6th Std Science Lesson Wise Questions in English – Part 2
6th Science Lesson 14 Questions in English
14] Water
1. By which of these the temperature of earth is regulated?
a) Atmosphere
b) Sun
c) Water
d) Revolution
Explanation
The Important basic substance of earth is water. It is used to regulate the temperature of earth and the temperature of living organisms.
2. In how many natural forms water is available in earth?
a) 1
b) 2
c) 3
d) 5
Explanation
Water is available in nature in three forms namely solid, liquid and vapor. Ice bergs and ice caps in solid and oceans, sea, lake and rivers are liquid forms of water. It is found in air as gaseous form.
3. Match the distribution of fresh water in various forms.
1. Glaciers A. 0.3%
2. Surface water B. 30.1%
3. Ground water C. 68.7%
a) CAB
b) BAC
c) ABC
d) ACB
Explanation
Water is available in two forms Salty water and Fresh water. Fresh water is used for daily purpose. Totally 3% of available water in earth is fresh water. Fresh water is available in various sources like glaciers, Ground water and Surface water and other sources.
4. State the correct statements given below
i) Saline water is suitable for drinking.
ii) It has large amount of dissolved solids.
a) i only
b) ii only
c) i and ii only
d) None of the above
Explanation
Ocean and sea water are dissolved with huge amount of salts and minerals. This is called as saline water which is not suitable for human consumption.
5. Define the qualities of water.
a) Transparent
b) Tasteless
c) Odorless
d) All the above
Explanation
Water is chemical substance with two hydrogen atom and one oxygen atom. Basically water is transparent, tasteless and odorless substance. The physical composition of water changes from place to place.
6. How many categories of water are classified based on its salinity?
a) 3
b) 5
c) 4
d) 2
Explanation
The amount of salt in water is termed as salinity. Based on its salinity water is classified into three main categories such as freshwater, brackish water and sea water.
7. Which of these salts is not present in the Ocean water?
a) Calcium chloride
b) Magnesium chloride
c) Ammonium chloride
d) Sodium chloride
Explanation
Ocean water is composed of many substances. The salts include sodium chloride, magnesium chloride and calcium chloride.
8. What is the freezing temperature of water at normal pressure?
a) 0 oC
b) 273 o C
c) -273 o C
d) 100 o C
Explanation
Water freezes at 0o Celsius at normal pressure. The boiling point of water is 100 deg Celsius.
9. Which of these substances may dissolve in the water?
a) Chalk powder
b) Charcoal
c) Copper sulphate
d) Sand
Explanation
The Common salt and copper sulphate dissolve in water and contribute their properties like color and other properties to water but sand, chalk powder and charcoal powder do not dissolve in water.
10. What is the other name of water cycle?
a) Renewal Cycle
b) Hydrological cycle
c) Purity cycle
d) Neutral cycle
Explanation
Water cycle is a continuous process which involves three major steps. It is a natural process by which water gets renewed and the other name of water cycle is Hydrological cycle.
11. Match
Classification Amount of salt
i) Fresh water A. upto 3%
ii) Brackish water B. > 3%
iii) Sea water C. 0.05% to 1%
a) CAB
b) BCA
c) ABC
d) CBA
Explanation
The amount of salt in water is termed as salinity. Based on salinity water is classified into three main categories as Fresh water, Brackish water and Sea water.
Fresh water contains 0.05% to 1% of salt. Brackish water contains upto 3% of salt and seawater contains more than 3% of salt.
12. Assertion (A): Salinity is defined as the amount of salt present in the water.
Reasoning(R): The physical composition of water remains the same in all places.
a) Both A and R is True and R is the correct explanation of A.
b) Both A and R is True but R is not the correct explanation of A.
c) A is True but R is False.
d) Both A and R is False.
Explanation
The physical composition of water changes from place to place. It can be clear or cloudy, oxygenated or not very oxygenated and it can be fresh or salty. The amount of salt in water is termed as salinity.
13. We can obtain surface water through _____ and _____.
a) Ponds and lake
b) Tanks and Tube wells
c) Taps and Rain water
d) Wells and springs
Explanation
Water obtained from ponds, rivers, wells are classified as Fresh Water which is used for human consumption. These are naturally available as Glaciers, Ground water and Surface water.
