Brain Grain · braingrain.in
Science — Practice Paper · Set 1
Class: 6Samacheer KalviMax Marks: 57
Name: ____________________Reg No: ____________
Part I — Multiple Choice Questions 10 × 1 = 10
Choose the correct answer. (Answer all questions.)
1.Which of the following medicinal plants has anti-cancer properties?A. AmlaB. TulasiC. TurmericD. Aloe[1]
2.Main organ of respiration in human body isA. StomachB. SpleenC. HeartD. Lungs[1]
3.Pen drive is ……… device.A. OutputB. InputC. StorageD. Connecting cable[1]
4.Usage of chemical pesticides and fertilisers causes ……… pollution.A. Air pollutionB. Water pollutionC. Noise pollutionD. None of the above[1]
5.Magnets lose their properties if they are _______A. dipped in waterB. dipped in oilC. heatedD. in freezer[1]
6.Filtration method is effective in separating _____ mixture.A. solid – solidB. solid – liquidC. liquid – liquidD. liquid – gas[1]
7.Which of the following processes add water vapour to the atmosphere?A. ii and iiiB. ii and ivC. i and ivD. i and ii[1]
8._______ was able to identify highly reactive gas called oxygen.A. LavoisierB. IngenhouszC. RutherfordD. Joseph Priestley[1]
9.Identify the freshwater ecosystem.A. PondB. LakeC. RiverD. All of them[1]
10.One day in 1922, the air temperature was measured at 59°C in the shade in Libya ________A. AmericaB. AfricaC. AntarcticaD. Europe[1]
Part II — Fill in the Blanks 5 × 1 = 5
Fill in the blanks. (Answer all questions.)
11.In every year October ……….is celebrated as world food day. ………… is an example of textile fibre. I am the state tree of Tamilnadu. Who am I ………… ? The juice of the leaves of ……… plant relieves cough and bronchitis. The edible seeds of leguminous plants are called …………[1]
12.Kicking a ball: contact force :: falling of leaf : ………… Distance : metre :: Speed : …………. circulatory motion : a spinning top oscillatory motion : …………[1]
13.Data is ………… Information. World’s first general purpose computer is ………. Information is ……… data Fifth generation computer has ………. Intelligence. ………… is the device that uses Index number.[1]
14.Heat flows from a ……….. body to a ………… body. The hotness of the object is determined by its ……….. The SI unit of temperature is ………… Solids ……….. on heating and ………… on cooling. Two bodies are said to be in the state of thermal ………… if there is no transfer of heat taking place.[1]
15.Earth’s surface is covered by ……….. % of water. The driest places on earth are ………. Fixation and absorption are the main functions of ………. Primary organs of photosynthesis are ……….. Taproot system present in ……….. plants.[1]
Part III — True or False 3 × 1 = 3
Write True or False. (Answer all questions.)
16.A cell is the smallest unit of life. Nerve cell is the longest cell Prokaryotes were the first form of life on earth. The organelles of both plants and animals are made up of cells. (Organelles – Found inside the cell) New cells are produced from existing cells.[1]
17.Heat is a kind of energy that flows from a hot body to a cold body. Steam is formed when heat is released from water. Thermal expansion is always a nuisance. Borosilicate glass do not expand much on being heated. The unit of heat and temperature are the same.[1]
18.Air is not compressible. Liquids have no fixed volume but have fixed shape. Particles in solids are free to move. Then pulses are washed with water before cooking, the water is separated from them by the process of filtration. Strainer is a kind of sieve which is used to separate a liquid from solid Grain and husk can be separated by winnowing Air is a pure substance Butter from curds is separated by sedimentation.[1]
Part IV — Short Answer Questions 12 × 2 = 24
Answer briefly. (Answer all questions.)
19.Classify the Fibre yielding plants based on use.[2]
20.Why should the fruits and vegetables not to be washed after cutting? Vitamins are of two types.[2]
21.Write any two viral diseases.[2]
22.Middle ear → Pinna → Outer ear → Inner ear[2]
23.What will happen if we remove the fish from the aquarium and keep it (with green plants) in a dark place?[2]
24.What are the sources of heat?[2]
25.What kind of change is associated with the decaying of plants?[2]
26.Why gypsum is used in cement production?[2]
27.Can deforestation be considered a desirable change? Explain.[2]
28.Write a short note on Data.[2]
29.Distinguish between properties of solid, liquid, gas. Draw a suitable diagram.[2]
30.How will you identify two objects are said to be in thermal equilibrium?[2]
Part V — Long Answer Questions 3 × 5 = 15
Answer in detail. (Answer all questions.)
31.What will happen if the diaphragm shows no movement?[5]
32.Explain thermal expansion with suitable examples.[5]
33.Unicellular organisms grow by mitotic division. The streamlined body of fish helps in swimming. The tail of the bird helps it to control the direction of the movement and balance. The hind limbs of birds are modified into wings The tail of birds help in controlling the direction of the movement[5]
🔑 Show Answer Key — Set 1
- 1. (c) Turmeric
- 2. (d) Lungs
- 3. (c) Storage
- 4. b. Water pollution
- 5. (c) heated
- 6. (b) solid – liquid
- 7. c. i and iv
- 8. (d) Joseph Priestley
- 9. d. All of them
- 10. (b) Africa
- 11. 16 Cotton Palm tree Tulsi pulses
- 12. non contact forces m/s Pendulum
- 13. Processed Electronic Numerical Integrator and computer a form of processed Artificial Analog Computer
- 14. hot, cold temperature Kelvin expand, contract equilibrium
- 15. 70% Deserts roots leave dicot.
