202110186-APEX-STUDENT-WORKBOOK-SCIENCE-G06-PART2

Science Workbook_6_P_2.pdf 1 18-10-2019 17:15:23 Name: ___________________________________ Section: ________________ Roll No.: _________ School: __________________________________

Table of Contents 1 22 9 PLANTS: PARTS AND FUNCTIONS 39 12 SIMPLE ELECTRIC CIRCUITS 62 13 LEARNING HOW TO MEASURE 79 14 MOVEMENTS IN ANIMALS 99 15 LIGHT, SHADOWS AND IMAGES 100 PROJECT BASED PRACTICE QUESTIONS ADDENDUM: ADDITIONAL AS- BASED PRACTICE QUESTIONS TABLE OF CONTENTS

9. PLANTS: PARTS AND FUNCTIONS SESSION 1 PARTS OF PLANT, ROOTS 1.1 Mind Map SESSION 1. PARTS OF PLANT, ROOTS 1

1.2 Terminology i. Tap root –is the main root in some plants which becomes thick and possesses thin rootlets. ii. Fibrous roots –are the small, hair–like roots arising from the base of the stem. iii. Lateral Root –The rootlets of tap root are called as lateral roots. iv. Rootlets –are the tiny and thin lateral roots arising from the main root of plants. 1.3 Key Concepts i. A plant body consists mainly of root, stem and flower. Small leaves and buds are borne on branches present on the stem. ii. Plants vary in shape and size of its leaf, roots and colors of flower. iii. Roots are broadly categorized as tap root and fibrous root. iv. In some plants only a single, thickened main root is present. It is called as tap root which gives rise to numerous thin rootlets called as lateral roots. v. In certain plants, small, thin, hair like roots arise from the base of stem. These are called fibrous roots. vi. Roots help the plants to fix tightly to the soil, so that it cannot be uprooted easily. vii. Roots also help in absorption of water and minerals from the soil. 1.4 Conceptual Understanding Q1. What are the important parts of a plant? ([Refer to TB page 92 Q1] A. The most important parts of a plant include Stem, Leaf and Roots. Flowers, Buds and Fruits are other essential parts of plants. Q2. How will you tell, which part of a plant is the stem and which is the root? [Refer to TB page 92 Q2] A. i. The stem is usually the part of the plant that grows above the ground and it bears the structures like leaves, flowers, fruits, buds and branches. ii. The stem may be green and tender, hard or woody, or branched and provide struc- ture to the plant. SESSION 1. PARTS OF PLANT, ROOTS 2

iii. However, roots are usually the part of the plant that grows under the ground in the soil. iv. They are mostly brown in colour and help in absorption of water and minerals from the soil. Q3. John has no place in his house but he wants to plant vegetables like tomato in his house. Suggest him different ways to do so. [Refer to TB page 92 Q4] A. For planting vegetables like tomato in his house, John can follow the ways given below: i. John can take some fertile soil in a polythene bag. ii. In this soil, he can put tomato seeds or directly put tomato plant. iii. With this arrangement, this plant could be put in the front yard of the house where sun light falls. iv. This arrangement can also be put on the terrace or any other part of the house where appropriate sunlight falls. 1.5 Experimentation and Field Investigation Q1. How can you show that plants absorb water through their roots? [Refer to TB page 92 Q11] A. i. Take two glass tumblers filled with water. ii. Collect two plants having soft stems, along with their roots. iii. Put one plant in water without ink and the other plant with water containing red ink. SESSION 1. PARTS OF PLANT, ROOTS 3

iv. Place them in their respective tumbler. v. If we observe the plants after 2 –3 hours, we would see red spots on the stem of the plant placed in the tumbler with coloured water. vi. Thus, we can conclude that roots of a plant absorb water along with the minerals dissolved in it from the soil. 1.6 Communication Through Drawing and Model Making Q1. Collect any plant from your surroundings. Draw its root structure. What can you say about its root system? [Refer to TB page 92 Q3] A. i. In some plants, main root becomes thick and has thin rootlets. ii. The main root is known as tap root and rootlets are called lateral roots. SESSION 1. PARTS OF PLANT, ROOTS 4

iii. In some plants, we find small hair–like roots arising from the base of the stem. iv. This type of root system is known as fibrous root. Here all roots are similar and there is no main root. Q2. Explain the various parts of a plant with the help of a diagram. [Refer to TB page 92 Q9] A. SESSION 1. PARTS OF PLANT, ROOTS 5

i. Flower : It is usually the most attractive part of the plant carrying the reproductive structures for plant reproduction. ii. Leaf : It is the most important part of the plant where transpiration and photosyn- thesis take place. iii. Fruit : This is the yield of the plant. iv. Stem : It is usually the part of the plant that grows above the ground and bears structures like leaves, flowers, fruits, buds and branches. v. Roots : They usually grow under the ground in the soil, provide the plant anchor- age to the soil and help in absorption of water and minerals from the soil. 1.7 Application to Daily Life, Concern to Bio Diversity Q1. In Activity 1, your teacher suggested not to harm other plants when you collect plants for observation. Why did she suggest so? [Refer to TB page 92 Q15] A. While collecting plants for observation, our teacher suggested not to harm other plants as: i. Plants are our resources for many things like food, medicines, shelter etc. ii. Plants play a major role in maintaining balance in our environment and provide habitat for a number of organisms. iii. They keep the atmosphere replenished with oxygen. iv. They hold the soil firmly and also provide shade. SESSION 1. PARTS OF PLANT, ROOTS 6