14. Rain water can be used for human consumption.
a) Yes, it can be used after appropriate method of filtering techniques.
b) No, it contains more chlorides which make it unusable for human consumption.
c) No, it can’t be used as it contains more salt.
d) None of the above
Explanation
Rain water is considered as the purest form of water. But it contains some impurities and particles present in atmosphere. These supplies may need to be filtered to ensure it for human consumption.
15. What is the source of energy for the water cycle?
a) Rain
b) Moon
c) Atmosphere
d) Sun
Explanation
The water on earth evaporates into atmosphere due to the heat of Sun. These Vapors forms clouds by which water reaches earth by rain or snow.
16. Most of the earth fresh water is available from?
a) Rivers
b) Oceans
c) Springs
d) Glaciers and ice caps
Explanation
The Total fresh water of earth is distributed among various forms like Glaciers, Ground water, Surface water. In that 68.7% of total fresh water is available from polar ice caps and glaciers.
17. How many stages are involved in Water cycle?
a) 2
b) 1
c) 4
d) 3
Explanation
Water cycle is a continuous process. It involves three stages- Evaporation, Condensation and Precipitation.
18. What is the process of loss of water from aerial parts of a plant in vapor form?
a) Transpiration
b) Ionization
c) Dissociation
d) Hydrogenation
Explanation
Transpiration is the process of loss of water from the aerial parts of plants in vapor form. Water evaporates from Lakes, rivers, Rain water and also from polar ice caps.
19. How many types of Natural sources of fresh water are available?
a) 2
b) 1
c) 3
d) 5
Explanation
Three types of natural sources of fresh water are available on earth. They are from Surface water, frozen water and Ground water.
20. Which is not categorized as a surface water source?
a) Lakes
b) Clouds
c) Streams
d) River
Explanation
Water present on the surface of the earth such as river, lake, ponds, streams or fresh water wetland is called surface water.
21. How much percentage of fresh water is available in frozen state?
a) 30.3%
b) 56%
c) 68.7%
d) 43%
Explanation
Water present in frozen form as polar ice-caps and glaciers are called as frozen water. About 68.7% of the total available fresh water is in frozen state.
22. Water levels in the reservoir are measured in _________
a) Liter
b) Gallon
c) TMC /feet
d) Milliliters
Explanation
Water levels in reservoirs are measured in TMC/feet. Water released from dams is measured in cusec (cubic feet/sec).
23. Gallon is used as a measure the ____ of liquids.
a) Capacity
b) Volume
c) Surface tension
d) Melting point
Explanation
Water is measured in liter and milliliter. Gallon is also a measure of volume of liquids. 1Gallon = 3.785 liter.
24. Assertion (A): During winter season Aquatic animals under the ice layer is alive.
Reasoning (R): Floating layer of ice acts as a protective coat.
a) Both A and R is true and R is the correct explanation of A.
b) Both A and R is true and R is not the correct explanation of A.
c) A is false but R is true
d) Both A and R is false.
Explanation
During winter season water in lakes and ponds in cold countries will be frozen and a solid layer of ice is formed on the surface of water. This layer does not permit heat to escape from water which is the reason for the existence of aquatic animals under the ice layer.
25. What are the reasons for the water scarcity?
a) Water availability on earth is low.
b) Because of monsoon changes Rain water is reduced.
c) Ocean evaporation level is increasing due to global warming.
d) Useful water for human and plants is decreasing day by day.
Explanation
The Total quantity of water available in earth is not changed. But the useful water which is essential for mankind and plants is decreasing day by day. This is known as water scarcity.
26. Water scarcity is prevented by ____ of water.
a) Conservation
b) Consumption
c) Alternate usage
d) Prevention
Explanation
The only method of preventing water scarcity is Conservation of water. Or else it is impossible for organisms to live on the earth.
27. In which year the Rain Water Harvesting movement was launched in Tamilnadu?
a) 2000
b) 2001
c) 2004
d) 1999
Explanation
Rain water harvesting is a methodology to collect the water from rainfall area and where it flows.
28. Which of these is the wetland meeting point of fresh water and sea water?
a) Estuaries
b) Ponds
c) River
d) Swamps
Explanation
Estuaries are wetlands where a water body meets the sea. It is the combination of fresh water from land meets the salty sea water.
29. Human body averagely requires _____ liters of water for proper functioning.
a) 1-2 liters
b) 2-3 liters
c) 1.5 to 2.5 liters
d) 3-4 liters
Explanation
Human body uses water for all its cells, Organs and tissues to regulate its temperature and other functions. Averagely human body requires 2-3 liters of water per day for proper functioning.