- 16. True, True, True, False, True. A cell is indeed the smallest unit of life capable of independent functioning. The nerve cell is the longest cell found in living organisms, particularly in animals. Prokaryotes were the first form of life to appear on Earth, billions of years ago. However, organelles are not found inside all cells; they are found specifically inside eukaryotic cells such as plant and animal cells, but not in prokaryotic cells like bacteria. New cells are produced from existing cells through the process of cell division, as stated in the cell theory.
- 17. True. Heat is a kind of energy that flows from a hot body to a cold body. False. Steam is formed when heat is absorbed by water, not released from it. During the process of vaporization, water molecules gain energy and escape as steam. False. Thermal expansion is not always a nuisance; it has many useful applications in daily life and industry. For example, thermal expansion is used in thermometers to measure temperature, and in bimetallic strips for automatic temperature control devices. True. Borosilicate glass does not expand much on being heated because it has a very low coefficient of thermal expansion, making it resistant to thermal shock and cracking. False. The unit of heat and temperature are different. Heat is measured in joules or calories and represents the total energy transferred, while temperature is measured in degrees Celsius, Fahrenheit, or Kelvin and represents the average kinetic energy of molecules.
- 18. False. Air is compressible. False. Liquids have no fixed shape but have fixed volume. False. Particles in solids are not free to move; they are tightly bound and can only vibrate about fixed positions. False. When pulses are washed with water before cooking, the water is separated from them by the process of decantation, not filtration. False. A strainer is a kind of sieve which is used to separate a solid from a liquid. True. Grain and husk can be separated by winnowing. False. Air is a mixture, not a pure substance, as it contains nitrogen, oxygen, argon, carbon dioxide, and other gases. False. Butter from curds is separated by churning, which involves vigorous agitation to separate the fat globules from the liquid buttermilk.
- 19. Fibre-yielding plants can be classified into three main categories based on their use. The first category is textile fibres, which are used to make cloth and clothing. Cotton is the most important textile fibre, widely used in the textile industry to produce various types of fabrics and garments. The second category is cordage fibres, which are used to make ropes, twines, and other cordage products. Coconut fibre, also known as coir, is a major cordage fibre obtained from the husk of coconut and is used for making ropes, mats, and brushes. The third category is filling fibres, which are used as stuffing material in pillows, mattresses, and cushions. Silk cotton is an important filling fibre that is soft, light, and provides good insulation. These three categories represent the main commercial uses of fibres obtained from plants.
- 20. We should not wash the fruits and vegetables after cutting because water-soluble vitamins and minerals present in them will dissolve and be washed away with the water. When fruits and vegetables are cut, their cells are damaged and their nutrients become exposed to water. Vitamins such as vitamin C and B-complex vitamins are water-soluble and easily lost during washing. Additionally, minerals and proteins in the fruits and vegetables will also be washed away, reducing their nutritional value. Therefore, it is better to wash fruits and vegetables before cutting them to retain their maximum nutritional content.
- 21. Two viral diseases are common cold and smallpox. Common cold is a mild respiratory infection caused by viruses that affects the nose and throat, causing symptoms like sneezing, coughing, and runny nose. Smallpox is a more serious viral disease that causes fever and characteristic skin rashes and has been largely eradicated through vaccination programs. Other examples of viral diseases include polio, which affects the nervous system and can cause paralysis.
- 22. The correct sequence of the ear structure through which sound travels is: Pinna → Outer ear → Middle ear → Inner ear. The pinna is the visible external part of the ear that collects sound waves. The outer ear includes the ear canal that directs sound waves to the eardrum. The middle ear contains tiny bones that vibrate and transmit sound vibrations. The inner ear contains the cochlea where sound vibrations are converted into electrical signals that are sent to the brain for interpretation.
- 23. If we remove the fish from the aquarium and keep it with green plants in a dark place, the plants will not be able to carry out photosynthesis because photosynthesis requires light energy. Without photosynthesis, the plants will not produce oxygen, and the oxygen level in the water will gradually decrease. The plants may eventually die due to lack of light. Additionally, without fish, there will be no source of carbon dioxide and nutrients that fish waste provides, which plants need for their growth. The aquarium will become an imbalanced ecosystem unable to sustain life.
- 24. The main source of heat is the Sun, which provides heat energy to the Earth through radiation. Other important sources of heat include combustion, which is the burning of fuels such as wood, coal, gas, and oil that releases heat energy. Friction is another source of heat, generated when two surfaces rub against each other, such as when striking a match or rubbing hands together. Electricity is also a significant source of heat, produced when electric current flows through a conductor with resistance, as seen in electric heaters, light bulbs, and other electrical appliances. Additionally, chemical reactions and nuclear reactions can also produce heat energy.
- 25. Decaying of plants is associated with both slow change and chemical change. It is a slow change because the process of decay takes place over a long period of time, spanning days, weeks, or months as the plant material gradually breaks down. It is also a chemical change because during decay, the complex organic compounds in the plant tissues are broken down by microorganisms and bacteria into simpler substances like carbon dioxide, water, and other compounds. The original plant material is transformed into completely different substances, and this process cannot be reversed.
