Selina Concise Class 9 Physics Solution Chapter No. 6- ‘Heat and Energy’ For ICSE Board Students.
Exercise – A Solution
1.) Solution
Ans:
- When a molecules of a substance are in random motion there will be some energy is produced called as heat energy.
- Heat energy is transferred from one body to other when there is temperature difference between them.
- And heat flows from high temperature region to low temperature region.
- The SI unit of heat is joule or J.
2.) Solution:
Ans:
We know that, heat will be transferred from one body to another body only when there is a temperature difference between them.
And the direction of flow of heat is from high temperature region to the low temperature region.
3.) Solution:
Ans:
The SI unit of heat is joule or J.
The relation between joule and calorie for heat is given by,
1 J = 0.4 calorie
4.) Solution:
Ans:
- The thermal state of any object or substance can be determined from its temperature only.
- Also we can say that the temperature decides the degree of or measure of hotness or coldness of body.
- The SI unit of temperature is kelvin or K.
5.) Solution:
Ans:
- We know that, temperature is the measure of hotness or coldness of body. And it decides the thermal state of body.
- And also we know that, temperature flows from hot body to cold body.
- When we touch ice cubes then we feel cool because our body is at high temperature as compared to ice. So heat flows from our body to ice hence temperature of our body will be decreased and we feel the ice would be cool.
6.) Solution:
Ans:
Heat:
- The energy produced in a substance due to random motion of molecules is called as the heat energy.
- It’s SI unit is joule or J.
- The heat of any substance depends on its mass, temperature and it’s material also.
- Principle of calorimetry is used for measuring the heat energy.
- Two bodies having different temperatures may also have the same amount of heat.
- Suppose two bodies are in contact, then total heat contained is the addition of heat of each individual body.
Temperature:
- Temperature is the quantity which decides the thermal state of any object or the degree of coldness or hotness of body can be determined from its temperature.
- The SI unit of temperature is kelvin or K.
- As the temperature of body is due to the random motion of molecules in it hence temperature depends on the kinetic energy of the molecules in a substance.
- Thermometer is used to measure temperature of body.
- The heat contained in two bodies may be different but their temperature is same.
- If two bodies are at different temperatures are kept in contact then the resultant temperature of two bodies lies between these two temperatures.
7.) Solution:
Ans:
- We know that, substances contract on cooling while expands after heating. When substances expands due to the application of heat energy then that phenomenon is called as thermal expansion of substances.
- In case of solids, when heat is given the solid expands in all directions i.e. in length, area and volume also.
- If due to application of heat length is increased then it is called as linear expansion of the solid.
- If due to application of heat area is increased then it is called as superficial expansion of solid.
- And if due to heat applied the volume of solid is increased then it is called as cubical expansion of solid.
- We know that, liquids and gases are not having specific shape so on heating their volume increases only hence they shows cubical expansion only. As the degree of randomness of gases is more than that of liquids and degree of randomness of liquids is more than solids, liquids shows more expansion than solids and gases shows more expansion than liquids.
For example:
Water from 0°C to 4°C, silver iodide from 80°C to 141°C contract on heating and expands on cooling.
8.) Solution:
Ans:
Brass and iron are the two substances which expands on heating.
9.) Solution:
Ans:
Water from 0°C to 4°C and silver iodide from 80°C to 141°C contract on heating.
10.) Solution:
Ans:
When water is cooled between the range 4°C to 0°C then it expands which is called as anomalous expansion of water.
11.) Solution:
Ans:
At 4°C temperature the density of water is maximum and it has value 1000kg/m3.
12.) Solution:
Ans:
- When water is heated in the temperature range 0°C to 4°C it contracts due to which volume of water decreases.
- While when water is heated further after 4°C to 10°C it expands due to which volume of water increases.
The following temperature-volume graph shows the behaviour of water in different range of temperatures.
13.) Solution:
Ans:
- We know that, from 0°C to 4°C if water is heated it starts contracting due to which its volume decreases and hence it’s density increases.
- While if water is heated in the temperature range 4°C to 10°C it starts expanding due to which its volume increases and hence it’s density decreases.
