Jharkhand Board JAC Class 10 Science Important Questions Chapter 14 Sources of Energy Important Questions and Answers.
JAC Board Class 10 Science Important Questions Chapter 14 Sources of Energy
Additional Questions and Answers
Question 1.
Distinguish between :
(1) Solar Cooker and Solar Cell Panel
Answer:
| Solar Cooker | Solar Cell Panel |
| 1. It converts solar energy into heat. | 1. It converts solar energy into electricity. |
| 2. It is mainly designed for cooking purpose, i.e., for domestic use | 2. It is designed for delivering enough electricity for commercial use. |
| 3. It consists of mirror, glass sheet, black wooden box. | 3. It consists of large number of solar cells and silicon is used in solar cells. |
| 4. It is useful for cooking only at certain times of the day. | 4. The limitation of using solar energy is overcome by using it. |
(2) Fossil fuels and Bio fuels
Answer:
| Fossil Fuels | Bio Fuels |
| 1. It is a conventional source of energy mainly used in industries and vehicles. | 1. It is a conventional source of energy mainly for domestic use. |
| 2. Coal, petroleum and natural gas are fossil fuels. | 2. Wood, cow-dung cakes, biogas, etc. are bio fuels. |
| 3. The fossil fuels are non-renewable and exhaustible source of energy. | 3. Bio fuels are renewable source of energy in the form of biomass. |
| 4. Fossil fuels are the major fuels used all over the world. | 4. Bio fuels are mainly used in rural area. |
Question 2.
Give scientific reasons for the following statements:
(1) From environmental point of view, we should reduce the use of fossil fuels.
Answer:
The fossil fuels are non-renewable source of energy and in limited reserves.
- The growing demand for energy at global level are largely meet by fossil fuels.
- Excessive burning of fossil fuels – coal and petroleum increases the level of air pollution. example:
- Carbon dioxide, sulphur dioxide and oxides of nitrogen are released in excess in atmosphere causing such air pollution.
- Carbon dioxide is a main greenhouse gas that causes global warming.
- Sulphur dioxide and oxides of nitrogen lead to acid rain which affects water and soil resources.
So, to reduce the adverse effects on environment, we should reduce the use of fossil fuels.
(2) Though hydropower is renewable source of energy, it creates certain problems.
Answer:
Hydropower is renewable source of energy because water gets refilled in reservoir during raining.
- High-rise dams are constructed to generate hydroelectricity.
- Such dams are constructed in hilly areas causing environmental changes.
- Large eco-systems are submerged under water and destroyed.
- The submerged vegetation decaying anaerobically releases large amount of greenhouse gas, i.e., methane.
- Large areas of agricultural land is also submerged. Many natives are thus displaced.
- Rural-tribal human races may lose their habitat.
So, Hydropower plant construction creates certain problems.
(3) The use of dung as raw material for biogas production is profitable than using it only as fertiliser or fuel.
Answer:
Animal dung is used as raw material c for production of biogas. It provides a safe and i efficient method of waste disposal.
- Besides it, by supplying biogas as a fuel gas, cooking, lighting, etc. we can save natural gas.
- The residual slurry can be used as excellent manure that is rich in nitrogen and phosphorous.
This natural fertiliser maintains soil fertility and agriculture practice becomes more economical.
(4) Inspite of the high cost, solar cells are widely used.
Answer:
A special grade silicon is used for making solar cells and silver is used for interconnection of cells in panel.
- This makes the solar cells expensive.
- But it converts solar energy into electricity and about 0.7 W of electricity is produced when exposed to the Sunlight.
- Solar cells and panels are widely used in artificial satellite, space probes like Mars orbiters, wireless transmission systems, radio or TV relay stations, traffic signals, calculators and in many toys.
- At domestic level, maximum use of solar energy can be achieved by using solar roof top thus saving electricity.
- So, solar cells are widely used.
(5) Generation of nuclear energy is hazardous.
Answer:
Nuclear fission and nuclear fusion are two processes used to generate nuclear energy.
- Radioactive heavy atoms such as uranium, plutonium or thorium are used in a nuclear fission process whereas hydrogen isotopes are used in a nuclear fusion.
- There is a risk of accidental leakage of nuclear radiation.
- There is a possibility of high risk of environmental contamination i.e., radioactive pollution.
- Radioactive waste is hazardous to human health and environment. Radiations which are emitted from the radioactive waste can cause mutation (Change in DNA) in living organisms.
- It creates various disorders and cancer in human beings.
So, generation of nuclear energy is hazardous.
Question 3.
Carefully observe the given diagram / chart and answer the questions based on it.