- 26. Gypsum is added to cement during its production to control the setting time of the cement. Without gypsum, the cement would set too quickly, making it difficult to work with and apply. Gypsum slows down the hydration process, allowing workers sufficient time to mix, transport, and place the cement before it hardens completely.
- 27. Deforestation cannot be considered a desirable change because it is harmful to our environment and is not desired by us. Deforestation is classified as an undesirable change. When forests are cut down, it leads to loss of habitat for wildlife, reduces oxygen production, increases carbon dioxide in the atmosphere, causes soil erosion, disrupts the water cycle, and contributes to climate change. Deforestation also destroys the natural resources and biodiversity that forests provide. Therefore, it is a change that has negative consequences for both the environment and human society.
- 28. Data is the information that has to be processed. They are in the form of numbers, alphabets, and images.
- 29. (refer textbook)
- 30. Two objects are said to be in thermal equilibrium when they are in thermal contact with each other and have the same temperature. In this state, there is no net flow of heat between the two objects because the kinetic energy of molecules in both objects is equal. When two objects at different temperatures are brought into contact, heat flows from the hotter object to the cooler one until both reach the same temperature and achieve thermal equilibrium.
- 31. The diaphragm is the primary organ responsible for breathing in the human body. When the diaphragm contracts, it moves downward, which increases the volume of the chest cavity and decreases the air pressure inside the lungs. This pressure difference causes air to be sucked into the lungs. When the diaphragm relaxes and moves upward, the volume of the chest cavity decreases, pushing air out of the lungs. If the diaphragm shows no movement and fails to contract and relax, the lungs cannot expand or contract properly. As a result, air cannot enter or leave the lungs, and breathing stops completely. Without the ability to breathe and take in oxygen, the body cannot survive, and the person will die within minutes due to lack of oxygen supply to the brain and other vital organs.
- 32. Thermal expansion: The expansion of a substance on heating is called, the thermal expansion of that substance. Fitting the iron rim on the wooden wheel: The diameter of the iron ring is slightly less than that of the wooden wheel. So, it cannot be easily slipped on from the rim of a wooden wheel. The iron ring is, therefore, first heated to a higher temperature so that it expands in size and the hot ring is then easily slipped over to the rim of the wooden wheel. Coldwater is now poured on the iron ring so that it contracts in size and holds the wooden wheel tightly. Rivetting: Rivets are used to join two steel plates together. Hot rivet is driven through the hole in the plates. One end of the rivet is hammered to form a new rivet head. When cooled, the rivet will contract and hold the two plates tightly together. Cracking of a thick glass tumbler: Glass is a poor conductor of heat. When hot liquid is poured into the tumbler, the inner surface of the tumbler becomes hot and expands while the outer surface remains at room temperature and does not expand. Due to this unequal expansion, the tumbler cracks.
- 33. False – In unicellular organisms, the size of the cell increases as it grows True True False – The forelimbs of birds are modified as wings. True
Brain Grain · braingrain.in
Science — Practice Paper · Set 2
Class: 6Samacheer KalviMax Marks: 57
Name: ____________________Reg No: ____________
Part I — Multiple Choice Questions 10 × 1 = 10
Choose the correct answer. (Answer all questions.)
1.If the total water on earth be 100% the percentage of freshwater is ………..A. 97%B. 93%C. 3%D. 0.3%[1]
2.……….. fish is able to produce an electric current.A. GoldfishB. Electric EelC. KatlaD. Salamon fish[1]
3.The important function of stomata is ______A. ConductionB. TranspirationC. PhotosynthesisD. Absorption[1]
4.Around 97% of water available on earth is water.A. freshB. pureC. saltyD. polluted[1]
5.Which animal has the special organs of breathing called gillsA. EarthwormB. foxC. FishD. frog[1]
6.Scurvy is caused due to the deficiency of _______A. Vitamin AB. Vitamin BC. Vitamin CD. Vitamin D[1]
7.Which one of the following is an example for wireless connections?A. Wi-FiB. Electric wiresC. VGAD. USB[1]
8.If 50 kg of Superphosphate is added to the soil, how much phosphorus would the soil get?A. 4 – 4.5 kgB. 8 – 9 kgC. 12 – 13 kgD. 16 – 18 kg[1]
9.People walking in a crowded street is an example of _______ motion.A. linearB. circularC. rotatoryD. zigzag[1]
10.Completes one or more than two works of the end-user?A. System softwareB. Operating systemC. Free softwareD. Application software[1]
Part II — Fill in the Blanks 5 × 1 = 5
Fill in the blanks. (Answer all questions.)