- The following graph shows this variation of density of water with temperature range from 0°C to 10°C.
14.) Solution:
Ans:
- As we know that, in the temperature range 0°C to 4°C when water is heated it starts contracting due to which its volume decreases.
- While further after 4°C to 10°C if water is heated it starts expanding due to which its volume increases.
- The following temperature-volume graph shows the changes in volume of water at different temperatures.
15.) Solution:
Ans:
Hope’s experiment demonstrate the anomalous expansion of water which proves the water has maximum density at 4°C.
The Hope’s apparatus is as shown in figure.
- It contains a tall metallic cylinder having two side holes at point P which is at top and point Q which is at bottom which are connected to thermometers T1 and T2 respectively.
- The freezing mixture of ice and salt is kept within a cylindrical trough and it surrounds the middle part of the Hope’s apparatus.
- Initially the at room temperature the cylinder is made full of pure water and temperature is noted after equal interval of time by both the thermometers.
The observations taken are as follows:
- At room temperature, the readings shown by both the thermometers is the same.
- The readings of temperature in thermometer T2 are continuously decreasing and it stops decreasing at 4°C and then it remains constant.
- While during this interval of time the readings of temperature shown by thermometer T1 are continuously unchanged.
- When temperature shown by thermometer T2 becomes constant at 4°C at that time the thermometer T1 shows decrease in reading of temperature and stops at 0°C and remains constant at that temperature.
- Thus we can say that, temperature T1 shows reading as 0°C and the thermometer T2 shows reading 4°C.
- This shows that the water has maximum density at 4°C.
- The consequences of anomalous expansion of water are as follows:
- The aquatic life during the very cold weather is preserved with the help of anomalous expansion of water.
- Due to the anomalous expansion of water the during cold nights the crop gets destructed and also water pipelines burst.
17) Ans.
18.) Solution:
Ans:
a)
In colder countries, in winter the atmospheric temperature falls below 4°C where water starts to expand due to which there will be huge pressure created. And this pressure acts on the inner walls of pipes and hence they cause to burst.
b)
- In winter the atmospheric temperature falls to 0°C at which the temperature of layer of water is 4°C which starts lowering by emitting heat outside. Due to which initially temperature of top layer of water starts falling.
- When the temperature of top layer of water is below 4°C it starts to contract thereby increasing the density and hence it sinks to bottom. This process will continued till the temperature of whole water becomes 4°C.
- Again, top water below 4°C starts expanding thereby decreasing the density due to which it doesn’t sink but remains on the surface as it is.
- Now when the atmospheric temperature falls below 0°C due to which water on the surface starts loosing heat to the surrounding and hence freezes to ice. At this moment the water below the top layer is at the 4°C temperature only.
c)
According to anomalous expansion of water, up to the 4°C temperature the water starts contracting. But when the temperature is below 4°C the water starts expanding. Because of this fishes survive in ponds even when the atmospheric temperature is below 0°C.
d)
- As we know that, the water at the temperature 4°C starts contracting due to which its volume decreases and hence density of water increases.
- At that time the density of water is more than the density glass sphere. And already we know that water has maximum density at 4°C. Due to which the glass sphere floats easily at that temperature.
- But, when water is heated above 4°C it starts to expand and hence it’s density decreases.
- At that time the density of water is less than the density of glass sphere. And hence the glass sphere sinks when water is heated above 4°C.
e)
According to anomalous expansion of water, when water is cooled from 4°C to 0°C it starts expanding. Hence even at room temperature, the glass bottle filled with water and tightly closed is likely to burst when kept in freezer of refrigerator because water inside the bottle starts expanding in the temperature range 4°C to 0°C.
Multiple choice type:
1.) Calorie is the unit of
Ans: a) Heat
2.) 1J is equal to
Ans: a) 0.24 cal
3.) SI unit of Temperature is
Ans: d) kelvin
4.) Water is cooled from 4°C to 0°C, it
Ans: b) expands
5.) Density of water is maximum at
Ans: c) 4°C
Exercise-B Solution
1.) Solution:
Ans:
- Ecosystem is the important part of environment which consists of all living organisms, non-living organisms and their life processes.
