KSEEB SSLC Class 10 Science Solutions Chapter 14 Sources of Energy are part of KSEEB SSLC Class 10 Science Solutions. Here we have given Karnataka SSLC Class 10 Science Solutions Chapter 14 Sources of Energy.
Karnataka SSLC Class 10 Science Solutions Chapter 14 Sources of Energy
KSEEB SSLC Class 10 Science Chapter 14 Intext Questions
Text Book Part I Page No. 110
Question 1.
What is a good source of energy?
Answer:
We could then say that a good source of energy would be one.
- Which would do a large amount of work per unit volume or mass.
- be easily accessible.
- be easy to store and transport, and
- perhaps most importantly, be economical.
Question 2.
What is a good fuel?
Answer:
A good fuel is one which
- produces more heat per unit mass. It has high calorific value.
- produces less harmful gases on combustion.
- is cheap and easily available.
- is every to handle safe to transport and convenient to store.
Question 3.
If you could use any source of energy for heating your food, which one would you use and why?
Answer:
We should select which is easily available and it should be cheaper. Bio-gas is an excellent fuel as it contains. It burns without some. Its heating capacity is high. This gas is convenient for consumption and transportation.
Text Book Part I Page No. 115
Question 1.
What are the disadvantages of fossil fuels?
Answer:
- The fossil fuels are non renewable source of energy. If we were to consuming these sources as such an alarming rate, we would soon run out of energy.
- Air pollution is. caused bybuTnmg fossil fuels.
- The oxides of carbon, nitrogen and ‘ sulphur drat are released on burning fossil fuels am acidic oxides. This lead to acid rain which affects our water and soil resources.
- Carbon dioxide produced by burning these fuels produces green house effect
Question 2.
Why are we looking at alternate sources of energy?
Answer:
Fossil fuels are a non-renewable source of energy. So we need to conserve them. If we were to continue consuming these sources at such alarming rates, we would soon run out of energy. In order to avoid this, alternate sources of energy were explored.
Question 3.
How has the traditional use of wind and water energy been modified for our convenience?
Answer:
(1) Wind energy: The kinetic energy of the wind can be used to do work. This energy was harnessed by wind mills in the past to do mechanical work. For example in a water lifting pump, the rotatory motion of windmill is utilized to lift water from a well. Today wind energy is also used to generate electricity. A windmill essentially consists of a structure similar to a large electric fan that is erected at some height on a rigid support.
A number of windmills are erected over a large area, which is known as wind energy farm. The energy output of each windmill in a farm is coupled together to get electricity on a commercial scale wind energy farms can be established only at those places where wind blows for the greater part of a year. The wind speed should also be higher than 15 km/h to maintain the required speed of the turbine, since, the tower and blades are exposed to the vagaries of nature like rain, sun, storm and cyclone, they need a high level of maintenance.
(2) Water energy: In order to produce hydel electricity, high rise dams are constructed on the river to obstruct the flow of water and thereby collect water in larger reservoirs. The water level rises and in this process the kinetic energy of flowing water gets transformed into potential energy. The water from the high level in the dam is carried through pipes, to the turbine, at the bottom of the dam. Sine the water in the reservoir would be refilled each time. It rains (hydropower is a renewable source of energy) we would not have to worry about hydro electricity sources getting used up the way fossil fuels would get finished one day.
Text Book Part I Page No. 120
Question 1.
What kind of mirror – concave, convex or plain – would be best suited for use in a solar cooker? Why?
Answer:
A concave mirror would be best suited for use in a solar cooker. When a concave mirror reflector is. attached to a solar; cooker, it converges a large amount of sun’s be radiations at its focus due to which a high temperature is produced at die focus area.
Question 2.
What are the limitations of the energy that can be obtained from the oceans?
Answer:
Tidal energy wave energy and ocean thermal energy are the sources of the energy that can be obtained from the oceans. Their limitations are as follows:
- Tidal energy: The locations where such dams can be built are limited.