SESSION 2 PARTS OF LEAF 2.1 Mind Map SESSION 2. PARTS OF LEAF 7

Stomata 2.2 Terminology i. Petiole –is the stalk–like structure by which a leaf is attached to the stem. ii. Lamina –is the flat, expanded area of the leaf. iii. Stomata –are pores present on the surface of leaf surrounded by bean–shaped guard cells which help in the exchange of gases between the plant and the atmosphere. iv. Veins –are the lines present on the surface of leaf. v. Midrib – is the prominent long vein present in the middle of the lamina of leaf. vi. Veinlets –are the fine divisions of veins that branch out from the midrib. vii. Venation –is the arrangement of veins on the lamina of leaf. viii. Reticulate venation –is the arrangement of veins in a web–like pattern on the leaf lamina. ix. Parallel venation –refers to parallel arrangement of veins on the lamina of leaf. x. Transpiration –is the process of loss of excess water through the stomata and other parts of the plant in the form of vapours. xi. Photosynthesis –is the process by which green plants prepare their food in the presence of sunlight. 2.3 Key Concepts i. The shape and size of leaf vary from plant to plant but the function remains the same. SESSION 2. PARTS OF LEAF 8

ii. Leaves carry on two major functions in plants. These are photosynthesis and transpi- ration. iii. Photosynthesis is the process of food production in plants in the presence of sunlight. iv. Transpiration helps plant to get rid of excess water. Leaves are also the site of gaseous exchange. v. Exchange of gases takes place with the help of minute openings called stomata present in the leaf lamina. vi. Structurally a leaf consists of a leaf base, a small stalk–like structure called petiole, and a flat expanded surface called lamina. vii. Various line–like structures are present over the leaf lamina called as veins. viii. The central prominent vein called midrib, veins and still smaller branches called vein- lets together form a web–like pattern on the leaf surface called venation. ix. Leaf venation is of two types namely –Reticulate venation and Parallel venation. 2.4 Conceptual Understanding Q1. What will happen if a plant does not have any leaves? [Refer to TB page 92 Q5] A. If the plants do not have any leaves : i. Plants would not be able to make their own food as leaves play an important role in this activity. ii. Excess of water in the plant is removed in the form of vapours from the leaf surface by the process called transpiration, which would not happen. iii. The exchange of gases would not take place as there will be no stomata. iv. In the absence of all these vital processes, the plant would not give the desirable yield and would not grow at all. Q2. What type of venation is found in the leaves of plants with fibrous roots? [Refer to TB page 92 Q7] A. Plants with fibrous roots have parallel venation in the leaves. SESSION 2. PARTS OF LEAF 9

Q3. If the leaves have reticulate venation what would be the type of root? [Refer to TB page 92 Q8] A. i. If the leaves have reticulate venation, the plant will have a primary main and long root from which small lateral roots grow. ii. The roots go much deeper into the soil as compared to fibrous roots. iii. These roots cannot be separated from the soil easily. iv. This type of root is called tap root. Q4. Rajani said ‘Respiration takes place in leaves. Is she correct? How can you support this statement? [Refer to TB page 92 Q12] A. Yes, Rajni’s statement that respiration takes place in leaves is correct. i. Small pores surrounded by bean–shaped cells, together called stomata are present in the leaves. ii. These stomata act like nose of the leaf. iii. These help in the exchange of gases between the plant and the atmosphere. 2.5 Information Skills and Projects Q1. Collect the leaves of various plants. Prepare a herbarium. Write a brief report on their shape, size and venation. [Refer to TB page 92 Q13] A. Students’ Activity Herbarium (plural: herbaria) – is a collection of preserved plant specimens. These spec- imens may be whole plants or plant parts: these will usually be in a dried form mounted on a sheet. Sample : SESSION 2. PARTS OF LEAF 10

After preparing the herbarium, complete the information in the table given below. ( Stu- dents’ Activity) Name of the Venation in the Shape of the Size of the plant leaf leaf leaf SESSION 2. PARTS OF LEAF 11

Q2. Prepare a greeting card with dry leaves. [Refer to TB page 92 Q14] A. Students’ Activity The student can prepare a greeting card with dry leaves in his own way using his imagi- nation and creativity. 2.6 Communication Through Drawing and Model Making Q1. Explain the parts of a leaf with the help of a diagram. [Refer to TB page 92 Q10] A. SESSION 2. PARTS OF LEAF 12

