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Types of Motion Std X Choose the correct answer Which of the following represent the circular motion---------( Ball sliding down an inclined plane pendulum b. d) motion of simple of A freely falling body to a thread and whirled d. A stone tied The waves carries --------------( b ) Power d. work b. energy c. displacement Which of the following is longitudinal wave---------------( d ) Radio wave d. sound waves b. X- rays c. light wave The S.I unit of wave length is -----------------( c ) Cm b. d. dm c. m km The wavelength of a wave is 4 m and two wave per second possess a point , Then the speed of the wave is ----------------- Q II 2 m/s 6m/s b. d. 8 m/s 4 m/s Complete the following sentences Waves are produced by distrubances . The speed of a wave depends on nature of the medium c. The distance between two consecutive compressions wave length . / rarefaction The type of wave to which electromagnetic wave belongs to transverse wave . In a longitudinal wave the vibration of particles wave are same Q III , and the direction of Match the following A B Longitudinal wave Oscillations in spring Transverse wave Crests and tough Simple harmonic motion simple pendulum Q IV Oscillation of a Answer the following Give differences between a transverse wave and a longitudinal wave Transverse wave Longitudinal wave The wave propogates in the propogates in the form of crests and toughs form of compressions and The wave Rarefaction One crests and one trough compression and one one Constitute a wave rarefaction constitute a wave Q 2. Does the particles of the medium in which a wave moves travel along with the wave? Explain with an example. Ans The particles of the medium in which a wave moves, do not travel along with the wave. This can be shown by the following activity. Place a paper ball on the surface of water in the pond. Throw a small pebble to the still water. You will find the waves forming and these waves are transverse waves observe the paper ball it is moving up and down only , but it is not moving forward along with the waves . Only energy is carried. If we double the frequency of a vibrating object, what happens to its time period ? Ans. Time period and frequency are inversely proportional to each other. If we double the frequency of a vibrating object, then the time period of vibration reduces to half. 4 If the frequency of tranverse wave is 10hz and the distance between the two consecutive wave crests is 2m. Calculate the wave speed. A.If the frequency of a wave motion is f and the distance between the two consecutive wave crests λ, then the speed of the wave is denoted as ‘v’ V=fλ given f = 10Hz λ = 2m v = 10 X 2 = 20m/s 5 define simple harmonic motion and give two example of the same . A A particle is said to be in simple harmonic motion if the acceleration of the particle is always directed towards a fixed point called mean position and the magnitude of the acceleration is directly proportional to the displacement of the particle from mean position. Eg – i) Oscillation of a simple pendulum. ii) When a tuning fork is hit against rubber pad, its prongs execute Simple Harmonic Motion. 6 Give two practical applications of Simple Harmonic Motion. A 1. Simple Harmonic Motion of a pendulum used for calculating time in clocks 2. Tuning the musical instrument is done with the vibrating tuning fork which executes simple harmonic motion. Std VII Q Cellular Organization I Choose the correct answer Microscope was invented by Leeuwenhoek. Leeuwenhoek c. Robert Hook Robert Brown b. d. Cell was discovered by Robert Hook Leeuwenhoek Robert Hook Brown b. b. The power house of a cell is Q II b. bacteria cell tissue d. Robert c. virus mitochondrion ribosome d. lysosome c. A group of cells with similar structure and function is a. system c. eukaryotic cell Prokaryotic cell d. eukaryotic cell 5. Parashara d. A true nucleus is present in a..Nucleus mitochondrion Parashara b. organ a tissue c. organ organism Fill in the blanks The combination of different system organs which out a particular function is a Ribosome helps in protein synthesis. Lysosome helps in the digestion of organic substance. Paramecium is an example for unicellular organism The part which controls and co-ordinate nucleus all the activities of the cell is In a prokaryote , genetic material is represented by chromatin Q III Answer the following Define a cell. Explain the structure of a typical cell Ans. A cell is the structural and functional unit of an organism. The cell has a and organelles like mitochondria , endoplasmic reticulum , and golgi complex. Draw a neat diagram of Ans eukaryotic cell and Refer page No . 