6th Class General Science Notes PDF

6TH CLASS www.ignitephysics.net GENERAL SCIENCE Components of Food Exercises: 1. Name the major nutrients in our food. A) The major nutrients in our food are carbohydrates, proteins, fats, vitamins and minerals. In...

6TH CLASS www.ignitephysics.net GENERAL SCIENCE Components of Food Exercises: 1. Name the major nutrients in our food. A) The major nutrients in our food are carbohydrates, proteins, fats, vitamins and minerals. In addition, food also contains dietary fibres and water. 2. Name the following: (a) The nutrients which mainly give energy to our body. A) Carbohydrates, Fats. (b) The nutrients that are needed for the growth and maintenance of our body. A) Proteins, Minerals. (c) A vitamin required for maintaining good eyesight. A) Vitamin 'A' (d) A mineral that is required for keeping our bones healthy. A) Calcium. 3. Name two foods each rich in: (a) Fats (b) Starch (c) Dietary fibre (d) Protein A) (a) Fats: Groundnuts, Ghee. (b) Starch: Rice, Potatoes. (c) Dietary fibre: Whole grains, Fresh fruits. (d) Protein: Grams, Fishes 4. What is a balanced diet? A) BALANCED DIET (1) The food we normally eat in a day is our diet. (2) For growth and maintenance of good health, our diet should have all the nutrients that our body needs, in right quantities. (3) Not too much of one and not too little of the other. (4) The diet should also contain a good amount of roughage and water. (5) Such a diet is called a balanced diet. 5. Why do deficiency diseases occur? What is it called? A) (1) Sometimes the food may not contain a particular nutrient. (2) If this continues over a long period of time, the person may suffer from its deficiency. (3) Deficiency of one or more nutrients can cause diseases or disorders in our body. (4) Diseases that occur due to lack of nutrients over a long period are called deficiency diseases. 6. Tick (√) the statements that are correct. A) (a) By eating rice alone, we can fulfill nutritional requirement of our body. ( × ) (b) Deficiency diseases can be prevented by eating a balanced diet. ( √ ) (c) Balanced diet for the body should contain a variety of food items. ( √ ) (d) Meat alone is sufficient to provide all nutrients to the body. ( × ) R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE 7. What is fortified food? What is the logo given to it? A) Fortification of food is the addition of keyvitamins and minerals to staple foods such as rice, wheat, oil, milk and salt to improve their nutritional content. This is a logo for fortified foods as per standards by FSSAI. 8. What is Obesity? A) (1) Obesity is a condition that occurs in an individual due to excess accumulation of fat due to a fat-rich diet. (2) If a person's body weight is at least 20% higher than it should be, he or she is considered obese. 9. Make a table of some diseases/disorders caused by deficiency of vitamins and minerals? 10. Fill in the blanks: (a) ----------- is caused by deficiency of Vitamin D. (b) Deficiency of ---------- causes a disease known as beri-beri. (c) Deficiency of Vitamin C causes a disease known as -------- (d) Night blindness is caused due to deficiency of -------- in our food. Answers: (a) Rickets (b) Vitamin 'B1' (c) Scurvy (d) Vitamin 'A' R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE Key words: Balanced diet: A balanced diet is a diet that contains a variety of foods that provide adequate amounts of nutrients needed for good health. Beriberi: A disease in which the body doesn't have enough vitamin B1 (thiamin). Carbohydrates: Carbohydrates are essential nutrients which include sugars, fibers and starches. Energy: The ability to do work. Fats: Along with proteins and carbohydrates, one of the three nutrients used as energy sources by the body. Minerals: Minerals are biochemical elements. These are nutrients that organisms need to perform the functions necessary for metabolism. Nutrients: It is a substance available in food that helps us to stay healthy. Proteins: Proteins are the macronutrient needed to build muscle mass. Roughage: Roughage is a food component derived from plants that are not completely broken down by human digestive enzymes. Scurvy: A condition caused by a severe lack of vitamin C in the diet. Starch: Starch is a long chain of sugars that is made by plants. Vitamins: Vitamins are substances that our bodies need to develop and function normally. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE Sorting Materials into Groups Exercises: 1. On what basis can we sorting the materials around us? A. Can be sorted according to shape, colour, use, material of manufacture etc. 2. Name five objects which can be made from wood. A. Table, Chair, Bed, Doors, Bullock cart, Bench, Box, etc. 3. What are the properties of Materials? A. (i) Appearance (ii) Hardness (iii) Soluble or Insoluble (iv)Float or sink (v) Transparency. 4. Select those objects from the following which shine: Glass bowl, plastic toy, steel spoon, cotton shirt. A. Glass bowl and steel spoon. 5. Match the objects given below with the materials from which they could be made. Remember, an object could be made from more than one material and a given material could be used for making many objects Table: Objects Materials A. Book Paper Tumbler Glass Chair Wood Toy Plastic Shoes Leather 6. State whether the statements given below are True or False: (i) Stone is transparent, while glass is opaque. A. False (ii) A notebook has lustre while eraser does not. A. False (iii) Chalk dissolves in water. A. False (iv) A piece of wood floats on water. A. True (v) Sugar does not dissolve in water. A. False (vi) Oil mixes with water. A. False (vii) Sand settles down in water. A. True R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE (viii) Vinegar dissolves in water. A. True 7. Given below are the names of some objects and materials: Water, basket ball, orange, sugar, globe, apple and earthen pitcher Group them as: (a) Round shaped and other shapes (b) Eatables and non eatables A. (a) Round shaped: Basket ball, orange, globe, apple and earthen pitcher. Other shapes: Water and sugar (b) Eatables: Water, orange, sugar and apple Non eatables: Basket ball, globe and earthen pitcher. 8. List all items known to you that float on water. Check and see if they will float on an oil or kerosene. A. (i).Generally, substances have less density than oil and water can float. (ii)For example, few types of wood have densities higher than oil but less than water, so it floats on water (iii) Wooden block, Paper, Balloon, Hair, plastic bottle, wooden logs, Boat etc. will float on water. (iv) A few of these like hair, balloon can float on kerosene or oil. 9. Find the odd one out from the following: a) Chair, Bed, Table, Baby, Cupboard A. Baby (living thing) b) Rose, Jasmine, Boat, Marigold, Lotus A. Boat (not flower) c) Aluminium, Iron, Copper, Silver, Sand A. Sand (not metal) d) Sugar, Salt, Sand, Copper sulphate A. Copper sulphate (not in crystal form) Key words: Hard: Materials which are difficult to compress are called Hard. Soft: Materials which can be compressed or scratched easily are called Soft. Insoluble: Substances do not mix with water and do not disappear even after long time is called Insoluble in water. Lustre: The quality of reflecting light from their surface. Material: The matter of which an object is made, is called material. Metals: Metal is a solid material that conducts heat & electricity, hard, shiny etc.. Opaque: If we cannot see through an object at all, it is an opaque object. For example: wooden door, wall etc. Rough: Some materials have uneven surface and feel rough on touching. Soluble: Materials which dissolve in water are called soluble. Translucent: Materials which partially allow light to pass through them are called Translucent. Transparent: Substances or materials that allow things to be seen through them. Example: Glass, pure water, air, some plastics. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE Separation of Substances 1. Why do we need to separate different components of a mixture? Give two examples. A. Among different components of mixture there are many substances which are harmful or not useful for us. To remove these harmful or unuseful components we need to separate them. Ex: (a) Tea leaves are separated from the liquid with a strainer while preparing tea. (b) Stone pieces from wheat, rice or pulses are picked out by hand. 2. Write various methods of separation of compounds from their mixture.. A. Some simple methods of separating substances that are mixed together. They are 1. Handpicking, 2. Threshing, 3.Winnowing, 4.Sieving, 5.Sedimentation, Decantation And Filtration, 6. Evaporation. 3. Why do we use hand picking method? A. The method of handpicking can be used for separating slightly larger sized impurities like the pieces of dirt and stones. 4. How is grain separated in threshing method? A. The process that is used to separate grain from stalks etc. is threshing. (ii) In this process, the stalks are beaten to free the grain seeds. (iii) Sometimes, threshing is done with the help of bullocks. (iv) Machines are also used to thresh large quantities of grain. 5. What is winnowing? Where is it used? A. (i) Winnowing is used to separate heavier and lighter components of a mixture by wind or by blowing air. (ii) This process is used by farmers to separate lighter husk particles from heavier seeds of grain. 6. How will you separate husk or dirt particles from a given sample of pulses before cooking? A. Husk or dirt particles can be separated by winnowing, being lighter they wall fly away from pulses. 7. What is sieving? Where is it used? A. (i) The process of separating small particles like flour from larger particles by using a device with small holes (sieve) is called sieving. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE (ii) Sieving is used components of a mixture have different sizes. 8. Define the following. (a) Sedimentation, Decantation and Filtration A. Sedimentation: When the heavier component of a mixture settles after water is added to it, the process is called sedimentation. Decantation: A process of separating the lighter liquid by tilting and draining or pouring it into another vessel. Filtration: A purification method that can separate a mixture consisting of a liquid substance and the impurities in it. 9. How will you separate sand and water from their mixture? A. (i) We will separate sand and water by sedimentation and decantation method. (ii) First we leave this mixture for some time. (iii) After some time, the sand which is; heavier is settled down at the bottom. (iv) After that we wall pour water into another container and the mixture will be separated. 10. Is it possible to separate sugar mixed with wheat flour? If yes, how will you do it? A. Yes. Sugar can be separated from wheat flour by sieving. Due to difference in the size of particles, sugar will stay on sieve and wheat flour will pass through it. 11. How would you obtain clear water from a sample of muddy water? A. (i) We will obtain clear water from a sample of muddy water by the process of filtration. (ii) A filter paper is one such filter that has very fine pores in it. (iii)A filter paper folded in the form of a cone is fixed in a funnel. (iv) The mixture is then poured on the filter paper. (v) Solid particles in the mixture do not pass through it and remain on the filter. 12. Fill in the blanks: (a) The method of separating seeds of paddy from its stalks is called -------- A. Threshing (b) When milk, cooled after boiling, is poured onto a piece of cloth the cream (malai) is left behind on it. This process of separating cream from milk is an example of ______ A. Filtration (c) Salt is obtained from sea water by the process of ____________ A. evaporation R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE (d) Impurities settled at the bottom when muddy water was kept overnight in a bucket. The clear water was then poured off from the top. The process of separation used in this example is called ____________ A. Sedimentation and Decantation 13. True or false? (a) A mixture of milk and water can be separated by filtration A. False (b) A mixture of powdered salt and sugar can be separated by the process of winnowing A. False (c) Separation of sugar from tea can be done with filtration A. False (d) Grain and husk can be separated with the process of decantation A. False 14. Lemonade is prepared by mixing lemon juice and sugar in water. You wish to add ice to cool it. Should you add ice to the lemonade before or after dissolving sugar? In which case would it be possible to dissolve more sugar? A. (i) We should add ice after dissolving sugar. (ii)When the temperature is high then more sugar can be dissolved. (iii) After mixing ice it gets cool and less sugar will dissolve in it. 15. What is Evaporation? A. The process of conversion of water into vapour is called evaporation. 16. Define Condensation. A. The process of conversion of water vapour into liquid form is called condensation. 17. Why is water a universal solvent? A. Water can dissolve different kinds of substances. That is why water is commonly called as a universal solvent. 18. What is the difference between Evaporation and Condensation? A. The process of conversion of water into its vapour is called Evaporation. The process of conversation of water vapour into its liquid form is called Condensation. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE Key words Churning: The process of shaking up is called Churning. Condensation: The process of conversation of water vapour into its liquid form is called condensation. Decantation: A process of separating the lighter liquid by tilting and draining or pouring it into another vessel. Evaporation: The process of conversion of water into its vapour is called evaporation. Filtration: A purification method that can separate a mixture consisting of a liquid substance and the impurities in it. Handpicking: The process used to separate slightly larger particles from a mixture by hand is called handpicking. Saturated solution: When no more solute (e.g. Salt) can be dissolved in the amount of solvent (e.g. Water) taken, the solution is said to be saturated solution. Sedimentation: When the heavier component of a mixture settles after water is added to it, the process is called sedimentation Sieving: A method of using a sieve to distinguish small particles from bigger particles. Solution: A mixture of two or more substances that stays evenly mixed. Threshing: Threshing is the process of separating grain from the husks and straw. Winnowing: Winnowing is the method of separating husk from grains with the help of wind. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE Getting to Know Plants 1. Draw the diagram of plant, label the parts and colour it. A. 2. Correct the following statements and rewrite them in your notebook. (a) Stem absorbs water and minerals from the soil. (b) Leaves hold the plant upright. (c) Roots conduct water to the leaves. (d) The number of petals and stamens in a flower is always equal. (e) If the sepals of a flower are joined together, its petals are also joined together. (f) If the petals of a flower are joined together, then the pistil is joined to the petal. A. (a) Root absorbs water and minerals from the soil. (b) Stem holds the plant upright. (c) Stem conducts water to the leaves. (d) The number of petals and sepals in a flower may be different in different plants. (e) If the sepals of a flower are joined together, then its petals may or may not be joined together. (f) If the petals of a flower are joined together, then the stamen may or may not be joined to the petal. 