c) Bathing
d) All of these
Answer : D

Question. The world water day is celebrated every year on:
a) 22 April
b) 24 March
c) 22 March
d) 22 May
Answer : C

Question. Which of the following is responsible for depletion of ground water?
a) Increasing population
b) Increasing industries
c) Deforestation
d) All of these
Answer : D

Question. Oceans and sea cover about ………. of the earth surface.
a) 75%
b) 71%
c) 97%
d) 29%
Answer : C

Fill In The Blanks :

(i). The water we drink is in liquid state.

(ii). The process of seeping of water into the soil is called infiltration.

(iii). The upper level of ground water is called water-table.

(iv). Water management means dealing with water in the best possible ways.

(v). A farmer can use water economically in the field, by drip irrigation.

Write True Or False.

Question. About 97% of total water present on the earth is fresh water.
Answer : False

Question. Turn on taps while brushing.
Answer : False

Question. Repair leaking taps and pipes at the earliest.
Answer : True

Question. Water cycle helps in maintaining water on the earth.
Answer : True

Question. We are quickly moving towards global water crisis.
Answer : True

Match The Column:-

Answer : (i) - (e) (ii) - (a), (iii) - (b), (iv) - (c), (v) - (d),

 

ACTIVITY- 

Question. Should we check the wastage of water and why?
Answer : Yes, because there are very limited sources of fresh water on earth.

Question. Name three activities by which water is being wasted?
Answer : Cleaning of houses and animals, washing car and opening tap during brushing our teeth.

ACTIVITY- 

Question. ________ is the process by which water is converted from its gaseous state to a liquid state.
Answer : Condensation.

Question. ________ is the process by which water is converted from its liquid state to a gaseous state.
Answer : Evaporation. 

ACTIVITY- 

Question. Which beaker represents the surface water?
Answer : Water remained in beaker ‘A’.

Question. Which beaker represents the underground water?
Answer : Beaker ‘C’.

Very Short Answer Type Questions.

Question. Name the three states of water.
Answer : Solid, liquid and gas.

Question. Why is sea and ocean water not fit for drinking?
Answer : Because sea and ocean water have large amounts of dissolved salts.

Question. Define aquifers.
Answer : Groundwater present between the layers of hard rocks below the water table is known as aquifer.

Question. What do you mean by ground water?
Answer : Groundwater is the water present below the earth’s surface in the cracks and spaces in soil, sand and rocks.

Question. How is groundwater recharged?
Answer : Rainwater and water from other sources such as rivers and ponds seeps into the soil due to gravity until the empty spaces and cracks deep below the ground are filled with water. This process is known as infiltration. Hence groundwater gets recharged.

Short Answer Type Questions.

Question. How will you minimize the use of water to maintain a garden?
Answer : We should water the garden early in the morning and late afternoon taking shorter showers. We should reuse the waste water of cleaning purposes in watering the plants.

Question. Why do plants wilt and finally dry up if they do not get water for some days?
Answer : Plants use water in photosynthesis. Also plants lose some water by transpiration. So if plants do not get water for some days, they wilt and finally dry up.

Question. Enlist some activities by which water is being wasted by people.
Answer : Water is being wasted by people in cleaning of houses and animals, washing car and opening taps during brushing teeth.

Question. How is water important to us?
Answer : (1). About 70% of human body consists of water.
(2). Water helps to control our body temperature.
(3). Water helps to excrete waste products from our body.
(4). Water is important for growth of plants.
(5). Water maintains the temperature of earth.
(6). Water is essential for our many daily life activities.

Question. How increase in human population is leading to depletion of water table?
Answer : As the human population increase, consumption of water by them increases for their daily activities. Often groundwater is used for construction of houses, shops and roads etc. Hence groundwater is used at high rate, but the area for seepage of water decreases. So water table is depleted by growth in human population.

Long Answer Type Questions.

Question. What steps will you take to save water?
Answer : (1) Make efforts to stop the leakage of water from taps and water pipes.
(2) Turn off taps while brushing or shaving.
(3) Mop the floor instead of washing, reuse the waste water to water the plants.
(4) Water the garden early in the morning and late afternoon taking shorter showers.
(5) Wash vegetables and fruits in big containers and use this water for cleaning or watering the plants.