X SS1 SOURCES OF ENERGY
Sources of energy—Fuels Class X ( For X-2011 )
Prepared by : Inderjeet Bhatia
Source of energy:-A source of energy is one which can provide amount of energy in a convient form over a long period of time. Eg : Solar energy, Tidal energy, Fuels, Bio mass.
Non Renewable Source of energy:-Those sources of energy which have arrounded in nature over a very,very long time and a cannot be quickly replaced when exhausted are called non-renewable resources. of energy. Coal, petrolum, natural gas and uranium are non-renewable source of energy because they have accumulated in the earth over a very, very long period of time and if all the coal gets exhausted, it cannot be produced quickly in nature. The non renewable source of energy are. Fossil fuels.Non renewable source of energy are dug out from the earth.The non renewable source energy are also called convential source of energy. The non-renewable source of energy like fossil fuel,petrolum, coal, natural gas are present in a limited amount of the earth.Once exhausted, they will not be available to us again
Renewable source of energy:-Those source of energy which are being produced continously in nature and are inexhaustible, are called renewable source of energy. For example, wood is a renewable source of energy because if treees are cut from the forests for obtaining wood.then more trees will grow in the forests for obtaining wood.then more trees will grow in the forests for obtaining wood then more trees will grow in the forests in due to course of time.So the loss of wood by cutting trees is made good by nature. The renewable source of energy are :Hydroenergy (energy from flowing water); wind energy, Solar energy. Energy from sea(tidal energy,Sea wave energy and ocean thermal energy), Geothermal energy, Biomass energy(Energy from Bio-fuels such as wood,Bio gas and Alochol) and hydrogen.The renewable source of energy are also called as non-conventional source of energy.These sources of enegry can be used again and again endlessely.They will never get exhausted.Since renewable source of energy will never get exhausted so they are also known as inexhaustible source of energy A yet anothername for renewable source of energy is altenative source of energy
Q-1 What is the ultimate source of energy for every fuel?
Ans. Sun is the ultimate source of energy for every fuel. Sun helps in photosynthesis to store solar energy in the form of chemical energy which is present as biomass in plants, animals or their products when these objects changed into fossil fuel like coal, petroleum and natural gas therefore every fossil fuel. So every fossil fuel is the source of solar energy.
Q-2 Fuel
1.Fuel : The material which are burnt to produce heat energy. E.g. Coal, Petrol, Wood.
2.Calorific value: The amount of Heat produced by complete combustion of unit mass (1 gm) of fuel completely in sufficient air is called as calorific value. Its unit is KJ/gm
Q = m x c. v {m in gm}
3. Role of fuels in Everyday life:
(a) The fuels are used in houses for cooking food and for other domestic purposes.
(b) The fuels are used in industries.
(c) The fuels are used in generating electricity.
(d) The fuel is used for transporting men and material from one place to another’s.
(e) The fuels are used in rockets missile.
Q-3 Types of Fuels
(a) Solid fuel: Those fuels which are solid at room temperature are called as solid fuel. E.g. Wood, Coal, Charcoal, Coke, etc.
(b) Liquid fuel: Those fuels which are liquid at room temperature are called as liquid fuel. E.g. Petrol, Diesel, Kerosene, Alkali oil, etc.
(c) Gases fuel : Those fuels which are gases at room temperature is called as gases fuel .e.g. LPG, Natural gas, Biogas, Coal gas, Water gas, Producer gas, etc.
(d) Natural, raw, primary fuel : Those fuel which are obtain from nature and used directly in their natural form are called as natural fuel. E.g. Wood, Animal Dung, Coal.
(e) Secondary fuel, manufactured as processed fuel: that fuel which prepared from the natural fuel by physical or chemical process then used called as processed fuel. e.g. Charcoal, Coke, Petrol, Coal gas, etc.
(f) Biomass fuel : That fuel which is directly or indirectly obtain from body or waste of plants, animals or micro-organisms called as Bio mass fuel. e.g. Animal Dung, Bagasse.
Bagasse : It is the waste which remains after extraction of juice from sugarcane called as bagasee. It is dried and used as industrial fuel.
(g) Fossil fuel: That fuel which is formed by slow decomposition of remains of plants animals or micro-organisms. When they buried under the earth called as fossil fuel. e.g. Coal, Petroleum, Natural gas, etc.
Q.4 Even the hydrogen has highest calorific value though it is not used as domestic fuel?
Ans. Hydrogen has highest calorific value (150 KJ/g) but it cannot be used as a domestic fuel because
(a)It is unsafe to use because it form explosive mixture in air.
(b)It can unsafe to store because handling need very high care.
(c)It ignition temperature is low so it may catch fire by its own.
(d)The amount of heat produced during combustion cannot be tolerated by containers. So it requires special burner and pure oxygen it is very difficult in homes.
Q 5 A what is power plant.Give the type and brief descrption ?
