Detailed explanations in West Bengal Board Class 7 Science Book Solutions Chapter 1.5 Use of Environment Friendly Energy offer valuable context and analysis.
WBBSE Class 7 Science Chapter 1.5 Question Answer – Use of Environment Friendly Energy
(Page no. 63)
Write some other uses of thermal energy in the gaps given below :
Answer:
(Page no. 64)
Mention some of other uses of electric energy to the gaps given above. Similarly fill in the gaps given below about the uses of fossil fuels known to you.
Answer:
(Page no. 65)
What are directly related to population explotion? (Fill up the blanks) :
Answer:
(Page no. 67)
Foreign countiies are using solar energy since long time back.
We have also started using solar energy extensively in our state.
Fill in the blanks if you have noticed it.
Where is solar energy used?
Answer:
Solar energy is used in homes and on streets.
What purpose is it used for?
Answer:
Solar cooker is used to prepare food and solar light is used on streets.
(Page no. 68)
Write the names of the places in our state or other states where you have seen such wind mills.
Answer:
Rajasthan and Tamil Nadu.
(Page no. 68)
Write the uses of bio-gas.
Answer:
1. For cooking
2. To lit bulbs.
Discuss the potentials of degradable organic municipal waste or weeds like water hyacinth. How can we use them?
Answer:
Energy can be obtained from wastes. It can be used to lit bulb, run fans and cook food.
Class 7 Science Chapter 1.5 Question Answer West Bengal Board –Use of Environment Friendly Energy
Fill in the blanks : (1 mark for each question)
1. We need _______ to do any kind of work.
Answer:
energy.
2. To run power tiller ______ is used.
Answer:
diesel.
3. ______ is used as Jet fuel.
Answer:
Kerosene.
4. ______ is used in motor cycle.
Answer:
Petrol.
5. ______ is used to run fan and use light.
Answer:
electrical energy.
6. ______ fuels are formed from the remains of plants and animals over a span of millions of years.
Answer:
Fossil.
7. The large portion of electrical energy is produced in our country by burning ______.
Answer:
coal.
8. _______ of years are required for the formation of energy sources like coal or petroleum under the soil of earth.
Answer:
Millions and millions.
9. Demands for the conventional forms of energy are increasing day by day due to ______.
Answer:
Population explosion.
10. Petroleum is obtained by ______ holes in the Earth crust, where the oil is found.
Answer:
drilling.
11. Due to excessive use of fossil fuel ______ is increasing.
Answer:
pollution.
12. ______ is an environment friendly energy.
Answer:
Solar energy.
13. Coal, petroleum and natural gas are _____ fuels.
Answer:
fossil
14. Solar energy can be used to generate electricity in _______ cells.
Answer:
solar.
State whether True or False: (1 mark for each question)
1. Coal and petroleum is formed from the remains of plants and animals buried under the earth.
2. Animals depend upon sun indirectly.
3. Drilling of petroleum first started in Asia continent.
4. Solar energy is being used in our country since long time back.
5. Solar panel didn’t cause any harm to our environment.
6. Solar panel lasts for 100 years.
7. There are large wind mills in Bakkhali in our state.
8. Natural gas is obtained from organic waste.
9. Remains of plants and animals are called fossils.
10. Bio-gas is produced from the various organic waste.
Answer:
1. true
2. true
3. true
4. false
5. true
6. false
7. true
8. false
9. false
10. true
Short Questions & Answers : (1, 2 marks for each question)
Question 1.
What are the uses of fossil fuels?
Answer:
Fossil fuels are used to – a) run generator. b) run power tiller. c) for running launch, aeroplane.
Question 2.
What are directly related to population explosion?
Answer:
With the growth of population – a) production of more food, b) Construction of more accomodation, c) increase of transport and d) establishment of more factories are necessary.
Question 3.
In early days how people used to go from one place to another?
Answer:
In early days people used bullock cart, horse, ass, elephant, stagecoach, boat etc or walked on foot to go from one place to another.
Question 4.
Nowadays how people travel from one place to another?
Answer:
Nowadays people use train, tram, bus, aeroplane, motorcycle, ship, launch etc to travel from one place to another.
Question 5.
What are environment-friendly forms of energies?
Answer:
Conventional forms of energies are exhausting day by day, they have also detrimental effects on our environment. Hence, we have to explore the posibilities of some new sources of energy. These energies would have less harmful effect on us. These are environment friendly forms of energies. Some such energies are – solar energy, wind energy, energy from biomass.
Question 6.
How solar energy is produced?
Answer:
The solar cell generates electricity during the day-time using the sunlight directly. The energy thus generated, is being accumulated in the batteries connected with solar pannels. It has got its use at night or during dimlight of day.
Question 7.
What are the various uses of solar energy?
Answer:
The various uses of solar energy are solar light, solar cap, solar cooker, solar bike, solar water-heater, solar signal, solar mobile charger
Question 8.
What are the advantages of using wind energy?
Answer:
The advantages are –
i) Their is no shortage of air flow.
ii) Once installed, the wind mills serve for a long time.
iii) The wind mills can be used as local generators for areas where installation of long transmission cable is not possible.
Question 9.
How energy from Bio-mass is produced?
Answer:
The excreta of animals the various organic wastes and different materials of plant and animal origin can be gathered in a large ditch. After anacrobic digestion, it produces bio-gas which can be used for different purposes.
Question 10.
Name some other eco-friendly sources of energy?
Answer:
Some other eco-friendly sources of energy are Tidal energy, Geo-thermal energy etc.
Long Questions & Answers : (3 marks for each question)
Question 1.
Mention some of the uses of heat energy.
Answer:
Heat energy is used –
a) for cooking.
b) electricity generation.
c) sterilising of knife, scissors before operation.
d) making bricks.
e) driving the steam engine.
f) burning of clay made things.
g) in smithy to make different kinds of tools.
Question 2.
Write down some uses of electrical energy.
Answer:
Electrical energy is used –
a) to operate the machine in industry.
b) for using computer.
c) for playing loudspeaker.
d) for running rail, tram.
e) to operate washing machine.
f) charging of mobile phone.
g) X-ray.
Question 3.
Is the source of underground fossil fuels in exhaustible?
Answer:
Yes, the source of under guound fossil is exhaustible. It took many millions and millons of years for the formation of the energy sources like coal or petroleum under the soil of earth. We are spending the resources in very short time comparable to the time of their formation. In this way a day will come when all the sources of coal or minerals would be exhausted.
Question 4.
Discuss the ways how the use of energy could be done as minimum as possible?
Answer:
a) The over use and wastages of energy have to be scaled down.
b) The life of coal and petroleum can be lengthened by producing less-polluting fuel in an appropriate way.
c) The gases emitted from the bed of rocks underneath or from the crevices of the hills, are generally wasted, we have to make use of such gases.
d) Instead of pumping out underground water for irrigation or drinking purposes, we can use the surface water from rivers etc.
e) If possible use of non-machanised boat for transportation or use of bicycles would be encouraged, it will save fossil-fuel.
f) Unnecessary use of energy in various types of amusements is to be curtailed down.
g) We have to ensure the awareness of everyone about the use of non-conventional sources of energy.