WBBSE Class 9 Life Science Solutions Chapter 5.2 Natural Resources and its Sustainable Use

Detailed explanations in West Bengal Board Class 9 Life Science Book Solutions Chapter 5.2 Natural Resources and its Sustainable Use offer valuable context and analysis.

WBBSE Class 9 Science Chapter 5.2 Question Answer – Natural Resources and its Sustainable Use

Very Short Questions and Answers : (1 mark for each question)

Question 1.
Name two natural resources.
Answer:
Two natural resources are forest and water.

Question 2.
What are the types of natural resources?
Answer:
Natural resources are of two types-

1. Renewable natural resources
2. Nonrenewable resources.

Question 3.
Name two renewable natural resources.
Answer:
Two renewable natural resources are water and wind.

Question 4.
Name two non-renewable natural resources.
Answer:
Two non-renewable natural resources are coal and petroleum.

Question 5.
In West Bengal, what percentage of land is under forest cover?
Answer:
16.5. % of West Bengal is covered by forest.

Question 6.
What percent of the total area of a country should be under forest cover?
Answer:
33 % of the total area of a country should be under forest cover.

Question 7
Name one economically important forest product.
Answer:
Wood is an economically important forest product.

Question 8.
Name some products, which we get from the forest.
Answer:
We get honey, timber, latex, resin etc. from forest.

Question 9.
What is the best way to conserve biodiversity?
Answer:
Afforestation is the best way to conserve biodiversity.

Question 10.
What is the medicinal utility of forest?
Answer:
Forest comprises several varieties of medicinal herbs, from which medicines are obtained.

Question 11.
What is the main cause of deforestation?
Answer:
Human population explosion is the main cause of deforestation.

Question 12.
Write down one natural cause of deforestation.
Answer:
Forest fire is a natural cause of deforestation.

Question 13.
Write down one man-made cause of deforestation.
Answer:
Urbanisation is a man-made cause of deforestation.

Question 14.
Which is the ‘natural buffer’ of an environment?
Answer:
Forest is the ‘natural buffer’ of an environment.

Question 15.
How much water on the earth do we get as freshwater?
Answer:
Only 2 % of the total water on the earth is utilised as freshwater.

Question 16.
In which two states of India, rain water harvesting is necessary.
Answer:
In Rajasthan and Gujrat, rain water harvesting is necessary.

Question 17.
By which natural process, earth gets freshwater?
Answer:
Earth gets freshwater in the form of rain.

Question 18.
Which branch of economic botany includes the cultivation of medicinally important herbs?
Answer:
Cultivation of medicinally important herbs is included under horticulture.

Question 19.
In Gangetic plains, which is the main source of dietary protein?
Answer:
Fish is the main source of dietary protein in the Gangetic plains.

Question 20.
Which decade was famous for green revolution?
Answer:
The decade of nineteen sixties was famous for green revolution.

Question 21.
Name of the food products of animal husbandry.
Answer:
The food products of animal husbandry are meat, milk and egg.

Question 22.
Name two edible mushrooms.
Answer:
Name of two edible mushrooms are Agaricus bisporus and Boletus edulis.

Question 23.
Mention one cause of global food crisis.
Answer:
Population explosion is an important cause of global food crisis.

Question 24.
Give some examples of fossil fuel.
Answer:
Some examples of fossil fuel are coal, petroleum, natural gas, mineral oil etc.

Question 25.
Mention one process of energy conservation in daily life.
Answer:
Using LED bulbs instead of ordinary bulbs reduces energy consumption atleast by \(\frac{2}{3}\) times.

Short Questions and Answers : (2 marks for each question)

Question 1.
What is meant by natural resources?
Answer:
Natural resources are those components, which occur in nature, are invaluable for humans and on which our survival depends.

Question 2.
What is meant by sustainable development?
Answer:
Sustainable development is the developmental process that meets the demand of the present, without destroying the scope of the future generation to meet their needs. In this process, industrial, agricultural and other developmental processes are carried out without causing any harm to the environment.