AnsThat establishment where electricity is generated called as power palnts E.g. Hydro electric power plant, themal power plant,atomic power plant
(i) Hydroelectric power plant:- Flowing water posses kinetic energy.The energy of flowing watre has been traditionally used for rotating the watre wheels and drive water millis to grind wheat to make flour.The traditionally use of energy of flowing watre has been modified by improvements intechnology and used to generate electricity.This is done by establishing hydro power plant.At hydro plant the energy of falling water(or flowing watre) is tapped by using a ‘water turbine’ and then made to drive generators.
In hydro electric power plant wayter stored in dams gain potential energy, when water flows through cannal then the potential enegry change into kinetic which force s the turbine fan to generate electricity ( about ¼ th of our requirement is met by this)
Advantage (a) The generation of electricity from flowing water does not produce anyenvironmental pollution.(b)Flowing water is a renewable source of electric energy which will never get exhausted.(c) The construction of dams on rivers helps in controlling floods, and in irrigation.
Disadvantage(a) Constructing dams the large area of argiculture, satellments,plants and animals get destroyed foreveer.(b) The ecosystem submerver in water.(c) Large silt coming during floods stopped in dams by which fertility of soil repleshiments stops (d) Large area of fish and watre animals get confined, their inter breeding increases and free movement stops(e) shifing of villages nad their working area pose new threats(f)watre cyvle disturbs.
So The opposition to the construction of tehri dam on the river Ganga and Sardar Sarovar Project on the river.Narmada are due to such problems.So, before taking a decision to generate hydroelectricity by constructing high rise dams on rivers,It is necessary to consider its long term effects on the environment and social life carefully.
(b)Thermal power plant:-An Installation where electricity ( or electric power) is generated is called a power plant.It is also called a power house.A power plant where heat is required to make steam to drive turbiness
( or to make electricity) is obtained by burning fuels(coal,oil or gas) is called thermal power plant.Coal (fuel oil or natural gas) is burned in a furnace to produce heat.This heat boils the watre in a boiler to form steam.The steam formed from boiling water builds up a preesure.The hot steam at high preesure is introduced into a turbine cahmber having a steam turbine.The steam passes over the blades of the turbine as a high preesurejet making the turbine rotate.The shaft of turbine is connected to generate.when the turbine rotates,its shafts also rotates and drives the generator.The generator produces electricity.The spent steam coming out of turbine cahmber is cooled.On cooling,stema condenses to formwater.This water is again sent to the boiler to form fresh steam.This process is repeated again and again.
Q-43 Is really, source of enegry said to be pollution free ?
Ans:-The use of fossil fuel causes air pollution and the production of hydroelectricity causes ecological imbalance. In some cases,the actual operation of the device used for harnesing energy may be pollution free but the making of device itself must have caused some environmental damage E.g. the use of wind generator, solar cooker and solar cells obtaining energy is pollution free but the processes involved in main gthe material for these energy is pollution free but the processes involved in making the materials for these energy devices must have damaged the environment in some way From this we conclude that, in realty, no source of enegry said to be pollution free. When we talk about a clean fuel, it actually means that it is a cleaner fuel than some other fuel when we say that CNG is a clean fuel, it means that a CNG is a cleaner fuel than, say p[etrol or diesel.
Q6 Give various pollutants produce during burning coal(fossil fuel)?
Ans. The main pollutants are CO2, CO, SO2 and Smokes along with fly ash.
Q.7 Name the pollutants produce during burning of petroleum and oil fossil fuel)?
Ans. The main pollutants are carbon monoxide, Hydro carbons, un burnt carbon particles, some alcohols, some acids, oxide of Nitrogen and lead compound.
Q.8. Give ill effect of various pollutants?
Ans. During combustion various pollutants are produce and cause their ill effect.
(a) CO2 : It is most common pollutants produce during combustion. It is an acidic gas which can mix in rainy water and create acidic rain. This rain changes the useful compounds into carbonates and bicarbonates of very little use CO2 has tendency of storing solar heat and infra red rays to increase the temperature of atmosphere (Green house effect) by which glacier and snow melts and cause coastal flooding.
(b) Carbon Monoxide (CO) : It is colourless, odourless most dangerous pollutants produce during incomplete combustion of substance. When this CO is inhaled then it combine with haemoglobin to form a stable compound carboxy haemoglobin. This compound lead to less transportation of oxygen by blood, by which the persons suffocate and becomes uncoinsous, may die.
(c) Sulphur dioxide : It is an acidic oxide which form during combustion. It get dissolved in water of rain and form acid. The rain become acidic and called acidic rain. It is very dangerous for plants, animal and metal object and stone objects.
(d) Fly ash : It is very thin and minute type of particle of ash. It causes blocking of buildings, walls, clothes. It can be deposited on leaves and cause less photosynthesis. It is responsible for various respiratory diseases.
(e) Lead Particles : These particles are produced during burning of oils. These particles are very dangerous for health. These particles can damage formation of blood, cells and tissues. Its main effect on reproductive system.