SESSION 3 STEM 3.1 Mind Map SESSION 3. STEM 13

3.2 Terminology i. Stem –is the main body or stalk of a plant or shrub, typically rising above the ground but occasionally underground that supports other parts like leaf, flower or fruit. ii. Sub–branches – are parts of a tree that grow out from stem or axis of a tree, shrub, or other plant as divisions or subdivisions of the stem. iii. Tubers –are swollen, fleshy, usually underground outgrowths of the stem or rhizome of a plant having buds that can produce new plants. iv. Flowers –are usually the coloured parts of a plant that produce seeds and consist of the reproductive organs. v. Petals –are often the brightly coloured parts of a flower immediately surrounding the reproductive organs. vi. Buds –are small swellings on a plant from which a shoot, leaf, or flower usually develops. 3.3 Key Concepts i. Stem is the upper ground part of the plant which provides support to the plant. ii. The stem bears branches and sub branches that has leaves, flowers and fruits. iii. Stem helps in transport of water and minerals absorbed by the roots to different parts of the plant. iv. In some plants such as potatoes, turmeric etc., stem is modified into bulge and stores food materials. v. Stem also bears flowers that are another important part of the plant which attract insects for pollination and produce fruits. 3.4 Conceptual Understanding Q1. How does the stem help the plant? [Refer to TB page 92 Q6] A. The stem of a plant serves the following functions: i. It provides support to the plant. ii. It forms the main axis of the plant and bears the leaves, buds, flowers, fruits etc. SESSION 3. STEM 14

iii. It helps in transport of water and minerals absorbed by the roots to different parts of the plant. iv. Stems in some plants like Potato, yam, ginger, onion etc., though present in soil, are actually stems and store food within them. 3.5 Appreciation and Aesthetic Sense, Values Q1. Observe a plant which has healthy green leaves and beautiful flowers. Write your feel- ings about the plant in your notebook. [Refer to TB page 92 Q16] A. i. A green and healthy plant indicates that it is getting all the necessary nutrients and is free from pests and insects. ii. The good health indicates that it is planted in fertile soil. iii. Also, this shows that the plant is getting enough sunlight and water, and so, in turn is yielding beautiful flowers and fruits. iv. The greenery of the plant adds beauty to the nature and our surroundings. —— CCE Based Practice Questions —— AS1-Conceptual Understanding Very Short Answer Type Questions 1. State true or false. [Refer to Session 9.1 ] (i) All plants have similar types of roots. [] (ii) In tap root system, there is a main root. [] (iii) The rootlets found on the main root are called fibrous roots. [ ] SESSION 3. STEM 15

2. State true or false. [Refer to Session 9.2 ] (iv) Leaves are a part of the plant. [ ] ] (v) All the leaves we see around us are similar. ] ] [ ] ] (vi) We should not pluck leaves from plants. ] ] [ (vii) Leaves have a midrib. [ (viii) Lamina is a part of the leaf. [ (ix) Rotten leaves cannot be used as manure for plants. [ (x) The arrangements found on a leaf are known as petiole. [ (xi) All the leaves found on the same plant are similar in size and shape. [ 3. Answer the following questions in one sentence. [Refer to Session 9.2 ] (xii) What should we do with rotten leaves? (xiii) What is the flat portion of the leaf called? (xiv) What happens when we burn all the waste and rotten leaves? (xv) What is generally the colour of the leaf you see around you? CHAPTER 9. PLANTS: PARTS AND FUNCTIONS 16

4. State true or false. [ ] [Refer to Session 9.3 ] [ ] [ ] (xvi) Stem supports the plant. [ ] [ ] (xvii) We should not damage the stem of a plant. (xviii) Food does not get stored in the stem. (xix) Garlic is a modified stem which is used in cooking. (xx) Some stems bulge in size due to the storage of food material. 5. Answer the following questions in one sentence. [Refer to Session 9.3 ] (xxi) Name one plant in which the food is stored in their stem. (xxii) Name one plant in which the food is not stored in their stem. Short Answer Type Questions 6. Answer the following questions in 3-4 sentences. (i) [(Session 9.1)] What are the different parts of a plant? (ii) [(Session 9.1)] What are tuberous roots? Give examples. Can they be eaten raw? Long Answer Type Questions 7. Answer the following questions in 6-8 sentences. (i) [(Session 9.1)] In which type of root system are lateral roots absent? What is the relation between the root system and the venation seen in leaves? CHAPTER 9. PLANTS: PARTS AND FUNCTIONS 17

(ii) [(Session 9.1)] Describe different types of roots and write a few lines about them. AS2-Asking questions and making hypothesis Long Answer Type Questions 8. Answer the following questions in 6-8 sentences. (i) [(Session 9.1)] Archana observed that when her brother tied a small polythene bag around the leaves of a plant for a few hours, there were small droplets of water inside bag. What questions might Archana have in her mind? AS3-Experimentation and field investigation Short Answer Type Questions 9. Answer the following questions in 3-4 sentences. (i) [(Session 9.1)] Take few seeds of a carrot plant and sow them in the soil. After a few days observe the type of roots the plant has developed. What do you observe? Long Answer Type Questions 10. Answer the following questions in 6-8 sentences. (i) [(Session 9.3)] How will you show that stems carry water? AS4-Information skills and projects Long Answer Type Questions 11. Answer the following questions in 6-8 sentences. (i) [(Session 9.2)] Collect leaves from five different plants. Draw their structure and make a table noting down their venation, size, shape and root system. AS5-Communication through drawing and model making Long Answer Type Questions 12. Answer the following questions in 6-8 sentences. (i) [(Session 9.1)] Observe the given diagram and label its parts. CHAPTER 9. PLANTS: PARTS AND FUNCTIONS 18