Question 3.
Why is sustainable development necessary?
Answer:
The natural resources that are present in our environment are continuously being utilized to maintain human lifestyle. With the advancement of human civilization and increase in population, these resources are being misused and wasted, rather than utilized. As a result, scientists and environmentalists have been trying to adopt measures to conserve these resources and save the environment, and subsequently carrying out all activities necessary for human development. For this reason, sustainable development is necessary.

Question 4.
What do you mean by forest?
Answer:
A forest is defined as a large area of land, that is covered with trees as well as other woody and non-woody vegetation. Forests are the predominant terrestrial ecosystem of earth and are distributed across the globe.

Question 5.
Why is forest considered as a resource?
Answer:
Forest plays important roles in improving the socio-economic condition of a country. They are-

1. Forest serves as a source of raw materials for various industries.
2. Forest serves as an important source of timber, which is used for making houses, furniture, boats etc.
3. Forest serves as an important source for honey, latex, resin and other medicinal plants.
4. Forest plays an important role in the conservation of biodiversity, regulation of climate and prevention of soil erosion. For these reasons forest is considered as an important natural resource.

Question 6.
What is meant by forest conservation?
Answer:
Forest conservation is the practice of maintaining forested areas for the benefit and sustainability of future generations. By this process over-utilization and improper use of forest resource is prevented and the biodiversity is conserved as well.

Question 7.
What is water cycle?
Answer:
Surface water from seas, lakes etc. evaporates to form water vapour and rises upwards. Transpiration by plants also contributes to this. This water vapour mixes with dust particles and combine with each other to form clouds. The clouds precipitate on the earth as rain, which mixes with rivers and streams and ultimately reverts back to sea. This continuous cyclic flow of water is known as water cycle.

Question 8.
Write down two important effects of water cycle?
Answer:
Two important effects of water cycle are[1] It maintains water balance between landmass and water bodies. [2] It maintains the supply of drinking water and surface water.

Question 9.
What is ground water?
Answer:
The water present beneath the surface of the earth in the tiny spaces between soil particles to large fractures of rocks, is known as groundwater.

Question 10.
What is drinking water?
Answer:
The water that is safe enough for drinking and food preparation and does not cause any harm to human being, is known as drinking water. Drinking water is also known as potable water.

Question 11.
What do you mean by over-utilization of water?
Answer:
The water, collected from the surface and underground sources, are often misused or used indiscriminately. This is known as over-utilization of water.

Question 12.
Give examples of over-utilization of water.
Answer:
Over utilization of water occurs in many ways, such as-

1. While brushing teeth, bathing and washing, leaving the tap running.
2. In urban areas, fresh water is suctioned from underground much more than its normal demands, thereby lowering the underground reserve of fresh water.
3. Agricultural fields are irrigated with underground water.
4. Large amount of water is exploited in various industries.

Question 13.
Mention two causes of lowering of ground water level.
Answer:
Two causes of lowering of groundwater level are-

1. The groundwater is suctioned in large quantity by means of motor pumps in order to meet human demands.
2. In rural areas, huge quantity of groundwater is being used for irrigation.

Question 14.
Why is rain water considered pure as compared to the water of other water hodies?
Answer:
Only the water particles present on the surface of water bodies evaporate and accumulate to form clouds, which comes down as rain. The mineral salts or the harmful pollutants present in the water bodies do not evaporate to form clouds. As a result, these harmful particles do not come down with rain. So, rain water is considered pure as compared to the water of other water bodies.

Question 15.
What is meant by agriculture?
Answer:
Scientific practice of farming, including cultivation of soil for growing economically important crops and rearing of animals for food, wool, silk and other products, is called agriculture.

Question 16.
What is meant by horticulture?
Answer:
Horticulture is a branch of agriculture that includes the cultivation of fruits, vegetables, seeds medical plants, mushrooms, ornamental plants.

Question 17.
What is meant by pisciculture?
Answer:
Pisciculture is a branch of agriculture that deals with the scientific practice of breeding, rearing and marketing of fish, prawn and other economically important aquatic animals.

Question 18.
What is poultry farming?
Answer:
Poultry farming is a branch of agriculture that deals with the scientific practice of breeding and rearing of birds like chicken, duck, quail, turkey etc. for meat and egg.

Question 19.
What is meant by animal husbandry?
Answer:
Animal husbandry is the branch of agriculture that deals with the scientific practice of breeding and rearing of farm animals (cattle, sheep, poultry birds).

Question 20.
What is meant by energy crisis?
Answer:
With the development of industry and upliftment of lifestyle, the utilization of energy has increased to a great extent. But the generation of energy has not been increased to meet up that demand. This situation has developed a worldwide problem, that is popularly known as energy crisis.

Question 21.
Mention two common examples of wastage of electrical energy.
Answer:
Examples of wastage of electrical energy are as follows-

1. Leaving the rooms, office, classrooms etc. vacant with fans and lights switched on.
2. Keeping the street lights switched on duing the daytime.

Question 22.
What do you understand by energy resources?
Answer:
Energy resources are the main sources of energy from which energy can be extracted and utilized for mankind.

Question 23
What is a renewable natural resource?
Answer:
The renewable natural resources are those, which may drop quantitatively after being harvested but are replenished naturally after a certain period of time. Examples-Trees of forest, Population of fish etc.

Question 24.
What is a non-renewable natural resource?
Answer:
The non-renewable natural resources are those, which drop quantitatively after utilization and are never replenished by means. ExamplesCoal, Petroleum etc.

Question 25.
How different natural resources are intimately connected with our existence on earth?
Answer:
Forests, water, food and energy are the basic resources offered by nature. Forest acts as the habitat of life. It provides shelter to thousands of living organisms. Water is the main substance of life. Without water, no organism can survive. Food is the fuel of life, which provides energy, that perpetuates life. Thus, natural resources are intimately connected with our survival on earth.

Question 26.
What is White revolution?
Answer:
To achieve sustainability in milk production, advanced cattle breeding programme has been undertaken. This programme is called operation flood. Now this drive has shown its success. This is known as white revolution.

Question 27.
What is Blue revolution?
Answer:
To achieve the target of feeding the growing population of India, modern techniques of fish culture have been developed. This programme is popularly known as blue revolution, which has successfully reached its goal.

Question 28.
What is Green revolution?
Answer:
In the middle of sixties, in order to achieve sustainability in crop production, intensive agricuitural management has been practiced by applying hybrid crops, proper application of

Question 29.
fertilisers, agricultural equipments, proper irrigations etc. This is known as green revolution.
What is meant by food?
Answer:
The edible matters, which are taken in by the living organisms for nutrition, growth, generation of heat for physiological processes and to develop immunity against diseases, are collectively called food.

Question 30.
What is SCP?
Answer:
Single cell protein (SCP) refers to the sources of mixed protein that has been extracted from pure or mixed culture of various microorganisms (such as algae, fungi or bacteria) and are used as protein-rich foods for human beings and animals. Example-Spirulina.

Long Questions and Answers : (5 marks for each question)

Question 1.
Discuss the environmental and economic importance of a forest.
Answer:
Importance of a forest :
Importance of a forest is described below.
1. Watershed protection: Afforestation along the slope of watershed prevents runoff and reduces the deposition of slit in riverbed. Some plants with mycorrhizal root absorb heavy and toxic metals from soil and reduce the chance of water toxicity.

2. Atmospheric regulation: Scarcity of plants and excessive industrialization in urban areas reduces O₂ and increases CO₂ content in the atmosphere. Forest regulate O₂-CO₂ balance. By respiration organisms release CO₂ and absorb O₂ from the atmosphere. By the process of photosynthesis, green plants of a forest release O₂ and absorb CO₂. In this way, balance of O₂ and CO₂ in the atmosphere is maintained.

3. Erosion control: Erosion means washing or blowing away of top layer of soil. Forests prevent soil erosion by several methods. They are-

• The branches of roots firmly bind the soil particles with the ground.
• The dense leaves of forest prevent raindrops from hitting the soil particles directly and loosening it from the upper layer of soil.
• The litter formed by the leaves on the forest floor, partly decompose to form sticky humus. This sticky humus increases the adhering capacity of the soil particles and prevents soil erosion.

4. Local use: Humans exploit forest in different ways. People living in nearby villages collect firewood from forest. Forest provide honey, timber, resin, honey, cotton, fur, wool, meat (from herbivores) etc. that are collected and marketed.

5. Productive use: From productive point of view, forest has immense importance. Timber is the main economically important product of forest, used to prepare sleepers, posts, log houses, plywood, laminates, galleries, furniture etc. Ecotourism is another productive aspect of the forest, from which the government earns huge amount of revenue. Honey, rubber and several medicinally important materials are collected from the forest.

Question 2
Briefly discuss the causes of deforestation.
Answer:
Causes of deforestation :
The different causes of deforestation are discussed below-
1. Subsistence agriculture: It is an unscientific method of farming, where farmers concentrate on growing enough food for themselves and their family. They cut trees and burn smaller vegetation to prepare land for cultivation and cattle grazing.

2 Indiscriminate felling of trees: Growing population has increased demand of wood products, starting from match-sticks to furniture. Accordingly, price of wood has also been increased. Due to this high price of wood, traders encourage indiscriminate felling of trees.

3. Urbanisation: For development of the state infrastructure, roads and railway tracks are laid through forestland. Moreover, miners acquired the forestland for oil, coal and ore mining. This level of human intervention has affected the lifestyle of both animals and plants and leads to habitat fragmentation.

4. Forest fire: In drier seasons, the local farmers and forest communities burn dry grasses to expand grazing area. High concentration of oxygen in forest atmosphere drives this small fire into a firestorm. It goes out of control and destroys hundreds of trees and many smaller and bigger wild animals.

5. Desertification: Rivers and streams flowing through forestlands often carry industrial pollutants. These toxic materials cause soil pollution, which leads to polluting forest ecosystem.

Question 3.
Describe the consequences of deforestation.
Answer:
Consequences of deforestation :
Consequences of deforestation are as follows-
1. Global warming: Due to deforestation and rapid pace of industrialisation, concentration of greenhouse gases like CO₂ increases in the atmosphere. This results in global warming.

2. Climatic change: Transpiration by trees increases humidity in atmosphere, which in turn enhances the chance of rainfall. In many parts of the world, rate of rainfall has dropped significantly due to deforestation.

3 Change of soil character and erosion: The litter, deposited in forest floor, decomposes to form humus, that keeps the soil healthy and moist in normal situation. Due to deforestation, soil gets exposed to sun and dries out. Moreover, soil particles become loose without binding of roots. Due to this, rain and wind washes off and blow away soil particles, reduce chance of humification resulting in soil erosion.

4. Flood and drought: Incidence of flood and drought has increased in every part of the world due to deforestation.

5. Wildlife extinction: Forests provide habitat for millions of species of flora and fauna. Deforestation makes them homeless. As a result, certain number of species as well as part of wildlife gets extinct.

6 Environmental pollution: Deforestation results in decrease in atmospheric oxygen level. At the same time carbon dioxide increases, which is a cause of air pollution. Mycorrhiza developing in the root system of some trees can remove heavy and toxic metals from the soil. In case of deforestation soil becomes polluted.

Question 4.
Why should we conserve forests? Mention few methods of forest conservation.
Answer:
Reasons of forest conservation
Conservation is protection, augmentation and scientific management of resources so as to maintain them in their optimum level providing benefit to the present as well as future generations. Forests must be conserved because of their immense economic, protective and regulative properties. Forest conservation is important-

• to maintain ecosystem of forest
• to maintain O₂ – CO₂ balance in the environment
• to maintain the supply of forest products like timber, food etc.
• to maintain natural beauty and livelihood of the local people.

Methods of forest conservation

1. Afforestation: It is growing of forests on unprotected barren lands.
2. Reforestation: It is developing forest cover in the area which has been damaged or cleared during exploitation.
3. Separation of commercial forestry: Useful plants required by industry should be planted separately preferably on waste land.
4. Grazing: Grazing should be regulated according to the availability of pasturage.
5. Social Forestry: It is growing of useful multipurpose trees and shrubs on common village lands, roadsides, railsides, etc. by cooperative efforts of people of the area. The plants provide fodder, small timber and fire wood to villagers.
6. Agroforestry: Multipurpose trees and shrubs are planted on the sides of crop fields to provide fodder, fuel and timber.

Both social forestry and agroforestry reduce pressure on the forests. Trees are also planted at all vacant place and along roads in urban areas (urban forestry) for reducing air and noise pollution.

Question 5.
Mention the uses of water. Briefly describe the causes of water scarcity. 2 + 3
Answer:
Uses of water :
Water is an essential component of life. Water is one of the most vital natural resources on Earth for life to sustain. The availability and the quantity of water have always played a significant part in determining not only where population can grow but also their quality of life. It is used in several ways.

1. Drinking: Water is the most essential and a universal drink necessary for life.
2 Agriculture and industrial purpose: A large quantity of water is used for irrigation of crop fields. Different industries, such as metal, paper, chemical, wood, petrochemical etc. and boilers of power plants require large quantity of water. Water is used as raw material, solvent, coolant and washing medium.

Causes of water scarcity :
The main causes of global water scarcity are-

1. Drop in rainfall: Rainfall has dropped radically in different parts of the world, resulting in moderate to severe water scarcity.
2. Global warming: Excessive heat dries out surface water. But this loss is not totally replenished by rain.
3. Over-utilisation of water: Over-utilization of ground water is a result of poor water management, that leads to water scarcity and increased chance of arsenic contamination.
4. Pollution: Disposal of sewage water in streams and lakes is a wasteful technique. By this process, sources of freshwater are polluted and wasted.

Question 6.
How is rain water utilised to counter scarcity of fresh water. Mention the advantage and disadvantage of rain water harvesting? 3 + 2
Answer:
Utilisation of rain water :
Rain water is the largest source of fresh water. By scientific harvesting of rain water, the fresh water scarcity can be controlled to a great extent. Rain water harvesting is a simple and effective method of water management by which rain water is collected, stored and used to meet the demand for fresh water.

The easiest and popular method is rooftop rain water harvesting. In this process, rain water : of roof are connected to a ground level or underground reservoir. The rain water is stored ; reservoir and is used according to necessity. This water can be used directly for any non-F purposes like watering plants, washing and cleaning, bathing and toilets. For cooking and dr this water must be disinfected and filtered. For using rain water at community level, resecreasing and disinfected centrally and then pumped to the overhead water supply tank or the main well of the village.

Advantages and disadvantages of rain water harvesting –
Advantages and disadvantages of rain water harvesting are as follows –
1. Advantages:

• Rain water is generally free from germs and contaminants.
• It is soft water with slightly acidic pH} and does not contain any salt.
• Rain water contains no corrosive substances, so it does not harm water pipes and reservoirs.

2. Disadvantages: Rain water harvesting is not practiced in areas with excessive suspended particulate matters in air. Toxic gaseous materials pollute the atmosphere at regions near chemical industries and fertilizer factories. These gaseous pollutants mix with rain water and make it harmful.

Question 7.
Briefly describe different sources of food for human consumption.
Answer:
Different sources of food for human consumption –
Different sources of food for human consumption are mentioned below-
1. Crop production: The maximum quantity of food we consume are plant products. These include cereals (paddy, wheat, maize, millets etc.), pulses (moong, masur, gram, pea etc.) and oil seeds (mustard seed, sunflower seed, groundnut seed, rape seed etc.)

2. Horticulture: Horticulture includes the cultivation of fruits, vegetables, nuts, seeds, herbs etc. We get fruits and vegetables from horticultural farms. The fruits and vegetables which we use in cooking, are also horticultural products.

3. Cattle farming: This industry is involved in breeding and rearing of animals like cows, goats, pigs etc. It provides us with animal products like meat and milk.

4. Poultry: This industry is involved in breeding and rearing domestic birds like chickens, ducks etc. This industry provides us with poultry producers like meat and eggs.

5. Fishery: Fisheries are meant for scientific breeding and rearing of fishes. Fisheries supplies fishes to our platter.

Question 8.
Briefly describe the situation of food scarcity on global basis. Mention the impacts of food scarcity on earth. 2+3
Answer:
Global food scarcity :

During the last century, industrialization and urbanization have reached the peak. This situation has pushed agriculture already at the back row. Now the rate of agricultural production cannot neet the global demand of food crops. The environmental changes and increasing population have ggravated this problem. All these factors have developed scarcity of food all over the world.

The uation has become more adverse in poorer and developing countries. Out of 70 billion of total rld population, about 10 billion have been suffering from malnutrition and partial starvation. A millions are dying out of starvation or diseases caused by malnutrition. People of Africa, Latin serica and Asia are the main victims of food scarcity.

Impact of food scarcity :

Food scarcity is not only taking lives due to starvation and malnutrition, besides these, it also has some other impacts on human life and environment. To increase crop production, a land is cultivated two or three times in a year. In developing countries, chemical fertilizers are applied indiscriminately to increase yield. By this practice, the natural fertility of soil is lost, also the soil pH changes.

Forest lands are encroached upon by farming. This practice results in deforestation which is followed by soil erosion and flood. Random use of pesticides in the crop fields cause soil and water pollution that may result into many incurable diseases. Irrigation of crop fields by suction of underground water is reducing the underground water reserve and causing arsenic pollution.

Question 9.
Refer to a specific incident related to world food probiem. Give examples of different alternative food sources. 2+3
Answer:
Special incident related to world food problem :
Between July 2011 and mid 2012, a severe drought affected the entire East Africa region. The drought caused a severe food crisis across Somalia, Ethiopia and Kenya that threatened the liveliheed of 9.5. million people. The United Nations officially declared famine in two regions in the southern part of Somalia.

Alternative food sources :
To meet the additional demand for food, scientists and nutrition experts have found dietary potentials in some plant products, other than the common food materials.

1. Moringa oleifera has incredible nutritional value. Many edible parts, like fruits, seeds, leaves, flowers are rich in protein, iron, Vit. A and Vit. C. It also has great medicinal importance.
2. Yam bean contains enough carbohydrates, dietary fibres and Vit. C. it can be consumed raw as salad or cooked, baked and even fried. Yam bean seeds contains oil.
3. Sago is a carbohydrate rich matter, extracted from the stem of some palm trees. The granular shape is obtained by mechanical processing. It is tasty and has good nutritive value.
4. Gum arabic is used to prepare chewing gum. Gaur gum is applied as thickener in confectionary formulations.
5. Green gaur beans are eaten as vegetable and are used as fodder.

Question 10.
Discuss the causes of world food problem.
Answer:
Causes of world food problem :
The main causes of world food problem are-
1. Increase in price of food: For the last three decades, the price of food has been it globally. Due to high price rise, people of developing countries are facing serious prob

2. Old method of farming: The practice of conventional farming like monoculture (without crop rotation), using of low yielding seed varieties, using of chemical fertilizers, farming without soil testing and lack of co-ordination between farmers and marketing sectors are the main reasons of food problems in developing countries.

3 Climatic change and natural calamities: Scarcity of rainfall or excessive rain may affect the production rate. Natural calamities, like flood or drought, also reduces the productivity of food throughout the world.

4. Erosion of soil and soil pollution: Soil erosion reduces the land, available for cultivation. Extensive use of chemical fertilizer reduces soil fertility and productivity. This is another cause of food problem.

5. Population explosion: On an average, 80 million people are born every year. But yearly production of food does not always reach that level to feed those new mouths. Therefore, increase in total number of population also increase food scarcity.

Question 11.
Classify the resources of energy on the basis of use. Mention the importance of conservation of energy resources. 3+2
Answer:
Classification of energy resources :
On the basis of use, energy resources can be classified into two types, which are mentioned below.
1. Conventional energy resources: Conventional energy resources are those which have been traditionally used for many years. These resources are also widely used at present and likely to be depleted. Example-Coal, Petroleum, Natural gas, Hydel power.

2. Non-conventional energy resources: Non-conventional energy resources are alternate energy resources to the conventional energy resources which are being considered to be used on large scale. The conventional energy resources are likely to be depleted in about 50-60 years and non-conventional energy resources should be fully developed by then to meet the energy requirement. Example-Solar energy, Wind energy, Geothermal energy, Tidal power, Biogas etc.

Importance of conservation of energy resources :

1. Energy is of the basic needs of life, therefore resources of energy must be conserved.
2. The conventional resources of energy, especially coal and petroleum are non-renewable, therefore they must be conserved for future generation.

Question 12.
Mention three basic steps towards conservation of energy resources. Mention the different uses of energy. 2+3
Answer:
Basic steps towards conservation of energy resources –
Steps towards conservation of energy resources are as follows-

• Thermal power generation is to be regulated to conserve coal.
• Conventional sources of energy are to be replaced by nonconventional energy sources as far as practiceable.
• Misuse and wastage of energy resources must be cut down substancially.

Different uses of energy :
Energy requirements in different purposes are –
1. Domestic use: In rural areas, wood, coal and kerosene oil are utilized for heating and lighting purpose. In urban areas, energy is used for cooking, lighting rooms, heating, cooling, running electronic gadgets, washing machines, dishwasher, vacuum cleaners, water suction pumps etc.

2. Commercial use: In commercial buildings, such as shops, malls, hotels and restaurants, energy is used for lighting, cooling, heating and running utility gadgets.

3. Industrial use: In industries, coal, oil and natural gas are used for heating, burning and melting purposes. Lighting and running machines depend upon electrical energy.

4. Use in transport: Most of the vehicles, ranging from motor-bikes to aeroplanes, motor-boats to huge ships, run by petroleum based fuels.
Nowadays atomic energy is used to run huge submarines and aircraft carriers.

Question 13.
Mention the methods of energy conservation in daily life.
Answer:
Method of energy conservation in daily life –
Energy can be consumed to a large extent in daily life by the following measures –
1. Lighting: Walls to be painted in lighter shade. Lamps should be kept dust free. Incandescent bulbs needs to be replaced with CFL to LED lamps. Electronic chokes be used instead of copper chokes.

2 Fans: Fans to be switched off before leaving room. Electronic regulators be fitted.

3. Electric iron: Ironing is to be done at right temperature. Sprayer is to be used for moistening.

4. Kitchen appliances: Grinders should be used for wet grinding. Machines are not to be run in over or under-load condition. Door of micro-oven is not to be opened frequently to check food. Flat bottom pans are to be used for induction oven.

5. Gas oven: Cooking should be done in regulated flame. Pressure cookers are to be used as much as possible. Pans to be kept covered while cooking. Before cooking items to be allowed to reach room temperature after taking out of refrigerator.

6 Water heater: Solar water heaters to be used replacing electric water heater

7. Electronic devices: Before leaving room even for short intervals, TV and audio systems should be turned off.

8. Computers: Computer monitor to be turned off during long time downloading.

9. Refrigerator: Star-rated energy saver models are to be used. Frequent opening of the door should be avoided. Door padding should be air-tight.

10. Washing machines: Washing machines should be run in full load condition at optimum water level. Perfect water and detergent quantity should be maintained.

11. Air conditioners: Energy saving star-rated equipments are to be installed and to be selected according to cooling capacity and room size. Outdoor unit is to be fitted in shady place. Filters be cleaned regulatory. Doors and windows of the room are to be sealed perfectly.