RBSE Class 6 Science Important Questions Chapter 14 Water

Rajasthan Board  RBSE Class 6 Science Important Questions Chapter 14 Water Important Questions and Answers.

RBSE Class 6 Science Chapter 14 Important Questions Water

Multiple Choice Questions

Question 1. 
The process of conversion of water into vapour by heating is called:
(a) condensation 
(b) melting 
(c) evaporation 
(d) storm
Answer:
(c) evaporation 

 

Question 2. 
The process of conversion of vapour into water by cooling is called:
(a) condensation 
(b) melting 
(c) evaporation 
(d) storm
Answer:
(a) condensation 

Question 3. 
Plants release water vapour into the atmosphere by the process of:
(a) evaporation 
(b) condensation 
(c) precipitation 
(d) transpiration
Answer:
(d) transpiration

Question 4. 
Water circulation between ocean and land is known as:
(a) water cycle 
(b) rain cycle 
(c) drought 
(d) hail
Answer:
(a) water cycle 

Question 5. 
The rise of water levels in rivers, ponds, and lakes leads to:
(a) flood 
(b) drought
(c) water scarcity 
(d) dry lands 
Answer: 
(a) flood 

Fill in the Blanks

Question 1. 
Oceans cover a major part of ...............
Answer:
Earth

Question 2.    
...............is essential to convert water into its vapour.
Answer:
Heating

Question 3. 
Most of the water is available to us as ...............
Answer:
ground-water

Question 4.  
............... is essential for life.
Answer:
Water

Question 5. 
The circulation of water between ocean and land is known as ...............
Answer: 
water cycle

State whether True or False

Question 1. 
The groundwater is not the rainwater.
Answer:
False

Question 2. 
The process of evaporation is opposite to condensation.
Answer:
True

Question 3. 
The amount of usable water on Earth is limited so it needs to be used carefully.
Answer:
True

Question 4. 
We should use as much water as we can use.
Answer:
False

Question 5. 
Rainwater which falls on concrete surface seeps into the ground.
Answer: 
False

Match the followings

Column I	Column II
1. Evaporation	(a) purest form of water
2. Dew	(b) tiny ice-crystal
3. Snow	(c) excessive rain
4. Water cycle	(d) release of water from plants
5. Rainwater	(e) changing water into vapour
6. Flood	(f) forms during winters due to cooling of moist air
7. Drought	(g) vapour into water
8. Condensation	(h) saline water
9. Ocean	(i) conversion of water in various forms
10. Transpiration	(j) scarcity of water

Answer:

Column I	Column II
1. Evaporation	(e) changing water into vapour
2. Dew	(f) forms during winters due to cooling of moist air
3. Snow	(b) tiny ice-crystal
4. Water cycle	(i) conversion of water in various forms
5. Rainwater	(a) purest form of water
6. Flood	(c) excessive rain
7. Drought	(j) scarcity of water
8. Condensation	(g) vapour into water
9. Ocean	(h) saline water
10. Transpiration	(d) release of water from plants

Very Short Answer Type Questions

Question 1. 
List some freshwater bodies. 
Answer: 
Ponds, lakes, rivers, wells, etc.
 
Question 2. 
What is the ultimate source of water?
Answer: 
Rain is the ultimate source of water.

Question 3. 
Mention the name of two processes which are responsible for the cloud formation.
Answer: 
Evaporation and condensation.

Question 4. 
Name two processes by which water vapours enter the air.
Answer: 
Water wapours enter the air through the process of evaporation and transpiration.

Question 5.
Why we rarely notice evaporation from a bucket full of water?
Answer: 
We rarely notice loss of water from a bucket full of water because evaporation of water is a slow process.

Question 6. 
Define floods.
Answer: 
Heavy rivers, ponds and lakes overflow and spread over large areas causing floods.

Question 7. 
In which season, most of the rain occur in our country?
Answer: 
Monsoon season.

Question 8. 
What are the major losses due to flood?
Answer: 
Floods cause extensive damage to crops, domestic animals, property and human life.

Short Answer Type Questions

Question 1. 
How water is supplied to our homes?
Answer: 
The taps in our houses are connected to a water tank. The water tank is filled with water that comes to our houses through the network of pipes from freshwater sources such as lakes, rivers, etc.

Question 2. 
We cannot use seawater for domestic purposes. Why?
Answer: 
The water in the oceans and seas has many salts dissolved in it. Hence, it is not suitable for drinking, cooking and other domestic purposes.

Question 3. 
How is salt obtained?
Answer: 
The sea water is collected and kept for evaporation. When water evaporates from water of seas and oceans, it leaves behind salt. 