18 Difference label its parts. fig. 2.2 between an organ and a tissue Organ It is a combination of different types of tissues which performs specific function. Tissue A tissue is a group of cells with similar structure and function. Mention the Ans Nucleus functions of the parts of a eukaryotic cell. Controls and co-ordinates all the activities of the cell. Mitochondrion Helps in producing energy from food . Ribosome Helps in protein synthesis. Centriole Helps in cell division . Vacuole Stores wastes , secretions and reserve food products in the cell. Endoplasmic reticulum It transports substances cell to the other and from one cell to another. from one part of the a Golgi complex activities . It helps in the secretion of chemicals required for cellular Lysosome Helps in the digestion of organic substances present in the cell. It destroys its own cell when cell become old or damaged. Distinguish between the following pairs Ans Prokaryotic cells Eukaryotic cells The cytoplasm shows The cytoplasm shows small ribosome large ribosome. Genetic material is Genetic material is present in the represented by form of chromatin. DNA b) Unicellular organisms Multicellular organisms Organisms with a singke cell are many cells are organisms with called unicellular organisms . organisms. Eg. Banyan tree, elephant Amoeba, euglena etc multicellular etc. Draw a neat labelled diagram eg. of a prokaryotic cell. Ans Refer page No 17 Fig . 2.1 Describe the structure of a prokaryotic cell. Ans The cell is surround by cell membrane and a cell wall. The genetic material is represented by nacked Deoxy Ribo Nucleic Acid. The cytoplasm shows small ribosome. A cell with this pattern of organization is called a prokaryotic cell. Name the four levels of our body organization in organisms Ans The four levels of our body organization in organisms are Cell. Organ, and System . Tissue , n the advantage of tissue-organ level of body organization. Ans . The advantages of tissue – organ level of body organization is that cell differentiate into true tissues and organs for specific functions. Std X Q I Physics Stars and Galaxies Choose the correct answer The raw material for the formation of protostar is In which of the following stage is the Sun Red giant, white dwarf, protostar, hydrogen. steady state steady state The first element formed within few minutes after supernova is The heaviest element formed in the stellar evolution before supernova explosion is iron oxygen. The diameter of Milky Way is about one lakh light year Q II Match the following A B The Sun Yellow The Sirius Yellowish white The Rigel Bluish white Q III Answer the following How is a protostar formed ? Ans. The inner stellar space contain huge gaseous clouds of hydrogen. This huge cloud continuously contracts under its own force if gravity with increase in density. This leads to increase in pressure with maximum density at the centre. This central portion ,which constitute about 99% of the mass of gaseous cloud is refered as protostar. When does a star attain Steady state? Ans. The continuous contraction of the gaseous cloud of the protostar leads to an increase in the temperature so much so that hydrogen molecules begin to fuse to form helium. This nuclear reaction releases tremendous amount of energy , which tries to push the matter away the from the centre. However the force of gravity eventually balances the pressure caused by the radiation from the nuclear reaction and the star reaches the steady state. Explain the evolution of a star whose mass is five times the mass of a star Ans. Stars which are five times the mass of the sun evolve differently after red giant stage. Their evolution has several stages of nuclear reactions ignited one after other . The carbon nuclei produced during the fusion of helium ,forms the carbon core . The carbon nuclei fuse and liberate energy synthesizing heavier element like oxygen, magnesium and silicon. This fusion cycle repeats until the element iron is formed . At this stage the star explodes in the form of supernova. The remnant condenses in the form of neutrons to form neutron star. Explain the Big Bang theory. Ans. It is proposed that the universe might have begun with a start of explosion known as big bang . Everything what we have in the universe was once concentrated in a very small hot place called ‘’Primordial Fire Ball’’ something triggered and the fire ball exploded with a bang and the matter in it was thrown away. This is known as big bang theory. State Hubbles’s law Ans. The velocity of recession of a celestial body is proportional to its di stance from us ( B) Q I Rockets and Artificial Satellites Answer the following Explain the principal of rockets Ans. Working of a rocket is based on the following