(1) Observe the following pie-chart showing the major sources of energy.
Questions:
(1) Identify ‘a’ and state where is it used as a fuel to generate electric energy through conversion of heat energy.
Answer:
Coal. It is used as a fuel in thermal power plant.
(2) Label ‘b’ and give the name of processes to generate it.
Answer:
Nuclear energy. The processes to generate nuclear energy are: nuclear fission and nuclear fusion.
(3) Label ‘c’ and state the name of any two place where such power plants are established.
Answer:
Hydropower. Hydropower plants are established at Tehri Dam on the Ganga river and Sardar Sarovar Project on the Narmada river.
(4) Refer to the pie-chart above and arrange the sources of energy in an ascending order.
Answer:
Nuclear < hydro < petroleum and natural gas < coal
Questions:
(1) Label a, b and c in given diagram.
Answer:
a – Digester, b – Slurry, c – Gas outlet
(2) How is biogas obtained from slurry?
Answer:
Slurry consists of bio-wastes / biomass and biogas can be obtained through decomposition by anaerobic microorganisms.
(3) Why is biogas considered as an excellent fuel?
Answer:
Biogas is considered as an excellent fuel because it burns without smoke, leaves no ash residue and has high heating capacity.
(4) Which are the gases present in biogas?
OR
What are components of biogas?
Answer:
Biogas mainly consists gases like methane, carbon dioxide, hydrogen and hydrogen sulphide.
(5) Which are abundant nutrients in the slurry left behind in a biogas plant?
Answer:
Nitrogen and phosphorous are abundant nutrients in the slurry left behind in a biogas plant.
Questions :
(1) Which metal is used in the panel for the interconnection of cells?
Answer:
Silver
(2) Which energy conversion occurs by using solar cells?
Answer:
Solar energy is converted into electricity.
(3) Write any two uses of solar cells for space science.
Answer:
Solar cells are used as a main energy source in an artificial satellites and space probes like Mars orbiters.
(4) If 12 solar cells are interconnected in the panel. How many watt of electricity can be produced from it when exposed to Sun?
Answer:
About 8.4 W
(5) Why is silicon used in a solar cells?
Answer:
Silicon is a natural semiconductor, easily obtained and easily modified to convert solar energy into electricity.
Objective Questions and Answers
Question 1.
Answer the following questions in short:
(1) Name the form of energy obtained from sea.
Answer:
The forms of energy obtained from sea are tidal energy, wave energy and ocean thermal energy.
(2) Which fuel is considered as a cleaner source for vehicles?
Answer:
CNG (Compressed Natural Gas)
(3) State the name of fuels that we are using.
Answer:
We are using wood, coal, petrol, diesel, CNG, kerosene, LPG, etc. as fuels.
(4) What is a source of energy?
Answer:
A source of energy is one which is capable of providing useful energy in sufficient amount.
(5) Which energy conversion occurs in a hydropower plant?
Answer:
In a hydropower plant, potential energy of stored water is converted into electrical energy.
(6) Which is a main constituent of biogas? What is its content?
Answer:
Methane gas is a main constituent of biogas and it is about 75 %.
(7) What are the conventional sources of energy?
Answer:
Fossil fuels, i.e., coal and petroleum are the conventional source of energy, which are used on a large scale.
(8) Name two elements that are used in manufacturing solar cell panels.
Answer:
Silicon, Silver
(9) Name the devices to harness solar energy.
Answer:
Solar cell, solar cooker, solar water heater.
(10) Where are the fossil fuels used directly?
Answer:
In gas stoves, vehicles and thermal power plants, fossil fuels are used directly.
(11) Why is charcoal used as a fuel?
Answer:
Charcoal is used as a fuel because it burns without flames is comparatively smokeless s and has a higher heat generation efficiency.
(12) Why is the term thermal power plant used?
Answer:
The term thermal power plant is used because in such power plants fuel is burnt to produce heat energy which is converted into electrical energy.
(13) State the name of any two greenhouse gases.
Answer:
CO2 and CH4
(14) Which fuels leave residue like ash on burning?
Answer:
Wood, charcoal and coal leave residue like ash on burning.
(15) How anaerobic microorganisms help in formation of fuel?
Answer:
Anaerobic microorganisms (Methanogenic bacteria) produce biogas by decomposition of complex compounds that present in cow-dung slurry.
(16) State two advantages of wind energy.
Answer:
Advantages of wind energy :
- It is an environment-friendly energy
- It is efficient source of renewable energy.
(17) What is the age of the sun? What will be its expected lifespan?
Answer:
The sun is 5 billion years old and another 5 billion years will its expected lifespan.
(18) Why is our demand for energy increasing day by day?
