202110206-APEX-STUDENT-WORKBOOK-PHYSICAL_SCIENCE-G08-PART2

2. Protection against earthquakes 2.2 Terminology i. Earthquake – A sudden movement of the earth’s crust caused by the release of stress accumulated along geologic faults or by volcanic activity. Also called seism, temblor. ii. Earth’s plates – Earth’s lithosphere is divided into large rigid blocks (plates) that are floating on semi-fluid rock and are thus able to interact with each other at their boundaries. iii. Richter scale – The Richter scale is used for measuring the magnitude of earth- quakes. iv. Seismograph – An instrument that measures and records details of earthquakes, such as force and duration. v. Seismoscope – An instrument for recording only the time or fact of occurrence of earthquakes. SESSION 2. EARTHQUAKE - CAUSES AND PROTECTION 99

2.3 Key Concepts i. An earthquake is caused due to the adjustments of the outer most layers of the earth’s plates. ii. Earthquake tends to occur at the boundaries of earth’s surface known as seismic or faulty zones. iii. Intensity of earthquake is measured by Richter scale. iv. An earthquake is a sudden shaking or trembling of the earth. v. It is not possible to predict the occurrence of an earthquake. vi. Earthquakes tend to occur at the boundaries of earth’s plates. These boundaries are known as fault zones. vii. Destructive energy of an earthquake is measured on the Richter scale. The earth- quake measuring 7 or more on Richter scale can cause severe damage to life and property. viii. We should take necessary precautions to protect ourselves from earthquakes. 2.4 Conceptual Understanding Q1. Name the scale on which the destructive energy of an earthquake is measured. An earthquake measures 3 on this scale. Would it be recorded by a seismograph? Is it likely to cause much damage? [Refer to TB page 158 Q6] A. The destructive energy of an earthquake is measured by a Richter scale. This scale has readings from 0 to 9. The reading of magnitude 3 on the Richter scale would be recorded by a seismograph. If the Richter scale gives the reading of magnitude 3, then the earthquake is not likely to cause much damage. Generally earthquakes of magnitude more than 5 are considered destructive in nature. Q2. List three states in India where earthquakes are likely to occur. [Refer to TB page 158 Q9] A. Gujarat, Assam, and Jammu and Kashmir. Q3. Write True or False sentences among the following [Refer to TB page 158 Q3] (d) Earthquakes can be predicted in advance, A. False 100 SESSION 2. EARTHQUAKE - CAUSES AND PROTECTION

Q4. Which place in Andhra Pradesh experiences earthquakes most of the time? [Refer to TB page 158 Q11] A. Prakasham district and YSR Kadapa in zone III and city of Hyderabad in zone II. Q5. Does your habitation lie in a earthquake prone area? Explain. [Refer to TB page 158 Q10] A. Earthquakes occur at the boundaries of the earth’s plates. These boundaries are known as fault zones. In India the fault zone area that are most threatened are Kashmir, western and central Himalayas, the whole of north–east India, the Rann of Kutch, Rajasthan and the Indo – Gangetic plain. In Andhra Pradesh, the south eastern districts of Chittor , Nellore and Godavari delta regions in zone III ; and the city of Hyderabad in zone II in Telangana state are earthquake prone areas. 2.5 Information Skills and Projects Q1. Which country in the world is frequently affected by earthquakes? Collect the information and photographs on the recently occurred earthquake in Japan. [Refer to TB page 159 Q16] A. Japan is frequently affected by earthquakes. Students’ activity. Q2. Find out if there is any organisation in your area which provides relief to those suffering from natural disasters. Enquire about the type of help they render to the earthquake victims of earthquake. Prepare a brief report on the problems of earthquake victims. [Refer to TB page 159 Q17] A. Students’ activity. Relief organisations provide food, water, shelter and first aid to earthquake victims. They also make lists of the refugees at different camps so that locating the loved one of a victim becomes easier. Earthquake causes: i. Damage to man–made structures. ii. Damage to towns and cities. iii. Devastating fires. iv. Loss of human and animal life. v. Spread of diseases. Q3. How do you relate the energy release during collisions of fault lines during earthquakes to the atmospheric variation on the surface of earth? [Refer to TB page 159 Q18] SESSION 2. EARTHQUAKE - CAUSES AND PROTECTION 101

A. An earthquake affects the atmosphere by creating amounts of debris and dust which will add to the air that we breathe. Earthquakes can also trigger volcanoes which will release tonnes of ashes and other debris into the atmosphere. This can also cause the blocking out of the sun, air pollution and increased amount of CO2 . 2.6 Communication Through Drawing and Model Making Q1. Colour seismic zones in India out line map. [Refer to TB page 159 Q20] A. Students’ activity. Q2. Prepare a model of seismograph. [Refer to TB page 159 Q21] A. Students’ activity. 2.7 Appreciation and Aesthetic Sense, Values Q1. How would you appreciate the efforts of scientists to develop an instrument to measure the intensity and detect the source of earthquakes? [Refer to TB page 159 Q22] A. The efforts of scientists to develop an instrument to assess the intensity and source of an earthquake is thoroughly appreciated because they provide an assessment of earthquake and what are the rescue measurements to be taken by the government, private organizations and also provide preventative measurements that would be taken when earthquake occurs. So these scientists providing life for people and services are thoroughly appreciated. 2.8 Application to Daily Life, Concern to Bio Diversity Q1. Suppose you are outside your house and earthquake occurs. What precautions would you take to protect yourself? [Refer to TB page 159 Q23] A. According to me following precautions should be followed: i. Try to find an open place away from tall buildings, tall trees, electrical poles, etc. ii. If travelling in a bus or car then do not come out when an earthquake strikes. Ask the driver to drive to an open field. Q2. If earthquake occurs in your area what will you do? [Refer to TB page 159 Q25] A. i. Avoid using lift. ii. Leave our homes, school buildings, etc. and move to an open area. iii. Take shelter under a table and do not move until the shaking stops. iv. Do not stay near windows, mirrors, hanging pots, bookcases, etc. SESSION 2. EARTHQUAKE - CAUSES AND PROTECTION 102