- Wave energy: Wave energy would be a viable proposition only where waves are very strong.
- Ocean thermal energy: Efficient commercial exploitation is difficult for this energy.
Question 3.
What is geothermal energy?
Answer:
Due to geological changes, molten formed in the deeper hot regions of earth’s crust are pushed upward and trapped in certain regions called ‘hot spots’. This is called Geothermal energy.
Question 4.
What are the advantages of nuclear energy?
Answer:
- It produces huge amount of energy form very small amount of a nuclear’ fuel.
- It does not produce gases like carbon 2. dioxide which contribute to green house effect or sulphur dioxide which causes acid rain.
- Once the nuclear fuel is loaded into the reaction, the nuclear power plant can go on producing electricity for 3. two to three years at a stretch. Hence, there is no need for putting in the nuclear fuel again and again.
Text Book Part I Page No. 120
Question 1.
Can any source of energy be pollution-free? Why or why not?
Answer:
No source of energy be pollution free. Because fossil fuels cause air pollution. Nuclear energy causes more hazards for environment. In some cases, the actual operation of a device like the solar cell may be pollution-free, but the assembly of the device would have caused some environmental damage.
Question 2.
Hydrogen has been used as a rocket fuel. Would you consider it a cleaner fuel than CNG? Why or why not?
Answer:
Hydrogen gas burns and produce steam. Because of this environment is not polluted. Hence it is used in rockets as fuel. But this gas is explosive. It is not a cleaner fuel than CNG. Because CNG is cleaner than the other sources of energy.
Text Book Part I Page No. 121
Question 1.
Name two energy sources that you would consider to be renewable. Give reasons for your choices.
Answer:
Solar energy and wind energy are the two renewable sources of energy.
i) Solar energy: The sun has been radiating an enormous amount of energy at the present rate for nearly 5 billion years and will continue radiating at that rate for about 5 billion year more. A large number of solar cells are, combined in an arrangement called solar cell panel that can deliver enough electricity for practical use.
The principal advantages associated with solar cells are that they have no moving parts, require little maintenance and work quite ossificatory without the use of any focussing device. Another advantage is that they can-be set up in remote and in accessible hamlets or very sparsely inhabited areas in which laying of a power transmission line may be expensive and not commercially viable.
ii) Wind energy: Unequal heating of the landmass and water bodies by solar radiation generates air movement and causes winds to blow. This kinetic energy of the wind can be used to work. Wind energy is an environment-friendly and efficient source of renewable energy. It requires no recurring expenses for the production of electricity.
Question 2.
Give the names of two energy sources that you would consider to be exhaustible. Give reasons for your choices.
Answer:
- fossil fuels
- Nuclear fuels
Fossil fuels are present in a limited. amount in the earth. Once exhausted, they will not be available to us again. It takes millions of years for fossil fuel to be formed. The nuclear materials which can be conveniently extracted from earth 7. are limited and hence they will get exhausted one day.
KSEEB SSLC Class 10 Science Chapter 14 Textbook Exercises
Question 1.
A solar water heater cannot be used to get hot water on
(a) a sunny day
(b) a cloudy day
(c) a hot day
(d) a windy day
Answer:
(b) a cloudy day.
Question 2.
Which of the following is not an example of a bio-mass energy source?
(a) wood
(b) gobar-gas
(c) nuclear energy
(d) coal
Answer:
(c) nuclear energy.
Question 3.
Most of the sources of energy we use represent stored solar energy. Which of the following is not ultimately derived from the Sun’s energy?
(a) geothermal energy
(b) wind energy
(c) nuclear energy
(d) bio-mass.
Answer:
(b) wind energy.
Question 4.
Compare and contrast fossil fuels and the Sun as direct sources of energy.
Answer:
Air pollution is caused by burning of coal or petroleum products. The oxides of carbon, nitrogen and sulphur that are released on burning fossil fuels are acidic oxides. These lead to acid rain which affects our water and soil resources. In addition to the problem of air pollution, recall the green house effect of gases like carbon dioxide.