11.People walking in a crowded street is ……….. type of motion. Object moves not at a constant speed then the motion is ……….. If Priya in her cycle travels 40 km in 2 hours then what is her average speed? Motion is of ………… types. The movement of a body about its own axis is ………….[1]
12.Down: 1. A method of water conservation. 2. Process of getting water vapour from seawater. 6. Water stored in dams is used for the generation of ……….. Across: 3. ………. is a large body of non -potable water found in nature. 4. In summer, the body loses water as …….. 5. Plants undergo ………….. and contribute to the water cycle.[1]
13.Tropical rain forests, grasslands, and deserts are known as ……….. Some living things are made of a single cell, they are called a……….. organism The breathing organ of a fish is known as ……….. The lizard ……….. on the ground with its claw on its feet. Camel stores ………… in its hump.[1]
14.The Motion of train – uniform motion. The motion of vehicles ……….. Periodic motion – The motion of the moon revolves around the earth. Oscillatory motion ………..[1]
15.Aquatic, deserts, mountains are called ………. Based on the number of cells present animals are classified into ………. and ……….. Tail of a bird acts as a rudder which helps to ……….. Amoeba moves with the help of …………[1]
Part III — True or False 3 × 1 = 3
Write True or False. (Answer all questions.)
16.Air is not compressible. Liquids have no fixed volume but have fixed shape. Particles in solids are free to move. Then pulses are washed with water before cooking, the water is separated from them by the process of filtration. Strainer is a kind of sieve which is used to separate a liquid from solid Grain and husk can be separated by winnowing Air is a pure substance Butter from curds is separated by sedimentation.[1]
17.A cell is the smallest unit of life. Nerve cell is the longest cell Prokaryotes were the first form of life on earth. The organelles of both plants and animals are made up of cells. (Organelles – Found inside the cell) New cells are produced from existing cells.[1]
18.Heat is a kind of energy that flows from a hot body to a cold body. Steam is formed when heat is released from water. Thermal expansion is always a nuisance. Borosilicate glass do not expand much on being heated. The unit of heat and temperature are the same.[1]
Part IV — Short Answer Questions 12 × 2 = 24
Answer briefly. (Answer all questions.)
19.Give some examples of a unicellular and multicellular organisms.[2]
20.Give an example for mixture and justify your answer with reason.[2]
21.What is meant by food adulteration?[2]
22.Define – heat.[2]
23.Name the places where water is found as ice.[2]
24.Make a list of electrical types of equipment at home from which we get heat.[2]
25.Define the term “Trachea”[2]
26.List out the parts required to make an electric circuit[2]
27.Growth of a child, Blinking of eye, Rusting, Germination of a seed.[2]
28.Tabulate the vitamins and their corresponding deficiency diseases.[2]
29.To and fro motion is called oscillatory motion. Vibratory motion and rotatory motion are periodic motions. Vehicles moving with varying speeds are said to be in uniform motion. Robots will replace human in future.[2]
30.What is the clock used to measure the time accurately?[2]
Part V — Long Answer Questions 3 × 5 = 15
Answer in detail. (Answer all questions.)
31.What is biodegradable waste?[5]
32.The rotation of the earth is a periodic motion. Justify.[5]
33.In a parallel circuit, the electricity has more than one path. To make a battery of two cells, the negative terminal of one cell is connected to the negative terminal of the other cell. The switch is used to close or open an electric circuit. Pure water is a good conductor of electricity. Secondary cell can be used only once.[5]
🔑 Show Answer Key — Set 2
- 1. (c) 3%
- 2. (b) Electric Eel
- 3. (b) Transpiration
- 4. c. salty
- 5. c. Fish
- 6. (c) Vitamin C
- 7. (a) Wi-Fi
- 8. (a) 4 – 4.5 kg
- 9. (d) zigzag
- 10. (d) Application software
- 11. Irregular on- uniform motion 20 km /hr four Rotatory motion
- 12. (refer textbook)
- 13. habitat unicellular gills walk and run fat
- 14. non – uniform motion. Motion of simple pendulum.
- 15. Habitat Unicellular, multicellular control the direction of the movement Pseudopodium.
- 16. False. Air is compressible. False. Liquids have no fixed shape but have fixed volume. False. Particles in solids are not free to move; they are tightly bound and can only vibrate about fixed positions. False. When pulses are washed with water before cooking, the water is separated from them by the process of decantation, not filtration. False. A strainer is a kind of sieve which is used to separate a solid from a liquid. True. Grain and husk can be separated by winnowing. False. Air is a mixture, not a pure substance, as it contains nitrogen, oxygen, argon, carbon dioxide, and other gases. False. Butter from curds is separated by churning, which involves vigorous agitation to separate the fat globules from the liquid buttermilk.
- 17. True, True, True, False, True. A cell is indeed the smallest unit of life capable of independent functioning. The nerve cell is the longest cell found in living organisms, particularly in animals. Prokaryotes were the first form of life to appear on Earth, billions of years ago. However, organelles are not found inside all cells; they are found specifically inside eukaryotic cells such as plant and animal cells, but not in prokaryotic cells like bacteria. New cells are produced from existing cells through the process of cell division, as stated in the cell theory.
- 18. True. Heat is a kind of energy that flows from a hot body to a cold body. False. Steam is formed when heat is absorbed by water, not released from it. During the process of vaporization, water molecules gain energy and escape as steam. False. Thermal expansion is not always a nuisance; it has many useful applications in daily life and industry. For example, thermal expansion is used in thermometers to measure temperature, and in bimetallic strips for automatic temperature control devices. True. Borosilicate glass does not expand much on being heated because it has a very low coefficient of thermal expansion, making it resistant to thermal shock and cracking. False. The unit of heat and temperature are different. Heat is measured in joules or calories and represents the total energy transferred, while temperature is measured in degrees Celsius, Fahrenheit, or Kelvin and represents the average kinetic energy of molecules.