Q.9 Give the fuel of body and tell how it gives energy?
Ans. the food which we eat is a kind of fuel for our body which supplies us with energy. It gives us energy by the process of respiration. Respiration is the process by which living things breakdown food and obtain energy required for living.C6H12O6 + 6O2 6CO2 + 6 H2O + Energy.It occur at normal body temperature (37°C). The energy produced get backed in A.T.P. It is also called as slow combustion.
Q.9 A What is the ultimate source of energy for every fuel?
Ans. Sun is the ultimate source of energy for every fuel. Sun helps in photosynthesis to store solar energy in the form of chemical energy which is present as biomass in plants, animals or their products when these objects changed into fossil fuel like coal, petroleum and natural gas therefore every fossil fuel. So every fossil fuel is the source of solar energy.
Q.10 Why fossil fuel are precious?
Ans. The fossil fuel are non-renewable type of source so they cannot be regenerated in a short time thus take many years to regenerate. Their quantity is limited and most of the such fuel are used up now. Only very little of fossil fuels are present or available for further use. Therefore they are precious. Therefore there wastage can be prevented.
Q11A What is distillation? Gives its example and types?
Ans. Distillation simple distillation : That process in which a mixture of solid or liquid in liquid is heated to a first boiling point by which vapors are produced which are cooled separately to obtain pure liquid is called distillation.Examples: Purification of solid, liquid mixture.
Types of distillation:
(I )Simple Distillation: This method is used to separate liquid from a liquid mixture or solid-liquid mixture.
(ii) Dry of Destructive Distillation: The process in which usually a solid complex material is heated at a very high temperature in a closed vessel in absence of air to decompose it and give various useful products called Dry of Destructive Distillation. E.g. cracking of coal or wood.
(iii) Fractional Distillation: The process by which a mixture of various substances containing solid, liquid, gaseous compound is heated at high temperature in the absence of air to forms vapors. These vapors are cooled at different temperature in fractional chamber to obtain various products called as Fractional Distillation. E.g. Refining of Petroleum.
Q.7 What is coal? How it is formed? Give types and uses?
Ans. Coal is a fossil fuel which is a complex mixture of free carbons and compounds of hydrogen, oxygen with carbon. It has various hydrocarbons with some compound of nitrogen and sulphur.
Carbonization : It is the process of slow converging of wood and plants bodies into free carbons and complex compounds under high temperature and pressure caused when they get buried inside. It takes millions of years by plant bodies to become coal. By this method coal is formed.
Types of coal :
(i) Antharacite : It contains 96 percent of carbon 1% voltile matter and 3% moisture. It is oldest coal having highest calorific value. It is smokeless and pollution free. It has hard coal.
(ii) Bituminous : It is seon type of coal having carbon 65% with hydrocarbons and compound of sulphur and nitrogen. It has medium calorific value. It gives smoke and pollutants. It can be used in household cooking.
(iii) Liginite : It is 3rd type of little brownish cool also called as a soft coal. It has carbon 38%, 19% volatile matter and 43% moisture. It has low calorific value. It gives lot of smokes and pollution having the compound of sulphure. It is used in homes, rail engines and furnaces.
(iv) Peat : It is waste type of coal having very little carbon about 20% with lot of non-combustable poisonous compounds. It is burnt before using once to remove harmful gases. It has very low calorific value. It gives lot of smokes, pollutants and poisonous gases so it is used in industries only or in destructive distillation of coal.
Uses of coal :
(i)Coal is used as a fuel.
(ii)Coal is used in the manufacture of fuel gases like coal gas.
(iii)Coal is used in the manufacture of synthetic petrol and synthetic natural gas.
(iv)Coal is used to make coke.
(v)Coal is used as a source of organic compounds like benezene, ioluene.
Q.8 Give the destructive distillation of coal formed product and uses?
Ans. When coal is heated strongly in iron retoat in vary limited supply of air to decompose it to obtain following objects :
(a)Coal gas : It is the gaseous fuel which is a mixture of hydrogen, methane and carbon monoxide. It is a good fuel which is smokeless and pollution free. It is supplied in Mumbai for domestic and industrial use .
(b) Ammonia liquior : It is solution of ammonia in water. It is used to obtained ammonia and further in fertilizer industry.
(c) Coal tar : It is thick black viscious liquid which is obtain from the destructive distillation of coal. When this coal tar is used in further fractional distillation then following products are obtained which are used from making drugs, dyes, explosive, paints, varnish, plastic, synthetic fibre and pesticides. The main products are :
(d) Benzene : Benzene is used as a motor fuel and in the manufacture of synthetic fibers, dyes.
(e)Coke : It is residual solid having 98% of carbon. It is good source of carbon which is used as fuel, reducing agent in metallurgy. It is also used to manufacture gaseous fuel like :
(1)Water gas (CO + H2): This is formed when steam is passed red hot cake
C + H2O CO + H2
(2)Producer gas (2CO + 4N2): Gas formed when red hot cake reacts with air
2C + O2 + 4N2 2CO + 4N2
Q.9 Give the importance of coke as fuel?