- The ecosystem has two main components biotic and abiotic components.
- Biotic components includes producers, consumers and decomposers while abiotic components includes light, heat, rain, humidity, inorganic and organic substances.
2.) Solution:
Ans:
All the living organisms which are plants, animals , humans requires energy to survive. The most significant source of energy for all ecosystem is the sun.
3.) Solution:
Ans:
- Green plants plays most important role in the ecosystem. Green plants are the producers which produce the food by the process of photosynthesis.
- In the process of photosynthesis the sunlight and carbon dioxide from the environment is used for the production of complex organic substances.
- They uses the some amount of the energy produced for the process of respiration. Hence, the stored chemical energy is called as gross primary production.
- And the energy remained after the use for respiration is the net primary production which is mainly used for the growth, development and for some metabolic activities of green plants.
- In this way, green plants by producing food plays very important role in the ecosystem.
4.) Solution:
Ans:
Producers:
- Producers are the organisms which produces their own food and doesn’t depends for food on others.
- As they produces their own food called as autotrophs.
- The green photosynthetic plants are the producers.
Consumers:
- Consumers are the organisms which depends on other for food to fulfill their nutrition.
- Hence, they are called as heterotrophs.
- The organisms like grasshopper, frogs are the consumers which depends for food on the others.
5.) Solution:
Ans:
- The decomposers plays very important role in the ecosystem. They ruptures the dead animals and plants and also feed through them.
- After breaking of these dead animals some nutrients will be transferred further to the soil which is again used by producers for the production of food.
- Bacteria and fungi may uses these dead animals as food and converts them from complex organic substances to simple nutrients.
- These nutrients are used by the producers from the soil for the production of food. In this way a cycle is formed in which decomposers plays very important role.
6.) Solution:
Ans:
The food chain consist of producers at its top such as photosynthetic green plants and bacteria which produces their own food. For the food prepared by the producers the primary consumers depends on them. Primary consumers are feed by secondary consumers and then secondary consumers are eaten by tertiary consumers. Finally this tertiary consumers are eaten by the humans which are the last part of the food chain. This process involved is the food chain.
7) Solution:
8.) Solution:
Ans:
The following figure shows the energy flow in the ecosystem.
- The producers produces food by the process of photosynthesis. Mainly the green plants produces food using sunlight and CO2 from environment. The chemical energy stored is the gross primary production.
- While some amount energy is used by producers itself during the process of respiration. And the remaining energy is the net primary production which can be used by plants for their growth, development and some metabolic activities.
- In producers the gross primary production energy is 20,810 cal from which 11,977 cal energy is used in the process of respiration and 8,833 cal energy is the net primary production.
- The primary consumers such as herbivores depends for their food on the producers. They uses small amount of energy for respiration and remaining as food in them taken from the producers.
- The primary consumers takes 3,368 cal energy from the producers and remaining energy 5,465 cal is wasted during the decay of producers. Out of 3,368 cal energy primary consumers uses 1,890 cal energy for respiration and 1,478 cal energy is stored as food in them.
- The energy which is stored in the primary consumers is taken by the secondary consumers. The secondary consumers takes 383 cal energy from the primary consumers while the remaining energy 1,095 cal energy is wasted during the decay process of primary consumers. 316 cal energy is used by the secondary consumers for their process of respiration and the remaining energy 67 cal is stored as food.
- In similar manner, the tertiary consumers uses energy from secondary consumers for respiration and remaining energy is stored as food in them.
- The energy taken by tertiary consumers is 21 cal out of which 15 cal energy is used for respiration and remaining 6 cal energy is wasted in the process of decay.
- This shows the energy flow in the ecosystem is linear i.e. it is transferred in particular direction. The final stage is the degraded state and where it stops. It doesn’t go back to the sun to complete the cycle.
9.) Solution:
Ans:
- The laws of thermodynamics governs the energy flow in an ecosystem.