principle Newton’s third law of motion The principle of conservation of momentum. According to Newton’s third law of motion “ For every action there will be an equal and opposite reaction” According to principle of conservation of momentum “The total momentum of a system is conserved when the net force acting on the system is zero” Let a bullet of mass ‘m’ is fired with a velocity ‘v’ from a rifle of mass ‘M’ Before firing both the bullet and rifle are at rest which means the total momentum is zero When the bullet is fired ,the bullet leaves the nozzle of the rifle with a momentum ‘mv’ and the rifle recoils with a velocity ‘V’ There momentum of the rifle is ‘MV’ Total momentum after firing is mv +MV The total momentum must be zero. MV+mv=0 or MV mv The rocket works in the same principle During the firing of a rocket the fuel burns and is converted into gas at high pressure. The gas escape from NOZZLE of the rocket with a high velocity and rocket is pushed with a high velocity in the opposite direction. 2 Ans. Page no 403 3 Ans. Draw a neat diagram of single stage rocket and label the parts. fig 24.13 Define orbital velocity of a satellite The velocity of the satellite along a circular path is called orbital velocity. 4 and orbital velocity What is meant by escape velocity? Write the relation between escape velocity Ans. The maximum velocity with which a body must be projected so that it escapes from the gravitational field of earth is called escape velocity (V e ) Relation between Orbital velocity and escape velocity Orbital velocity V 0 = Escape velocity V e = :. Ve 5 = V0 What are the factors that decide the value of escape velocity Ans. Escape velocity depend upon the radius of the earth (R) and acceleration due to gravity (g) 6 Ans . What are multistage rockets? What are their advantages . Multistage rockets are several rockets joined together one on top of the other to provide Advantages of multistage rockets 1) The fuel consumption can be reduced 2) Increases the efficiency of the rocket 3) At a greater height satellites can be placed. 7 Make a list of artificial satellites. Ans. following are the main uses of artificial satellites. Communications Agriculture. Weather forecasting Flood forecasting Identifying Geological mineral resources Identifying underground water sources Monitoring air, water, sound and thermal pollution Forest fire detection Detecting ‘’Elmino’ type weather changes etc 8 Write an essay on Indian space programme Ans. Indian space programme was started in 1963 with launching of a research rocket from Thumba . In 1969 Indian space Research Organization ( ISRO) was established. In the past five decades ,India has many achievements to its credit in space. ISRO had built and successfully launched various types of satellites .They include communication satellites ,and scientific satellites These satellites are providing many valuable services to India like telephone calls, internet data rely, accurate weather forecasting , accurate survey of the country’s resources, etc ISRO constructed many satellites such as Polar Satellite Launch Vehicles( PSLV), Geosynchronous Satellite Launch Vehicles( GSLV), INSAT series of satellites were also constructed. PSLV launched many foreign satellites in addition to the Indian ones. India took a giant leap towards the moon In 2008 ISRO sent “”Chandrayaan—1 an unmanned spacecraft to explore the moon. This Chandrayana mission succeeded in finding water on the surface of the moon. This is the greatest achievement in space by India. In November 5th 2013 ISRO launched a spacecraft to explore planet Mars. This spacecraft was sent using cryogenic engine fitted rocket. Construction of cryogenic engine is the most modern technology. India can hope to have manned mission to moon in future. Sound I Choose the correct answer i Echo of sound is due to reflection of sound. ii The property of ultrasonic waves used in manufacturing emulsion for photographic films is its higher wavelength. iii When a source emits light of particular wavelength and the source is moving away from us, the wavelength appears longer. iv The audible range in human is 20 Hz to 20000 Hz. v The speed of ultrasonic sound in air is 340ms -1 II Fill in the blanks i The sound wave is of the type longitudinal wave. ii Ultrasonic is preferred to X ray in medical field because it is less harmful. iii When ultrasound is used to examine heart, it is called Echo cardiography iv The shift caused in visible spectrum of light emitted by galaxies is red shift. III Match the following A B IV 1 Radar a) electromagnetic 2 Sonar b) ultrasound 3 Doppler Effect c) apparent shift in frequency Answer the following What is an echo? Mention the condition for echo