Answer:
Our demand for energy is increasing day by day because –
- We use machines to do more and more of our tasks, which needs more energy.
- Industrialisation improves our living standards. The energy requirement therefore constantly rises.
(19) Where is solar cell panels are mounted for domestic use? What is its advantages?
Answer:
The solar cell panels are mounted on specially designed inclined rooftops. More solar rays are incident over it, producing more electric
energy.
(20) Name the two oxides that causes acid rain.
Answer:
Oxides of nitrogen and sulphur cause acid rain.
(21) What is the minimum speed of wind required by a windmill to maintain the necessary speed of turbine in electric generator?
Answer:
More than 15 km/h
(22) Which are the renewable sources of energy?
Answer:
Hydropower, biomass, solar energy, energy from the sea, wind energy, etc. are renewable sources of energy.
Question 2.
Define: OR Explain the terms :
(1) Nuclear fission
Answer:
The process of splitting a heavy nucleus into smaller nuclei along with the release of large amount of energy is called nuclear fission.
(2) Nuclear fusion
Answer:
The process of joining lighter nuclei to make a heavier nucleus along with release of tremendous amount of energy is called nuclear fusion.
(3) Solar constant
Answer:
The solar energy reaching unit area on outer surface of the earth’s atmosphere which is exposed perpendicularly to the rays of sun at the average distance between the sun and earth is called solar constant.
(4) Geothermal energy
Answer:
The heat energy obtained in the form of steam from hot spots region is called geothermal energy.
(5) Biogas
Answer:
A fuel gas that is produced anaerobically from biomass is called biogas.
(6) Conventional sources of energy
Answer:
Those sources of energy which meet our major energy requirement are known as conventional sources of energy.
(7) Non-conventional sources at energy
Answer:
Those sources of energy which meet only a limited energy requirement are known as non-conventional sources of energy.
(8) Wind energy farm
Answer:
A number of windmills erected over a large area for the commercial use of wind energy is known as wind energy farm.
(9) Fossil fuels
Answer:
The fuels such as coal, petroleum and natural gas, that were formed millions of years ago from dead and fossiliged animals or plants in the ground are called fossil fuels.
Question 3.
Fill in the blanks:
- Biogas obtained from decomposition of biomass by the activity of ……………… microorganisms.
- Petroleum products are ……………… fuel.
- Hydropower plants convert the ……………… of falling water into electricity.
- When wood is burnt in a limited supply of oxygen, ……………… is left behind as a residue.
- Manure obtained from biogas plant is rich in ……………… and ………………
- ……………… plant is an efficient method of bio waste disposal.
- ……………… is the best process to capture solar energy and convert it into biomass.
- Use of ……………… mirror would be best for in solar cooker.
- ……………… is abundant in nature but availability of its special grade is limited.
- The hydrogen bomb is based on ……………… reaction.
- India is ranked ……………… in harnessing wind-energy for the production of electricity.
- The total ……………… of the universe remains constant because it can neither be created nor destroyed.
Answer:
- anaerobic
- fossil
- potential energy
- charcoal
- nitrogen, phosphorous
- Biogas
- Photosynthesis
- concave
- Silicon
- thermonuclear fusion
- fifth
- energy
Question 4.
State whether the following sentences are true or false:
- The air pollution is caused by burning of fossil fuels.
- The potential energy of flowing water gets, transformed into kinetic energy by collecting the water in dam.
- In solar cookers, a plain mirror is used to converge the sunlight.
- Fossil fuels are the major fuels used for generating electricity.
- Submerged vegetation rots under anaerobic condition producing large amounts of methane.
- Biogas is derived totally from animal biomass.
- The level of water in the sea rises and falls due to the gravitational pull of the moon on the spinning earth.
- Nuclear energy is the best alternative of fossil fuel because of its environment friendly nature.
- The nuclear bomb is embedded in a deuterium and lithium containing substance.
- The assembly of the solar cell may be pollution free but the actual operation of it may cause some environmental harm.
- The energy sources that can be regenerated are called renewable energy sources.
- Nuclear fusion reactions are the source of energy in the sun and other stars.
Answer:
- True
- False
- False
- True
- True
- False
- True
- False
- True
- False
- True
- True
Question 5.
Graph / diagram based question :
Which of the following graph is correct for Burning of fossil fuel → level of air pollution?
Answer:
Question 6.
Match the following:
(1)
| Column I | Column II |
| 1. Silicon | a. nuclear reactor |
| 2. Hot-springs | b. leaves residue like ash |
| 3. Fission of uranium atom | c. used in solar cells |
| 4. Charcoal | d. geothermal energy |
Answer:
(1 – c), (2 – d), (3 – a), (4 – b).