- 19. Unicellular organisms are those that consist of a single cell and can perform all life functions within that one cell. Examples of unicellular organisms include Amoeba, Paramecium, and Euglena. Multicellular organisms are composed of many cells that work together and are organized into tissues and organs to perform various life functions. Examples of multicellular organisms include Fish, Frog, Lizard, Birds, and Man.
- 20. An example of a mixture is 22 carat gold. This is a mixture composed of gold and copper, or gold and cadmium. This is a good example of a mixture because it contains two or more different substances that are physically combined but not chemically bonded. The gold and copper (or cadmium) retain their individual properties and can theoretically be separated by physical means such as melting and selective dissolution. The reason 22 carat gold is a mixture rather than a pure substance is that it contains approximately 92 percent gold and about 8 percent other metals like copper or cadmium, which are added to increase the hardness and durability of the gold for jewelry making.
- 21. Food adulteration is the process of mixing harmful, unwanted, or inferior substances with pure foodstuffs that we buy in the market. These adulterants are added to increase the quantity of food, reduce its cost, or improve its appearance, but they are often injurious to health. Common examples of food adulteration include adding water to milk, mixing cheap oils with expensive oils, adding artificial colors or preservatives, or mixing stones or dirt with grains. Food adulteration is a serious problem that affects public health and is illegal in most countries. Consumers should be aware of adulterated food and purchase from trusted sources to ensure they consume pure and safe food.
- 22. Heat is a form of energy that flows from a hotter object to a cooler object, causing an increase in temperature by making the molecules in that object move faster and vibrate with greater intensity. Heat is transferred through conduction, convection, and radiation. The transfer of heat continues until both objects reach the same temperature, at which point thermal equilibrium is established. Heat is measured in units called joules or calories.
- 23. Water is found as ice in several places around the world. Polar ice-caps are large sheets of ice covering the North Pole and South Pole regions. Ice sheets are extensive areas of interconnected ice found in Greenland and Antarctica. Glaciers are large masses of ice found in mountainous regions, particularly in the Arctic region and Antarctica. These frozen forms of water store a significant portion of the world's fresh water. The Arctic region, which includes areas around the North Pole, contains sea ice and glaciers. Antarctica, the continent at the South Pole, is covered with a massive ice sheet and contains numerous glaciers. These ice formations play an important role in regulating global climate and sea levels.
- 24. Common electrical equipment at home from which we get heat include water heaters used for heating water for bathing and washing, electric iron boxes used for pressing clothes, electric kettles used for boiling water quickly, microwave ovens used for cooking and heating food, electric room heaters used for warming rooms during winter, electric stoves and cooktops used for cooking, and electric toasters used for toasting bread.
- 25. The trachea, commonly called the windpipe, is a tube-like structure that serves as the main airway for breathing. It is supported and kept open by cartilaginous rings, which are rings of cartilage arranged along its length. The trachea connects the pharynx and larynx to the lungs, forming an important part of the respiratory system. It allows the passage of air from the upper respiratory tract down into the lungs during inhalation and out of the lungs during exhalation. The cartilaginous rings prevent the trachea from collapsing and maintain its shape even when air pressure changes during breathing.
- 26. The main parts required to make a complete electric circuit are a dry cell or battery to provide electrical energy, connecting wires made of conducting material like copper to form the path for current flow, an electric bulb or other load that consumes the electrical energy and produces light, and a switch or key to control the flow of electricity by opening and closing the circuit. All these components must be connected in a continuous loop for the circuit to function properly.
- 27. Blinking of an eye is a fast change because it occurs in a fraction of a second. Fast changes are those that happen very quickly in a short period of time, usually in seconds or minutes. In contrast, growth of a child is a slow change taking months or years, rusting is a slow chemical change taking days or weeks, and germination of a seed is a slow change taking several days. Blinking is an involuntary reflex action of our eyelids that protects our eyes and happens almost instantaneously.
- 28. Vitamin A — night blindness; Vitamin B1 (thiamine) — beriberi; Vitamin B12 — pernicious anemia; Vitamin C — scurvy; Vitamin D — rickets; Vitamin K — bleeding disorders.
- 29. The first statement is true because to and fro motion, where an object moves back and forth along the same path repeatedly, is indeed called oscillatory motion. The second statement is true because vibratory motion, which involves rapid back and forth movements, and rotatory motion, which involves spinning around an axis, are both examples of periodic motions that repeat at regular intervals. The third statement is non-uniform motion because vehicles moving with varying speeds do not travel equal distances in equal intervals of time, which is the definition of uniform motion. The fourth statement is false because robots are machines programmed to perform specific tasks automatically, but they operate based on programmed instructions and cannot develop consciousness or independent thought like humans do. Robots will continue to assist and automate many tasks in the future, but they cannot replace human consciousness, creativity, and decision-making abilities.
- 30. An electronic clock or a stop clock is used to measure time accurately. An electronic clock provides precise digital or analog time display with high accuracy, while a stop clock is specifically designed to measure short time intervals with precision, making it useful for timing experiments and activities in scientific work.