Sun is the main source Of energy, we get all sources of energy by solar energy. Hence this a renewable source of energy which we get in plenty and free of cost.
Question 5.
Compare and contrast bio-mass and hydro electricity as sources of energy.
Answer:
Bio-mass: Cow-dung, various plant materials like the residue after . harvesting the crops, vegetable waste and sewage are decomposed in the absence of oxygen to give biogas. Since the starting material is mainly cow-dung, it is popularly known as ‘gober gas’. Biogas is produced in biogas plant.
Bio gas is an excellent fuel as it contains up to 75% Methane. It burns without smoke, leaves no residue like ash in wood, charcoal and coal burning. The slurry left behind is removed periodically and used as excellent manure. This is one of the renewable source of energy.
Hydro Electricity: In order to produce hydel electricity, high rise dams are constructed on the river to obstruct the flow of water and thereby collect water level rises and in this process the kinetic energy of flowing water, gets transformed into potential energy. The water from the high level in the dam is carried through pipes to the turbine, at the bottom of the dam. Since the water in the reservoir would be refilled each time it rains. We would not have to worry about hydro electricity sources getting used up the way fossil fuels would get finished one day.
Question 6.
What are the limitations of extracting energy from—
(a) the wind?
(b) waves?
(c) tides?
Answer:
(a) The wind:
- Wind energy farms can be established only at those places where wind blows for the greater part of a year.
- The wind speed should also be higher than 15 km/h to maintain the required speed of the turbine.
- Establishment of wind energy farms require large are of land.
These are the limitations of extracting energy from the wind.
(b) Limitations of extracting waves energy: The waves are generated by strong winds blowing across the sea. Wave energy would be a viable proposition only where waves are very strong.
(c) Limitations of extracting tidal energy: The locations where such dams can be built are limited.
Question 7.
On what basis would you classify energy sources as
(a) renewable and non-renewable?
(b) exhaustible and inexhaustible?
Are the options given in (a) and (b) the same?
Answer:
The options given in (a) and (b) are the same.
Question 8.
What are the qualities of an ideal source of energy?
Answer:
The qualities of an ideal source of energy are as follows:
- Which would do a large amount of work per unit volume or mass.
- Be easily accessible.
- Be easy to store and transport, and
- Perhaps most importantly, be economical.
Question 9.
What are the advantages and disadvantages of using solar cooker? Are there places where solar cookers would have limited utility?
Answer:
Solar cookers have limited utility at places which remain cloudy or have larger winters eg, hilly areas. Advantages of using a solar cooker
- It cooks food without causing any kind of pollution.
- It is economical to use solar cooker because nothing is to be paid for using solar energy.
- It is easy to handle solar cooker and there is no chance of any kind of accident.
- It nutrients in the food do not get destroyed.
Disadvantages of using a solar cooker.
- Solar cooker cannot be used at night and during cloudy weather.
- It takes more time to cook food.
- The direction of solar cooker is to be changed
Question 10.
What are the environmental consequences of the increasing demand for energy? What steps would you suggest to reduce energy consumption?
Answer:
They are:
- Burning of fossil fuels to meet the increasing demand for energy causes air pollution.
- Construction of dams and rivers to generate hydroelectricity destroys large ecosystems which get submerged underwater in the dams further, a large amount of methane [which is a green house gas] is produced when submerged vegetation rots under anaerobic conditions.
In order to reduce energy consumption
- Fossil fuel should be used with care and caution to derive maximum benefit out of them.
- Fuel saving devices such as pressure cookers etc should be used.
- Efficiency of energy sources should be maintained be getting them regularly serviced.
- And last of all, we should be economical in our energy consumption as energy saved is energy produced.
KSEEB SSLC Class 10 Science Chapter 14 Additional Questions and Answers
Question 1.
Draw a neat diagram showing a model to demonstrate the process of thermoelectric production and label the parts.
Answer
Question 2.
Draw a neat diagram of a solar cooker and label the parts.
Answer:
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