Q3. What measures would you take in your house if earthquake occurs? [Refer to TB page 159 Q26] A. i. Avoid using lift. ii. Leave our homes, school buildings, etc. and move to an open area. iii. Take shelter under a table and do not move until the shaking stops. iv. Do not stay near windows, mirrors, hanging pots, bookcases, etc. —— CCE Based Practice Questions —— AS1-Conceptual Understanding Very Short Answer Type Questions 1. State true or false. [Refer to Session 11.1 ] (i) We must take shelter under a tall tree during a thunderstorm. [ ] (ii) Electrical appliances like T.V and computers must not be used during a thunderstorm. [] (iii) During a thunderstorm if one is travelling outside in a car they must close the doors and windows of the car and stay inside. [] 2. Match the following. [] Column B [(Session 11.1)] a. Current Column A i. Electric spark ii. Copper [] b. Repel iii. Like charges [] c. Attract iv. Unlike charges [ ] d. Lightning v. Moving charges [ ] e. Good conductor CHAPTER 11. SOME NATURAL PHENOMENA 103

3. Fill in the blanks. [Refer to Session 11.1] (i) A metallic rod, taller than the building is installed in the walls of the building during its construction to protect it from . (ii) We must not travel in an during a thunderstorm. 4. State true or false. [Refer to Session 11.2 ] (i) Natural phenomena can be predicted to some extent. [ ] 5. Answer the following questions in one sentence. [Refer to Session 11.2 ] (i) What are seismic zones? (ii) How is moment magnitude scale more accurate than Richter scale? (iii) Who are seismologists? (iv) Name two devices used to measure earthquakes. (v) What are seismic waves? (vi) What is a seismograph? (vii) What is a seismoscope? 6. Fill in the blanks. [Refer to Session 11.2 ] (i) The magnitude of an earthquake is expressed in terms of . CHAPTER 11. SOME NATURAL PHENOMENA 104

(ii) A thunderstorm is accompanied by . (iii) Most of the destructive earthquakes have a magnitude higher than . (iv) are the only natural phenomena whose occurrence cannot be predicted. (v) The outer most layer of the earth is made of fragments called . (vi) Unlike many other scales, Richter scale is not . (vii) Zones which are more prone to earthquakes are called . (viii) The instrument other than seismograph which can be used to measure the intensity of an earthquake is called . Short Answer Type Questions 7. Answer the following questions in 3-4 sentences. (i) [(Session 11.1)] What is an electroscope? (ii) [(Session 11.1)] What is earthing? 8. Answer the following questions in 3-4 sentences. (i) [(Session 11.2)] Define an earthquake. (ii) [(Session 11.2)] How is an earthquake caused? Long Answer Type Questions 9. Answer the following questions in 6-8 sentences. (i) [(Session 11.1)] Where must one take shelter during a thunderstorm? (ii) [(Session 11.1)] What is that one must not do during a thunderstorm? CHAPTER 11. SOME NATURAL PHENOMENA 105

10. Answer the following questions in 6-8 sentences. (i) [(Session 11.2)] Mention a few safety measures that need to be taken during an earth- quake. AS2-Asking questions and making hypothesis Short Answer Type Questions 11. Answer the following questions in 3-4 sentences. (i) [(Session 11.1)] Rakesh says it is important to install a lightning conductors on the tall buildings. Why does he say so? AS3-Experimentation and field investigation Long Answer Type Questions 12. Answer the following questions in 6-8 sentences. (i) [(Session 11.1)] Write an experiment to prove that a glass rod rubbed with silk cloth contains charge. AS4-Information skills and projects Long Answer Type Questions 13. Answer the following questions in 6-8 sentences. (i) [(Session 11.2)] Which regions in Andhra Pradesh are more prone to earthquakes? Collect pictures and information about the earthquakes which have occurred in Andhra Pradesh. AS5-Communication through drawing and model making Long Answer Type Questions 14. Answer the following questions. (i) [(Session 11.1)] Draw a diagram to show what would happen when two balloons which are hung from threads and kept close to each other acquire: a) similar charges. b) different charges. CHAPTER 11. SOME NATURAL PHENOMENA 106