30. Match the location of swamps in India.
i) Pichavaram A. Odisha
ii) Bhitarkanika B. Chennai
iii) Pallikaranai C. West Bengal
iv) Sundarbans D. Chidambaram
a) ADBC
b) BDCA
c) DABC
d) CBAD
Explanation
Swamps are wetlands that occur along large river or on the shores of lakes. Swamps are important for fresh water and oxygen to all life. It is spread across various parts of India.
31. Which of these factors reduce the ground water pollution?
a) Minimizing the usage of chemical fertilizers.
b) Deforestation
c) Rainwater harvesting
d) Recycling
Explanation
Water is essential for healthy growth of farm crops and farm stock. But minimizing the use of chemical fertilizers in agriculture reduces the pollution of underground water.
32. The Swamp water may contain,
a) Fresh water
b) Brackish water
c) Sea water
d) All the above
Explanation
Swamps are forested wetlands. The water of swamp may be freshwater, brackish water or sea water.
33. What is the disinfectant chemicals used for cleaning the polluted water?
a) Chlorine
b) Sodium
c) Ammonia
d) a and c
Explanation
Sea water is distributed after passing through a treatment system which converts sea water to consumable fresh water. In this process water is filtered through sand filtration method and then sends to disinfection stage. This process removes the microorganisms present in it. Disinfection is done with chlorine and ammonia.
34. Who proved the Chemical composition of water?
a) Lavoisier
b) Dalton
c) Bohr
d) Einstein
Explanation
Lavoisier (1743-1794) conducted various experiments to conclude that air is a mixture it is not a basic element. Likewise he also proved that water is made up of oxygen and hydrogen.
35. Which of the following is used to regulate and distribute the water flow?
a) Canals
b) Well
c) Dam
d) Recycle units
Explanation
Several systems and methodologies are practiced to distribute the water in all level. Huge quantity of water is saved in reservoirs and dams to regulate the water supply and for proper distribution.
36. Which is the largest ice caps and glaciers source of India?
a) The Himalayas
b) The Western Ghats
c) The Ganges
d) The Eastern Ghats
Explanation
The Total fresh water is available mainly in the form of ice bergs and glaciers. The Himalayas contain ice caps and glaciers from which most of the Asian rivers originates.
37. How many types of Rain water harvesting methods are available?
a) 2
b) 3
c) 5
d) 4
Explanation
There are two methods followed for the conservation of water. One of the most important method is Rain water harvesting. In that two types of rain water harvesting is done (a) Collecting water from where it falls. (b) Collecting flowing rain water.
38. What is the total percentage of sea water found in oceans and seas?
a) 98%
b) 99%
c) 97%
d) 93%
Explanation
Water is most important component for all human beings, animals and plants. Water is available in various forms naturally. 97% of the total water on earth is found in seas and oceans.
39. In which year the Elements of chemistry was published?
a) 1788
b) 1789
c) 1777
d) 1776
Explanation
Lavoisier is a pioneer in the revolution of chemistry. He published the book “Elements of Chemistry“ in the year 1789 which was the foundation of Modern Chemistry.
40. The World water day is observed on,
a) June 5
b) July 22
c) May 20
d) March 22
Explanation
Every year march 22nd is observed as the world water day.
41. Which is not an industrial usage of water?
a) Solvent
b) Electricity generation
c) Cooking
d) Cleaning
Explanation
Industry depends on water at all levels of production. It is used as a material, a solvent and for generating electricity.
42. What are the Human bodily functions of water?
a) Temperature regulation
b) Food digestion
c) Toxin removal
d) All the above
Explanation
Our body uses water in all its cells, organs and tissues to help regulate its temperature and maintain other bodily functions. On an average, the human body requires 2 – 3 liters of water per day for proper functioning. Water helps in digestion of food and removal of toxins from the body.
43. Which of these is indicated by the moisture in the soil?
a) Salinity of water
b) Underground water
c) PH level
d) Total Surface water
Explanation
The moisture in the soil indicates the presence of underground water.
44. Which of these is not present in the Himalayas?
a) Glaciers
b) River
c) Streams
d) Ice caps
Explanation
The Himalayas contain ice caps, ice bergs and glaciers. Ten of Asia’s largest rivers flow from the Himalayas and more than a billion people’s livelihoods depend on those rivers.
45. Which of the human part has the minimum water content?
a) Bones
b) Blood
c) Brain
d) Lymph
Explanation