to be heard. A The sound heard after reflection from a rigid surface is called echo. The conditions for the echo to be heard i To hear a distinct echo the time interval between the original sound and the reflected sound must be equal to 0.1s. ii The reflecting surface should be at a minimum distance of 17m from the listener. An ultrasonic sound sent from a ship travels with the speed 1530 ms -1 in sea water. How deep is the water if the time delay of the echo from the sea bed is 6s ? A Speed ‘v’ of the sound in sea water = 1530 ms -1 Time taken by the sound to reach the ship = 6s = t The depth of the sea water = ‘d’ Then d= = = 1530 X 3 = 4590 m Depth of sea water = 4590m What is SONAR? How does it work? A Sonar is the acronym of “Sound Navigation and Ranging“. This is a technique by which ultra-sonic waves are used to measure the distance, direction and speed of under water objects. Working of Sonar A sonar contains a transmitter and a receiver (detector). The transmitter produces and transmits ultrasonic waves. These waves travels through water until they strike an object. They get reflected and the reflected and the reflected waves return to the detector of the sonar. The detector converts the received ultrasonic waves into electrical signals which are interpreted. The time interval between transmission and reception is recorded. The distance of the object is calculated. What is Doppler’s effect ? explain with an example. A When either the source of the wave of sound/light or an observer is moving relative to each other, then there is an apparent change in the frequency of the wave. This is known as the Doppler Effect. When the source of the sound/light is moving towards the observer the waves on front appear to be compressed. The observer feels sound to be of higher frequency. Therefore he feels the pitch of the sound to be higher. The same effect is observed when the observer is moving towards a stationary source of sound. Mention three applications of Doppler’s effect. A 1 Doppler effect can be used to track artificial satellite. 2 Doppler effect of sound can be used to determine the velocity of submarines. 3 astronomers use Doppler effect to gauge the movement of stars and galaxies with relative earth. *************************************** Electromagnetic Induction I Fill in the blanks Device that converts mechanical energy into electrical energy is dynamo. The type of electric current that changes its direction twice during one cycle of the dynamo is called alternating current. Device that converts electrical energy into mechanical energy is motor. In Fleming’s rule the middle finger indicates the direction of induced current. The device that detects the induced emf is called galvanometer. II Choose the correct answer Electricity and magnetism are mutually ___complementary. The SI unit of potential difference is ____volt. Carbon brushes are not necessary in a dynamo, if the coil remains stationary and the magnet moves because___-current is drawn from a stationary source. AC is not suitable for electrolysis because----polarity of the current changes. Which of the following graph indicates direct current------d. When the plane of the rectangular coil is parallel to the to the direction of the magnetic field in a dynamo, then--- induced current will be zero. A small AC dynamo is connected to a galvanometer and gently rotated ,then the needle of the galvanometer -----moves towards both right and left. A dynamo makes 100 cycles per second. The frequency of the AC is 100 Hz III Answer the following What is electromagnetic induction ? When the magnetic field linked with a circuit changes an emf will be induced in the current. This phenomenon is called electromagnetic induction. State Faraday’s laws of electromagnetic induction. I Law---Whenever a magnetic field linked with a conductor changes an induced e.m.f is generated in the conductor. II law---The magnitude of induced emf is directly proportional to the rate of change of magnetic field linked with the conductor. State Fleming’s right hand rule . For what purpose it is used ? Fleming’s right hand rule----Arrange the first three fingers of right hand mutually perpendicular to each other. The fore finger indicates the direction of the magnetic field, the thumb the direction of the conductor, then the middle finger will indicates the direction of the induced emf. This rule is used in the working of dynamo. Draw neat diagram of the following and label the parts i) Ans AC dynamo ii) DC dynamo iii) DC motor i) AC dynamo refer page no 264 fig 16.5 ii) DC dynamo refer page no 266 fig 16.7 iii)DC motor refer page no 267 fig 16.10 Mention any two uses of DC and any two uses of AC Uses of DC current Battery charging ( adoptor ) electrolysis Charging of mobile phones Uses of AC current In domestic appliances like lamps , fans To produce required frequency of radio waves. Q V Give reason In the experiment conducted by Faraday the induced electricity current was not DC. Magnet pushed into the coil gives one direction of the current and removal of the magnet gives the opposite direction of the current which is AC not DC. Split rings are used instead of slip rings to construct DC dynamos. The split rings reversed the connection to the external circuit. This makes the current to flow in the same direction. Therefore split rings are used to construct DC dynamo. Stationary coil and stationary magnet cannot produce induced electric current. An emf will be induced in the circuit only when the magnetic field associated with a close circuit changes. So stationary coil or stationary magnet cannot produce clear current. VII Draw neat diagram of the following and label the parts Step down transformer ----- refer fig 16.12 a Step up transformer --------- refer fig 16.12 b Induction coil --------------- refer fig 16.12 c Heat Engine I 1 The energy transformation in a heat engine is a mechanical into heat b heat into mechanical c mechanical into potential d mechanical into chemical 2 forward movement of a piston in steam engine is called a expansion stroke b exhaust stroke c intake stroke d ignition stroke 3 In a steam engine the steam cylinder is connected to the condenser by a piston b crankshaft c outlet valve d inlet valve 4 both the valves of a petrol engine are closed during a intake stroke b exhaust stroke c compression stroke d fuel in the stroke 5 An engine is designed to convert 20% of the heat energy into work. If the steam in the engine has 50kj of heat energy , the useful work done by the engine is a 16kj b 100kj c 40kj d 50kj 6 In a temporary forest camp, the best way to generate electricity for several hours is to use the following engine a steam engine b petrol engine c hand operated dynamo d diesel engine II Fill in the blanks 1 the part of petrol engine in which petrol vapour and air are mixed is carburettor. 2 Linear movement of the piston in a heat engine is converted into circular motion by crank shaft. 3 The stroke of a heat engine in which outlet valve opens is exhaust stroke. 4 internal combustion engine that does not use spark plug is diesel engine. 5 The fuel used in Raichur thermal power plant is coal. III Answer the following 1 An engine is 40% efficient. What is the meaning of this statement? A 40% of the heat energy is converted into mechanical energy. 2 Make a list of the differences between petrol engine and diesel engine Diesel engine i diesel engine are compression ignition engines. Petrol engine i petrol engine are spark ignition engines. ii spark plug is not required ii spark plug is required iii micells of diesel are as fuel. iii petrol vapour is used as fuel iv the cost of diesel is comparatively less. v expansion against constant pressure. vi efficiency is comparatively more. iv the cost of petrol is comparatively high. v expansion of gaseous products with pressure impulse vi efficiency is comparatively less. 3 Make a list of the limitations of a steam engine. A i Construction of steam engine is not simple. The bulk and the heavy weight of the engine is not suitable for small vehicles. ii The efficiency of the engine is very low. iii Heating water to produce steam, takes time and the engine cannot start instantly. 4 Explain the intake stroke of a petrol engine. A In a petrol engine the vapourised mixture of petrol and air is let in through the inlet valve. The outlet valve remains closed. Piston moves away from the spark plug. 5 diesel engines do not require spark plug. Why ? A In the place of spark plug there will be compressor in which reverse intake and compression takes place. Due to high pressure of air diesel burns. 6 Draw a neat diagram of expansion stroke of a steam engine. Ans Refer page no. 113 figure 9.3 (a) 7 Draw a neat diagram of petrol engine and label the parts. Ans Refer No 115 figure 9.5 8 An engine is designed to convert 10kj of heat energy into work. If the heat energy consumed by the engine is 60kj. How high would this engine lift an object of mass one kilogram from the ground ? A Assume that g = 10m/s2 W = mgh Efficiency = E= or E = 40% W= H \ 60kj m = 1kg (1000g) g = 10m/sec2 h = the height to be found W= = = 24kj W = mgh = h = = = 2.4m Electronics The conductivity of a semiconductor is Greater than the conductivity of metals Less than the conductivity of metals Equal to the conductivity of metals Intermediate between the conductivity of metals and insulators Answer --- d The conductivity of a semiconductor can be increased by Heating the semiconductor Doping the semiconductor Both a and b None Answer ---- c In a n-type semiconductor which of the following statement is true ? Electrons are majority carriers and trivalent impurity are the dopants Electrons are minority carrier and pentavalent atoms are dopants Holes are minority carriers and pentavalent atoms are dopants Holes are majority carriers and trivalent atoms are the dopants Answer ----- b Which of the statements given in question 3 is true for p-type semiconductor? D When a forward bias is applied to p-n junction it Raises the potential barrier Reduces the majority carrier current to zero Lowers the potential barrier None of the above Answer ----- c For transistor action which of the following statements is correct ? Base,emitter and collector regions should have similar size and doping concentration The base region must be very thin and lightly doped The emitter junction is forward biased and collector junction is reverse biased Both emitter junction and collector junction are forward biased Answer ---- c II Fill in the blanks In p-n-p transistor the majority carriers are holes. In n-p-n transistor the majority carriers are electrons. During reverse bias of the diode there is a small current of the order of micro ampere due to minority charge carriers. In an n-p-n transistor p type semi conductor sandwiched between two n type semi conductor. Pentavalent impurity is called n type impurity. Trivalent impurity is called p-type impurity. The traces of impurity added for doping are called dopants. III What is electronics ? Electronics is an extended field of physics and engineering both pure and applied. What are conductors and insulators. Give examples. Conductors Materials which conduct electric current smoothly eg. All metals Insulators Materials which do not conduct electric current smoothly. They are also called non conductors or bad conductors. Eg; all non metals except graphite Mention any four electronic gadgets. C.D players, computers, mobiles, phones, amplifiers etc. Which are the areas influenced by electronics? The areas influenced by electronics are Industrial field, military requirements fiels, communication field and medical science field. What are most recent advancements in the field of electronics ? The areas influenced by electronics are digital circuits, micro processor, digital computers, photo electronics laser technology, nano technology and so on. What are semiconductors?give examples. The substances which have conductivity in between conductors and insulators are called semi conductors. Ex : silicon, Germanium How many electrons are there in the outermost shell of silicon atom ? There are four electrons in the outermost shell of silicon atom. What is called a hole ? When an electron from a neighbouring atom moves a vacancy is created. This vacancy is called hole. This is a positive charge carrier. Distinguish between extrinsic and intrinsic semiconductors. Intrinsic Semiconductors Extrinsic Conductor i semiconductor are the crystalsi when some impurity atoms are of pure elements like silicon added to this intrinsic semiconand germanium.-doctor we get extrinsic semicoii the number of electrons is equal -ndoctor. to number of holes ne = nn ii the number of electrons is not equal to the number of holes. ne≠nn Explain the term doping When a few atoms of trivalent or pentavalent element is added into intrinsic semiconductor ( Germanium or silicon ) it converts to extrinsic semiconductor. The process of adding impurity atom is also called doping. Distinguish between n-type and p-type semiconductors. n-type semiconductor semiconductors p-type i when pentavalent impurityi when trivalent impurity atoms atoms like phosphorous, arseniclike gallium, indium, aluminium or antimony are added to the intretc are added to the intrinsic semi insic semi-conductor,we get n-type conductor. semi conductor. ii the majority carriers in n-type ii the majority carriers in p-type semiconductor are electrons and semi conductor are holes and minority carriers are holes due to minority carriers are electrons. thermal energy. Name two pentavalent impurities. A.Pentavalent impurities are antimony,arsenic and phosphorous Name two trivalent impurities. Gallium, indium , Boron and aluminium ( any two ) What is semiconductor diode or junction diode. A single crystal of semiconducting material whose one side is doped with donor impurity and the other side is doped with acceptor impurity forms a p-n junction diode or semiconductor diode. What is meant by forward bias and reverse bias of a diode ? Indicate in a figure. Forward bias of a diode : when the positive terminal of the battery is connected to p-region and the negative terminal of the battery is connected to n-region of the junction diode it is said to be forward biased. For fig refer page no 281 fig 17.7 Reverse Bias of a diode : When the positive terminal of the battery is connected to n-region and negative terminal of the battery is connected to p-region of the junction diode it is said to reversed biased. For fig refer page no 281 fig 17.8 Give the circuit symbol of a diode. Ans For fig refer page no 282 fig 17.10 Mention important characteristics and applicatons of a diode. The important characteristics of diode is it allows electricity to flow in one direction and blocks the flow in the opposite direction. Applications – diodes are used in voltage regulation systems. They are used in logic circuits which are used in computers. What is a transistor ?distinguish between p-n-p and n-p-n transistor. A transistor is a three terminal semiconductor device. It is a resistor to amplify electrical signal passing through its input to output terminals. p-n-p transistor two segments of p-type semi n-p-n transistor two segments of n-type semiconductor are separated by a segment of n type semiconductor conductor are separated by a segment of p-type. What are the functions of three regions of a transistor ? A transistor consists of three regions. They are emitter (E), base (B) and collector (C) Functions of E,B and C of transistor. Emitter : it supplies a large number of majority carriers for the flow of current through the transistor. Base : it regulates the flow of charges from emitter to collector. Collector : this segment collects a major portion of majority carriers supplied by the emitter. Mention the applications of a transistor. Transistors are used in Amplifiers Oscillators Switching circuits. Alternative Q I Sources of Energy Choose the correct answer Identify from the following , a conventional source of energy---- ---(c) Solar energy d. bio energy 2. 3. natural gas b. Kanyakumari c. Gujarath d. soil quality b. it enhances water it reduces carbon dioxide content in the atmosphere d. it increases pollution One of the following is an indirect form of energy--------( d ) a. tidal energy energy d. Q c. Which of the following is not a feature of bio energy-------( d ) a. it improves retention 4. tidal energy The largest installation of wind turbines in our country is found in-------( b ) a. Ladakh Madhya Pradesh c. b. b. energy from waste c. Geo thermal electricity II Fill in the blanks The principle involved in the conversion of solar energy into electrical energy is called photovoltaic effect The conversion of crude oil from plant seeds into a useful fuel involves process called trans esterification Wind energy is a converted form of a solar energy The energy trapped within 10 km of earth’s crust is known as geo thermal energy Q III Answer the following What is the need for trapping alternative sources of energy? We are using conventional sources of energy on a large scale. Due to this their reserves are depleting at a faster rate. At the same time , it is becoming increasingly difficult to discover new deposits. This led to the attempt to trap alternative sources of energy all over the world. List the advantages of nonconventional sources of energy over conventional sources. Non conventional Conventional Sources sources Non-conventional sources sources of Of energy are permanent. temporary. Non-conventional sources of sources of energy Energy are eco-friendly friendly Non-conventional sources of energy Of are very efficient efficient Almost all non-conventional produce Energy produce high energy. effffect Conventional energy are Conventional non echo conventional sources are not Conventional sources Reduced energy Differentiate between solar collectors and solar cells. Solar collectors Solar cells Solar energy on the surface convert solar energy Of the earth can be converted energy. solar cells into electrical Into thermal energy. What is bio energy ? The process in which biological matter such as plant and plant product provide the basis for energy and its conversion is called bio energy Name any two plants that are sources of bio fuel ? The plant ‘ Jatropha’ is used to get bio energy (bio diesel ) which produces bio energy is ‘ Pongamia pinnata. Another plant Write a brief note on Geothermal energy. Geo thermal energy is one which is got from the depth of the earth. 10 km deep into the earth , heat is available and this heat can be converted into electrical power . The temperature of Geo thermal energy is about 1300 0 c There are about 340 hot springs (hot water gushing out from the earth ) identified in different parts of our country. They are Puga , Manikaran, Tatapani and Bakneshwar. ®