(ii) [(Session 11.1)] Draw a diagram of a lightning conductor and show how the charge flows to the ground during a lightning strike. AS6-Appreciation and aesthetic sense,Values Long Answer Type Questions 15. Answer the following questions in 6-8 sentences. (i) [(Session 11.2)] Express your feelings on the following topic: Loss incurred to biodiversity by earthquakes. AS7-Application to daily life, concern to biodiversity Short Answer Type Questions 16. Answer the following questions in 3-4 sentences. (i) [(Session 11.1)] Why is earthing done? (ii) [(Session 11.1)] What is a lightning conductor? Long Answer Type Questions 17. Answer the following questions in 6-8 sentences. (i) [(Session 11.1)] On your street you see a very tall building, but it does not have any protection against lightning. What would you suggest the owner of the building to do and why ? 18. Answer the following questions in 6-8 sentences. (i) [(Session 11.2)] You and your family are in the midst of an earthquake. What are the measures you would take to protect your family and yourself? CHAPTER 11. SOME NATURAL PHENOMENA 107

Objective Questions AS1-Conceptual Understanding 19. Choose the correct answer. (i) Two objects which have like charges will always (A) attract each other (B) repel each other (C)either attract or repel (D)neither attract nor repel (ii) The charge acquired by a glass rod when it is rubbed with silk is considered as (A) neutral (B) negative (C)either positive or negative (D) positive (iii) The process of transferring charge from a charged body to earth is called (A) earthing (B) processing (C) transferring (D) charging (iv) Earthquake is caused due to the following reason: (A) Series of large waves from the ocean (B) Strong winds on the earth’s surface (C)Electric discharge between clouds and the earth (D)Disturbance deep inside the earth’s crust AS3-Experimentation and field investigation 20. Choose the correct answer. (i) Which of the following cannot be charged by friction, if held by hand? (A) A plastic scale (B) A copper rod (C)An inflated balloon (D)A woollen cloth CHAPTER 11. SOME NATURAL PHENOMENA 108

AS4-Information skills and projects 21. Choose the correct answer. (i) Which of the following is not a safety measure to be followed during a lightning? (A) Taking shelter under a short tree instead of a tall tree (B) Close the windows and doors if you are travelling in a car or bus (C)Stand near electric poles or telephone poles (D)Stay in a multi storied building only if it has a ligting conductor (ii) Name the scientist who showed that lightning and the spark from clothes are essentially the same phenomena. (A) Thomas Alva Edison (B) Franklin D. Roosevelt (C)Benjamin Franklin (D)Isaac Newton (iii) Magnitude of an earthquake is measured using the following scale: (A) Celsius (B) Pascal (C) Richter (D) Kelvin AS6-Appreciation and aesthetic sense, Values 22. Choose the correct answer. (i) Which device is used to measure the occurrence or the time of occurrence of an earthquake? (A) Lightning conductor (B) Seismograph (C) Barometer (D) Seismoscope (ii) A device which can be used to test whether an object is carrying charge or not is called (A) Telescope (B) Electroscope (C) Periscope (D) Microscope CHAPTER 11. SOME NATURAL PHENOMENA 109

12. STARS AND THE SOLAR SYSTEM SESSION 1 INTRODUCTION AND MOVEMENTS OF SUN 1.1 Mind Map SESSION 1. INTRODUCTION AND MOVEMENTS OF SUN 110

1.2 Terminology i. Meridian – An imaginary great circle on the earth’s surface passing through the North and South geographic poles. ii. Shadow – A dark figure or image cast on the ground or other surface by a body intercepting light. iii. Dakshinayanam – When the sun looks like it is traveling towards the south of the sky, it is called the dakshinayanam. iv. Uttarayanam – When the sun looks like it is traveling towards the north of the sky, it is called the uttarayanam. v. Hemisphere – A half of the earth, usually as divided into northern and southern halves by the equator, or into western and eastern halves by an imaginary line passing through the poles. 1.3 Key Concepts i. We observe different objects in the sky. ii. The objects which are found in the sky are known as celestial objects. iii. We get light from the Sun. iv. Shadows form when objects obstruct the path of the light ray. v. The shortest shadow cast by a vertical object on the ground always falls in the north–south direction. vi. Movement of earth around the sun causes change in seasons. 1.4 Conceptual Understanding Q1. What is your local noon time? [Refer to TB page 181 Q1] A. The time at which the shortest shadow of a vertical object occurs at that place is called the local noon time. Q2. How do day and night occur? [Refer to TB page 182 Q11] A. Due to rotation of earth around its imaginary axis, day and night occur. The portion of earth facing the sun at any time experiences day and the portion facing away experi- ences night. SESSION 1. INTRODUCTION AND MOVEMENTS OF SUN 111

1.5 Asking Questions and Making Hypothesis Q1. While observing the shadow of a stick from morning to evening, some questions arose in Ramya’s mind. What may be those questions? [Refer to TB page 158 Q17] A. i. Why is the shadow longest in the morning and evening? ii. Why the shadow changes its direction? iii. Why is the shadow, the shortest at noon? Q2. Even though we do not have clock, we can know the time by observing some shadows in day time. Think and discuss with your friends how we can know the time at night. [Refer to TB page 158 Q19] A. We can find out the time in the night by tracing the placement of moon and locations of other constellations. 1.6 Experimentation and Field Investigation Q1. How can you find out north–south direction at your place? [Refer to TB page 182 Q20] A. The sun seems to rise in the east and sets at the west. If you face towards the sun in the morning, the left hand side is north and the right hand side is south. Q2. In which direction (towards north to south) is the sun moving day by day when you read this lesson? [Refer to TB page 182 Q21] A. The sun moves towards north in the summer and moves towards south in winter. From December 21st to till June 21st the sun appears to shift northward. From June 21st to December 21st, the sun appears to shift southward. Now the answer depends on the above information. If you are reading the lesson in the month of November then the sun is moving towards south direction. SESSION 1. INTRODUCTION AND MOVEMENTS OF SUN 112