AS6-Appreciation and aesthetic sense, Values Short Answer Type Questions 13. Answer the following questions in 3-4 sentences. (i) [(Session 9.2)] Appreciate the role of leaves in plants. AS7-Application to daily life, concern to bio diversity Short Answer Type Questions 14. Answer the following questions in 3-4 sentences. (i) [(Session 9.1)] Give some examples where you come across adaptation in plants. CHAPTER 9. PLANTS: PARTS AND FUNCTIONS 19

Objective Questions AS1-Conceptual Understanding 15. Choose the correct answer. (i) help to fix the plant firmly in the soil. (A) Roots (B) Stem (C) Branches (D) Water (ii) Plants prepare food by a process called . (A) respiration (B) digestion (C) photosynthesis (D) transpiration (iii) Banana oil is made from . (A) bananas (B)flax seeds (C) petroleum (D) potatoes (iv) are swellings on a plant from which a shoot, a leaf or a flower develops. (A) Buds (B) Bulbs (C) Tubers (D) Roots (v) Which of the following does not store food in their roots or stems? (A) Beet root (B) Spinach (C)Sweet potato (D) Carrot (vi) The flat portion of the leaf is called (A) Lamina (B) Leaf base (C) Petiole (D) Spores CHAPTER 9. PLANTS: PARTS AND FUNCTIONS 20

(vii) The long vein present in the middle of the lamina is called . (A) petiole (B) leaf base (C) midrib (D) stalk (viii) acts as a skeleton of the leaf. (A) Petiole (B) Midrib (C) Venation (D) Lamina (ix) Plants with roots have venation. (A) Tap, parallel (B) Fibrous, reticulate (C)Fibrous, parallel (D)Tap, fibrous (x) are useful in the exchange of gases between the plant and atmosphere. (A) Lamina (B) Stem (C) Midrib (D) Stomata (xi) In the process of , water is released from plants in the form of vapour. (A) transpiration (B) photosynthesis (C) transportation (D) osmosis (xii) attract insects for pollination. (A) Plants (B) Flowers (C) Stems (D) Leaves CHAPTER 9. PLANTS: PARTS AND FUNCTIONS 21

12. SIMPLE ELECTRIC CIRCUITS SESSION 1 CELL, BULB, THE STORY OF BULB 1.1 Mind Map SESSION 1. CELL, BULB, THE STORY OF BULB 22

1.2 Terminology i. Electricity – A form of energy resulting from the existence of charged particles. ii. Electric cell – A device, such as a battery, that is capable of changing some form of energy, such as chemical energy or radiant energy, into electricity. iii. Light bulb –A light–emitting device that consists of a gas–filled glass tube which is used inside electric light fixtures and flashlights. iv. Terminals –A point of connection for closing an electric circuit. v. Filament –A conducting wire. 1.3 Key Concepts i. A cell is a cylindrical metal can filled with chemicals and capable of generating elec- trical energy. ii. It has got a protrusion towards one end, that terminal is called as positive terminal and opposite to it is negative terminal. iii. A bulb is a device capable of converting electricity into light. iv. It consists of two terminals and a filament. It glows and emits light. SESSION 1. CELL, BULB, THE STORY OF BULB 23

1.4 Conceptual Understanding Q1. In a bulb, the part which gives us light is [Refer to TB page 120 Q3] a) Metal base b) Glass chamber c) Filament d) Terminals. A. In a bulb, the filament gives us light. 1.5 Appreciation and Aesthetic Sense, Values Q1. You have studied the story of Thomas Alva Edison. Write a note appreciating his efforts in inventing the bulb. [Refer to TB page 121 Q11] A. i. Many scientists worked hard for many years before Edison for inventing a bulb but no one succeeded. Eventually, Thomas Alva Edison was the first scientist who succeeded in inventing a light bulb. ii. Edison invented a bulb which could work effectively for a number of days. iii. We appreciate his genius, intelligence, diligence and patience which lead to this important invention, thereby influencing our lives in an important way. iv. Edison was inquisitive in nature and had learned science by performing experi- ments himself. v. Like him, we must also keep the curiosity and inquisitiveness alive in our learning for a better understanding. Q2. If you put the switch on, a light will glow, a fan will rotate, an iron box heats up etc. All these different functions will be performed by electricity. How do you feel about the comforts given by this great invention to human beings? [Refer to TB page 121 Q13] A. i. Electric energy is the type of energy that can be converted into any form of energy. ii. With the efforts of many scientists, this energy has been tamed to provide comfort to us through various electronic appliances. SESSION 1. CELL, BULB, THE STORY OF BULB 24

iii. Due to our dependence on electricity, a number of scientists are presently strug- gling to generate electricity from various natural and renewable resources of en- ergy. iv. This great invention has revolutionised the life style of human beings, making it easier and more comfortable. 1.6 Application to Daily Life, Concern to Bio Diversity Q1. List the daily activities in which we use electricity. [Refer to TB page 121 Q12] A. i. From dawn to dusk and even during night, we make use of electricity. ii. We use the electric geyser/Heating rod to get hot water for bathing. iii. Electricity is used to run the mixers/grinders in the kitchen. iv. Fans, air coolers and air conditioners keep us comfortable in the hot summer days. They also run on electricity. v. We use refrigerators to keep the food materials cold and to make ice creams or to prevent them from melting. vi. Television and DVD’s, computers etc. all need electricity to run. vii. These days, even electric bikes and cars are used which run on battery. viii. Electricity is also used in industries to run big machines. Q2. Write a list of electrical appliances in your house. Classify them as follows. [Refer to TB page 121 Q14] A. Works with Works with Works with both cell cell as a electric current as and electric current as source a source source Torch light Electric bulb Tape recorder Remote of a Television Transistor radio TV Flood Lights Electric Piano Electric scooter Electric Grinder Piano Wall clocks SESSION 1. CELL, BULB, THE STORY OF BULB 25

SESSION 2 SIMPLE ELECTRIC CIRCUITS, WHAT IS A CIRCUIT, SWITCH, TORCH LIGHT 2.1 Mind Map SESSION 2. SIMPLE ELECTRIC CIRCUITS, WHAT IS A CIRCUIT, SW... 26

2.2 Terminology i. Electric circuit – An electric circuit is a closed path in which current flows. ii. Open circuit –When current does not flow through a circuit, the circuit is called open circuit. iii. Closed circuit – When current flows through a circuit, the circuit is called a closed circuit. iv. Conducting wire –is a metal conductor that carries electricity over a distance. SESSION 2. SIMPLE ELECTRIC CIRCUITS, WHAT IS A CIRCUIT, SW... 27

v. Appliance – A device or piece of equipment designed to perform a specific task. vi. Battery – A container consisting of one or more cells, in which chemical energy is converted into electricity and used as a source of power. vii. Switch –A device which is used to break an electric circuit is called switch. 2.3 Key Concepts i. Electricity flows in a closed path known as circuit. ii. A cell (power source), a bulb and connecting wires make a simple circuit. iii. In our houses, two electric supply wires namely live and neutral are connected to the two terminals of the bulb through a switch. iv. Electric switch is an arrangement to close or open (break) an electrical circuit by allowing or breaking the electricity flow in the circuit. 2.4 Conceptual Understanding Q1. What is an electric circuit? Explain with a diagram. [Refer to TB page 120 Q1] A. i. Source of electricity, an appliance, and a switch connected with an electric con- ducting wire together forms an “ electric circuit ”. ii. Source of electricity (battery), an electronic appliance (bulb) and a switch are con- nected by a wire as shown in the figure. iii. Using battery as a source of electricity, the bulb glows when we switch on the circuit. iv. Switch is used to open and close the circuit. SESSION 2. SIMPLE ELECTRIC CIRCUITS, WHAT IS A CIRCUIT, SW... 28

Q2. What are the parts of a torch light? [Refer to TB page 120 Q2] A. The parts of a torch light are 1) Hollow cylindrical barrel 2) Torch cells 3) Bulb 4) Glass cover 5) Reflector 6) Switch 7) Metal spring Q3. What will happen if the cells in a torch are arranged as shown in the following figure? Why? [Refer to TB page 121 Q8] A. The torch light will not glow if the cells in a torch are arranged like this. Because to complete the circuit ‘+ve’ and ‘–ve’ terminals are to be connected in order. The correct arrangement should be like this. 2.5 Asking Questions and Making Hypothesis Q1. A circuit is connected with a cell, bulb and a switch. But the bulb is not glowing. Write all possible reasons for this. [Refer to TB page 121 Q10] A. A circuit is connected with a cell, bulb and a switch. But the bulb is not glowing. The reasons may be i. The bulb could be faulty. ii. The connections in the circuit could be wrong. iii. The cell could be faulty and not working. SESSION 2. SIMPLE ELECTRIC CIRCUITS, WHAT IS A CIRCUIT, SW... 29

2.6 Experimentation and Field Investigation Q1. In activity 4, we observed some situations where the torch bulb glows. Niharika chal- lenged her friends that she could make the bulb not glow even with the cells kept in proper position. What would she have done? [Refer to TB page 121 Q6] A. i. The lid of the torch might not be tightly screwed, leaving the circuit open. So the bulb does not glow. ii. Niharika might have put an insulator in between the two cells. iii. The switch lever might have been bent in such a way that it did not touch the bulb, making the circuit open. Q2. Connect a circuit as shown in the following diagram [Refer to TB page 121 Q7] a) Does the bulb glow? Why? b) Draw the circuit so that the bulb glows. A. a) The bulb does not glow because the connections in the circuit have been made wrong. The +ve terminal of cell A should be connected to –ve terminal (bottom) of second cell. And, the +ve terminal of second cell should be connected to the bulb. b) SESSION 2. SIMPLE ELECTRIC CIRCUITS, WHAT IS A CIRCUIT, SW... 30

Q3. Connect circuits as shown in the following figure. Write your observation in each case. [Refer to TB page 122 Q15] A. i. Bulb will not glow because like terminals of batteries are connected together. ii. Bulb will glow because the circuit is closed. iii. Bulb will glow because the circuit is closed. iv. Bulb will glow because the circuit is closed. 2.7 Communication Through Drawing and Model Making Q1. Draw a circuit diagram showing a cell, switch and a bulb. [Refer to TB page 121 Q9] A. SESSION 2. SIMPLE ELECTRIC CIRCUITS, WHAT IS A CIRCUIT, SW... 31

SESSION 3 CONDUCTORS AND INSULATORS 3.1 Mind Map 3.2 Terminology i. Conductor – A material through which electric current can pass. ii. Insulator – A substance or device which does not readily conduct electricity. iii. Metal – A solid material which is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivity. iv. Non–metals – An element or substance that is not a metal. 3.3 Key Concepts i. On the basis of property of a substance to allow the passage of electricity through them, they can be classified as conductors and insulators. ii. Conductors are those substances which allow electric current to flow through them such as copper, iron etc. iii. Substances which do not allow electric current to flow through them are insulators. Example rubber, wood etc. SESSION 3. CONDUCTORS AND INSULATORS 32

iv. Invention of many electrical devices mark our history. These includes invention of electric bulb by Thomas Alva Edison and electric generator by Michael Faraday. 3.4 Conceptual Understanding Q1. Classify the following into conductors and insulators: [Refer to TB page 120 Q4] Water, Plastic pen, Pencil lead, Dry cotton cloth, Wet cotton cloth, Dry wood, Wet wood A. S. No. Material Conductor Insulator 1. Water x 2. Plastic pen x √ 3. Pencil lead √ 4. Dry cotton cloth √ 5. Wet cotton cloth x 6. Dry wood x √ 7. Wet wood √ x x √ √ x Note: Pure water is a bad conductor of electricity, whereas light impurity in it makes it a good conductor. Generally water we get is impure; so here water acts as good conductor of an electricity. SESSION 3. CONDUCTORS AND INSULATORS 33

Q2. Match the following. [Refer to TB page 122 Q16] Group – A Group – B 1. Conductor A) Cell 2. Source of electricity B) Switch 3. Filament C) Safety pin 4. To close or open a circuit D) Eraser 5. Insulator E) Glowing of bulb A. Group – A Group – B 1. Conductor C) Safety pin 2. Source of electricity A) Cell 3. Filament E) Glowing of bulb 4. To close or open a circuit B) Switch 5. Insulator D) Eraser 3.5 Asking Questions and Making Hypothesis Q1. Niharika observed an electrician repairing a street light wearing gloves on his hand. She asked him some questions. What would be those questions? [Refer to TB page 122 Q5] A. The questions Niharika asked the electrician would probably be: SESSION 3. CONDUCTORS AND INSULATORS 34

i. The gloves you are wearing on your hands appear to be different; with what mate- rial are they made up of? ii. Why do you wear gloves made up of that particular material? iii. Don’t you experience an electric shock, if you wear those gloves? iv. What are the other materials the gloves can be made of, so that we do not get an electric shock? —— CCE Based Practice Questions —— AS1-Conceptual Understanding Very Short Answer Type Questions 1. State true or false. [Refer to Session 12.1 ] (i) A bulb should never be touched when electricity is passed through it. ] [ ] ] (ii) William Gilbert was the first person to use the word electricity. ] [ (iii) A cell is a triangular object. [ (iv) In a bulb the two terminals touch each other. [ 2. Answer the following questions in one sentence. [Refer to Session 12.1 ] (v) Who discovered static electricity? (vi) In olden days, what was believed to be the cause of electricity? (vii) What do the (+) and (–) signs on a cell indicate? CHAPTER 12. SIMPLE ELECTRIC CIRCUITS 35

Short Answer Type Questions 3. Answer the following questions in 3-4 sentences. (i) [(Session 12.1)] What was the mistake that Niharika realised when the torch wasn’t working? How did she rectify it? (ii) [(Session 12.1)] Describe a cell. Long Answer Type Questions 4. Answer the following questions in 6-8 sentences. (i) [(Session 12.1)] Write short notes on bulb. AS2-Asking questions and making hypothesis Long Answer Type Questions 5. Answer the following questions in 6-8 sentences. (i) [(Session 12.2)] Raju doesn’t know what a torch is. When he saw a torch for the first time, he had some questions. What might these questions be? AS3-Experimentation and field investigation Long Answer Type Questions 6. Answer the following questions in 6-8 sentences. (i) [(Session 12.3)] Design an experiment to identify conductors and insulators. 7. Answer the following questions in 6-8 sentences. (i) [(Session 12.1)] On a visit to a factory your teacher identified certain materials as conductors and insulators. How can you describe the two based on your observation. Give examples of each. AS4-Information skills and projects Long Answer Type Questions 8. Answer the following questions in 6-8 sentences. (i) [(Session 12.2)] Collect the information about electricity and the working of electric appliances in our houses. CHAPTER 12. SIMPLE ELECTRIC CIRCUITS 36

AS5-Communication through drawing and model making Long Answer Type Questions 9. Answer the following questions in 6-8 sentences. (i) [(Session 12.2)] Draw a well labelled diagram of the inside view of a torch light. AS7-Application to daily life, concern to bio diversity Long Answer Type Questions 10. Answer the following questions in 6-8 sentences. (i) [(Session 12.3)] Discuss the daily life examples where we come across conductors and insulators. Objective Questions AS1-Conceptual Understanding 11. Choose the correct answer. (i) part of the bulb glows. (A) +ve terminal (B) –ve terminal (C) Filament (D)Glass chamber (ii) Electric wires are often covered with . (A) plastics (B) copper (C) aluminium (D) iron (iii) named the two kinds of electric charge. (A) William Gilbert (B) Benjamin Franklin (C)Thales of Miletus (D)Luigi Galvani (iv) An experiment with which animal lead to the belief that electricity is made inside CHAPTER 12. SIMPLE ELECTRIC CIRCUITS 37

animals’ bodies? (A) Rat (B) Rabbit (C) Frog (D) Dog (v) Who discovered that electricity can make magnetism? (A) Christian Oersted (B) William Gilbert (C)Luigi Galvani (D)Thales Miletus (vi) Who discovered the electric generator? (A) Thomas Faraday (B) Michael Faraday (C)Christian Oersted (D)Benjamin Franklin (vii) is a good conductor of electricity. (A) Metal (B) Wood (C) Plastic (D) Rubber (viii) The world’s first experimental electric power plant was opened in . (A) USA (B) England (C) India (D) Germany (ix) Filaments in bulbs are made of . (A) Copper (B) Silver (C) Aluminium (D) Tungsten (x) Electricity requires a for it to flow. (A) open path (B) closed path (C)neutral path (D)no path CHAPTER 12. SIMPLE ELECTRIC CIRCUITS 38

13. LEARNING HOW TO MEASURE SESSION 1 MEASURING LENGTHS, STORY OF SCALE 1.1 Mind Map SESSION 1. MEASURING LENGTHS, STORY OF SCALE 39

• Metre not a convenient unit for measuring large distances • A large unit called KILOMETRE was defined • One Kilometre is 1000 times larger than a metre • 1 Kilometre =1000 metres SESSION 1. MEASURING LENGTHS, STORY OF SCALE 40

1.2 Terminology i. Measure –To find out the size, amount, or degree of (something) by using an instru- ment or device marked in standard units. ii. Standard unit – A unit of measurement is a definite magnitude of a physical quantity, defined and adopted by convention or by law, which is used as a standard for mea- surement of the same physical quantity. iii. Foot span – Foot span is the distance covered in an average step, either from heel to heel or toe to toe. iv. Hand span – The maximum distance between the tips of the thumb and little finger, taken as the basis of a measurement equal to 9 inches. v. Cubit – An ancient measure of length, approximately equal to the length of a forearm. vi. Metre –The fundamental unit of length in the metric system, equal to 100 centimetres or approximately 39.37 inches. 1.3 Key Concepts i. We come across many examples of measurement in our daily life. ii. To obtain lengths, width, height, area, volume etc., of any object we need to get their measurements. iii. Traditionally, people used hand span, foot span and cubit as units of measurement. But the measurement were not accurate. iv. Units of measurement also varied from person to person or country to country. v. People decided to use the distance between the nose and the tip of the middle finger of their king as a measure. They called this distance one yard. vi. To get an accurate and uniform measurements standard units are required. vii. A standard unit of measurement is necessary to be adopted all over the world. viii. France decided that a certain length of rod made of a special material (Platinum–Iridium) would be called a metre. This is now the accepted standard unit of length worldwide. 1.4 Conceptual Understanding Q1. What is the smallest distance that you can measure with a centimeter scale? [Refer to TB page 135 Q1] A. Millimeter is the smallest distance that we can measure with a centimeter scale. SESSION 1. MEASURING LENGTHS, STORY OF SCALE 41

SESSION 2 MEASURING LENGTH ACCURATELY, MEASURING SMALL THICKNESS 2.1 Mind Map SESSION 2. MEASURING LENGTH ACCURATELY, MEASURING SMALL TH... 42

2.2 Terminology i. Height –It is the distance from the bottom of the feet to the top of the head in a human body, standing erect. ii. Straight path –Continuing in the same direction without deviating. iii. Curved path – A continuously bending line, without angles. iv. Parallax error –It is a displacement or difference in the visible position of an object viewed along two different lines of sight, and is measured by the angle or semi–angle of inclination between those two lines. 2.3 Key Concepts i. In Paris, the capital of France, a certain length of rod made up of an alloy of platinum and Iridium is taken as the standard measure and is called a “metre”. ii. The meter scale is internationally accepted instrument for measuring lengths. One meter (m)=100 centimetres (cm). iii. One centimetre = 10 millimetres (mm). iv. Meter can be used as a standard unit of measuring length for shorter distances how- ever for longer distance kilometre is used. 1km=1000m. v. We use different instruments like plain tape, roller tape, and centimetre scales of different sizes made of wood, plastic or metal. SESSION 2. MEASURING LENGTH ACCURATELY, MEASURING SMALL TH... 43

vi. The error that creeps in due to keeping of eye not perpendicularly to the exact division on the scale is called parallax error. vii. The length of curved lines can be measured by using a thin thread. 2.4 Conceptual Understanding Q1. Are we able to measure the thickness of a metal wire using a scale? Explain. [Refer to TB page 135 Q2] A. i. It is not possible to measure the thickness of a metal wire using a scale. ii. But taking the metal wire in the form of loops we can find the thickness. iii. Eg. Let the number of loops be ‘5’. The corresponding length on the scale is ‘3’ cm. Then the thickness of wire = Length on the scale/Number of loops = 3/5 = 0.6 cm. 2.5 Asking Questions and Making Hypothesis Q1. Make a visit to Panchayat Office, collect information how VRO (Village Revenue Officer) measures areas of agricultural lands in your village. Prepare a questionnaire for this. [Refer to TB page 137 Q14] A. The VRO measures areas of agricultural lands by noting the distances of certain points using a survey chain. He divides the shape of the irregular field into a number of trapez- iums and triangles and by adding the areas of all the figures, he determines the area of the land. The questions in the questionnaire would be: i. By which instrument does he measure the area? ii. Why does he find the area of the land? iii. What is the reason for dividing the land into trapeziums and triangles? iv. In which unit does he expresses the area? 2.6 Experimentation and Field Investigation Q1. The distance between numbers in a clock is accurately same. List out the things that SESSION 2. MEASURING LENGTH ACCURATELY, MEASURING SMALL TH... 44

you observe in your surroundings with accurate distance between them. [Refer to TB page 137 Q16] A. The distance between the numbers in a clock is accurately same. Other things from our surroundings with numbers marked at equal space between them are: (1) Clinical thermometre (2) The scale in my geometrical instrument box (3) Weighing machine (4) A vertical wooden scale used to record our heights 2.7 Appreciation and Aesthetic Sense, Values Q1. A carpenter who makes wooden furniture needs accuracy in measurements. Do you ever notice how he measures? How would you appreciate him? [Refer to TB page 137 Q13] A. i. A carpenter takes measurements very accurately and nearest to a millimeter. ii. As the carpenter is a practical worker, any wrong measurement taken will affect the furniture he is making. iii. The carpenter puts his mind and concentration on the measurements as his quality of work depends on these measurements. iv. The carpenter takes measurements with a metal tape. SESSION 2. MEASURING LENGTH ACCURATELY, MEASURING SMALL TH... 45

SESSION 3 MEASUREMENT OF AREA 3.1 Mind Map SESSION 3. MEASUREMENT OF AREA 46

3.2 Terminology i. Regular surface – A smooth surface. ii. Irregular surface –Surface which is not levelled or flat or symmetrical. iii. R ectangular body –A body with four sides, four right angles, and two pairs of parallel sides and unequal adjacent sides. iv. Graph paper – Paper printed with a network of small squares to assist the drawing of graphs or other diagrams or calculating area. 3.3 Key Concepts i. Area of closed figures or solid surfaces having the shape of a square or rectangle can be obtained by using the formulae (i) Area of square = side x side (ii) Area of rectangle = length x breadth ii. The units of area are : square centimetre (cm2 ) and square metre (m2 ) iii. Square centimetre is a standard unit of measuring the area of a surface. iv. The area of an irregular plane figure can be measured by using a standard graph paper. v. We use metre as a unit of length and subsequently, centimetres and millimetres as smaller units of length. 3.4 Conceptual Understanding Q1. A school hall measures 20 m in length and 15 m in breadth. Find its area. [Refer to TB page 136 Q3] A. i. As per the given measurements, it is evident that the shape of the hall is a rectan- gle. ii. The area of a rectangle = Length x Breadth iii. Length of hall = 20 m; Breadth = 15 m iv. The area of the hall = 20 m x 15 m = 300 m2 SESSION 3. MEASUREMENT OF AREA 47

Q2. Ramu’s father had a rectangular plot of length 60 ft and breadth 50 ft. He built a house occupying length of 40 ft of the plot and breadth 40 ft, and in the remaining area he planned a garden. Can you help Ramu to find the area of his garden? [Refer to TB page 136 Q4] A. Yes, I can help Ramu to find the area of his garden. He can find the area of the full plot and deduct the area of the house that he has decided to build from it. Step 1: Let us find the area of the rectangular plot. Area of rectangle = Length x Breadth Length of plot = 60 ft, its breadth = 50 ft Area of plot = 60 x 50 square ft = 3000 square ft Step 2: Let us find the area occupied by the house. It has the shape of a square. Area of square = side x side Length of side of square = 40 ft Area occupied by the house = 40 x 40 square feet = 1600 square feet Step 3: Area of the garden = Area of the total plot–Area occupied by the house = 3000 square feet -1600 square feet = 1400 square feet Therefore, area of the garden is 1400 sq ft. Q3. For measuring long distances, we can use as a unit. [Refer to TB page 136 Q7] A. kilometre Q4. How will you measure the area of your palm using graph paper? Explain [Refer to TB page 136 Q11] A. To measure the area occupied by my palm, I will follow the following steps: SESSION 3. MEASUREMENT OF AREA 48