3. Draw (a) a leaf. (b) A taproot and (c) a flower, you have studied for Table 4.3. A. 4. Can you find a plant in your house or in your neighbourhood, which has a long but weak stem? Write its name. In which category will you place it? A. (i) The money plant has a long and weak stem. (ii) It comes under the category of climbers. (iii) Climbers are plants that readily take support on neighbouring structures as they have a weak stem. 5. What are the functions of a stem? A. Main functions of stem in plants. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE (i) Transmission of water and minerals from stem roots to leaves and other plant parts. (ii) Giving support to plant branches, leaves, flowers, fruits and buds 6. Which of the following leaves have reticulated venation? Wheat, Tulsi, maize, grass, coriander (dhania), China rose A. Leaves have reticulate venation are: Tulsi, coriander(dhania) and China rose 7. If a plant has fibrous root, what type of venation do its leaves have? A. (i) Plants with fibrous roots have parallel venation in their leaves. For example, grass, wheat, maize, etc. have fibrous roots with parallel venation. (ii) Fibrous roots with parallel venation Fibrous roots have thin and moderately growing branches arising from the stem. (iii) Parallel venation, on the other hand, has leaves in which the veins are arranged parallel to each other. 8. If a plant has leaves with reticulate venation, what kind of roots will it have? A. (i) Plants with reticulate venation in their leaves are likely to have tap roots. Example: a carrot or a rose plant has leaves with reticulate venation and its roots are called tap roots. (ii)Taproots and reticulate venation In tap roots, there is one main root known as the ‘tap root’ that grows straight down from the stem. (iii) It also has smaller roots known as ‘lateral roots’. (iv) In leaves with reticulate venation, the veins are arranged in a net-like pattern. 9. Is it possible for you to find out whether a plant has taproot or fibrous roots by looking at the impression of its leaf on a sheet of paper? A. (i) Yes, we can recognize the roots of a plant by looking at the leaves. (ii) You can look for the type of roots of the plant and identify the type of leaf. (iii) If the plant has fibrous roots, then its leaves have parallel venation. (iv) If the plant has tap roots, then its leaves have reticulate venation. 10. What are the parts of a flower? A. A flower consists of sepals, petals, stamens, and pistils. A stamen has two parts called the anther and the filament. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE A pistil has three parts called the stigma, style, and ovary. 11. From the following plants, which of them have flowers? Grass, maize, wheat, chilli, tomato, tulsi, peepal, shisham, banyan, mango,jamun, guava, pomegranate, papaya, banana, lemon, sugarcane, potato, groundnut A. (i) The given all plants are flowering plants. (ii) But, in some plants such as tulsi, pipal, sugarcane, etc. the flowers are not visible. (iii) They are so small that they cannot be seen with naked eyes. 12. Name the part of plant which produces food. Name the process. A. (i) The part of plants which prepares food is the leaf. (ii) Leaves of a plant prepare food in the presence of sunlight. (iii) The process of making food by utilizing water and carbon dioxide in the presence of sunlight is called photosynthesis 13. In which part of a flower, you will find the ovary? A. Pistil is the part of the flower that contains the ovary. 14. Name two plants in which one has joined sepals and the other has separate sepals A. Flowers with joined sepals are: Periwinkle (Sadabahar) and Hibiscus (China rose). Flowers with separated sepals are: Rose and Magnolia. Key words Climbers: while those that take support and climb up are called Climbers. Conduct: Conduct is the process of transporting water and nutrients and food in both upward and downward directions through the stem. Creepers: Plants with weak stems that cannot stand upright but spread on the ground are called creepers. Fibrous roots: No main root, all the roots are of same size Herbs: Plants with green and tender stems are called herbs. Lamina: The broad green part of leaf is called Lamina. Lateral roots: The small roots attached to the main root are called lateral roots. Midrib: A prominent line in the middle of the leaf called the midrib. Ovule: Some small bead like structures inside the ovary is called ovules. Parallel Venation: Parallel venation is the term used to describe the arrangement of leaf veins in monocotyledonous plants. The veins are arranged parallel to each other. Petal: The colourful parts of the flower are called sepals. Petiole: The Petiole is the stalk that supports a leaf in a plant and attaches it to the stem. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE Photosynthesis: Photosynthesis is the process through which plants use water and carbon dioxide to create their food, grow and release excess oxygen into the air. Pistil: The innermost part of flower is called the Pistil. Reticulate venation: The design made by veins in a leaf is called the leaf venation. If the design is net like on both sides of midrib is called reticulate venation. Sepal: The small leaf-like structure that surrounds the top of the bud is called Sepal. Shrubs: Plants whose branches grow at the base of the stem and the stem is strong and not too thick are called shrubs. Stamen: The stamen is the structure in the flower after the Petals. Tap root: The main root which is larger and fast growing is called Tap root Transpiration: Transpiration is the process of losing water from the surface of the leaf through stomata. Transpiration helps a plant in cooling the leaves and transporting the nutrients. Trees: Large shaped plants with large stems are called trees. Veins: These lines on the leaf are called veins. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE Body Movements 1. What are joints? How many? What are they? A. (i) The point where two bones meet is called a joint. (ii) Joints are of two types. They are movable and immovable (fixed). (iii) Movable joints are four types namely 1. Ball and socket joint 2. Hinge joint 3. Sliding joint 4. Pivot joint. 2. What is Skeleton? Write the names of the main parts of the skeleton. A. (i) The different bones of different parts of the body combine together to form a single structure or system. This structure is called the skeleton. (ii) Skull, skull, spine, pelvis, arms, legs are the main parts of the skeleton. 3. Some important parts of our body are located in the ribcage and are protected by it. What are they? A. Lungs and heart are some important parts of our body are located in the ribcage and are protected by it. 4. Where are cartilage found in our body? A. The cartilage is present some parts of the ear, nose, between the tips of the rib, eyelids and sternum, between the vertebrae of the vertebral column etc. 5. Differentiate the ball and socket joint from hinge joint. A. Ball and Socket Joint Hinge Joint (i) It has around ball and cup shaped (i) Here only two ends of bones join socket structure. together. (ii) It has 360° rotation in movement. (ii) It has nearly 180° movement. (iii) Its present at shoulders and hip. (iii) Its present at knees and elbows. 6. What would happen if there is a single bone in your fingers? A. If we have a single bone in our fingers. (i) We can’t fold the fingers. (ii) We can’t catch or hold anything. (iii) We can't manage any operations. 7. Draw the neat diagram of skeleton A. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE 8. What are the uses of muscles and bones? A. (i) Muscles helps in the locomotion and movements of the body. (ii)They also provide shape and structure to the body. (iii) Bones provide a base to muscles. (iv)They have a key role in body movements. (v)They also provide the shape of the body. 9. Compile the gait of animals? A. Animal Movement Earthworm By alternate extension and contraction of the body. Snail With the help of a muscular foot. Cockroach With help of three pairs of legs and two pairs of wings. Birds With the help of light bones and wings. Fish By body shape of Streamlined. Snake By a large number of Bones and muscle. 10. Fill in the blanks: (a) Joints of the bones help in the ——————— of the body. A. Movement (b) A combination of bones and cartilages forms the _______ of the body. A. Skeleton (c) The bones at the elbow are joined by a ______________________ joint. A. Hinge joint (d) The contraction of the _____________ pulls the bones during movement. A. Muscles. 11. Indicate true (T) and false (F) among the following sentences. (a) The movement and locomotion of all animals is exactly the same A: (F) (b) The cartilages are harder than bones A: (F) (c) The finger bones do not have joints A: (T) (d) The fore arm has two bones A: (T) (e) Cockroaches have an outer skeleton A: (T) 12. Match the items in Column I with one or more items of Column II Column I Column II Upper jaw have fins on the body Fish has an outer skeleton Ribs can fly in the air Snail is an immovable joint Cockroach protect the heart shows very slow movement have a streamlined body R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE 13. Answer the following: (a) What is a ball and socket joint? A. The rounded end of one bone fits into the hollow end of the other bone. Such a joint allows movement in all directions. This joint is known as the ball and socket joint. (b) Which of the skull bones are movable? A. Lower jaw bone. (c) Why can our elbow not move backwards? A. The elbow has a hinge joint that allows only a back and forth movement. Hence we can't move it backwards. Key words Backbone: A long structure running down the middle of his back is called the backbone (vertebral column). Ball and socket joint: The rounded end of one bone fits into the hollow end of the other bone. Such a joint allows movement in all directions. This joint is known as the ball and socket joint. Bristles: Bristles are hair like structure, connected with muscles. Cartilage: Cartilage is a soft bone that is hard and tough and has flexible tissue. Cavity: Any hollow space or chamber-like part of an animal's body. Fixed joint: Some joints between bones in our body can't move; such joints are called fixed joints. Gait of animals: The "Gait of animals" refers to the pattern of movement of the limbs of animals and humans during locomotion. Hinge joint: Like the hinge of a door, the joint which helps the bones to move in one direction is called a hinge joint. Muscle: A band or bundle of fibrous tissue in a human or animal body that has the ability to contract, producing movement in or maintaining the position of parts of the body. Outer skeleton: The skeleton found outside the body is called outer skeleton. Pelvic bones: The bones with the same shape on both sides are called Pelvic bones. Pivotal joint: The joint that joins the skull to the backbone is called the Pivotal joint. Rib cage: Ribs are bent which join the chest bone and the back bone together to form a box. This is called the rib cage. Shoulder bones: The two bones that bend at the shoulder joint are called Shoulder bones. Skeleton: The different bones of different parts of the body combine together to form a single structure or system. This structure is called the skeleton. Streamlined: A shape that is wide in the middle and narrow at both ends is called Streamlined. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE Living organisms character sticks and habitat 1. What is a habitat? A. The place where organisms live is called habitat. Habitat means a dwelling place (a home). The habitat provides food, water, air, shelter and other needs to organisms. 2. What is Adaptation? A. The presence of specific features or certain habits which enable an organism to live naturally in a place is called adaptation. 3. What adaptations do camel and fish have to survive in their habitats? A. Camel: (i) The body structure of a camel helps it to survive in desert conditions. (ii) Camels have long legs which help to keep their bodies away from the heat of the sand. (iii) They excrete small amount of urine, their dung is dry and they do not sweat. (iv) Since camels lose very little water from their bodies, they can live for many days without water. Fish: (i) Fish have the streamlined shape, helps them move inside water. (ii) Fish have slippery scales on their bodies. These scales protect the fish and also help in easy movement through water. (iii) Fish have flat fins and tails that help them to change directions and keep their body balance in water. (iii) Gills present in the fish help them to use oxygen dissolved in water. 4. How many types of habitats? Write examples. A. (i) There are two types of habitats namely Terrestrial habitat and Aquatic habitat. (ii) Some examples of terrestrial habitats are forests, grasslands, deserts, coastal and mountain regions. (iii) Lakes, rivers and oceans are some examples of aquatic habitats. 5. How is cactus adapted to survive in a desert? A. Adaptation of cactus is as (i) Leaf is replaced by spine to reduce transpiration (ii) Stems carry out photosynthesis (iii) A thick waxy layer surrounds leaf to retain water (iv) Roots of cactus are deeply rooted inside soil to absorb water 6. Fill up the blanks (a) The presence of specific features, which enable a plant or an animal to live in a particular habitat is called ————. A. Adaptation (b) The habitats of the plants and animals that live on land are called ———— habitat. A. Terrestrial (c) The habitats of plants and animals that live in water are called ————habitat. A. Aquatic R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE (d) Soil, water and air are the ———— factors of a habitat. A. Abiotic (e) Changes in our surroundings that make us respond to them, are called ———— A. Stimuli 7. Which of the things in the following list are nonliving? Plough, Mushroom, Sewing machine, Radio, Boat, Water hyacinth, Earthworm A. Plough, Sewing machine, Radio and Boat are nonliving things 8. Give an example of a non-living thing, which shows any two characteristics of living things A. Example: Bus Features: It can move like living beings ; It needs energy to do work 9. Which of the non-living things listed below, were once part of a living thing? Butter, Leather, Soil, Wool, Electric bulb, Cooking oil, Salt, Apple, Rubber A. Butter, Leather, Wool, Cooking oil, Apple and Rubber were once part of a living thing. 10. List the common characteristics of the living things. A. Common characteristics of living things are as follows: (i) Movement (Certain living things such as plants do not move from one place to another as they are fixed to the soil.) (ii) Food (Plants make their own food.), (iii) Growth, (iv) Breathing (Plants have a specialized organ called stomata for exchange of gases.), (v) Get rid of waste, (vi) Giving birth to young ones (Plants produce seeds.), (vii) Responding to stimulus. 11. Explain, why speed is important for survival in the grasslands for animals that live there. (Hint : There are few trees or places for animals to hide in grasslands habitats.) A. Speed is important for survival in the grasslands for animals to avoid predation from their predators. For example Tiger eats deer, to survive deer has to run faster than the tiger. 12. How are trees adapted to the conditions prevailing in mountain regions? A. (i) Trees are normally cone shaped and have sloping branches. (ii) The leaves' of some of these trees are needle-like. (iii) This helps the rainwater and snow to slide off easily. (iv)There could be trees with shapes very different from these that are also present on mountains. 13. How are animals adapted to the conditions prevailing in mountain regions? A. (i) Animals living in the mountain are also adapted to the conditions there. (ii) They have thick skin or fur to protect them from cold. (iii) For example, yaks have long hair to keep them warm. (iv) Snow leopard has thick fur on its body including feet and toes. This protects its feet from the cold when it walks on the snow. (v) The mountain goat has strong hooves for running up the rocky slopes of the mountains. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE Key words Adaptation: The presence of specific features or certain habits which enable an organism to live naturally in a place is called Adaptation. Aquatic habitat: Habitats whose mode of survival is in water are known as Aquatic habitats. Biotic component: The organisms, both plants and animals, living in a habitat are its Biotic components. Excretion: The process of expelling wastes formed during metabolism is called Excretion. Growth: Growth means increase in size. The young ones of all the living things (plants and animals) grow and become bigger in size Habitat: Habitat is a dwelling place for plants and animals that gives them optimum conditions for life. Living: Those organisms that can move, respond to others, breath and reproduce are called Living. Reproduction: The ability of organisms to produce another new organism like themselves is called Reproduction. Respiration: Taking in oxygen and giving out carbon dioxide is called Breathing or External Respiration. Stimulus: The change in the surrounding that make which an organism responds to it is called Stimulus. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE Motion And Measurement Of Distance Exercises: 1. Give two examples each, of modes of transport used on land, water and air. A. (i) Land—Bus, truck, train. (ii) Water—Ship, boat. (iii) Air—Aeroplane, Helicopter. 2. Fill in the blanks: (1) One metre is---------- cm. A. (i) 100 (ii) Five kilometre is -------- m. A. (ii) 5000 (iii) Motion of a child on a swing is ------- A. (iii) periodic (oscillatory) motion (iv) Motion of the needle of a sewing machine is ----- A. (iv) periodic oscillatory (v) Motion of wheel of a bicycle is --------- A. (v) circular 3. Why can a pace or a footstep not be used as a standard unit of length? A. Pace or a footstep not be used as a standard unit of length, Because a pace or a footstep of each and every person is not equal. 4. Arrange the following lengths in their increasing magnitude: 1 metre, 1 centimetre, 1 kilometre, 1 millimetre. A. Increasing magnitude order of length: 1 millimetre < 1 centimetre < 1 metre < 1 kilometre 5. The height of a person is 1.65 m. Express it into cm and mm. A. (a) 1.65 m, (One metre = 100 cm) = 1.65 x 100 cm = 165 cm (b)1.65 x 100 x 10 mm = 1650 mm. 6. The distance between Radha's home and her school is 3250 m. Express this distance into km. A. One kilo meter = 1000m So 3250m = 3250/ 1000 = 3.250 km The distance between Radha's home and her school is = 3.250km 7. While measuring the length of a knitting needle, the reading of the scale at one end is 3.0 cm and at the other end is 33.1 cm. What is the length of the needle? A. The reading of the scale at one end is = 3.0cm The reading of the scale at the other end is = 33.1 cm. Length of the needle = 33.1 cm – 3.0 cm = 30.1 cm. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE 8. Write the similarities and differences between the motion of a bicycle and a ceiling fan that has been switched on. A. Similarities between the motion of a bicycle and a ceiling fan that has been switched on are: (i) The blades of the fan and the wheels of the bicycle are in a circular motion. (ii) The blades of the fan and spokes of the wheels of the bicycle are fixed at a certain point. Differences between the motion of a bicycle and a ceiling fan that has been switched on are: (i) The bicycle is in linear motion, unlike the fan. (ii) The motion of the blades of the fan is periodic whereas that of the cycle is rectilinear. 9. Why would you not like to use a measuring tape made of an elastic material like rubber to measure distance? What would be some of the problems you would meet in telling someone about a distance you measured with such a tape? A. An elastic measuring tape gives incorrect length of the distance between two points. Because: (i) The length of the elastic tape varies and depends upon the force by which it is stretched. (ii) Measurement would vary between 2 or 3 readings even when measured by the same person and by the same elastic tape. (iii) Measurement would also vary if different persons measure the same distance. 10. Give two examples of periodic motion. A. (i) Oscillations of a pendulum. (ii) Motion of swing ; (iii) Motion of earth round the sun. 11. State precautions to be observed while measuring length with the help of a metre scale. A. Precautions are: (i) The initial point of distance must coincide with the zero reading of metre scale. (ii) In some scales, the ends may be broken. You may not be able to see the zero mark clearly. In such cases, you should avoid taking measurements from the zero mark of the scale. You can use any other full mark of the scale, then you must subtract the reading of this mark from the reading at the other end (iii) The eye should be kept in line with the point of measurement. 12. Give the unit for measuring the following: (a) Distance between Delhi and Vijayawada. A. Kilometre (b) Thickness of a coin. A. Millimetre (c) Length of your book. A. Centimetre (d) Length of uniform cloths A. Metre and Centimetre R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE 13. Name the device used to measure the following: (a) Size of your shoulder (b) Your height (c) Your weight (d) Cloth for curtain (e) Length of curved line A. Measuring tape (b) Your height. A. Measuring tape (c) Your weight. A. Weighing balance (d) Cloth for curtain. A. Metre scale or measuring tape (e) Length of curved line A. A long thread and metre scale 14. How many types of motions? What are they? Give two examples for each of the motion: A. There are many types of motion. Some of them are: (i) Linear motion, Ex: Rolling of ball on ground and Moving of bicycle on road, (ii) Spinning motion, Ex: Rotating fan and Wheel of sewing machine. (iii) Oscillatory motion, Ex: Pendulum of clock and Motion of a child on a swing, (iv) Periodic motion, Ex: Pendulum of clock, Motion of a swing and heartbeat. (v) Vibrational motion, Ex: String of a guitar and Surface of drums. (vi) Circular motion, Ex: Rotation of fan and Bicycle wheel. (vii) Random motion, Ex: Motion of football players and Movement of insects. Key words Circular motion: Movement of an object while rotating along a circular path. Distance: The length of the space between two points or places is called distance. Measurement: Comparing an unknown quantity with some known quantity is called Measurement. Motion: Motion is a change in position of an object over time. Periodic motion: Motion that repeats itself after some period of time is called periodic motion. Rectilinear motion: Motion in a straight line is called rectilinear motion. SI units: A unit of measurement which has a fixed value which does not change from person to person or place to place is called a Standard Unit of measurement. Units of measurement: The units used are meters, centimetre, gram, kilogram etc. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE Light, Shadows and Reflections 1. What is light source? Give some examples. A. A substance which gives light is known as a light source. Sun, a glowing bulb, lighted candle are some sources of light. 2. How many types of materials are there based on light transmission? What are they? Explain A. There are 3 types of materials are there based on light transmission. They are (i) Opaque substances: The substances like paper, plank, wood, iron etc, don't allow light to pass through them. These objects form shadows. These are called Opaque substances. (ii) Transparent substances: The substances like glass and air allow light to pass through them and hence we don't get their shadows. Such substances are called Transparent substances. (iii)Translucent substances: The substances such as polythene cover and oily paper partially allows the light to pass through them. Their shadows are unclear. These are called Translucent substances. 3. Rearrange the boxes given below to make a sentence that helps us understand opaque objects. OWS AKE OPAQ UEO BJEC TSM SHAD A. OPAQ UEO BJEC TSM AKE SHAD OWS 4. Classify the objects or materials given below as opaque, transparent or translucent and luminous or non-luminous: Air, water, a piece of rock, a sheet of aluminium, a mirror, a wooden board, asheet of polythene, a CD, smoke, a sheet of plane glass, fog, a piece of red hot iron, an umbrella, a lighted fluorescent tube, a wall, a sheet of carbon paper, the flame of a gas burner, a sheet of cardboard, a lighted torch, a sheet of cellophane, a wire mesh, kerosene stove, sun, firefly, moon. A. (i) Transparent materials: air, water, glass plate, (ii) Translucent Materials: Piece of stone, CD, sheet of aluminium, mirror, wooden board, umbrella, wall, card board sheet, firefly. (iii) Semi-transparent materials: Polythene sheet, smoke, fog, carbon paper, cellophane sheet, a wire mesh. (iv)Illuminates: Sheet of aluminium, mirror, CD, red hot piece of iron, lighted fluorescent tube, flame of gas burner, lighted torch, firefly, moon. v) Non-luminous: Air, water, piece of stone, wooden board, polythene sheet, smoke, fog, umbrella, wall, a carbon paper sheet, cardboard sheet, cellophane sheet, a wire mesh. 5. Why do we get shadows of different shapes of the same object? A. (i) We are getting different shapes of shadows when the object is the same (ii) Because of the straight line path followed by light rays, shadow shape is changed depending upon the position of the light source. (iii) And angle position of the object. (iv) So we can get different shaped shadows for a single or same object. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE 6. Can you think of creating a shape that would give a circular shadow if held in one way and a rectangular shadow if held in another way? A. Yes, there are many things which give a circular shadow if held in one way and a rectangular shadow if held in another way. For example: a cylinder, a circular disc etc. 7. In a completely dark room, if you hold up a mirror in front of you, will you see a reflection of yourself in the mirror? A. (i)Mirror image of any object is formed due to the reflection of light in the mirror from the object. (ii) If you are in a dark room and there is no light. You hold a mirror in front of you; the image will not be formed on the mirror because reflection will not occur from object to mirror in the absence of light. (iii) Mirror image will not formed on a dark room in the absent of light. (iv) Therefore, in a completely dark room, if you hold up a mirror in front of you will not able to see your reflection in the mirror. 8. Why can't we see objects which are behind us? A. (i) Because we see objects due to reflection. (ii) And objects behind us don't get reflected from our eyes. 9. Malati noticed changes in the lengths of her shadows during the day time. She had some doubts about this. What could be those doubts? A. Her doubts are (i) Why sometimes shadows are small and large? (ii) What causes changes in shadow lengths? (iii) Why our shadows always follow us? (iv) Why the change of the length of the shadow in the different times of the day? (v) Can we guess the time when see the shadow? (v) How is the shadow length changes possible? 10. How can you explain the straight line motion of light? A. Light travels in a straight line. (i) Take a bent tube and try to look at an object with the help of this tube. (ii) We will not be able to see the object. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE (iii) Now take a straight tube and try to look at the same object with the help of this tube. (iv) We will be able to see the object clearly. (v)This shows that light travels in a straight line. 11. Explain how we can make pinhole camera. A. A pinhole camera is easy to make. (i) Take two boxes of cardboard such that one can slide into another with no gap in between them. (ii) Cut open one side of each box. On the opposite face of the larger box, make a small hole in the middle. (iii) In the smaller box, cut out from the middle a square with a side of about 5 to 6 cm. (iv) Cover this open square in the box with tracing paper (translucent screen). (v) Slide the smaller box inside the larger one with the hole, in such a way that the side with the tracing paper is inside. (vi) Pinhole camera is ready for use. KEY WORDS Luminous: Objects that emit or give out light or energy of their own. Mirror: A smooth shiny surface of glass which reflects light is called a mirror. Opaque: The substances like paper, plank, wood, iron etc, don't allow light to pass through them. These objects form shadows. This is called Opaque. Pinhole camera: A pinhole camera is a simple camera without a lens with a tiny aperture (the so-called pinhole). Reflection: When light falls on any object, it rebounds back. This is called Reflection. Shadow: Shadow is the dark space behind an opaque object where light does not reach. Translucent: The substances such as polythene cover and oily paper partially allows the light to pass through them. Their shadows are unclear. This is called Translucent. Transparent: The substances like glass and air allow light to pass through them and hence we don't get their shadows. This is called Transparent. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE Electricity and Circuits 1. Describe the cell used in the torchlight. A. i) The cell consists of a cylindrical metal can. ii) Its heaviness suggests that it is filled with some chemicals. iii) The protrusion on one end is due to a carbon rod in the centre. iv) At the top of the cell a metal cap is fixed. The entire can is sealed. v) (+) and (-) signs on a cell indicate the two terminals of a cell. (Do not connect the two terminals of a cell with a single wire.) 2. Draw a neat diagram of the bulb and label the parts. A. 3. What is an electric circuit? Explain with a diagram. A. The electric circuit is an arrangement that provides a pathway for the flow of electric current. It is a device comprising of switches, bulbs, wires and an electric cell. i) A closed circuit consist of a cell (power source), a bulb, and connecting wires. ii) An electric circuit provides a complete path for electricity to flow between the cell and the bulb. iii) The two electric supply wires (called live and neutral) are connected to the two terminals of the bulb through a switch. iv) When the switch is closed (put on) the circuit provides complete path for electricity. 4. What are the parts of a torch-light? A. The parts of a torch-light are a bulb, Reflector, Plastic casing, electric cells, , a slide switch, a glass cover and a metal spring. 5. Fill in the blanks: (a) A device that is used to break an electric circuit is called ------------ A. Switch (b) An electric cell has --------- terminals. A. Two 6. Mark True' or 'False' for following statements: (a) Electric current can flow through metals. A. True R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE (b) Instead of metal wires, a jute string can be used to make a circuit. A. False (c) Electric current can pass through a sheet of thermocol. A. False 7. Explain why the bulb would not glow in the arrangement shown in Fig. 9.13 A. The circuit is cut in the middle in the arrangement shown in Figure 9.13. Hence bulb does not glow up. 8. Complete the drawing shown in Fig. 9.14 to indicate where the free ends of the two wires should be joined to make the bulb glow. A. 9. What is a switch? A. Electric Switch is an electrical device which can make or break an electric circuit. 10. What is the purpose of using an electric switch? Name some electrical gadgets that have switches built into them. A. Purpose of using an electric switch: Switch is used to complete or break an electric circuit to use an electric appliance according our convenience. Some electrical gadgets that have switches built into them: Electric lamps, cooler, washing machines, table fan, TV, radio, etc.. 11. What are insulators and conductors? A. Substances which allow electric current to flow through them are known as conductors. Substances which do not allow electric current to flow through them are known as insulators. 12. Classify the following into conductors and insulators: Water, Plastic pen, Pencil lead, Dry cotton cloth, Wet cotton cloth, Dry wood, Wet wood Conductors: Water, Pencil lead, Wet cotton cloth, Wet Wood. Insulators: Plastic Pen, Dry cotton cloth, Dry wood. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE 13. Would the bulb glow after completing the circuit shown in Fig. 9.14 if instead of safety pin we use an eraser? A. No current flows through the eraser so the bulb does not glow up. 14. Would the bulb glow in the circuit shown in Fig. 9.15? A. No, the bulb will not glow. 15. Using the "conduction tester" on an object it was found that the bulb begins to glow. Is that object a conductor or an insulator? Explain. A. If a bulb begins to glows up when a substance is connected in the "conduction tester ", then the substance is a conductor. Because electricity flows through it. 16. Why should an electrician use rubber gloves while repairing an electric switch at your home? Explain. A. The rubber gloves used by the electrician are electrically insulators and thus prevent the electrician from getting electrocuted. Hence, when repairing an electric switch, an electrician wears rubber gloves. 17. The handles of the tools like screwdrivers and pliers used by electricians for repair work usually have plastic or rubber covers on them. Can you explain why? A. Plastic and rubber are both electrically insulators. As a result, they protect from electric shock. Key words Bulb: An electric bulb is a device which produces light when electricity is passed through its terminals. Conductors: Substances which allow the flow of electricity is known as conductors. Electric cell: An electric cell is a device, which converts chemical energy into electrical energy. Electric circuit: A path for an electric current to flow is called an electric circuit. Filament: The bulb has two thick contact wires in the centre with a thin wire attached between them. This thin wire is called filament. Insulators: Substances which do not allow the flow of electricity is known as insulators. Switch: A switch is an electric device that is used to break a circuit. When the switch is in 'OFF' position, then the circuit is not complete. Terminal: A terminal is the point at which a conductor from a component, device comes to an end. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE Fun With Magnets 1. How was the magnet discovered? A. Magnus, a shepherd, was herding sheep 2500 years ago in an area called Magnesia in Greece. He placed an iron-clad stick and nailed sandals on the stone to take rest.Surprisingly the iron-rimmed stick stood upright on the stone and the nailed sandals stuck to the stone. People were amazed to see this event and noticed that not only the magnus stick, but also the objects made of iron were also attracted. Later many such stones were discovered around the world. The rocks are named after the shepherd, and the ore is called magnetite. Thus the magnet discovery took place. 2. Fill in the Blanks. (i) Artificial magnets are made in different shapes such as __________ , __________ and ____________. A. Bar magnet, horse-shoe magnet, cylindrical or a ball-ended magnet. (ii)The materials which are attracted towards a magnet are called........... A. Magnetic material. (iii) Paper is not a........... material. A. Magnetic (iv) In olden days, sailors used to find direction by suspending a piece of.......... A. Magnet (v) A magnet always has............poles. A.Two 3. State whether the following statements are true or false: (i) A cylindrical magnet has only one pole. (×) - False (ii) Artificial magnets were discovered in Greece. (√) - True (iii) Similar poles of a magnet repel each other. (√) - True (iv) Maximum iron filings stick in the middle of a bar magnet when it is brought near them. (×) - False (v) Bar magnets always point towards North-South direction. (√) - True (vi) A compass can be used to find East-West direction at any place. (√) - True (vii) Rubber is a magnetic material. (×) - False 4. It was observed that a pencil sharpener gets attracted by both the poles of a magnet although its body is made of plastic. Name a material that might have been used to make some part of it. A. (i) The blade of a pencil sharpener is made of iron which is a magnetic material. (ii) Since magnets can attract objects made of magnetic materials, a pencil sharpener gets attracted towards both poles of a magnet. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE 5. Column I shows different positions in which one pole of a magnet is placed near that of the other. Column II indicates the resulting action between them for each situation. Fill in the blanks. Column I Column II N-N ……. N -…… Attraction S-N ……. ……- S Repulsion A. Column I Column II N-N Repulsion N-S Attraction S-N Attraction N-S Repulsion 6. Write any two properties of a magnet. A. (i) Each magnet has two magnetic poles-North and South. (ii) A freely suspended magnet always aligns in N-S direction. (iii) Opposite poles of two magnets attract each other whereas similar poles repel one another. 7. Where are poles of a bar magnet located? A. Poles are located at the ends of bar magnet. These are North Pole and South pole. 8. A bar magnet has no markings to indicate its poles. How would you find out near which end is its north pole located? A. (i) Take a magnet, mark one end of it and hang it from a wooden stand. Make sure that the magnet rotates freely. (ii) Mark two points on the earth showing the positions of the ends of the magnet when the magnet is at rest (iii) A freely suspended bar magnet is always It comes to rest especially in the north-south direction. (iv) The end facing north can be found as North Pole. 9. You are given an iron strip. How will you make it into a magnet? A. (i) Take a rectangular piece of iron. Place it on the table. (ii) Now take a bar magnet and place one of its poles near one edge of the bar of iron. (iii) Without lifting the bar magnet, move it along the length of the iron bar till you reach the other end. (iv) Now, lift the magnet and bring the pole (the same pole you started with) to the same point of the iron bar from which you began. (v) Repeat this process about 30-40 times. (vi) Bring a pin or some iron filings near the iron bar to check whether it has become a magnet. (vii) If not, continue the process for some more time. (viii) Remember that the pole of the magnet and the direction of its movement should not change. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE 10. How is a compass used to find directions? A.(i) A compass is a device that consists of a magnetic needle and a dial with directions marked on it. (ii) Its needle can freely rotate and align itself in the North-South direction, which helps in finding direction. 11. A magnet was brought from different directions towards a toy boat that has been floating in water in a tub. Affect observed in each case is stated in Column I. Possible reasons for the observed affects are mentioned in Column II. Match the statements given in Column I with those in Column II. Column I Column II Boat gets attracted towards the Boat is fitted with a magnet with magnet north pole towards its head Boat is not affected by the magnet Boat is fitted with a magnet with south pole towards its head Boat moves towards the magnet if Boat has a small magnet fixed along north pole of the magnet is brought its length near its head Boat moves away from the magnet Boat is made of magnetic material when north pole is brought near its head Boat floats without changing its Boat is made up non-magnetic direction material A. Column I Column II Boat gets attracted towards the magnet Boat is made of magnetic material. Boat is not affected by the magnet Boat is made of nonmagnetic material. Boat moves towards the magnet if north Boat is fitted with a magnet with a South pole of the magnet is brought near its Pole towards its head. head Boat moves away from the magnet when Boat is fitted with a magnet with North north pole is brought near its head Pole towards its head. Boat floats without changing its direction Boat has a small magnet fixed along its length. Key words Compass: A directional device made based on a Magnetic Directional Property is called Compass. Magnet: An object which attracts materials like iron, cobalt and nickel; is called Magnet. Magnetite: Magnetite is an ore of iron which has magnetic properties North pole: The end that point towards north direction is the North pole of the magnet. South Pole: The end that points towards south direction is the South Pole of the magnet. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE Air around us 1. What is the composition of air? A. Air is a mixture of nitrogen, oxygen, carbon dioxide, water vapour and a few other gases. Some dust particles may also be present in it. 2. What is air? Name the major constituents of air. Also give their volume proportions in air. A. (i) Air is a mixture of gases. (ii) The major constituents of air are nitrogen, oxygen together 99%. (iii) The remaining 1% is carbon dioxide and few 9ther gases and water vapour. The percentage composition of constituents of air is as given below: 3. Which gas in the atmosphere is essential for respiration? A. Oxygen is essential for respiration in the atmosphere. 4. How will you prove that air supports burning? A. (i) Fix two small candles of the same length on a table. (ii) Light both the candles. (iii) Cover one of the candles with an inverted glass tumbler. (iv) Observe both the candles carefully. (v) You must have observed that the candle covered with glass tumbler got extinguished after some time. (vi) This seems that a component inside of the glass tumbler, which supports burning. (vii) This component of air, which supports. Burning, is known as oxygen. By this activity it can be proved that air supports burning. 5. Explain why mountaineers carry oxygen cylinders with them? A. At higher altitudes, the oxygen content decreases which makes breathing difficult for mountaineers. That's why they carry oxygen cylinders. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE 6. Name the major gas present in the (a) inhaled air (b) exhaled air. A. (a) Inhaled air present: Oxygen (b) Exhaled air present: Carbon dioxide. 7. How will you show that air is dissolved in water? A. (i) Take some water in a glass or metal container. (ii) Heat it slowly on a tripod stand. (iii) We will observe tiny bubbles of water visible coming out from the bottom of the container. (iv) These tiny bubbles are coming due to the air dissolved in water. This shows that air is dissolved in water. 8. How will you prove that soil contains air in it? A. (i) Take a lump of dry soil in a beaker or a glass. Add water to it and note what happens. (ii) We observe bubbles coming out from soil. (iii) These bubbles indicate the presence of air in the soil. (iv) When the water is poured on the lump of soil, it displaces the air which is seen in the form of bubbles. 9. Why does a lump of cotton wool shrink in water? A. Lump of cotton wool has air among gaps of cotton fibres. When water replaces the air from these gaps, the cotton lump becomes heavy and also shrinks due to removal of air gaps. 10. How Is the oxygen in the atmosphere replaced? A. (i) In photosynthesis process, plants make their own food and oxygen is produced along with it. (ii) Plants also consume oxygen for respiration, but they produce more of it than they consume. (iii) The balance of oxygen and carbon dioxide in the atmosphere is maintained through respiration in plants and animals and by the photosynthesis in plants. 11. The layer of air around the earth is known as........... A. Atmosphere. 12. The component of air used by green plants to make their food, is........ A. Carbon di oxide. R Sailaja – S.A (P.S) – SPSR NELLORE 6TH CLASS www.ignitephysics.net GENERAL SCIENCE 13. List five activities that are possible due to the presence of air. A. Activities those are possible due to the presence of air. (i) Respiration, which is very important for survival is possible because of the presence of air. (ii) Photosynthesis (iii) Generation of electricity by wind mills (iv) Winnowing (it is the process of separation of grains from husk with the help of air) (v) Our clothes dry faster on windy days due to the presence of air. 14. How do plants and animals help each other in the exchange of gases in the atmosphere? A. Plants take in carbon dioxide during photosynthesis and give out oxygen into the atmosphere, while animals take in oxygen and breathe out carbon dioxide during respiration. In this way, plants and animals help each other in the exchange of gases in the atmosphere. 15. Name a device which uses wind energy to generate electricity. A. Windmills use the wind energy to convert wind energy into electrical energy Key words Atmosphere: The layer of air around the earth is known as Atmosphere. Carbon dioxide: Carbon dioxide is a colourless and non-flammable gas at normal temperature and pressure. Composition of air: 78% nitrogen, 21% oxygen and 1 % other gases and water vapour. Oxygen: Oxygen is a colourless, odourless, tasteless gas essential to living organisms, Nitrogen: Nitrogen is a colourless gas that has no smell and is usually found in atmosphere. Smoke: Smoke is a collection of tiny unburnt particles – very small carbon particles and tiny droplets of water vapour. Windmill: A windmill is defined as a machine that converts the kinetic energy of the wind into mechanical energy. R Sailaja – S.A (P.S) – SPSR NELLORE