1.7 Information Skills and Projects Q1. What is the duration of day and night today? Collect the information about the duration of day and night for past 7 days from the newspaper, analyse it and say whether summer or winter is going to come? [Refer to TB page 182 Q23] A. Students’ activity. Q2. What are the other districts on the same latitude as your district? [Refer to TB page 182 Q24] A. Degree of S.No. District names latitude 1. Nellore, YSR Kadapa, Anantapur 14 2. Prakasam, Kurnool, Guntur 15 3. West Godavari, Krishna, Mahabubnagar 16 17 4. East Godavari, Visakhapatnam,Ranga 18 Reddy, Hyderabad, Khammam, Nalgonda 5. Srikakulam, Vizianagaram, Medak, Nizamabad, Karimnagar, Warangal 6. Adilabad 19 7. Chittoor 13 SESSION 1. INTRODUCTION AND MOVEMENTS OF SUN 113

1.8 Communication Through Drawing and Model Making Q1. Make a sundial and explain how you made it? [Refer to TB page 182 Q26] A. Take a cardboard and cut a right angled triangle ABC from it. Angle C of the triangle should be equal to the latitude of your place and angle A should be 90°. i. Fix the cardboard triangle vertically in the middle of the rectangular wooden box. Glue strips of the paper along the edges of BC and the wooden board and make the triangle stand erect. ii. Place the wooden board with the triangle on level ground in an open space which gets sunlight throughout the day. Base BC of the triangle should be placed in north– south direction with B pointing on the earth. iii. At nine in the morning, draw a line along the shadow of side AC on the wooden board. Write the time alongside the line. Draw lines of the shadow of side AC at one hour intervals (use a clock to check the time) through the day till sunset and mark the time for each line. Your sun-dial is ready. SESSION 1. INTRODUCTION AND MOVEMENTS OF SUN 114

SESSION 2 PHASES OF THE MOON AND ECLIPSES 2.1 Mind Map 1. Solar Eclipse SESSION 2. PHASES OF THE MOON AND ECLIPSES 115

2. Lunar Eclipse SESSION 2. PHASES OF THE MOON AND ECLIPSES 116

3. Phases of Moon SESSION 2. PHASES OF THE MOON AND ECLIPSES 117

2.2 Terminology i. Moon – The natural satellite of the earth, visible (chiefly at night) by reflected light from the sun. ii. Phases – Any stage in a series of events or in a process of development. iii. Total Solar Eclipse – An eclipse of the sun in which the moon completely hides the solar surface or photosphere and thereby cuts off all direct rays of sunlight from the observer. iv. Total Lunar Eclipse – An eclipse in which the moon is completely immersed in the umbra of the earth’s shadow. 2.3 Key Concepts i. Changes in appearance of moon are called phases of moon. ii. Moon has no atmosphere like on the earth. iii. Solar eclipse occurs when the moon obstructs the view of the sun on the earth. iv. Solar eclipses occur only on New moon days. v. Lunar eclipse occurs when the moon is obstructed by the sun. vi. Lunar eclipses occur only on Full moon days. SESSION 2. PHASES OF THE MOON AND ECLIPSES 118

2.4 Conceptual Understanding Q1. Where do you find moon at night: [Refer to TB page 181 Q2] (a) 2 days before pournami (b) 2 days after amavasya A. (a) 2 days before pournami the moon is in the eastern sky. (b) 2 days after amavasya the moon is in the western sky. Q2. Why doesn't eclipse occur on every full moon day or on every new moon day? [Refer to TB page 181 Q3] A. A full moon is when the moon is exactly on the other side of the earth and sun. A lunar Eclipse happens when the moon travels into earth’s shadow and the earth is between the moon and sun. The plane of the lunar orbit is tilted with respect to the plane of the Earth’s orbit around the sun (ecliptic plane). When Earth and moon comes on the same plane in the straight line lunar eclipse happens. Q3. Why is Venus the brightest planet? [Refer to TB page 182 Q15] A. Venus appears bright due to its cloudy atmosphere and reflects 75% of the sun light that falls on it. Venus is commonly known as the evening and morning star, though it is not a star. 2.5 Asking Questions and Making Hypothesis Q1. Are you curious about going to the moon? Why? [Refer to TB page 182 Q16] A. Yes. I would like to find out about the possibilities of life on the moon and want to know about its climatic condition. There are many interesting stories told about the moon by my grandparents so I am curious to go to the moon. SESSION 2. PHASES OF THE MOON AND ECLIPSES 119

Q2. What are the questions that engage your mind when you look at the night sky? [Refer to TB page 182 Q18] A. i. How many stars are there in the sky? ii. Where are they going? iii. What is the distance between those stars? iv. How can we measure the distances? v. Why the Pole Star is not moving? vi. What are the streaks of light seen occasionally? vii. Is the distance between all the stars same? 2.6 Communication Through Drawing and Model Making Q1. Draw different phases of moon. Arrange them in a order from pournami to amavasya. [Refer to TB page 182 Q27] A. SESSION 2. PHASES OF THE MOON AND ECLIPSES 120