- Laws of thermodynamics includes first law and second law of thermodynamics.
- The first law of thermodynamics states that energy is not producible and destroyable but it is only transferred from one form to another form.
- While the second law of thermodynamics states that when energy is converted into work, its some part is converted into unusefull form called as heat and which is caused due to friction and radiation.
11) Solution:
12) Solution:
Multiple choice type:
1.) Food chain begins with
Ans: b) photosynthesis
2.) The source of energy in an ecosystem is
Ans: a) sun
3.) Energy enters in a food chain through
Ans: d) producers
4.) The place of human being in food chain in an ecosystem is as a
Ans: c) consumer
Exercise-C Solution
1.) Solution:
Ans:
The source of energy has following characteristics:
- Source of energy provides some adequate amount of useful energy at constant rate and for the long duration of time.
- Source of energy is easy to store and transport.
- It is also safe and convenient to use in our daily life.
2.) Solution:
Ans:
The sources of energy are classified in two groups as follows:
1) Renewable or non-conventional sources of energy
2) Non-renewable or conventional sources of energy
The energy sources are classified into two groups on the basis of their availability in our daily life.
3.) Solution:
Ans:
- Renewable energy sources are the sources which are available for long period of duration and can be produced continuously.
- Non renewable sources of energy are the sources which are not available for long period of duration and also cannot be produced continuously.
- Renewable sources of energy are non-conventional energy sources.
- While the non renewable sources of energy are conventional sources of energy.
- Renewable sources of energy after long use does not exhaust as they are produced naturally.
- Non renewable sources are also the natural energy sources but after long term use they may exhaust.
- Renewable sources of energy can be reproduced.
- But, non renewable sources of energy cannot be reproduced.
For example:
- Sun, tides, wind, oceans are the renewable sources of energy.
- While coal, natural gas and petroleum are the non renewable sources of energy.
4.) Solution:
Ans:
- Renewable sources of energy are wood, water and wind.
- Non renewable sources of energy are coal, diesel and oil.
5.) Solution:
Ans:
Although wood is a renewable source of energy it cannot be used as fuel. Because for using wood as fuel lots of trees would be cutted which harm the environment and leads to pollution also.
Again after burning wood most of the dangerous gases are evolved in environment causing danger to human life. So wood cannot be used as fuel although it is Renewable source of energy.
6.) Solution:
Ans:
The following are the renewable sources of energy:
Sun, wind, tides, oceans, nuclear fuel.
Following are the non renewable sources of energy:
Petroleum, natural gas and coal.
7.) Solution:
Ans:
1) Tidal energy:
- The rise in level of ocean water is called as the high tide while decrease or fall in ocean water is called as low tide.
- These rising and falling of water level of ocean causes two times in a day.
- And the energy which comes from the rising and falling of tides is called as tidal energy.
- By producing dams at the small openings of sea the tidal energy is used for producing electricity.
- But, huge amount of energy will not be produced from the tidal energy because the energy obtained from the tides is not enough for producing electricity.
- And there only some countable and suitable sites at sea where dams are created for producing electricity.
2) Ocean energy:
- The waves of water in sea are continuously rising and lowering. When there were a huge blowing wind occurs due to which waves of water in sea flows with high kinetic energy. This waves are also called as oceanic waves.
- And the kinetic energy possessed by theses waves is called as wave energy which indirectly comes from the sun.
- There were many models are developed for producing electricity from oceanic waves. But, we can’t produce electricity from oceanic waves on large scale.
3) Geothermal energy:
- As we know there is lot of natural energy sources present on the earth’s surface. But there are some energy sources which are inside the earth’s crust.
- The spots where we find rocks inside the earth’s surface are the hot spots as they are having huge amount of heat energy.
- These rocks inside the earth’s surface has huge hot heat energy which is called as geothermal energy.
- These heated rocks due their heat energy heats underground water and convert that water into stream which are then collected through pipes on the earth’s surface.
- This stream water through pipe is used to rotate turbines and there by to produce electricity.
- In India, the Madhya Pradesh has geothermal energy power station only.