- 31. Biodegradable waste refers to materials that can be easily broken down and decomposed by natural agents and microorganisms. These natural agents include water, oxygen, ultraviolet rays from the sun, and decomposing microorganisms such as bacteria and fungi. Common examples of biodegradable waste include vegetable and fruit peels, leftover food, grass clippings, leaves, twigs, paper, cardboard, and animal manure. When biodegradable waste is disposed of properly, it decomposes naturally and returns to the soil as nutrients, enriching it and making it fertile for growing plants. This type of waste is environmentally friendly because it does not persist in the environment and does not cause long-term pollution like non-biodegradable materials do.
- 32. The rotation of the Earth is a periodic motion because it satisfies the definition of periodic motion, which is motion that repeats itself after a fixed interval of time. The Earth completes one full rotation on its axis in exactly 24 hours, which is a fixed and constant time period. After every 24 hours, the Earth returns to the same rotational position relative to the sun, and this rotation repeats continuously in the same manner. Since the Earth's rotation repeats at regular and equal intervals of time with a fixed period of 24 hours, it is classified as a periodic motion. Other examples of periodic motion in astronomy include the revolution of the Earth around the sun, which repeats every 365 days, and the orbiting of the moon around the Earth, which repeats every 29.5 days.
- 33. In a parallel circuit, electricity has more than one path – True. To make a battery of two cells, the negative terminal of one cell is connected to the positive terminal of the other cell – True. The switch is used to close or open an electric circuit – True. Pure water is a good conductor of electricity – False, pure water is an insulator because it lacks ions; only impure water containing dissolved salts is a conductor. Secondary cells can be used only once – False, secondary cells can be recharged and used many times, unlike primary cells which can be used only once.
Brain Grain · braingrain.in
Science — Practice Paper · Set 3
Class: 6Samacheer KalviMax Marks: 57
Name: ____________________Reg No: ____________
Part I — Multiple Choice Questions 10 × 1 = 10
Choose the correct answer. (Answer all questions.)
1.Which of the following cannot be called as a habitat?A. A desert with camelsB. A pond with fish and snailsC. Cultivated land with grazing cattleD. A jungle with wild animals[1]
2.Which is not attracted by a magnet?A. IronB. CoboltC. NickelD. Rubber[1]
3.Quantity that can be measured is called ………A. Physical quantityB. MeasurementC. UnitD. Motion.[1]
4.Lighter impurities like dust, when mixed with rice or pulses, can be removed by _____A. filtrationB. sedimentationC. decantationD. winnowing[1]
5.The circulatory system transports these throughout the bodyA. OxygenB. NutrientC. HormonesD. All of these[1]
6.Which one of the following is an output device?A. MouseB. KeyboardC. SpeakerD. Pen drive[1]
7.One of the following birds is an example of plant-pollinatorA. DuckB. ParrotC. HummingbirdD. Dove[1]
8.Who is the computer’s first programmer?A. Lady WellingtonB. Augusta ado LovelaceC. Mary CurieD. Mary Comb[1]
9.The page on the monitor can be moved up and down using the _______A. Right buttonB. Scroll ballC. Left buttonD. Number key[1]
10.Drying of wet clothes in air is an example ofA. Chemical changeB. Undesirable changeC. irreversible changeD. physical change[1]
Part II — Fill in the Blanks 5 × 1 = 5
Fill in the blanks. (Answer all questions.)
11.……… particles are tightly packed into a definite shape. The tendency of particles to spread out in order to occupy the available space is ……….. The purest form of gold is denoted by ……….. Milk is a ……….. The principle of ………. is used in washing machines.[1]
12.Heat: Joule :: Temperature : ……… Ice cube : 0°C :: Boiling water : ……….. Total Kinetic Energy of molecules: Heat:: Average Kinetic Energy : …………….[1]
13.SI unit of length is symbolically represented as ……….. 500 gm = …………. kilogram. Distance between Delhi and Chennai can be measured in ………. 1 m = ………. cm. 5 km = ………. m.[1]
14.Urea : Inorganic fertilizer :: Vermi Compost: ………… ……….. : Natural Adhesives :: Cello tape : Artificial Adhesives[1]
15.A group of organs together make up an ………. system. The part of the skeleton that protects the brain is ………… The process by which the body removes waste is ……….. The ………. is the largest sense organ in our body. The endocrine glands produce chemical substances called …………[1]
Part III — True or False 3 × 1 = 3
Write True or False. (Answer all questions.)
16.Heat is a kind of energy that flows from a hot body to a cold body. Steam is formed when heat is released from water. Thermal expansion is always a nuisance. Borosilicate glass do not expand much on being heated. The unit of heat and temperature are the same.[1]
17.Air is not compressible. Liquids have no fixed volume but have fixed shape. Particles in solids are free to move. Then pulses are washed with water before cooking, the water is separated from them by the process of filtration. Strainer is a kind of sieve which is used to separate a liquid from solid Grain and husk can be separated by winnowing Air is a pure substance Butter from curds is separated by sedimentation.[1]
18.A cell is the smallest unit of life. Nerve cell is the longest cell Prokaryotes were the first form of life on earth. The organelles of both plants and animals are made up of cells. (Organelles – Found inside the cell) New cells are produced from existing cells.[1]
Part IV — Short Answer Questions 12 × 2 = 24
Answer briefly. (Answer all questions.)