SESSION 3 STARS, SOLAR SYSTEM AND SATELLITES 3.1 Mind Map 1. Solar system SESSION 3. STARS, SOLAR SYSTEM AND SATELLITES 121

2. Stars 3.2 Terminology i. Solar system – A solar system is the collection of planets, asteroids, and moons (moons orbit the planets) that occupy a space around a sun and are held within the gravitational pull of the Sun. Our solar system consists of eight planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune) and a planetoid, Pluto. ii. Stars – Any of the celestial bodies visible at night from Earth as relatively stationary, usually twinkling points of light. iii. Constellations – An easily recognized group of stars that appear to be located close together in the sky and that form a picture if lines connecting them are imagined. iv. Satellite –A celestial body orbiting around a planet or star. v. Comet – A comet is an icy small Solar System body that, when passing close to the Sun, heats up and begins to outgas, displaying a visible atmosphere or comma, and sometimes also a tail. SESSION 3. STARS, SOLAR SYSTEM AND SATELLITES 122

vi. Meteor –A small body of matter from outer space that enters the earth’s atmosphere, becoming incandescent as a result of friction and appearing as a streak of light. vii. Meteorite – A piece of rock or metal that has fallen to the earth’s surface from outer space as a meteor. viii. Asteroid –A small rocky body orbiting the sun.They are sometimes called minor plan- ets. 3.3 Key Concepts i. Pole Star is situated in direction of the earth’s axis. ii. We can find satellites, constellations, asteroids, meteors, meteorites, comets in the space. iii. Artificial satellites provide useful information. iv. Aryabhatta was the first Indian artificial satellite. 3.4 Conceptual Understanding Q1. Where do you find the Pole star? [Refer to TB page 181 Q4] A. The Pole Star lies on the axis of rotation of the earth. Q2. What is the difference that you find between the Pole star and other stars? [Refer to TB page 181 Q5] A. A Pole Star is a prominent star aligned with the axis of rotation of the earth. Stars appear to move from east to west, revolving around the Pole Star. Pole Star seems to be stationary. Q3. Why does the Pole Star seem to be stationary? [Refer to TB page 181 Q6] A. The pole star is situated in the direction of the earth’s axis and that is why it does not appear to move even though all stars appear to be moving because of the rotation of the earth. The Pole Star lies on the line of the imaginary axis of earth’s rotation. So it seems to be stationary. Q4. Name some constellations. [Refer to TB page 181 Q7] A. Saptarishi, Sharmistha, Orion, Leo etc. SESSION 3. STARS, SOLAR SYSTEM AND SATELLITES6 123

Q5. How many planets are there in the solar system? What are they? [Refer to TB page 181 Q8] A. There are 8 planets in our solar system. They are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Q6. Look at the table of planets and name which is the smallest and biggest in our solar system. [Refer to TB page 182 Q9] A. Smallest planet: Mercury Biggest planet: Jupiter Q7. Among all 8 planets what is the special thing about earth? [Refer to TB page 182 Q10] A. Earth is the only planet in the solar system where life exists. Q8. Do the stars appear moving? How can you say that? [Refer to TB page 182 Q12] A. Yes. The earth rotates from east to west on its axis. Hence all the stars in the sky appear to move from east to west with reference to earth except the Pole Star. Q9. Is it possible to see the Pole star for the people who live in the southern hemisphere of the earth? Why? [Refer to TB page 182 Q13] A. The Pole Star is not visible from southern hemisphere because it is situated on the North pole of the imaginary axis of the earth. SESSION 3. STARS, SOLAR SYSTEM AND SATELLITES 124

Q10. What is the use of artificial satellites in our life? [Refer to TB page 182 Q14] A. Use of artificial satellites – i. Provide telecommunication. ii. Help in remote sensing. iii. Identify minerals and metal deposits. iv. Help in weather forecasting. v. They are used for transmitting television and radio signal. 3.5 Experimentation and Field Investigation Q1. What are the planets that you have seen in the sky? When do you observe those planets? [Refer to TB page 182 Q22] A. Mercury, Venus, Mars and Jupiter. i. Mercury can be observed just before the sun rise or just after the sunset near the horizon. ii. Mars can easily be seen from Earth with the naked eye. It is seen as a reddish object in the sky. iii. Venus is the planet which is bright enough to be seen in a mid–day clear sky and the planet is easy to see when the Sun is low on the horizon. iv. Jupiter can be seen near the moon. It can be seen as a very bright object for about half the year in the evening sky. 3.6 Information Skills and Projects Q1. Collect information about cosmic dust from newspapers, internet and make a poster on your school panel board about the consequences of cosmic dust. [Refer to TB page 182 Q25] A. Cosmic dust consists of microscopic particles of solid materials floating in space be- tween stars. The materials that make cosmic dust are silicates, graphite, hydrocarbons and oxides. These are also found on earth, where they can be classified as pollutants. However they are not harmful in the interstellar space. Cosmic dust plays an important role in cosmology. Metals from the cosmic dust play a part in various phenomena that affect our climate. SESSION 3. STARS, SOLAR SYSTEM AND SATELLITES 125