Ans. Coke is smokeless, pollution free fuel with high calorific value. It also burns without flame so retain heat for long duration.
Q 12 Give destructive distillation of wood products with uses?
Ans.When wood is heated in closed container at high temperature by which wood decomposes to give various products.
In this method wood is taken in boiling tube having a cock with right angle delivery tube. This tube remains dipped in water. This test tube has a cock with two holes. From the 2nd holes another delivery tube is connected. Wood in the boiling tube is heated and formed gas pass through water.
(1) Charcoal: It is formed destructive distillation of wood. It is residual solid in the boiling tube. It is black, parent’s substance. It is combustion able substance having high percentage of carbon. It is pollution free, smokeless fuel with high calorific value 637 KJ/g.
Disadvantage of making charcoal from wood is that only 25% of charcoal is formed.
(ii)Wood gas: It is combustible gas formed by destructive distillation of wood. It has mainly methane with other gases. It is used as good fuel.
(iii)Wood tar: It is black viscous liquid condenses in water. It has various substances.
(iv)Methyl alcohol: It is first alcohol formed by destructive distillation of wood. It is used as solvent in various industries.
(b)Acidic acid: It is natural vinegar used as preservative.
Q.17Why charcoal is considered as a good fuel than wood?
Ans.Charcoal is considered as better fuel than wood because its calorific value is very high is
37 KJ. It is pollution free, smokeless and clean fuel and it does not leave much fuel.
Wood is not good fuel because it has low calorific value (17 KJ/Gm). It gives lot of smoke, pollution so it is not a good fuel. It leave large amount of ash.
Q:-13 What is natural gas? Give its composition source and uses?
Ans. Natural is a fuel formed along with formation of petroleum separates and collected over petroleum. It has mainly methane (95%) with small amount of ethane and propane. Natural gas is formed under the earth by the decomposition of vegatable matter lying underwater. This decomposition is carried out by anaerobic bacteria in the absence of oxygen. It is found in Tripura, Jaisalmer, off-shore are of Bombay and in the Krishna and Godvari delta. It is supplied through Hgirapur, Jagdish pur, Bijapur pipeline in Baroda city and Gujarat.
Natural gas is smokeless, pollution free, clean fuel with the high calorific value easy to use and stone.
Uses(a) Natural gas is used as a domestic and industrial fuel.(b) Natural gas is used as a source of hydrogen gas needed in fertilizer industry. CH4 ----- C + 2H2
(c) Natural gas is used as a source of carbon in tyre industry.
Disadvantages--------------It can not be liquefied.
Q.11
Q.9
Q-14 What is petroleum? How it is formed?
Ans. Petroleum is a fossil fuel. It is a black viscous fumming liquid. It is a mixture of solid, liquid and gaseous Hydrocarbons which are saturated and unsaturated. It is source of very useful fuel. Petroleum is formed by slow decomposition of oil squeesed out of micro-organisms when they get buried inside the earth billions of years ago. The oil after slow decomposition change into simple hydro carbon mixture, which is petroleum.
Occurence of Petroleums : Petroleums occur below rocks between two layer of in previous rocks. This oil obtained from natural source below earth. In India it is obtained from Bombay, offshore delta of Kaveri and Godavri. In Bombay high, Assam and in some parts of Gujarat.
25. Agency related to petroleums in India.
(a) ONGC – Oil and Natural Gas Commission
(b) OIL – Oil India Limited
(c) IOC – Indian Oil Corporation
Q15 Give process of refining of petroleum with principle main product?
Ans. Petroleum is refined by the process of fractional distillation. In this method petroleum is heated in closed chamber at very high temperature to form vapours, these vapours are cooled in functional chamber at different temperature to obtained its components.
Principle : The each component of petroleum has different points ranges or different condensing temperature which are directly proportional to molecular mass.During refining of petroleum different product are form from top to bottom :
(a)Petroleum gas : It is a first chamber in which uncondensed gases are obtained having C1 to C4 hydrocarbons and their boiling point are below 40°C. The main product is petroleum gas. This gas is liquified under pressure is called as LPG. It is used as domestic fuel, industrial fuel in cemen and fertilizer industries.
(b)Gasoline or petrol : It is second chamber in which the temperature range is 40°C to 170°C. Where C5 to C10 hydrocarbons are condensed. The petrol is used as light vehicles fuel, fuel for smaller generator set, solvent for drycleaning. More volatile petrol is used as aviation.
(c)Kerosene oil : It is third chamber having temperature range 170° to 250°C. Where C10 to C12 hydrocarbons get condensed. It is used as domestic fuel for cooking, illuminant in lamps and petromax. It is used to make gas oil or kero gas. It is used in jet aeroplane.
(d)Diesel oil : The temperature range of this chamber is 250 to 350°C where C13 to C15 hydrocarbons condenses as diesel. It is used as heavy vehicles fuel in buses truck, ships and trains. It is used in pumpset and generator sets.