(2)
| Column I | Column II |
| 1. Fossil fuel | a. Plutonium, thorium |
| 2. Biomass | b. coal, petroleum |
| 3. Nuclear fuel | c. CNG |
| 4. Clean fuel | d. wood, cow-dung cake |
Answer:
(1 – b), (2 – d), (3 – a), (4 – c).
(3)
| Column I | Column II |
| 1. Geothermal energy plant | a. Traffic signals |
| 2. Solar cell panels | b. New Zealand |
| 3. Wind energy farm | c. Tehri dam |
| 4. Hydropower plant | d. Kanyakumari |
Answer:
(1 – b), (2 – a), (3 – d), (4 – c).
Question 7.
Select the correct alternative from those given below each questions:
1. Which of the following is a main component of biogas?
A. Methane
B. Hydrogen
C. Hydrogen sulphide
D. Oxygen
Answer:
A. Methane
2. Which fuel is used in thermal power plant?
A. Biomass
B. Fossil fuel
C. Wood
D. Charcoal
Answer:
B. Fossil fuel
3. Which of the following is the adverse effect caused by burning of fossil fuels?
A. Acid rain
B. Greenhouse effect
C. Both A and B
D. Agricultural land submerged
Answer:
C. Both A and B
4. Find greenhouse gases.
A. Hydrogen and hydrogen sulphide
B. Sulphure dioxide and nitrogen
C. Nitrogen and hydrogen
D. Methane and carbon dioxide
Answer:
D. Methane and carbon dioxide
5. Which of the following fuel does not leave ash-like residue while burning?
A. Wood
B. Charcoal
C. Biogas
D. Coal
Answer:
C. Biogas
6. Which one of the following is a non-renewable source of energy?
A. Bio fuel
B. Fossil fuel
C. Wind power
D. Tidal energy
Answer:
B. Fossil fuel
7. Which of the following exploits energy due to temperature difference at surface water and water at depth?
A. Tidal energy
B. Wave energy
C. Ocean thermal energy
D. All of the given
Answer:
C. Ocean thermal energy
8. Statement A: We need to look for more and more source of energy.
Reason R: There are only limited reserves of fossil fuels.
Which option is correct for statement A and reason R?
A. Both A and R correct, R is explanation of A.
B. Both A and R correct, R is not explanation of A.
C. A is correct, R is incorrect.
D. A is incorrect, R is correct.
Answer:
A. Both A and R correct, R is explanation of A.
9. Charcoal is considered as a better fuel compared to wood because …
A. it burns without flames.
B. it is comparatively smokeless.
C. it has a higher heat generation efficiency.
D. all of the given.
Answer:
D. all of the given.
10. From which of following, electricity can be generated without the use of turbine?
A. Solar energy
B. Tidal energy
C. Geothermal energy
D. Wave energy
Answer:
A. Solar energy
11. Which is the fundamental reaction in nuclear weapon for destructive purposes?
A. Fusion chain
B. Fission chain
C. Radiation chain
D. Thermal chain
Answer:
B. Fission chain
12. By which of the following greenhouse effect can be achieved in a solar cooker?
A. Black surface
B. Concave mirror
C. Convex mirror
D. Covered glass plate
Answer:
D. Covered glass plate
13. Which one of following is used as a main source of energy in artificial satellite?
A. Fossil fuel
B. Uranium
C. Solar cells
D. Gravitation pull
Answer:
C. Solar cells
14. Statement X: Ocean thermal energy conversion plant can operate if the temperature difference is 20°C or more between the water at surface and water at depth. Statement Y: Wind energy farm can generate electricity only if the wind speed should be higher than 15 km/h.
Which is correct option for statement X and Y?
A. X is correct, Y is incorrect.
B. Both X and Y are correct.
C. X is incorrect, Y is correct.
D. Both X and Y are incorrect.
Answer:
B. Both X and Y are correct.
15. Which pf the following is the ultimate source of energy on the earth?
A. Solar
B. Wind
C. Ocean
D. Fossil fuel
Answer:
A. Solar
16. Which of the following is an environmental friendly source of energy?
A. Wind energy
B. Fossil fuel
C. Nuclear energy
D. Solar energy
Answer:
A. Wind energy, Solar energy
17. Statement A: Many of the sources ultimately derive energy from the sun.
Reason R: Nuclear fusion reactions are the source of energy in the sun.
Which option is correct for statement A and reason R?
A. Both A and R correct, R is explanation of A.
B. Both A and R correct, R is not explanation of A.
C. A is correct, R is incorrect.
D. A is incorrect, R is correct.
Answer:
B. Both A and R correct, R is not explanation of A.
Question 8.