Student may refer the following web link – http://goo.gl/yuA4lV 3.7 Communication Through Drawing and Model Making Q1. Draw the location of the Pole Star showing the direction of the Great Bear. [Refer to TB page 182 Q28] A. Q2. Draw the diagram of solar system. [Refer to TB page 182 Q29] A. SESSION 3. STARS, SOLAR SYSTEM AND SATELLITES 126

3.8 Appreciation and Aesthetic Sense, Values Q1. How do you appreciate the construction of knowledge about the universe by our ances- tors? [Refer to TB page 182 Q30] A. i. In olden days people observed the shadows to calculate the time. ii. They understood that day and night are formed due to rotation of the earth. iii. Sailors sailing boats in night time observed the Pole Star and other constellations to determine their time and location. 3.9 Application to Daily Life, Concern to Bio Diversity Q1. We launched so many artificial satellites around our earth for different purposes. What do you think about the impact of artificial satellites and their radiation on biodiversity? [Refer to TB page 182 Q31] A. Though we are having so many uses of artificial satellites, there are also some limitations. Non–functional satellites, blasted rocket parts etc. revolve around the earth as garbage. Due to satellites, radiations are released into the atmosphere which affects human DNA. Some species are badly affected due to cell phone radiations (e.g –Bees and Sparrows) and pollute the atmosphere causing greenhouse effect. Q2. Among 8 planets of our Solar system, Earth is the only planet supporting life. Explain how we should protect our earth and its environment? [Refer to TB page 182 Q32] A. i. If you pollute the environment, the temperature rises. ii. If the soil gets polluted, yielding of the crops decreases and food problem arises. iii. If the atmosphere is polluted due to industries and CFCs, the ozone layer may damage which is protecting us from UV rays coming from the sun. By planting trees and reducing industrial pollution, we can protect our earth and its environment. SESSION 3. STARS, SOLAR SYSTEM AND SATELLITES 127

—— CCE Based Practice Questions —— AS1-Conceptual Understanding Very Short Answer Type Questions 1. State true or false. [Refer to Session 12.1 ] (i) When the sun looks like it is travelling towards the south of the sky, it is called ‘dakshi- nayanam’. [] (ii) Sundial is based on the magnetic field of the Earth. [] (iii) The length of a shadow changes from morning to evening. [ ] 2. Answer the following questions in one sentence. [Refer to Session 12.1 ] (i) What is a sundial? (ii) What are the celestial objects that we can see in the sky? 3. State true or false. [Refer to Session 12.3 ] (i) Mercury is the brightest planet. [] (ii) Jupiter is the largest planet. [] (iii) Mars is called as the red planet. [] (iv) Venus is the smallest planet. [] CHAPTER 12. STARS AND THE SOLAR SYSTEM 128

4. Answer the following questions in one sentence. [Refer to Session 12.3 ] (i) What is a satellite? (ii) Name some uses of artificial satellites. (iii) What is the full form of NASA? (iv) Which was the first artificial Indian satellite? (v) Name a few artificial satellites launched by India. 5. Fill in the blanks. [Refer to Session 12.3 ] (i) Sun is a star located in the galaxy called . (ii) Asteroids can only be seen using a . (iii) Man made satellites are known as ___________________________________. (iv) Halley’s comet appears after every . (v) A definite path in which a planet revolves around the Sun is called an . (vi) is called the morning and evening star. (vii) Mercury, Venus, Earth and Mars are called . CHAPTER 12. STARS AND THE SOLAR SYSTEM 129

6. State true or false. [Refer to Session 12.2 ] (i) A total lunar eclipse occurs when the earth’s shadow obscures all of the moon’s visible surface. [] (ii) The moon’s surface is barren and dusty. [] 7. Answer the following questions in one sentence. [Refer to Session 12.2 ] (i) Write one objective of Chandrayaan –1. Short Answer Type Questions 8. Answer the following questions in 3-4 sentences. (i) [(Session 12.3)] What forms our solar system? (ii) [(Session 12.3)] What is a constellation? 9. Answer the following questions in 3-4 sentences. (i) [(Session 12.2)] Write about partial and total solar eclipse. (ii) [(Session 12.2)] Write about annular and hybrid eclipses. CHAPTER 12. STARS AND THE SOLAR SYSTEM 130

Long Answer Type Questions 10. Answer the following questions in 6-8 sentences. (i) [(Session 12.1)] Write a note on a sundial. 11. Answer the following questions in 6-8 sentences. (i) [(Session 12.3)] Give an account on the planets of our solar system. 12. Answer the following questions in 6-8 sentences. (i) [(Session 12.2)] Write about the types of lunar eclipses. AS2-Asking questions and making hypothesis Long Answer Type Questions 13. Answer the following questions in 6-8 sentences. (i) [(Session 12.2)] You have been observing the shape of the moon for a period of one month. What is the hypothesis you would make for the changing shapes of the moon? Give reasons. AS3-Experimentation and field investigation Short Answer Type Questions 14. Answer the following questions in 3-4 sentences. (i) [(Session 12.1)] Write a brief procedure of an activity which can be conducted to prove that the length of a shadow changes from morning till evening. (ii) [(Session 12.1)] Write an activity which can be performed to understand the North–South movement of the Sun. AS4-Information skills and projects Long Answer Type Questions 15. Answer the following questions in 6-8 sentences. (i) [(Session 12.1)] Collect information about the distance of each planet from Earth. Name the planets which are closest to Earth and farthest from Earth. CHAPTER 12. STARS AND THE SOLAR SYSTEM 131