(e)Fuel oil : This chamber has temperature range of 350°C to 400°C where C15 to C18 hydrocarbons condenses in the form of fuel oil. The fuel oil is better than coal from furnaces because it does not leave any residue also it has high calorific value. It is used as furnace fuel in industry.
(f)Lubricating oil : The compound having boiling temperature range above 400°C are condensed here having C17 to C20 hydrocarbons. The lubricating oil is used for lubrication in industries and in vehicles.
(g)Paraffin wax : It has C20 to C30 hydrocarbons with the boiling point range above 400°. It is used for making candle, vaseline, wax paper, Toilet good and grease.
(h)Asphalt : It is residual sticky substance having C30 to C50 hydrocarbons. IT is non-volatile non-evaporating semi-solid used for making roads and water proofing material .
Q.16-- What is LPG? Give its components? Name the smell added in it to detect leakage? Why is considered as good fuel?
Ans. LPG stands for Liquefied Petroleum Gas. This gas is obtain at the top of fractional chamber and remains uncondensed. Then it is liquefied under pressure. LPG contain mainly butune, isobutane with little amount of Ethane and propane. LPG is colourless, odourless gas so a bad smelling compound Ethyl mercaptan (C2H5SH) is added to detect leakage. LPG is smokeless, pollution free, clean fuel with high calorific value easy to use and transport, store.
Q.17 Why it is dangerous to used animal dung cake as fuel?
Ans. (i)If animal dung is changed and used then.
(ii) High amount of dung cakes are needed because of low calorific value.
(iii) It gives large amount of smokes and pollutants so very dangerous for health and environment.
(iv) The formation and storage cause extra work load on village women.
Q.18 Give proper use of animal dung?
Ans. When animal dung is changed into biogas then good fuel is form with lot of advantage.
Q.19 What is biogas?
Ans.Biogas is manufactured fuel produced by anaerobic fermentation of mixture of water animal dung and agricultural waste. Biogas has mainly methane with little amount of CO2, monoxide, hydrogen and hydrogen sulphide.
Q.20 How Biogas is prepared? Explain its plant by construction and working?
Ans.Biogas is prepared by anaerobic fermentation of mixture of animal dung, agricultural waste in water. The biogas is prepared in biogas plant. Biogas plants are of two types:
(a) Fixed dome biogas plant
Construction: It is made up of brick. It has cylinder type digester with fixed hemispherical dome. The dome and the digester remain inside the ground. The digester has two opening; one opening is connected to inlet chamber and other with outlet chamber. At the top of inlet chamber, their is mixing tank above the ground. The inlet chamber is covered with stone slab. The outlet chamber is connected with over flow tank. At the top of dome their is gas outlet pipe and valve.
Working : The sullary animal dung, agricultural waste in water is prepared in mixing tank. It is filled in the digester up to lower level of dome. This mixture left from 7 to 8 weeks at first time and decomposes anaerobically in that time to form biogas. This gas starts collecting in dome and taken through gas outlet pipe and use in gas stove. The used sullary become light and riser up in the outlet chamber then collected in overflow tank. The sullary has rich amount of Nitrogen and phosphoric compound. So it is use as good manuals by farmers.
(b)Floating dome type biogas plant: That biogas plant in which dome or holder floats over dung sullary called as Floating dome type biogas plant.
Construction: It has bigger digester tank fitted or formed inside the earth just touching the level. The tank has parathion wall which divide it into two halves. Left halves have a inlet pipe connecting to mixing tank made above the ground. The right portion has a outlet pipe connecting to overflow tank. At the top of digester their is metallic gas holder called as dome. Dome has high pressure release valve and gas outlet valve with pipe.
Working: Firstly, dung agricultural waste mixed in water to form slurry in mixing tank. This slurry is filled in left half for anaerobic fermentation. This takes 50 to 60 days for formation of biogas. By the pressure of gas dome floats, the gas is taken out for use. Now more slurry is added to fill both half but the spent slurry reaches on right part. In this part the spend slurry decomposer more to give gas. The slurry in over flow tank is used by farmer as manure. The efficiency of this plant is much higher.
Fixed dome Floating dome
1. It is small in size. 1. It is big in size.
2. Its dome is formed by bricks. 2. Its dome is made up of metal.
3. Its dome remain below the ground 3. Its dome lies just above the
Level. Ground.
4. It has no high pressure valve or 4. It has high pressure valve on safety
Safety valve. Valve.
5. It has low efficiency. 5. It has high efficiency.
6. It has no partition wall. 6. It has partition wall.
7. It has inlet and outlet chamber. 7. It has inlet and outlet pipes.
8. Incomplete fermentation occurs. 8. Complete fermentation occurs.
Q.21 Give the uses of biogas plants?
Ans. (i)It provides a useful gas called biogas or sewage gas.
(ii)It provides good manure for agriculture.
(iii)It control over water pollution by removing undesirable water pollution.
(iv)It reduces the work load, on village women.
(v)It reduces pollution. In village and cleans of the environment. Thus reduce diseases.
(vi)It is improves the life style of farmer in their family.
Q.22 Give uses of Biogas?
Ans.(i) Biogas is used as a good domestic fuel for cooking food.
(ii)Biogas is used in a street lighting.
(iii)Biogas used as a fuel in many engine to operate water pumps, agricultural instrument, generator sets and cutting.
Q.23 Why Biogas plant are called boon to farmer?
Ans. Biogas plants are very useful for farmers they provide free fuel along with manure. It helps to clean up the village environment, reduce pollution and workload on village women. It helps to change the life status of farmers and save up the money
Q-24 what is solar energy?
Ans:-The energy produced by sun and obtains by various objects in universe called as solar energy. It is about 1.36 KJ/m2/sec., This quantity is called the solar constant.We can define the square metere area of the near earth space (exposed perpendicularly to the rays of the sun) at an average distance between the sun and the earth, is called solar constant.
Solar devices:- Those devices which uses solar energy and do our various jobs called as solar device.
Solar heating devices:-Those devices in which solar energy is used for heating material as cooking purpose called as solar heating device. E.g. Solar heater and solar furnace . They are made up of black material or black colored because black color absorbs solar heats.
Solar electrical devices:-Those devices which can convert solar energy into electricity called as solar electrical devices. E.g. Solar cell, Solar panel, solar plant.
Q-25 Give the limitations of solar energy?
Ans (1) The first limitations of solar energy is that it the earth in a very different use from. the Intensity of solar energy is too small for doing useful work,
(2) Another limitation of solar energy all the time and at all the places. Moreover, the availability of solar enegry is more at some place on the earth and much less at other places.
(3) The solar energy is not availability during the night.
(4) If during the day time the sky is covered with clouds even then the solar enegry is not available to us.
(5) Tradition uses of solar energy
(i) Solar energy has been used for drying clothes.
(ii) Solar energy has been used for obtaining salt from the sea water.
(iii) Solar energy has been used for reducing the moisture content in food grains after harvesting the crops.
(iv) Solar energy has been used for the preservation of fruits, vegetables and fish etc by the process of sun drying.
Q-25 Solar cooker:-that solar heating device which is used to cook for solar energy called cooker. Solar cooker of 2 types:
(i) Plane mirror reflector type cooker:-Construction:-This solar has wooden box. In this box black painted metal tray is placed and between box and tray insulated between box and tray insulated material like thermo coal is filled. At the top of the box glass sheet cover or lid is attached. Alone side of solar cooker a plane mirror sheet is connected by wooden box. The wooden base has supporting arms. These arms helped in that setting of the reflector mirror.
Working:-Firstly all vegetables, pulses other cooking material are filled in the container and placed in the center of solar cooker. Now cover the cooker tightly by glass lid and keep this solar cooker in sun ray directly falling on container, now adjust the angle of reflector mirror so that sun rays reflect on container, leave this for 3 to 4 hours in sun by which temperature of the box rises about to 100 o C to 140 O C. by which material’s get cooked.
(2) Spherical mirror reflector type cooker
Solar cell :-It is that device which is used to convert solar energy into electrical energy. Solar cell are made up of semiconductor substance which have very low electrical conductivity. they are non conductor along non insulator completely when solar energy falls on these semiconductor materials then their electrical conductivity increases. Solar cell are made up of semi conductor materials like silicon, germanium, galivim and selenium. They are embedded by other semiconductor like Boron to construct a solar cell we use a two wafers of semiconductor material with added impurity of another semiconductor substance. These refers are placed parallel to each other and covered by thin glass sheet. One wire from each wafer is taken out. when solar energy falls on these wafer. Then a potential difference is created between both wafers which causes current to flow. A four cin2 size solar cell create 0.4 volt to 0.5 volt at 60 million per current.
Solar cell panel:- It is a big panel board on which number of solar cell are filled in a definite pattern. they are jointed together their in a required circuit providing required voltage at required current. They are used for street lighting and movement of water pump.
Uses of solar cell
(i) Solar cells are used for provided electricity in artificial satellites and space probes. Infact, all the artificial satellites and space probes depend mainly in the electricity generated by solar panels.
(ii) In, India, solar cells are being used for street lighting, operating water pumps and for running radio and television sets in remote areas.
(iii) Solar cells are used for providing electricity to light houses situated in the sea and to the offshore oil drilling plant.
(iv) Solar cells are used for operating electronic watches and calculators.
Other forms of Energy:-
(i)Ocean thermal energy:-In ocean the difference of temperatures of top level and bottom is never less than 10 o C but at some points the difference is above 20 O C. This heat of the ocean is called O.T.E and it can be changeable usable form by thermal couple.
(ii) Sea wave energy:-In sea or ocean waves are some time very fast so they have too kinetic energy called as sea wave Energy. If this energy is used to drive dynamo then electricity can be generated.