8.) Solution:
Ans:
Sun is the huge natural source of energy which giving energy free of cost and the energy is not exhaustible.
9.) Solution:
Ans:
- The energy which comes from the sun is called as solar energy.
- It is the energy coming directly on the earth form sun in the form of radiation’s. Inside the sun due to nuclear fusion reaction large amount of heat energy is generated and out of which only small fraction of it comes to our earth. Because sun is very far from the earth. The energy coming from the sun is inexhaustible and it is used to produce electricity on large scale.
- The solar energy is also used to produce electricity in a solar power plant which is discussed below.
- In solar power plant heat energy from the sun is converted into electrical energy. The concave mirror is used to concentrate light energy form the sun at the focus of it. And the energy concentrated is enough to boil the water.
- In solar power plant, big concave mirror are used to concentrate huge amount of heat energy from the sun and there is black painted water pipes at the focus of concave mirrors.
- When large amount of heat is concentrated at the focus of concave mirror the water inside the black painted pipes starts boiling and due to which stream is produced. These steams are used to rotate turbines and thereby electricity is generated.
- In Gurgaon of Haryana the solar power plant of capacity 50kW has been installed.
10.) Solution:
Ans:
- Solar is used to convert light energy or solar energy coming from the sun directly into the electrical energy.
- Solar cell produces DC current.
- Solar cells are used to provide large amount electricity in large areas of power farms.
- D
- Solar cells are also used in vehicles like cars, buses in order to save the non renewable energy sources.
Following are the disadvantages of the solar cell:
- The solar panels are having high cost.
- To convert solar energy into electrical energy the required efficiency is very low.
- As solar cells produces DC current, hence it cannot be used directly for domestic purposes.
11.) Solution:
Ans:
The advantages of producing electricity from solar energy are as follows:
- Solar panels doesn’t required any maintenance and they can be used for long duration of time.
- Due the use of solar cells or panels for producing electricity there would be no pollution and hence it is not harmful or dangerous to environment.
The limitations of producing electricity from solar energy are as follows:
- The solar panels are having high cost.
- To convert solar energy into electrical energy the required efficiency is very low.
- As solar cell produces DC current, hence it cannot be used directly for domestic purposes.
12.) Solution:
Ans:
The wind energy is the kinetic energy possessed by the large mass of air which is in motion.
The wind energy indirectly comes from the sun. Because due to the radiation’s coming from sun the earth’s surface is heating and there will be different heat is generated in different areas. Also due to rotation of the earth and local convection current there will be different wind cycles are generated. To generate electricity from wind energy large number of wind generators having specific electric power are arranged over a big area which is called as the wind farm. And total electricity will be collected generated by each wind generator and used for various purposes.
Using wind energy we are generating about 10,000MW electric power in India.
13.) Solution:
Ans:
The production of electricity from wind energy doesn’t cause any pollution.
Wind energy is renewable source of energy which does not exhaust and available at free of cost.
Limitations of producing electricity from wind energy:
- To produce electricity from wind energy we require a large area for wind farm.
- And the production of wind farms is mostly expensive.
14.) Solution:
Ans:
The energy possessed by the flowing water is called as the hydro energy and the production of electricity from hydro energy is called as hydro electric power.
The principle of generating electricity from hydro energy is as follows:
- The water flowing through rivers is collected and stored in the dams which are at high altitude. As water is stored in the dam it has huge amount of potential energy in it. These stored potential energy is converted into kinetic energy when that water is incident on blades of turbine.
- Then this kinetic energy is again converted into the rotational energy due to which the blades of turbine rotates continuously.
- Due to which the armature of the generator which is placed in strong magnetic field rotates. And an alternating emf is produced in the terminal.
- This is principle on which the hydro energy is converted into electricity.
- Out of total electricity generated in India only 14% electricity is produced by using hydro energy.
15.) Solution:
Ans:
The advantages of producing hydro electricity are as follows:
- By producing electricity from the hydro energy there will be no pollution.
- Hydro energy is the Renewable source of energy.