Question 4. 
How does evaporation of water take place in shade?
Answer: 
During the daytime, all the air surrounding us gets heated. This warm air provides heat for the evaporation of water in the shade. Thus, evaporation takes place from all open surfaces of water.

Question 5. 
What are the results of shortage of vegetation at some places?
Answer: 
The results of shortage of vegetation at some places are:
(a) The rainwater flows away quickly.
(b) Flowing rainwater also takes the top layer of the soil away with it. It leads to soil erosion.

Question 6. 
Why should we conserve water?
Answer:
Water is the most important substance for preserving life. Water is precious but limited for the use of the ever-increasing population. Hence, it is necessary that we should use water wisely and carefully and not waste it.

Question 7. 
Define rainwater harvesting.
Answer:
In this process, rainwater is harvested by collecting water from surfaces on which rainfalls, and then storing this water for later use. Water is also collected from the roofs of buildings and stored in rainwater tanks.

Long Answer Type Questions

Question 1. 
Mention some uses of water.
Answer: 

1. Water is used in our everyday activities such as drinking, brushing,  bathing, cooking, etc.
2. Water is used in industries for producing almost all the things that we use.
3. Water is needed for the growth of plants.

Question 2.
Explain the role of oceans in supplying the water that we use.
Answer: 
The water in oceans cannot be used as it is saline. It evaporates in the form of water vapour by the heating effect of the Sun. This vapour gets condensed and form clouds. Clouds come on the Earth in the form of rain. Rainwater goes back to ponds, lakes, rivers, etc. Now, water from freshwater sources is supplied to our houses.

Question 3. 
Write a short note on transpiration. 
Answer: 
Plants use water to grow, prepare their food and retain some of it in their different parts. Remaining part of this water is released by the plants into air as water vapour. Hence, loss of water by evaporation through tiny pores of leaves, stems and roots is called transpiration.

Question 4. 
How does rainfall occur?
Answer: 

1. Water evaporates from different water bodies and forms water vapour.
2. At high altitudes, water vapours get cooled and condensed and get converted into tiny droplets of water.
3. Many droplets of water come together to form larger-sized drops of water.
4. Some drops of water become so heavy that they begin to fall.
5. The falling of water drops are called rain.

Question 5. 
Differentiate between evaporation and condensation.
Answer: 
Difference between Evaporation and Condensation

Evaporation	Condensation
1. It is a process through which water is converted into water vapour on heating.	It is a process through which water vapour is converted into water droplets on cooling.
2. The rate of evaporation is high when the temperature is high.	The rate of condensation is more when the temperature is low.

Question 6. 
Discuss how water is recycled in nature.
Answer: 
Water brought back to the surface of the Earth by rain, hail or snow, goes back to oceans. Thus, water from the ocean and surface of the Earth goes into air as vapour; returns as rain, hail or snow and finally goes back to the ocean. The circulation of water in this manner is known as water cycle. This circulation of water between ocean and land is a continuous process. This maintains the supply of water on land and helps in rippling of water in nature.

Question 7. 
How does heavy rainfall affect us?
Answer: 
Heavy rainfall may cause:

1. Rise in the water level of rivers, lakes and ponds, etc. and can cause floods.
2. Floods can damage life and property.
3. Water may accumulate in houses, buildings, etc.
4. The crops, forests, villages, etc. may get submerged in water.
5. Sometimes aquatic animals also die as they get trapped on land areas because they are carried away with flood water.

Question 8. 
Mention some adverse effects of drought.
Answer: 
The continued absence of rainfall leads to drought:

1. It becomes difficult to survive in drought for living beings due to a shortage of water, food and fodder.
2. Dried soil may have a negative impact on agriculture.
3. Groundwater level depletes.
4. Lakes rivers, ponds, etc. dry up.
5. People and animals migrate to another place in search of water.

Question 9. 
Explain the techniques of rainwater harvesting.
Answer: 
Two methods of rainwater harvesting are:
(a) Rooftops rainwater harvesting:
In this method, rainwater from the rooftops is collected in a storage tank through pipes. This water may have soil in it, hence need filtering before it is used instead of collecting rainwater in the tank, the pipes can go directly into a pit in the ground, it will recharge groundwater.

(b) Rainwater harvesting through drains: 
In this method, water is allowed to go into the ground directly from the roadside drains that collect rainwater.

Question 10. 
What are the advantages of rainwater harvesting?
Answer: 
Advantages of rainwater harvesting are:

1. There is an increase in the level of groundwater.
2. The effect of drought is lessened.
3. Water logging of low-lying roads and streets is prevented.
4. Soil and water pollution is reduced.
5. Reduces soil erosion.