(iii) Tidal energy- The tides in ocean some time rises very high and then falls .this energy in these tides which can be converted into electricity by tidal dams as tidal barrage.
Q-26 What is chain reaction? Give its types?
Ans:- Chain reaction –that involves reaction in which initiations particle is also produced with other products by which reaction continuous itself is called as chain reaction E.g. fission of uranium.
+ 
–Fission- 
+ 
+ 3
+ Large amount of energy.
It is of 2 types.
(i) Uncontrolled chain reaction:-That chain reaction in which number of neutron and fission are increased in the power of three by which whole fuel used at once giving very large amount of energy and caused destruction E.g. Atom bomb.
(ii) Controlled chain reaction:- Those nuclear chain reaction in which number of fission and neutron are kept constant by absorbing extra neutron from the reaction is called as controlled chain reaction. In this reaction energy is produced in stepwise manner and used in peaceful purpose like generating electricity.
Q-26. What is fission or nuclear fission?
Ans:-Fission-That nuclear reaction in which bigger and unstable nucleii splits into two medium weight nucleii with lot of energy is generated when a slow moving neutron strikes on it called as fission E.g. Fission of U 235
+ 
-fission- 
+
+3 + large amount of energy
Q-27 What is atom bomb?
Ans:- It is highly destructive explosive device based on uncontrolled nuclear fission of U-235.It gives lot of heat energy and very dangerous radiation.
Q-28 What is nuclear power plant (Reactor).Give its various parts and their function?
Ans:-Nuclear power plant or reactor is a device in which controlled nuclear fission reaction is operated to generate electricity called as nuclear power plant it has reactor, coolant, nuclear fuel, moderator, controlling rod, heat exchanger and a turbine.
(i)Nuclear reactor or furnance:-It is steel chamber having lead and concrete shield. In this furnace controlled nuclear fission reaction of heavy radioactive material U-235 is carried to produce heat.
(ii) coolent:- That substance which is circulated in the nuclear reactor and take out the heat energy produced by the nuclear reaction into the heat exchanger liquid sodium, CO2 or water are the common coolent.
(iii)Nuclear fuel:- It is easily fissionable material used for generating energy in nuclear reactor called as Nuclear fuel. It is above to 2 to 3 percent enriched.Th-286 or P6-239 can also be used as nuclear fuel.
(iv)Moderator:- That substance which slows down the speed of fast moving neutron to optimal level so that chain reaction continues called as moderator.
(v) Controlling rod:-Those are the rod of cadmium or Boron which are used to absorb extra neutron from the reaction so that it can be control led and energy produced in step wise manner called as controlling rod.
(vi)Heat exchanger:- In this part the heat of the reaction carried by coolent which is given to normal water become steam and forced into turbine chamber while the cooled coolent forced back into reactor.
(vii) Turbine chamber:- In this chamber steam force the turbine fan to generate electricity.
Principle or working of power plant:-It is based on controlled nuclear fission reaction of U-235 or other nuclear fuel.
Working:-Firstly complete apparatus is fitted as plant. It has sealed nuclear reactor having controlling system. Now reaction is started by a slow moving neutron and controlling rod are adjusted such that reaction run as constant number of fission and neutron. The heat produced in this reaction is taken by coolent to heat exchanger where water is heated into steam. The steam force the turbine to generate electricity.
Q-29 Give peaceful uses of atomic energy?
Ans:- The atomic energy is used to generate electricity, treatment and detection of dangerous diseases like cancer, improvement of various plant varieties use in various Industries.
Q-30 Give major atomic installations in India and allied industries?
Ans(i)B.A.R.C:-Bhabha atomic research center another is situated in Gulmarg in Srinagar and Kolkatta in west Bengal for research.
(ii)Tarapur atomic power station at Tarapur in Maharastra for generating electricity.
(iii) Rajasthan atomic power station at rana pratap Sagar near Kota for generating electricity.
(iv)Madras atomic power station in Uttar pradesh for generating electricity.
(v) Uranium fuel complex at Hyderabad (UP) has enrichment plant of uranium and are change into rods at tarapur, kota, kalpakkam and Narora. The heavy water producing plants are situated at kota, Baroda, Tuticorin and Talcher.
Q-31 Give Einstein law?
Ans:- According to Einstence the matter and energy is mutually convertible. When matter changes into energy then energy is produce d in very large amount and given by formula E=MC2.Where E is energy produced, M is mass and C is speed of light.
M=1gm=
kg, C=3 X 108 m/s, E= X 3 X 3 X 108 X 108=9 X 1013 J.
Q-32 What is nuclear fusion? Give its temperature for starting. Give the energy produced per/g and compared with cool?
Ans .:- That nuclear reaction light nucleus combine together to give big nucleii at very high temperature called as nuclear fusion. It give very large amount of energy.
+ -Fusion-
+ Enoronoums amount of energy.
It starts at very high temperature which is 4 X 106 O C. It has been estimated that the nuclear fusion of 1 gram of hydrogen in sun gives out 6.2 X 1010 joules of heat energy whereas the burning of 1 gram of coal in air given only about 3.5*104 joules of heat energy.
Q-33 What is Hydrogen bomb?
Ans:- It is very destructive (thermonuclear) device based on fusion of deuterium called as hydrogen bomb.It is started by atom bomb so it is highly dangerous mass destruction device.
Q-34 Give the advantage of nuclear fusion over nuclear fission?
Ans:- Nuclear fusion has importance
(i)It gives very large amount of energy compare to fission.
(ii)It does not give any harmful reaction compare to fission.
(iii)The material formed or its waste is radioactive compare to fission.
Q-35 Give difference of nuclear fission and nuclear fusion?
Ans:-
| Nuclear fission (i)That nuclear reaction in which big nucleii is split into medium weight. (ii) Its starts at normal temperature by the help of slow moving neutron. (iii) It can be a chain reaction. (iv)It gives comparatively less energy. (v) It can be controlled and operated in laboratory. (vi) It can be used for peaceful purpose. (vii)
| Nuclear fusion (i)That nuclear reaction in which small nucleii combines to form big nucleus. (ii) Its starts high temperature due to heat. (iii) It cannot be a chain reaction. (iv)It gives comparatively more energy. (v) It cannot be controlled and operated in laboratory. (vi) It cannot be used for peaceful purpose (Vii)
|
Q-36 Give disadvantage of nuclear fission?
Ans:- The main disadvantage of nuclear fusion is that it cannot be controlled so cannot used for peaceful purpose.
Q-37 What is wind ? what is windmill and its uses?
Ans:- Moving air is called as wind. Wind has a kinetic energy. Wind is caused due difference in pressure of air at 2 Points. This pressure difference caused due to uneven heating of earth surface. At a point where the solar heat is stronger than the air of this place becomes right and rises up causing little low pressure. So the air from the surrounding places rushes towards this place to balance the pressure. Thus the wind is caused.
Wind mill:-That device which is used to convert energy of wind into usable form. Windmill is bigger setup blades fitted on the axis, the axis is fitted on a high platform and free to rotate. The other end of the axis is connected to usable device or other device in which the work can be used this end is connected to water pump to pull underground water.
Uses of windmill:- (i) It is used to generate electricity when other end of axis is connected with dynamo.
(ii) It is used to pump water from well or water table with the help of water pump.
(iii) It is used to grind grains into flour by the help of grinding stone.
(iv) It is used in transport through water with the help of sail boat and sail ship.
Q-38 (A) What is wind energy mapping ?
Ans:- Wind energy mapping represents various parameter of wind which can be needed to use wind energy.
(i) wind energy mapping gives the average speed of wind annually at various places during the month of January and July and then July to January.
(ii) This mapping shows average energy in 1 sq m of wind at the height of 10 m.
(B) Give the various applications of wind energy in India ?
Ans:-In India the various applications of wind energy are places in coastal areas only.
(i) Okra in Gujarat where 1 megawatt power plant was establishment in which so wind turbines are used.
(ii) In India, in Gujarat parts of Rajasthan western Madhya pradesh, coastal belt, southern tamil Nadu, Bay of Bengal and parts of Karnataka as great potential of wind energy.
(C) Give the limitation of wind energy?
Ans:- (i) Heavy system and high platform are needed.
(ii) It is seasonal.
(iii)The windmill must be sued near coastal areas or the high pressure difference zones.
Q-39 Hydrogen has been used as a rocket fuel.Would you consider it as a cleaner fuel than CNG? Why or Why not?
Ans:- Hydrogen is a cleaner fuel than CNG .This is because the burning of hydrogen produces only water,which is totally harmless.On the other hand,burning of CNG produces carbon dioxide gas and water.This carbon dioxide can produce greenhouse effect in the atmosphere and lead to the excessive heating of the environmet in the long run.
Q-40 Give Some of the enviromental conseques of the incresing demand of sources of energy ?
Ans:- (i) The combustion of fossil fuels is producing acid rain and damagaing plants(crps) soil and aquatic life.
(ii) The burning of fossil fuel is increasing the amount of greenhouse gas carbon dioide in the atomsphere.
(iii) The cutting down of trees from the forest(deforestation) for obtaining fire-wood is causing soil erosion and destroying wild life.
(iv) The construction of hydro power palnts is disturbing ecological balance
(v)Nuclear power plant are increasing radioactivity in the environment.
Q-41 What are the various factors which shoulkad be kept in mind while chossing a source of energy?
Ans:- The various factors which shoulkad be kept in mind while chossing a source of energy are:-u
(i) The case of extracting energy from that source
(ii) The cost of extracting energy from the source.
(iii) The efficency of technological available to extract energy from that source.
(iv) The damage to environmet which will be caused by using that source.
Q-42 ----------------