The disadvantages of producing electricity from hydro energy are as follows:
- The electricity is produced from the water which is flowing with high speed but it is not available everywhere.
- For hydroelectric power dams are constructed over a large area near the rivers due to which animals and plants from that area get harmed.
16.) Solution:
Ans:
When the heavy nucleus is bombarded with slow neutrons there will be fission of nucleus takes places and another nuclei are generated. The sum of total mass of these nuclei generated is less than the mass of heavy nucleus. That means some amount of mass is lost in this nuclear fission reaction. The mass lost in this reaction is evolved in the form of energy and that energy is called as nuclear energy.
Electricity is generated from nuclear energy by controlled chain reaction of nuclear fission of the radioactive substance like uranium-235.
17.) Solution:
Ans:
3% of total electrical power generated in India is obtained from the nuclear power plant.
Following are the places in India where electricity is generated from nuclear power plants:
- At Tarapur in Maharashtra
- At Kalapkkam in Tamil Nadu
- Kaiga in Karnataka
18.) Solution:
Ans:
Following are the advantages of generating electricity from nuclear energy:
- A small amount nuclear fuel may produces the tremendous amount of energy.
- If once the nuclear fuel is started working in nuclear power plant then it continuously release the energy over a long period of duration.
Following are the disadvantages of producing electricity from nuclear energy:
- During the process of producing nuclear energy very dangerous nuclear radiation’s are emitted which directly affects the human life and environment also. Hence, the person working with nuclear power plant requires high standard protection.
- Also the waste from the nuclear power plant is responsible for the pollution in the environment.
19.) Solution:
Ans:
a) Light energy is converted into electrical energy
b) wind energy or mechanical energy is converted into electrical energy
c) hydro energy or mechanical energy is converted into electrical energy
d) nuclear energy is converted into electrical energy
20.) Solution:
Ans:
- We have to use limitedly the non renewable energy sources such as coal, petroleum and natural gas. And we have to take it last option of our need.
- While using any form of energy which is may be renewable or non renewable source of energy we have not waste it.
- We have to design or construct many ideas which are helpful for public and society for the use of energy and their need.
- We have to avoid the energy which is taken from wood of plant and we have to plant more trees.
- We have to use energy sources only when there is real need of it and we have to maintain the sources for next future generations also.
21.) Solution:
Ans:
The slowly decreases in the useful energy which is due to the loss in radiation’s and friction is called as the degradation of energy.
The daily life examples of degradation of energy are as follows:
- When we use electrical appliances which are working on the basis of electricity, some amount of electrical energy is wasted in the form of heat energy in the atmosphere.
- When we cook something in fire, then most of the heat energy is evolved in the atmosphere which in not used properly. So the energy which is wasted is the degraded form of energy.
22.) Solution:
Ans:
The conversion of part of energy into an unusefull form of energy is called as degradation of energy.
Multiple choice type:
1.) The ultimate source of energy is
Ans: d) sun
2.) Renewable source of energy is
Ans: d) sun
Exercise- D Solution
1.) Solution:
Ans:
Greenhouse effect is the process in which earth’s surface becomes warmer and also the lower atmosphere of it which is caused due to the absorption of infrared radiation having long wavelength emitted from the greenhouse gases like CO2, nitrous oxide, methane, ozone and chlorofluorocarbons.
2.) Solution:
Ans:
Following are the greenhouse gases:
Carbon Dioxide, methane, nitrous oxide and chlorofluorocarbons.
3.) Solution:
Ans:
The solar radiation which pass through the atmosphere of the earth are visible light rays and infrared radiation.
4.) Solution:
Ans:
- The increase of carbon dioxide contents in the earth’s atmosphere is due to the deforestation.
- Extra use of fossil fuels and their combustion.
- Also industrialization is increased through which more pollution is occurring and causes to emit carbon dioxide in the atmosphere.
5.) Solution:
Ans:
The radiation which are absorbed by the greenhouse gases are the infrared radiation of longer wavelength.