19.Draw a neat labelled diagram of a prokaryotic cell.[2]
20.Give any three examples of eukaryotic cells.[2]
21.Name four different sources of water.[2]
22.How do people in cities and rural areas get water for various purposes?[2]
23.List out the types of forces on the basis of contact.[2]
24.An ordinary glass bottle cracks when boiling water is poured into it, but a borosilicate glass bottle does not.[2]
25.Give two examples of organic fertilizers?[2]
26.What are the types of rainwater harvesting?[2]
27.What are the body parts of the snake?[2]
28.Define ecosystem.[2]
29.What type of circuit is there in a torchlight?[2]
30.How can husk or fine dust particles be separated from rice before cooking?[2]
Part V — Long Answer Questions 3 × 5 = 15
Answer in detail. (Answer all questions.)
31.Why do we sweat more in summer?[5]
32.Concentrated phenol is used as a disinfectant. Gypsum is largely used in medical industries. Plaster of Paris is obtained from heating gypsum. Adhesives are the substances used to separate the components. NPK are the primary nutrients for plants.[5]
33.Why is the atmosphere essential for life on earth?[5]
🔑 Show Answer Key — Set 3
- 1. c. Cultivated land with grazing cattle
- 2. (d) Rubber
- 3. (b) Measurement
- 4. (d) winnowing
- 5. (d) All of these
- 6. (c) Speaker
- 7. c. Hummingbird
- 8. (b) Augusta ado Lovelace
- 9. (b) Scroll ball
- 10. (d) Physical change
- 11. Solid diffusion 24 carat mixture centrifugation
- 12. Kelvin 100° C Temperature
- 13. metre 0.5 Kilometre 100 5000
- 14. Natural Fertilizer Starch
- 15. Organ Skull Excretion Skin hormones
- 16. True. Heat is a kind of energy that flows from a hot body to a cold body. False. Steam is formed when heat is absorbed by water, not released from it. During the process of vaporization, water molecules gain energy and escape as steam. False. Thermal expansion is not always a nuisance; it has many useful applications in daily life and industry. For example, thermal expansion is used in thermometers to measure temperature, and in bimetallic strips for automatic temperature control devices. True. Borosilicate glass does not expand much on being heated because it has a very low coefficient of thermal expansion, making it resistant to thermal shock and cracking. False. The unit of heat and temperature are different. Heat is measured in joules or calories and represents the total energy transferred, while temperature is measured in degrees Celsius, Fahrenheit, or Kelvin and represents the average kinetic energy of molecules.
- 17. False. Air is compressible. False. Liquids have no fixed shape but have fixed volume. False. Particles in solids are not free to move; they are tightly bound and can only vibrate about fixed positions. False. When pulses are washed with water before cooking, the water is separated from them by the process of decantation, not filtration. False. A strainer is a kind of sieve which is used to separate a solid from a liquid. True. Grain and husk can be separated by winnowing. False. Air is a mixture, not a pure substance, as it contains nitrogen, oxygen, argon, carbon dioxide, and other gases. False. Butter from curds is separated by churning, which involves vigorous agitation to separate the fat globules from the liquid buttermilk.
- 18. True, True, True, False, True. A cell is indeed the smallest unit of life capable of independent functioning. The nerve cell is the longest cell found in living organisms, particularly in animals. Prokaryotes were the first form of life to appear on Earth, billions of years ago. However, organelles are not found inside all cells; they are found specifically inside eukaryotic cells such as plant and animal cells, but not in prokaryotic cells like bacteria. New cells are produced from existing cells through the process of cell division, as stated in the cell theory.
- 19. (refer textbook)
- 20. Three examples of eukaryotic cells are plant cells, animal cells, and cells found in fungi and algae. Plant cells contain a nucleus, cell wall, and chloroplasts. Animal cells contain a nucleus and various organelles but lack a cell wall and chloroplasts. Fungi and algae are also eukaryotic organisms whose cells contain a nucleus and membrane-bound organelles, though they differ in structure from typical plant and animal cells.
- 21. Four different sources of water are rivers, wells, lakes, and glaciers. Rivers are flowing bodies of water that carry fresh water from mountains to plains and eventually to the sea. Wells are deep holes dug into the ground to access groundwater stored in underground layers. Lakes are large bodies of fresh water that collect in depressions on land and serve as important water sources for many regions. Glaciers are large masses of ice found in mountainous regions and polar areas that contain frozen fresh water. Other sources include ponds, springs, and rainwater, which also provide water for various human needs and natural ecosystems.
- 22. People in cities and rural areas get water for various purposes through different sources and systems. In cities, water is typically supplied through municipal water supply systems that deliver treated water through pipes and hand pumps to households. In rural areas, people obtain water from wells, which are dug to access groundwater stored underground. Canals are used in agricultural regions to distribute water for irrigation purposes. Tanks and ponds serve as storage systems for collecting and storing water during rainy seasons for use throughout the year. Rivers and natural water bodies also provide water for drinking, irrigation, and other domestic purposes. Hand pumps and hand-operated wells are commonly used in villages where piped water supply is not available.
- 23. On the basis of contact, forces are classified into two main types. Contact forces are forces that act when two objects are in direct physical contact with each other, such as when you kick a ball or push a door. Non-contact forces are forces that can act on an object from a distance without any direct physical contact between the objects, such as gravitational force between the Earth and objects, magnetic force between magnets, and electrostatic force between charged objects. These two categories represent the fundamental ways in which forces can be applied to objects.