16. Answer the following questions in 6-8 sentences. (i) [(Session 12.3)] Following table shows some information about all the planets in the solar system: Planet Distance From the Volume (Earth =1) Surface Gravity Number of Mercury Sun (Astronomical 0.56 (Earth =1) moons(Known in Venus units) 0.87 0.38 2012) Earth 0.4 1 0.9 0 Mars 0.7 0.15 1 0 Jupiter 1 1,300 0.38 1 Saturn 1.5 760 2.36 2 Uranus 5.2 63 1.06 67 Neptune 9.5 58 0.89 62 19 1.1 27 30 13 Based on the information from the table answer the following questions: a) Which planet is closest to the Sun? b) Which planets have no moons? c) Is Mars bigger or smaller than Earth? d) Which planet is closest in size to Earth? e) Which planet is farthest from Sun? AS5-Communication through drawing and model making Long Answer Type Questions 17. Answer the following question. (i) [(Session 12.1)] Draw a diagram of the solar system. 18. Answer the following question. (i) [(Session 12.3)] Observe the sky at night. Identify and draw the diagram of constella- tions. 19. Answer the following question. (i) [(Session 12.2)] Draw the different phases of the moon. CHAPTER 12. STARS AND THE SOLAR SYSTEM 132

AS6-Appreciation and aesthetic sense, Values Long Answer Type Questions 20. Answer the following questions in 6-8 sentences. (i) [(Session 12.3)] How do you appreciate the beauty of the organized arrangement of the universe? AS7-Application to daily life, concern to bio diversity Long Answer Type Questions 21. Answer the following questions in 6-8 sentences. (i) [(Session 12.3)] The first artificial satellite launched by India was Aryabhatta. Mention some applications of artificial satellites which have been useful for human beings. Objective Questions AS1-Conceptual Understanding 22. Choose the correct answer. (i) A very rare form of solar eclipse that changes from an annular to a total solar eclipse along the path: (A) Partial solar eclipse (B) Hybrid solar eclipse (C)Total solar eclipse (D)Annular solar eclipse (ii) The different patterns formed by different group of stars in the night sky are called (A) star patterns (B) pole star (C)celestial objects (D) constellations (iii) Pournami is (B) half moon night (A) full moon day (C)old moon light (D)new moon light CHAPTER 12. STARS AND THE SOLAR SYSTEM 133

(iv) Any celestial body revolving around another celestial body is called its (A) axis (B) moon (C)heavenly body (D) satellite (v) The definite path in which a planet revolves around the sun is called its (A) milky way (B) galaxy (C) rotation (D) orbit (vi) A lunar eclipse occurs when (A) shadow of the earth falls on the moon (B) shadow of the moon falls on the earth (C)shadow of the sun falls on the earth (D)shadow of the earth falls on the sun (vii) How many days does it take for planet Venus to complete one revolution around the Sun? (A) 365 days (B) 88 days (C)687 days (D)225 days CHAPTER 12. STARS AND THE SOLAR SYSTEM 134

AS4-Information skills and projects 23. Choose the correct answer. (i) The planet which is known as the morning or an evening star is (A) Mars (B) Mercury (C) Venus (D) Moon (ii) The first artificial satellite built and launched by India is (A) INSAT (B) Aryabhatta (C) IRS (D) EDUSAT (iii) During a clear night sky, bright light streaks are often visible. These are commonly known as shooting stars. The actual name for these light streaks is (A) comet (B) meteors (C) asteroids (D)falling stars AS5-Communication through drawing and model making 24. Choose the correct answer. (i) Which of the following figures depicts the position of pole star correctly? (A) CHAPTER 12. STARS AND THE SOLAR SYSTEM 135

(B) (C) (D) CHAPTER 12. STARS AND THE SOLAR SYSTEM 136

PROJECT BASED QUESTIONS —— Project Based Questions —— (i) Being a student of science you know that lightning conductor is an important device to protect the house from lightning. Now consider that one of your neighbours have not installed it in his building. Write a letter to your neighbour mentioning the importance and working of a lightning conductor so that he gets convinced to install it in his building. (ii) Bio-diesel is an alternative fuel source. Make a project report on biodiesel. Include its preparation or formation, countries where it is produced and why it is not prepare in large scale. (iii) Make a project report on various consequences our future world is going to face because of the rapid uses and misuses of fuels. Also mention few suggestions to avoid such consequences. (iv) Taking examples from your nearby factories, industries and vehicles on the road, you make a report on harmful effects on the environment due to burning of fossil fuels. Also mention the steps to minimize the effect. (v) Make a report on various devices to measure earthquake. Mention how do they work with pictures and how helpful it is for mankind. (vi) Taking help from internet or magazines collect pictures of solar eclipse and lunar eclipse and make a detailed report describing them and their effects. (vii) In the 26th general assembly of International Astronomical Union it was decided that ‘Pluto’ would not be considered as a planet anymore. Do research and make a de- tailed report on why earlier Pluto was considered as a planet and why not now. Project Based Questions 137

Additional AS-Based Practice Questions Chapter 7: Coal and Petroleum 1. Your friend says ‘Coal is an ancient gift serving modern society’. Is it true? Why do you think so? [AS2] 2. Is petroleum exhaustible? [AS2] 3. How is petrol and diesel obtained? [AS3] 4. Expand LPG, CNG, and ONGC. [AS4] 5. Draw a table listing the natural resources which are limited and which are abundant. [AS5] 6. Draw a diagram showing existence of various fuels like natural gas, petroleum in earth crust? [AS5] 7. What are the advantages of CNG as fuel? [AS6] 8. Which was the most important fuel in the 19th century? [AS6] 9. What are the uses of coal tar and coal gas? [AS7] 10. Give two examples for petrochemical products. [AS7] Chapter 8: Combustion, fuels and flame 1. Sonam learnt that there are three things required to keep a fire going. She wondered if fire could be controlled if these factors are controlled. What do you think? Explain. [AS2] Additional AS-Based Practice Questions 138

2. Why does a scented stick with burning stub not catch fire when it is kept aside in air after putting its flame off? [AS2] 3. Name the products formed when a candle burns in air. [AS3] 4. In the experiment to prove that oxygen is required for burning, explain how oxygen is liberated. [AS3] 5. List different fuels that are used for: [AS4] i. Domestic purpose ii. Automobiles/ Aircraft/ Trains/ Rockets iii. Industry 6. How do you appreciate use of fossil fuels in daily life? [AS6] 7. LPG is better domestic fuel than wood? Explain why? [AS6] 8. How does a candle work? [AS7] Chapter 9: Electrical conductivity of liquids 1. When the free ends of a tester are dipped into solution, the magnitude needle shows deflection. What could be the reason? [AS2] 2. A child staying in a coastal region tests the drinking water and also the sea water with his tester. He finds that compass needle deflects more in the case of sea water. What is the reason behind it? [AS2] 3. Is it safe for electrician to carry out electrical repairs outdoor during heavy down pour? [AS2] 4. What is the name given to wires attached to LED? How are these wires connected to a battery? [AS3] 5. Mention any one requirement for fine coating in electroplating process? [AS4] Additional AS-Based Practice Questions 139

6. Prepare a table having various material used at home classifying as good conductor or poor conductor and their uses. [AS4] 7. Draw the diagram of an LED. [AS5] 8. Draw an experimental set up for testing conductivity of different liquids. [AS5] 9. What is the main threat to environment from electroplating factories? [AS6] 10. How do we appreciate Volta’s contribution in the field of electricity? [AS6] 11. Mention about the various application of electroplating in our daily life. [AS7] 12. What are the uses of electrolysis in our daily life? [AS7] Chapter 10: Reflection of Light at Plane Surfaces 1. Looking at the mirror Rani thinks, mirror reflects light but not all glasses. Help her understanding what qualities it should possess to reflect light. [AS2] 2. There is a mistake in the following ray diagram. Redraw it after making the necessary change. [AS5] 3. The angle between incident ray and reflected ray is 60°. What is the value of angle of incidence? [AS7] 4. The distance between the object and its image formed by a plane mirror appears to be 24 cm. What is the distance between the mirror and the object? [AS7] 5. A toy is placed at 10 cm in front of a plane mirror. What is the distance of image from the mirror? [AS7] Additional AS-Based Practice Questions 140

Chapter 11: Some natural phenomena 1. Is it possible to predict when and where the next earthquake might occur? [AS2] 2. Raman watched few pictures of earthquake victims on TV. What are the questions raised in his mind about earthquake? [AS2] 3. What is the cause of most earthquakes? [AS2] 4. Is there any alternative method to find the intensity of earthquake? [AS2] 5. What materials would you use to demonstrate presence of charge on a body? [AS3] 6. Write down the procedural steps for the activity ‘’Demonstrating transfer of charge”. [AS3] 7. Which is safe place during thunder storm? [AS4] 8. Which scale measures the destructive energy released by earth more accurately? [AS4] 9. Draw a table showing Richter scale reading and the effects of earthquake. [AS5] 10. Draw a neat diagram of different layers of earth and its part. [AS5] 11. How do you appreciate the efforts of the scientists to develop a lightning conductor to protect buildings from the effect of lightning? [AS6] 12. List the help rendered by relief organization to the victims of earthquake. [AS6] 13. We know that the clouds have charges. Can we produce current through these charges? [AS7] Additional AS-Based Practice Questions 141

Chapter 12: Stars and the solar system 1. Does the sun rise in the east in Venus? If the answer is no what is the reason? [AS2] 2. How does earth appear from space? [AS2] 3. Why Pluto is not considered as a Planet? [AS2] 4. What are the materials required to make your own sundial? [AS3] 5. Write the procedural steps for the activity “Observing the movement of constellations’’. [AS3] 6. Write down any one of the factors to be taken into consideration to view the pole star at your place? [AS4] 7. Write down few important information about Chandrayaan – I. [AS4] 8. Draw the diagram of solar eclipse. [AS5] 9. Draw the diagram of lunar eclipse. [AS5] 10. How do you appreciate the people of olden days to come to an understanding that earth is spherical? [AS6] 11. Why should we appreciate mother planet Earth? [AS6] 12. Write briefly about the sun. [AS7] 13. What are the celestial objects that we can see in the sky? [AS7] Additional AS-Based Practice Questions 142