6.) Solution:
Ans:
In absence of the greenhouse gases the temperature of earth’s atmosphere would be -18°C
7.) Solution:
Ans:
- The greenhouse gases absorbs the longer wavelength infrared radiation emitted from the earth’s surface and due to which the earth’s surface becomes warmer with an average temperature of 15.5°C.
- In 20th century, the rate of increasing temperature of the earth is observed that (0.74+/-0.18)°C.
- And it is found that this rate may increase upto 65°C till 2100.
8.) Solution:
Ans:
Global warming is the warming of earth’s surface due to which the average effective temperature near to the earth’s surface increases which is caused due to the increase in greenhouse gases in the atmosphere.
9.) Solution:
Ans:
The human activities like combustion of fossil fuels, industrialization, deforestation, large use of automobiles, and increase in the greenhouse gases in the atmosphere causes the rise in atmospheric temperature of the earth.
10.) Solution:
Ans:
- The following are the causes of increase in greenhouse effect:
- Due to industrialization, deforestation and continuous burning of fossil fuels has increased the concentration of carbon dioxide in atmosphere upto 25%.
- The overuse of agricultural sources such as rice cultivation, animal husbandry, natural gas exploration, burning of biomass, deforestation and natural gas leakage has doubled the concentration of methane in the atmosphere.
- Per year it will be observed that there is increase in 5% chlorofluorocarbons in atmosphere.
- Because of the all above causes there is increase in greenhouse gases which leads to greenhouse effect and finally cause the global warming.
11.) Solution:
Ans:
- The increase in greenhouse gases causes the greenhouse effect and which leads to global warming.
- Global warming is the increase in earth’s surface temperature.
- Due to the global warming main effect is observed at the poles where ice and snow melts due to increase in temperature and leads to flood in coastal areas.
- Also the icebergs in dark land and the oceans starts melting so the dark land and ocean become uncovered.
- This uncovered portion further absorbs the radiation from the sun and there is increase in further greenhouse effect.
12.) Solution:
Ans:
- The increase in greenhouse gases causes the greenhouse effect and which leads to global warming.
- Global warming is the increase in earth’s surface temperature.
- Due to the global warming main effect is observed at the poles where ice and snow melts due to increase in temperature and leads to flood in coastal areas.
- Also the icebergs in dark land and the oceans starts melting so the dark land and ocean become uncovered and the water level will be increased.
- This uncovered portion further absorbs the radiation from the sun and there is increase in further greenhouse effect.
13.) Solution:
Ans:
- Due to the increase in greenhouse gases there is a greenhouse effect which causes global warming i.e. increase in temperature of the earth’s surface.
- Due to the melting of ice the area of sea ice at the both poles is started shrinking. And it assumed that in 50 years there will be increase in temperature which causes melting of ice and thereby increase in the sea level.
- The buildings and coastal areas may go under floods and will suffered from hurricanes and tropical storms also.
14.) Solution:
Ans:
- Due to global warming i.e increase in temperature of the earth’s surface may causes in future increase in 3°C temperature due to which there will be poor yield production in lower latitude farms and hence increases the malnutrition.
- And it is expected only that crop yield should be increased in middle and high latitude regions.
- To overcome this problem farmers have to shift their farming from lower latitude regions to high latitude regions.
- All these are the effect of global warming on agriculture.
15.) Solution:
Ans:
Following are the ways to minimise the impact of global warming:
- We have to use renewable energy sources for producing electricity instead of the power plants which are based on the fossil fuels.
- We have to use only battery operated vehicles like cars, bikes and scooters.
- We have to use bio-char stoves while we cook the food.
16.) Solution:
Ans:
Carbon tax is determined on the basis of carbon emitted from the industries, number of employee hours and the turn over of the industries.
The carbon tax will pay the industries as they emits carbon at greater extent.
Multiple choice type:
1.) The greenhouse gas is
Ans: d) carbon dioxide
2.) The increase of carbon dioxide gas in atmosphere will cause
Ans: b) increase in temperature
3.) Without greenhouse effect, the average temperature of earth’s surface would have been
Ans: a) -18°C
4.) The global warming has resulted in
Ans: d) the increase in sea levels