- 24. An ordinary glass bottle cracks when boiling water is poured into it because ordinary glass has a high coefficient of thermal expansion. When the hot water comes into contact with the glass, the outer surface expands rapidly while the inner surface remains relatively cool and expands more slowly. This uneven expansion creates internal stress in the glass, causing it to crack. Borosilicate glass, on the other hand, does not expand much on being heated because it has a very low coefficient of thermal expansion. This means the outer and inner surfaces expand at nearly the same rate, preventing the buildup of internal stress and allowing the glass to withstand sudden temperature changes without cracking.
- 25. Two important examples of organic fertilizers are compost and vermicompost. Compost is produced by decomposing organic waste materials such as plant residues, kitchen waste, and animal manure through natural biological processes. Vermicompost is produced by the action of earthworms on organic waste materials, resulting in nutrient-rich castings that are highly beneficial for soil and plant growth.
- 26. There are two main types of rainwater harvesting methods. The first type involves collecting water from where it falls, which means capturing rainwater directly from rooftops, terraces, and other surfaces where it naturally falls and storing it in tanks or containers for later use. The second type involves collecting rainwater by constructing bunds, which are embankments or barriers built to prevent water from flowing away and to allow it to percolate into the ground, thereby recharging groundwater reserves. Both methods are effective ways to conserve water and reduce dependence on other water sources during dry seasons.
- 27. The body of a snake is divided into three main parts: the head, the body, and the tail. The head contains several important sensory organs and structures. On the head, a snake has two eyes that help it see its surroundings, two nostrils that allow it to breathe and sense odours in the environment, and a mouth that is used for consuming prey. The body is the longest part and contains the internal organs, while the tail extends from the end of the body and helps the snake with movement and balance.
- 28. An ecosystem is a community of living organisms (biotic components) and non-living things (abiotic components) that interact and work together in a specific environment. The biotic components include plants, animals, bacteria, and fungi, while the abiotic components include sunlight, water, air, soil, temperature, and humidity. All these elements are interconnected and dependent on each other, forming a balanced system where energy flows and nutrients cycle continuously.
- 29. A simple circuit system is used in a torchlight. This circuit consists of a battery or dry cell as the power source, a switch to control the flow of electricity, connecting wires to complete the path, and a bulb that produces light. When the switch is pressed, it closes the circuit and allows current to flow from the battery through the wires to the bulb, causing it to glow. When the switch is released, the circuit opens and the current stops, turning off the light.
- 30. Before cooking, husk or fine dust particles in rice are separated by winnowing, not sedimentation. Winnowing is a process in which the mixture is exposed to wind or air current. The lighter impurities like husk and dust particles are blown away by the wind due to their lower density, while the heavier rice grains fall straight down and are collected. This method is effective because it takes advantage of the difference in weight between the rice grains and the lighter impurities. Alternatively, sedimentation can be used where the rice and impurities are placed in water, and the heavier rice grains sink to the bottom while lighter particles may float or remain suspended.
- 31. Sweating plays an important role in maintaining a constant body temperature and keeping us cool. When the environmental temperature is hot, the body's temperature increases. To prevent overheating and maintain normal body temperature, the sweat glands in the skin produce sweat and release it onto the surface of the skin. When this moisture evaporates from the skin surface, it absorbs heat energy from the body and cools us down immediately. This process is called evaporative cooling. In summer, when the temperature is very hot, the body needs to lose more heat to maintain its normal temperature, so we sweat more profusely. The more we sweat and the more sweat evaporates, the more heat is removed from our body, helping us stay cool and comfortable even in extremely hot weather conditions.
- 32. The first statement is False because low concentrated phenol is used as a disinfectant, not concentrated phenol. Concentrated phenol is corrosive and harmful. The second statement is False because gypsum is largely used in medical and construction industries, not just medical industries. The third statement is True because plaster of Paris is indeed obtained from heating gypsum at controlled temperatures. The fourth statement is False because adhesives are substances that are used to join two or more components together, not to separate them. Adhesives create bonds between materials. The fifth statement is True because NPK, which stands for Nitrogen, Phosphorus, and Potassium, are the three primary macronutrients that are essential for plant growth and development. These nutrients are required in large quantities by plants for various metabolic processes and are commonly found in fertilizers.
- 33. The atmosphere is essential for life on Earth because it performs several critical functions that make the planet habitable. The atmosphere maintains an appropriate climate by regulating temperature through various mechanisms. During the daytime, the atmosphere prevents a sudden and extreme increase in temperature by absorbing some of the incoming solar radiation and scattering it. This protective layer ensures that the surface does not become excessively hot. During the nighttime, the atmosphere plays an equally important role by slowing down the escape of heat from the Earth's surface into outer space. Gases like carbon dioxide and water vapor in the atmosphere trap heat through the greenhouse effect, keeping the average temperature of the Earth fairly constant. This temperature regulation is vital because it allows organisms to survive within a range of temperatures suitable for life. Additionally, the atmosphere contains oxygen necessary for respiration in most living organisms, protects us from harmful ultraviolet radiation through the ozone layer, and provides the air we breathe. Without the atmosphere's insulating and protective properties, Earth would be either too cold at night or too hot during the day, making it impossible for life as we know it to exist.