Answer as directed (Miscellaneous):
(1) Write full form of CNG, OTEC; MeV
Answer:
CNG – Compressed Natural Gas
OTEC-Ocean Thermal Energy Conversion
MeV – Mega-electron Volts
(2) State the units of Solar constant, Electricity, Energy.
Answer:
Solar constant – kW / m²
Electricity – MW
Energy – eV or Joules
(3) Find mismatched pair :
I. Fossil fuel – Air pollution
II. Wind energy farm – Large area of land
III. Biogas – Aerobic microorganisms
IV. Geothermal energy – Hot springs
Answer:
III. Biogas – Aerobic microorganisms
(4) Find correct sequence for following events :
I. Winds to blow
II. Kinetic energy of huge waves near the sea-shore
III. Solar radiation
IV. Electricity generated
V. Waves generated
Answer:
III → IV → II → IV
(5) Find mismatched pair :
I. Bio fuel-wood, cow-dung cake
II. Solar cell panel – Silicon, copper
III. Windmill – Large fan, turbine of generator
IV. Nuclear energy – Fission and Fusion reaction
Answer:
II. Solar cell panel – Silicon, copper
(6) Sequentially arrange the events that occur in biogas plant.
p. activity of anaerobic microbes
q. The slurry left behind is used as manure
r. cow-dung and water is mixed and this slurry is fed into the digester
s. Methane gas is generated
t. Breakdown of complex compounds of the cow-dung slurry.
Answer:
r → p → t → s → q
Value Based Questions With Answers
Question 1.
Your father decided to fit CNG kit in his petrol car. Your mother is a working woman. Your father has managed their working time in such a way that he took your mother with him.
Your school is just 3 km away from your home. Your father also insists you to use bicycle instead of fuel using vehicle for going to school.
Questions:
- Why CNG is prefered as a fuel?
- Why we need to conserve fossil fuels?
- What value is reflected in the above family?
- State any two disadvantages of petrol as a fuel.
Answer:
- CNG is a cleaner fuel than petrol and it is economical. It is less polluting.
- The fossil fuels are non-renewable and exhaustible sources of energy. So we need to conserve them.
- This family shows the values of responsibility to environment and they contribute their efforts to save fuels.
- Disadvantages of petrol as a fuel: (i) It is expensive, (ii) It causes air pollution.
Question 2.
A group of students visited to a village. They noticed that village people uses dung cakes, agricultural wastes, etc. as a fuel. Students found smoke and ash particles in the environment. They requested the sarpanch to install a biogas plant and insist the people to collect the waste to produce biogas.
Questions:
- What is the use of slurry left behind?
- State the two uses of biogas.
- What are the advantages of biogas plant?
Answer:
- Slurry is used as nitrogen and phosphorous rich manure.
- Two uses of biogas : Cooking, lighting
- Biogas plant is a safe and efficient method for waste-disposal besides supplying energy and manure.
Question 3.
In high rised residential flats, maintainance expense per month per flat is high. Some members suggested to install solar panel and solar water heater. They explained that this would provide some electricity to light the building and may reduce electric bill amount.
Questions:
- Which energy conversion is achieved by installation of solar panel and solar water heater?
- What is the disadvantage of appliances which run on solar energy?
- How much electric power is generated by a solar cell?
Answer:
- Solar energy is converted to electricity by solar panel and in solar water heater, solar energy is converted to heat.
- Solar appliances do not work during cloudy and rainy days.
- 0.7 W
Practical Skill Based Questions With Answers
Question 1.
Two cars are parked In open parking area. One car is of black colour with black film on window glass. Other car is of white colour and without black film on window glass.
You just open the door and sit for 1-2 minute in each car.
Questions:
- Which car is more hot inside?
- Do both the cars have warm internal environment? Yes or no, why?
- Why is black car more hotter than a white s car?
- What are your suggestions to keep top floor cool in summer?
Answer:
- Black car
- Due to absorbing heat the cars are heated, making the inside very warm.
- A black surface absorbs more heat as compared to a white surface.
- Suggestions to keep top floor cool in summer:
-
-
- Paint white colour on the outer I side wall.
- Mount china mosaic on the s terrace.
- Prepare terrace garden.
-
Question 2.
A picture to demonstrate windmill and its function.
Questions :
- Which energy conversion is shown in the picture?
- What function does windmill show in the picture?
- Which is the structure similar to windmill?
Answer:
- Kinetic energy into mechanical energy.
- To lift water from a well.
- The structure of windmill is simillar to electric fan.
Memory Map:
