Category: Class 9

You can Download Samacheer Kalvi 9th Social Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 9th Social Science Economics Solutions Chapter 1 Understanding Development: Perspectives, Measurement and Sustainability

Understanding Development: Perspectives, Measurement and Sustainability Textual Exercise

I. Choose the correct answer.

9th Economics Samacheer Book Question 1.
Assertion (A): Development increases the quality of life.
Reason (R): People will have higher incomes, better education, better health and nutrition, less poverty. .
(a) Both (A) and (R) are true and (R) explains (A)
(b) Both (A) and (R) are true and (R) does not explain (A)
(c) (A) is correct and (R) is false
(d) (A) is false and (R) is true
Answer:
(a) Both (A) and (R) are true and (R) explains (A)

Expand The Following Ppp And Hdi Question 2.
The term‘Human resources’ refers to ……
(a) investment on poor people
(b) expenditure on agriculture
(c) investment on assests
(d) collective abilities of people
Answer:
(d) collective abilities of people

Expand The Following Nnp And Pci Question 3.
For comparing development between countries, their …… is considered to be one of the
most important attributes.
(a) growth
(b) income
(c) expenditure
(d) savings
Answer:
(b) income

Expand The Following Hdi Question 4.
……. is considered a true measure of national income.
(a) GNP
(b) GDP
(c) NNP
(d) NDP
Answer:
(c) NNP

Expand The Following Nnp Question 5.
The …… income is also called per capita income.
(a) average
(b) total
(c) people
(d) monthly
Answer:
(a) average

Expand Nnp And Pci Question 6.
Which one of the following country is not a G-8 country?
(a) Japan
(b) Canada
(c) Russia
(d) India
Answer:
(d) India

Class 9 Economics Chapter 1 Let’s Discuss Answers Question 7.
Which one of the following country is not a member of SAARC?
(a) India
(b) Pakistan
(c) China
(d) Bhutan
Answer:
(c) China

Class 9th Sst Economics Chapter 1 Question 8.
Assertion (A) : The Net Product (NNP) is considered as a true measure of national output.
Reason (R): It is also known as national income.
(a) Both (A) and (R) are true and (R) explains (A)
(b) Both (A) and (R) are true and (R) does not explain (A)
(c) (A) is correct and (R) is false
(d) (A) is false and (R) is true
Answer:
(a) Both (A) and (R) are true and (R) explains (A)

Sustainability Meaning In Tamil Question 9.
Assertion (A): Human resource is necessary for the progress of any country.
Reason (R): Investment in education and health of people can result in a high rate of returns in the future for a country.
(a) Both (A) and (R) are true and (R) explains (A)
(b) Both (A) and (R) are true and (R) does not explain (A)
(c) (A) is correct and (R) is false
(d) (A) is false and (R) is true
Answer:
(a) Both (A) and (R) are true and (R) explains (A)

Question 10.
The Human Development Index (HDI) does not take into account the following dimension in its calculation.
(a) Gender
(b) Health
(c) Education
(d) Income
Answer:
(a) Gender

Question 11.
Among the following states which state have the literacy rate (2011) higher than national average?
(a) Andhra Pradesh
(b) Uttar Pradesh
(c) Tamil Nadu
(d) None of these
Answer:
(c) Tamil Nadu

Question 12.
Sex-ratio means …..
(a) the ratio between adult-male and adult female in a population
(b) the ratio between female and male in a population
(c) the relationship between male of female
(d) the number of females per thousand males
Answer:
(b) the ratio between female and male in a population

Question 13.
Inter-generational equality is ensured under the process of
(a) Industrial progress
(b) Economic development
(c) Sustainable development
(d) Economic growth
Answer:
(b) Economic development

Question 14.
Find the odd one.
(a) Solar energy
(b) Wind energy
(c) Paper
(d) Natural gas
Answer:
(c) Paper

Question 15.
……….. is the state with highest installed solar capacity in India.
(a) Tamil Nadu
(b) West Bengal
(c) Kerala
(d) Andhra Pradesh
Answer:
(a) Tamil Nadu

Question 16.
……. resources are those which will get exhausted after years of use.
(a) Natural
(b) Renewable
(c) Non-Renewable
(d) New
Answer:
(c) Non-Renewable

Question 17.
Thermal plant emits large quantity of ……, which pollutes the environment.
(a) Oxygen
(b) Nitrogen
(c) Carbon
(d) Carbon dioxide
Answer:
(d) Carbon dioxide

II. Fill in the blanks

1. Economic progress of any country is known as ………
2. The head quarters of HRD Ministry is in ……..
3. The state having the highest literacy rate in India is ……….
4. Human Development Report of the world prepared and released by …….
5. Groundwater is an example of ……. resource.
6. The book An Uncertain Glory was written by ……..
Answers:
1. economic development
2. New Delhi
3. Kerala
4. UNDP
5. renewable
6. Prof. Amartya Sen

III. Match the following

Answers:
1. (d)
2. (c)
3. (b)
4. (a)

IV. Give Short answers

Question 1.
What do you mean by development?
Answer:

1. The word ‘development’ refers to the progress of a particular field (or) a particular person.
2. Similarly the economic progress of a country is known as ‘economic development’.
3. However, the interpretation of the concept development keeps On changing from time to time, from person to person.

Question 2.
What are the indicators of development?
Answer:
The major indicators to measure the level of economic development are Net National Product (NNP), Per Capita Income (PCI), Purchasing Power Parity (PPP) and Human Development
Index (HDI).

Question 3.
Why NNP is not considered as an useful measure to compare a country’s development with other countries?
Answer:

1. For measuring a country’s development, its income is considered to be one of the most
   important factors.
2. NNP is considered as a true measure of National output.
   So NNP is not considered as an useful measure to compare a country’s development with
   other countries.

Question 4.
Why human resources is considered as the foremost resource of any country?
Answer:

1. Human Resource is necessary for the progress of any country.
2. The ‘Human Resources’ refers to the collective abilities of people, which can be utilised in the production sector.

So human resource is considered as the foremost resource of any country.

Question 5.
Expand the following:
1. PPP
2. HDI
Answer:
1. PPI – Purchasing Power Parity
2. HD – Human Development Index.

Question 6.
Expand the following:
1. NNP
2. PCI.
Answer:
1. NNP – Net National Product
2. PCI – Per Capita Income

Question 7.
What is‘Solar Power’?
Answer:
Solar power is the conversion of energy from sunlight into electricity either directly using photovoltaic cells (or) indirectly using concentrated solar power.

V. Answer in detail.

Question 1.
Discuss the policies for sustainable development.
Answer:

1. India depends on thermal and hydro power plants to meet its power needs. Both these sources have an adverse environmental impact.
2. Thermal power plants emit large quantities of carbon dioxide, which pollute the
   environment.
3. Solar power is the conversion of energy from sunlight into electricity either directly
   using photovoltaic cells or indirectly using concentrated solar power.
4. Solar panels absorb the sunlight as a source of energy to generate electricity. A solar electric system can reliably produce electricity for our home and offices.
5. These distributed solar systems are often installed by home and business owners to reduce their electricity costs. Solar power in India is a fast-developing industry.
6. Tamil Nadu is the state with highest installed solar capacity in India.
7. Tamil Nadu is one of the leading solar power producing states in India. As on 31 July 2017, the total installed capacity in Tamil Nadu is 1,697 MW.

Question 2.
Describe in detail about environmental policies in India.
Answer:

1. Environmental policies in India have been evolved considerably over the past three decades.
2. These policies have covered a wide range of issues such as air, water pollution, waste management and biodiversity conservation.
3. India faces challenges in economic development, which has to be achieved with limited resources, minimum externalities and in the presence of an uncertain climate.
4. One of the approaches to overcome this challenge is through the path of sustainable development.
5. The Supreme Court of India has interpreted and introduced new changes in environmental protection through a series of directions and judgements.

Question 3.
Differentiate between renewable and non-renewable resources.
Answer:

Question 4.
Mention any five environmental acts and their action.
Answer:

VI. Projects and Activities.

List the various ways in which the problems of garbage and emissions are being dealt with around the world.
Plastic bags, broken glass, obsolete cell phone (or) used battery cells, they are all used products that require appropriate disposal to limit their harm to the environment.
The various ways in which the problem of garbage and emissions are being dealt:

1. Collection
2. transportation
3. dumping
4. recycling (or) sewage treatment.

Various waste disposal problems:

1. Production of too much waste.
2. Most of the waste is toxic.
3. Landfills are a problem as well.
4. Regulations are based on vested interests.
5. Reliance of dying technologies to reduce and recycle waste.
6. Some of the technologies marked as ‘green’ are not true in actual sense.

You can do this project with the help of your teacher.

VII. HOTS

Write in detail what kind of environmental problems you face in your locality.
Location: Velachery – Chennai.
Problem: “Despite being one of the fastest growing localities with several up market malls and hotels living in Velachery still face basic problems such as
(a) Overflowing sewage
(b) Poor drainage
(c) The under ground water-breeding grounds for mosquitoes.
(d) There is always fear of contamination of drinking water.
(e) Everytime it pours in the city, most of Velachery drowns.
The above mentioned problems are the dominant ones in Velachery.

VIII. Life Skill.

Question 1.
How is the Per Capita income calculated?
Answer:
The average income is calculated by dividing the country’s total income by its total population. The average income is also called per capita income. Calculations on the per capita income of all countries are calculated only in the US dollar in order to compare International level.

Understanding Development: Perspectives, Measurement and Sustainability Additional Questions

I. Choose the correct answer.

Question 1.
Assertion (A): The term ‘economic development’ refers to the overall growth of all sectors of
the economy.
Reason (R): By adoption of new technologies.
(a) Both (A) and (R) are true and (R) explains (A)
(b) Both (A) and (R) are true and (R) does not explain (A)
(c) (A) is correct and (R) is false
(d) (A) is false and (R) is true
Answer:
(a) Both (A) and (R) are true and (R) explains (A)

Question 2.
This is also known as National Income.
(a) NNP
(b) GDP
(c) PCI
(d) PPP
Answer:
(a) NNP

Question 3.
This is not a G8 country.
(a) Russia
(b) Canada
(c) France
(d) Nepal
Answer:
(d) Nepal

Question 4.
This is one among the ‘BRICS’ countries.
(a) China
(b) Afghanistan
(c) Nepal
(d) Pakistan
Answer:
(a) China

Question 5.
The enrolment for higher education in the highest in ……… in India.
(a) Kerala
(b) Tamil Nadu
(e) West Bengal
(d) Maharashtra
Answer:
(b) Tamil Nadu

Question 6.
This is a renewable resource.
(a) Metals
(b) Glass
(c) Wind energy
(d) Diesel
Answer:
(c) Wind energy

II. Fill in the blanks.

1. Every, human being has an ……… of his (or) her own to achieve progress in life.
2. Countries with higher income are considered to be ………
3. ………. became the third largest economy in terms of PPP.
4. ………. can be divided into renewable resources and non-renewable resources.
5. ……. absorb the sunlight as a source of energy to generate electricity.
Answers:
1. Ambition
2. More developed
3. India
4. Natural resources
5. Solar panels

III. Match the following

1. (d)
2. (a)
3. (b)
4. (c)

IV. Give short answers.

Question 1.
What leads to development?
Answer:
If our thinking turns towards progress and about the ways to achieve the many goals for progress, it leads to development.

Question 2.
For comparing the development of various countries, total income is not an useful measure. How?
Answer:
Since the countries have different populations comparing total income will not be suggestive of what an average person is likely to earn. So, for comparing the development of various countries total income is not an useful measure.

Question 3.
Define Purchasing Power Parity.
Answer:
Purchasing Power Parity is defined as the number of units of a country’s currency required to buy the same amount of goods and services in the domestic market as one dollar would buy in the U.S.

Question 4.
What do you mean by Human Resource Development?
Answer:
Human Resource Development means the development of a person’s physical and mental abilities through education, health care and training.

Question 5.
Why do we say that investment in education and health of people can result in a high rate
of returns?
Answer:
If a child is invested with good education and health, he or she may turn to be very productive in future in the form of higher earnings and greater contribution to the society. Therefore that, investment in education and health of people can result in a high rate of returns

Question 6.
What is the end result of Development?
Answer:

1. Development increases the quality of life.
2. People will have higher incomes, better education, better health and nutrition, less poverty and more equality of opportunity.

V. Answer in detail.

Question 1.
Describe sustainability of Development.
Answer:
Sustainable economic development is taken to mean development without damaging the environment and not compromising with the needs of the future generation.

The consequences of environmental degradation do not respect national or state boundaries. Sustainability of development is comparatively a new area of knowledge in which scientists, economists, philosophers and other social scientists are working together.

Natural resources can be divided into renewable resources and non-renewable resources.
Groundwater is an example of a renewable resource. The question arises as to how sustainable development is possible if the resources are over-used rather than getting replenished. Non-renewable resources get exhausted after certain number of years of extracting and using them and they cannot be replenished.

To achieve real sustainability, we need to balance economic, social and environmental sustainability in equal harmony.

In general, the question of development or progress is continuous. At all times, as a member of society and as individuals, we need to ask where we want to go, what we wish to become and what our goals are.

You can Download Samacheer Kalvi 9th Social Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 9th Social Science Geography Solutions Chapter 4 Hydrosphere

Hydrosphere Textual Exercise

I. Choose the correct answer.

Hydrosphere 9th Class Question 1.
The Sunda Trench lies in the ……………… ocean.
(a) Atlantic
(b) Pacific
(c) Indian
(d) Antarctic
Answer:
(c) Indian

Hydrosphere Lesson Of 9th Class Pdf Question 2.
The temperature of the ocean waters generally ……………. at greater depth.
(a) increases
(b) decreases
(c) remains constant
(d) none of the above
Answer:
(b) decreases

Hydrosphere Lesson Of 9th Class Question 3.
Ocean currents are produced due to ………………….
(a) due to rotation of earth
(b) due to variation in temperature
(c) due to earth’s movement
(d) all the above
Answer:
(d) all the above

9th Class Social Hydrosphere Question 4.
Consider the following statements.
1. Most of the fishing grounds occur in areas where the continental shelf is wide.
2. Fishing is well developed in warm tropical waters.
3. Mixing of warm and cold currents facilitates plant nutrients for fish.
4. Inland fishing became significant in India.
(a) 1 and 2 are correct
(b) 1 and 3 are correct
(c) 2, 3 and 4 are correct
(d) 1, 2 and 3 are correct
Answer:
(b) 1 and 3 are correct

Hydrosphere Class 9 Question 5.
The oceanic ridge comes into existence due to ……………….
(a) convergence of tectonic plates
(b) divergence of tectonic plates
(c) lateral movements of plates
(d) stearing of plates
Answer:
(b) divergence of tectonic plates

Hydrosphere Solutions Question 6.
Which of the following indicates the correct sequence of the topography beneath the surface of the sea?
(a) Continental shelf-Continental slope-Sea plain-Sea trench.
(b) Continental slope-Continental shelf-Sea plain-Sea trench.
(c) Sea plain-Continental slope-Continental shelf-Sea trench.
(d) Continental slope-Sea plain-Continental shelf-Sea trench.
Answer:
(a) Continental shelf-Continental slope-Sea plain-Sea trench.

The Temperature Of The Ocean Waters Generally Question 7.
Which of the following is not correctly matched?
(a) Gulf Stream—Pacific Ocean
(b) Labrador current—North Atlantic Ocean
(c) Canary current—Mediterranean sea
(d) Mozambique current—Indian Ocehn.
Answer:
(a) Gulf Stream—Pacific Ocean; (c) Canary current—Mediterranean sea

9th Class Social 4th Lesson Questions And Answers Question 8.
The amount of planktons to be found in the ocean is determined by
1. Depth of the water
2. Ocean currents
3. Temperature and Salinity
4. Length of day and night
(a) 1 and 2 are correct
(b) 1, 2 and 3 are correct
(c) 1, 3 and 4 are correct
(d) All are correct
Answer:
(b) 1, 2 and 3 are correct

Questions 9 to 12 are of Assertion (A), Reason (R) type.
(A) both A and R are correct and R explains A.
(B) both A and R are correct but R does not explain A.
(C) A is correct but R is false.
(D) A is false but R is correct

Samacheer Kalvi 9th Social Question 9.
Assertion (A): Oceans are always shown in blue in maps.
Reason (R): It indicates the natural colour of the oceans.
Answer:
(A) both A and R are correct and R explains A.

Samacheer Kalvi 9th Social Science Geography Chapter 1 Question 10.
Assertion (A): Flat topped seamounts are known as Guyots.
Reason (R): All guyot features are of volcanic origin.
Answer:
(C) A is correct but R is false.

Question 11.
Assertion (A): Submarine canyons are deep gorges on the ocean floor.
Reason (R): They are mainly restricted to continental shelf, slope and rise
Answer:
(B) both A and R are correct but R does not explain A.

Question 12.
Assertion (A): Atolls are more common in the Atlantic ocean.
Reason (R): The marine population at the depth is less.
Answer:
(A) both A and R are correct and R explains A.

II. Match the following:

Answer:
1. (c)
2. (d)
3. (f)
4. (g)
5. (a)
6. (b)
7. (e)

III. Answer the following in brief:

Question 1.
What do you mean by the term Hydrosphere?
Answer:
Hydrosphere, the third sphere of Earth is a collection of all forms of water on the earth.

Question 2.
What is the hydrological cycle?
Answer:
The continuous movement of water on, above and below the earth’s surface is called the Hydrological cycle.

Question 3.
Mention the various relief features of ocean floor.
Answer:
The ocean basins are characterised by the following major relief features:

• Continental shelf
• Continental slope
• Continental rise
• Deep sea plain or Abyssal plain
• Oceanic deep
• Oceanic ridge.

Question 4.
What are the factors that generate the ocean currents?
Answer:
The factors that generate ocean currents are:

• Earth’s rotation
• Prevailing winds and
• Differences in temperature and salinity of ocean water.

Question 5.
Write a brief note on sea waves.
Answer:
Sea waves are ripples on water caused when winds blow over the sea. The height of these waves depends on the speed of wind, its duration and the direction from which they blow.

IV. Distinguish the following:

Question 1.
Spring tide and Neap tide.
Answer:

S.No.	Spring tide	Neap tide
(i)	When the Sun, Moon and Earth aligned in the same line, the collective gravitation pull of the Sun and Moon on earth’s water strengthens to form a high tide known as spring tide.	When the Sun and Moon are at right angles their gravitational forces work against each other causing a low tide called Neap tide.
(ii)	These tides always occur on Full moon and New moon days.	A Neap tide occurs between two spring tides, i.e., twice a month when the first and last quarter moon appears.

Question 2.
Abyssal plains and Ocean deeps.
Answer:

S. No.	Abyssal plain	Ocean deeps
(i)	Abyssal plains are under water plains found on the deep ocean floor.	These are the deepest part of the oceans.
(ii)	These plains extend from continental rise to the mid-oceanic ridges.	Trenches are the deepest part of the oceans. They occupy about 7% of the total relief of the ocean flour.
(iii)	Abyssal plains are usually covered by the thick layer of sediments composed of clay, silt and sand.	These are sediment free. So most trenches are V-shaped with steep sides.
(iv)	Abyssal hills, sea mounts, guyots, coral atoll, etc., are the characteristic features.	Epicentre of the great earthquakes is all found in the trenches.

Question 3.
Tidal power and Hydel power.
Answer:

S.No.	Tidal power	Hydel power
(i)	Tidal power (or) tidal energy is a form of Hydro power that converts the energy obtained from tides into useful forms of power mainly electricity.	Hydel power (or) water power is derived from the energy of falling water (or) fast running water which may be harnessed for useful purposes.
(ii)	Tidal energy has potential for future electricity generation. Tides are more predictable than the wind and the sun.	This is a renewable energy source because the water cycle is constantly renewed by the sun. Hydro power was used for mechanical milling such as grinding grains.

V. Give reasons for the following.

Question 1.
The northern hemisphere and the southern hemisphere are called land and water hemispheres respectively.
Answer:
The continents and oceans are however, not evenly distributed in the northern and the southern hemispheres. The northern hemisphere holds 61% of land whereas the southern hemisphere holds 81% of water. It is because of this pattern of land and water distribution, the northern hemisphere is called as the land hemisphere and the southern hemisphere is called the water . hemisphere.

Question 2.
Continental shelf provides good fishing ground.
Answer:
They are shallower, thus enables sunlight to penetrate through the water. This encourages abundant growth of grass, sea weeds and plankton. Hence these zones become the richest fishing grounds in the world, e.g. The Grand Banks of Newfoundland.

VI. Answer in a paragraph:

Question 1.
Write a paragraph on the origin of oceans.
Answer:

1. The ocean is a continuous body of salt water that forms the major part of hydrosphere.
2. Geoscientists believe that the oceans were formed on Earth nearly three billion years ago.
3. It is difficult to believe that in the beginning there was no water on our planet.
4. In due course of time, when the Earth started cooling, steam escaped from the interior and entered the atmosphere to form clouds.
5. At first, the clouds brought incessant rains.
6. The rain water filled the depressions for tens of thousands of years and eventually a super ocean was formed.

Question 2.
Write a note on continental shelf and continental slope.
Answer:
Continental Shelf:

1. A shallow and gently sloping platform extending out from the adjoining continental land mass into the sea is called Continental Shelf.
2. It is almost a uniform zone of sea bed with a gentle gradient.
3. They are shallower, thus enables sunlight to penetrate through the water. This encourages abundant growth of grass, sea weeds and plankton. Hence these zones become the richest . fishing grounds in the world, e.g. The Grand Banks of Newfoundland.
4. The continental shelves have extensive deposits of minerals and mineral fuels. Hence, this zone becomes accessible for oil drilling and mining activities: e.g. Mumbai High in Arabian Sea.

Continental Slope:

1. A steep slope which descends from the edge of the continental shelf to the deep ocean- bed is called continental slope.
2. It forms a boundary between the Continental Crust and the oceanic crust.
3. This zone is free from deposits as they are steep. The most important characteristic of . continental slope is the presence of deep canyons and trenches.
4. Due to the low penetration of sunlight, the slope has nearly freezing temperature.
   Hence aquatic life has very slow rate of metabolism. .

Question 3.
What do you mean by ocean currents? Explain its types.
Answer:
Oceans Currents: The movement of oceanic water on the surface and at the depths in a definite direction is called ocean current. Ocean currents are in clockwise motion in the northern hemisphere and in the anti-clockwise motion in the southern hemisphere.
The factors that generate ocean currents are:

• Earth’s rotation
• Prevailing winds and
• Differences in temperature and salinity of ocean water.

On the basis of temperature, ocean currents are classified as warm currents and cold currents. The movement of ocean currents from the low latitudes (tropical zones) towards high latitudes (temperate and polar zones) is called warm current, e.g. Gulf Stream in Atlantic Ocean, North Equatorial Current in Pacific Ocean.

The movement of ocean currents from high latitudes (temperate and polar regions) to low latitudes (tropical regions) is called cold currents, e.g. Labrador Current in Atlantic Ocean and Peruvian Current in Pacific Ocean.

Question 4.
Explain the influences of the marine resources on mankind.
Answer:
The biotic and abiotic resources found in the oceanic water and at the bottoms are called marine resources. The ocean’s resources play a vital role in sustaining the needs of society.
A diverse array of marine organisms is used for food, medicine, cosmetics, and a wealth of • industrial applications. The world’s demand for energy,
minerals and water have become increasingly dependent on non-living marine resources.

Hydrosphere Additional Questions

I. Choose the correct answer.

Question 1.
The ……………. is called the Blue Planet.
(a) Earth
(b) Jupiter
(c) Mars
(d) Mercury
Answer:
(a) Earth

Question 2.
The …………… is the watery part of the earth.
(a) Lithosphere
(b) Atmosphere
(c) Hydrosphere
(d) Biosphere
Answer:
(c) Hydrosphere

Question 3.
The land of thousand lakes is ……………
(a) Norway
(b) Finland
(c) Britain
(d) Swedwen
Answer:
(b) Finland

Question 4.
The purest form of water is …………….
(a) rain water
(b) well water
(c) river water
(d) sea water
Answer:
(a) rain water

Question 5.
Extensive deposits of Minerals and Mineral fuels are found in ……………
(a) Continental slope
(b) Continental shelf
(c) Continental rise
(d) Deep Sea Plains
Answer:
(b) Continental shelf

Question 6.
Consider the following statements.
(i) Submarine Fans which are similar to the alluvial fans found in water.
(ii) Aquatic life has very slow rate of metabolism.
(iii) Dragon Hole is the deepest known under water sink hole in the world.
(iv) Abyssal plains are usually covered by the thick layer of sediments. ,
(a) (i) and (ii) are correct
(b) (ii) and (iii) are correct
(c) (iii) and (iv) are correct
(d) (ii), (iii) and (iv) are correct
Answer:
(d) (ii), (iii) and (iv) are correct

Question 7.
The humankind depends on the Marine resources for its …………….
(a) Agricultural purposes
(b) Survival
(c) Industrial purposes
(d) None of the above
Answer:
(b) Survival

Question 8.
Which of the following correctly matched?
(a) Pacific ocean and Green land
(b) Atlantic ocean and Mariana Trench
(c) Arctic ocean and Trinity Islands
(d) Indian ocean and Andaman Nicobar Islands
Answer:
(d) Indian ocean and Andaman Nicobar Islands

Questions 9 to 12 are Assertion (A) Reason (R) type.
(A) Both A and R are correct and R explains A.
(B) Both A and R are correct but R does not explain A.
(C) A is correct but R is false.

Question 9.
Assertion (A): Continental slope is free from deposits as they are steep.
Reason (R): Abyssal plains appear as a uniform flat and featureless plain.
Answer:
(B) Both A and R are correct but R does not explain A.

Question 10.
Assertion (A): Continental shelf is almost a uniform zone of sea bed with gentle gradient.
Reason (R): This enables sunlight to penetrate through the water.
Answer:
(A) Both A and R are correct and R explains A.

Question 11.
Assertion (A): Ocean currents are in clockwise motion in the Northern Hemisphere and in the anti-clockwise motion in the Southern hemisphere.
Reason (R): The movement of ocean currents from high latitudes to low latitudes is called warm currents.
Answer:
(C) A is correct but R is false.

Question 12.
Assertion (A): The ocean/sea water does not contains calcium in great quantities.
Reason (R): Many of the aquatic animals with shells use the dissolved calcium in the sea water to build their protective shells.
Answer:
(A) Both A and R are correct and R explains A.

II. Match the following.

Answer:
1. (e)
2. (f)
3. (a)
4. (b)
5. (c)
6. (d)

III. Answer the following in brief.

Question 1.
Mention the three major processes involved in the Hydrological cycle.
Answer:
The three major processes involved in the water cycle are evaporation, condensation and precipitation.

Question 2.
Why do we consider the oceans and seas as resource bowl of the earth?
Answer:
Oceans and seas are considered as resource bowl of the earth because of the immense availability of food, minerals, etc.

Question 3.
What Is Hypsometric curve?
Answer:
A Hypsometric Curve is a graphic representation which shows the height of a certain place • found on land and the height of ocean features at sea. ‘Hypso’ means height in Greek.

Question 4.
What do you know about Water Table?
Answer:
Water table is a level below the ground, where water is found collected beneath the Earth’s surface,

Question 5.
What is Dragon Hole?
Answer:
Dragon Hole is the deepest known underwater sink hole in the world. The local fishermen call it the‘eye’of the South China Sea.

Question 6.
Write a short note on the movement of the ocean water.
Answer:
The ocean water is dynamic. Temperature, salinity, density, external forces of the sun, moon and the winds keep the ocean waters in movement, both horizontally and vertically. . Waves and currents are in horizontal motion while tides have vertical motion.

Question 7.
What is called continental rise?
Answer:
At the base of the continental slope is a gently sloping layer of sediments which merge into the deep-sea floor. This underwater feature found between continental slope and abyssal plains is called the continental rise.

Question 8.
How is the energy of the falling wave water used?
Answer:
The energy of the falling wave water is used to turn hydro turbines to generate power. Wave energy power plants have been installed at Vizhinjam in Kerala coast and Andaman and Nicobar islands of India.

Question 9.
When was the National Institute oceanography established? What do they do?
Answer:
NIO (National Institute of Oceanography) was established in 1st January 1966. The headquarters of NIO is located at Dona Paula, Goa. It Conducts research and observations to understand oceanic features, Ocean engineering, marine Archaeology etc.

Question 10.
What is Sea Mount?
Answer:
Sea mount is an underwater mountain that rise from the sea floor due to undersea volcanic

IV. Distinguish the following.

Question 1.
Warm current and Cold current.
Answer:

Warm current	Cold current
The movement of ocean currents from the low latitudes (tropical zones) towards high latitudes (temperate and polar zones) is called warm current, e.g. Gulf Stream in Atlantic Ocean, North Equatorial Current in Pacific Ocean.	The movement of ocean currents from high latitudes (temperate and polar regions) to low latitudes (tropical regions) is called cold currents, e.g. Labrador Current in Atlantic Ocean and Peruvian Current in Pacific Ocean.

Question 2.
Water table and Aquifers.
Answer:

Water table	Aquifers
Water table is a level below the ground, where water is found collected beneath the Earth’s surface.	Aquifers are porous rock strata filled with water, found below the earth’s surface.

Question 3.
Isobath and Isohaline.
Answer:

Isobath	Isohaline
An imaginary line on a map joining the points of equal depths.	An imaginary line on a map joining the points of equal salinity in oceans.

V. Give reasons for the following.

Question 1.
The earth is called the Blue Planet.
Answer:
The Earth is also called the Blue planet, as it holds water in abundance and thus stands unique among all other planets.

Question 2.
Oceans are the lifelines of Earth and Mankind.
Answer:
Oceans are the life blood of planet earth and mankind. The humankind depends on the marine resources’ for its survival. They are also essential for the economic prosperity, social wellbeing and quality of life.

Question 3.
Most of the Creek area get submerged.
Answer:
Most of the Creek area gets submerged due to high tide and at times of low tide, the creek emerges out along with poisonous creatures like snakes, scorpions.

Question 4.
Continental shelf provides good fishing ground.
Answer:
They are shallower, thus enables sunlight to penetrate through the water. This encourages abundant growth of grass, sea weeds and plankton. Hence these zones become the richest fishing grounds in the world, e.g. The Grand Banks of Newfoundland.

VI. Answer in a paragraph.

Question 1.
The Great Barrier Reef. Explain.
Answer:
The Great Barrier Reef: The Great Barrier reef is the world’s largest coral reef system composed of 2,900 individual reefs and 900 islands stretching for about 2,000 kilometres. It covers an area of about 3,50,000 km. The reef is located in the Coral sea, off the coast of Queensland, Australia. The Great Barrier Reef can be seen from the outer space. This sprawling coral reef system is one of the most biologically diverse places on the planet. .Coral reefs are built by billions of tiny organisms, known as Coral polyps.CNN labelled it as one of the seven natural wonders of the world.

In-text HOTs Questions

Question 1.
“71% of the earth is covered by water but very little can be used by humans. Why?
Answer:
“A little amount of fresh water which is suitable for human consumption is present on the earth. Rest of the water we find in oceans. Sea water is saline and not suitable for consumption.

Question 2.
The oceans are salty. Why?
Answer:

1. As the rain erodes the rock acids in the rain water break down the rock.
2. Ions (or) electrically charged atomic particles are created.
3. These ions are carried away in runoff to streams and rivers and ultimately to the ocean.
4. Many of the dissolved ions are used by organisms in the ocean are removed from the water.
5. Others are left for long periods time where their concentrations increased overtime.
6. Sodium and chloride are the most prevalent ions in Sea water, (about 90%) making sea water salty as it is salty.

Question 3.
Why is the salinity at the equator less even though it experiences high temperature.
Answer:
The salinity at the equator is less even though it experiences high temperature, because of heavy rainfall and high relative humidity as precipitation adds good amount of fresh water to ocean water.

Question 4.
“Though Caspian Sea is enclosed its salinity is just 14 to 17 parts per thousand. Why is it so?
Answer:

1. The Caspian Sea is a fresh water lake in its Northern portions due to the current inflow of fresh water, and is most saline on the Iranian shore where the catchment basin centributes little flow.
2. Currently the mean salinity of the Caspian sea is one third that of Earth’s oceans.

Question 5.
What will happen if the seas and oceans contain only fresh water?
Answer:

1. Marine organisms would die as they are capable of surviving only in sea water (salt water).
2. Coral formation could not take place as they are made up of calcareous minerals.
3. Salt is quite important in daily usage.
4. We would have to rely on artificial production without natural salt, which would incur a lot of monetary and infrastructural expenses.
5. Salt water can hold heat better.
6. Sea life is adapted to salt water.
7. Ocean currents would be completely disrupted.

VIII. Enrichment Activity.

Question 1.
A) Study the map of ocean currents and then complete the table given below:

Major Ocean currents
Oceans	Northern Hemisphere	Southern Hemisphere
Pacific Ocean	Kurashio Current (Warm) Oyashio/Kurile Current (Cold) Alaska Current (Warm) California Current (Cold)	Peruvian/Humboldt Current (Cold)
Atlantic Ocean	Canaries (Cold) Gulf Stream (Warm) North Atlantic Drift (Warm) Labrador (Cold)	Benguela (Cold)
Indian Ocean	North East Monsoon Current (Warm) South West Monsoon Current (Warm)	West Australian Current (Cold)

B) Map Work:
Mark the cold currents in blue and the warm currents in red in a World outline map.

You can Download Samacheer Kalvi 9th Maths Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 9th Maths Solutions Chapter 6 Trigonometry Ex 6.1

9th Maths Trigonometry Exercise 6.1 Question 1.
From the given figure find all the trigonometric ratios of angle B.
Solution:

9th maths trigonometry exercise 6.1 Question 2.
From the given figure, find the values of
(i) sin B
(ii) sec B
(iii) cot B
(iv) cos C
(v) tan C
(vi) cosec C
Solution:

trigonometry exercise 6.1 Question 3.
If 2 cos θ = \(\sqrt{3}\), then find all the trigonometric ratios of angle θ.
Solution:

Trigonometry solutions exercise 6.1 Question 4.
If cos A = \(\frac{3}{5}\), then find the value of \(\frac{\sin A-\cos A}{2 \tan A}\)
Solution:

trignometry solution of 9th class Question 5.
If cos A = \(\frac{2 x}{1+x^{2}}\) then find the values of sin A and tan A in terms of x.
Solution:

9th Maths Exercise 6.1 Samacheer Kalvi Question 6.

Solution:

9th Maths Exercise 6.1 Question 7.
If 3 cot A = 2, then find the value of \(\frac{4 \sin A-3 \cos A}{2 \sin A+3 \cos A}\)
Solution:

9th Std Maths Trigonometry Question 8.
If cos θ : sin θ = 1 : 2, then find the value of \(\frac{8 \cos \theta-2 \sin \theta}{4 \cos \theta+2 \sin \theta}\)
Solution:

9th Maths Exercise 6.1 Solution Question 9.
From the given figure, prove that θ + ϕ = 90°. Also prove that there are two other right angled triangles. Find sin α, cos β and tan ϕ
Solution:


(∴ By Pythagoras theorem, in a right angled triangle square of hypotenuse is equal to sum of the squares of other two side)
And also in the figure, ∆ADC, ∆DBC are two other triangles.
As per the data given,
9²+ 12² = 81 + 144 = 225 = 15²
∴ ∆ ADC is a right angled triangle, then 12² + 16² = 144 + 256 = 400 = 20²
∴ ∆ DBC is also a right angled triangle

9th Maths Trigonometry Question 10.
A boy standing at point O finds his kite flying at a point P with distance OP = 25 m. It is at a height of 5 m from the ground. When the thread is extended by 10 m from P, it reaches a point Q. What will be the height QN of the kite from the ground? (use trigonometric ratios)
Solution:
In the figure,
∆OPM, ∆OQN are similar triangles. In similar triangles the sides are in the same proportional.

You can Download The Cat and the Pain-killer Questions and Answers, Summary, Activity, Notes, Samacheer Kalvi 9th English Book Solutions Guide Pdf Supplementary Chapter 4 help you to revise complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 9th English Solutions Supplementary Chapter 4 The Cat and the Pain-killer

The Cat and the Pain-killer Warm Up:

There has always been a close bonding between children and animals. Studies have revealed that living with pet animals increases empathy, compassion and self-esteem among children.

The Cat And The Painkiller Summary Question 1.
Do you have a pet at home?
Answer:
Yes.

The Cat And The Painkiller Question 2.
If yes, what animal is it and what is its name?
Answer:
I have a puppy, and its name is Tommy.

The Cat And The Painkiller Book Back Answers Question 3.
Did you have any humourous moments with it? If yes, what was it?
Answer:
After work, my mum bought our dad a kebab for his tea-time. Hungry, dad just put the fork to his mouth when the doorbell went. The plate went down. By the time, my dad answered the doorbell and came back through the hall, Tommy had wiped off the plate and looked innocent. It was even funnier because of the way Tommy’s legs were moving faster than ever but they just slipped on the carpet in cartoon fashion.

The Cat And The Painkiller Pdf Question 4.
How do you care for your pets?
Answer:
I take my pet for a walk, give it food on time, play with it, and give it bath every weekend.

The Cat and the Pain-killer Textual Questions

A. Choose the most suitable option.

The Cat And The Painkiller Questions And Answers Question 1.
Tom was disturbed because __________________.
(a) he didn’t sleep well
(b) his scores were low at school
(c) his friend Becky Thatcher stopped coming to school
(d) he had picked up a fight with Becky Thatcher
Answer:
(c) his friend Becky Thatcher stopped coming to school

The Cat And The Painkiller 9th Standard Question 2.
Aunt was an experimenter in __________________.
(a) trying new recipes
(b) designing fashionable frocks
(c) modem gardening techniques
(d) trying out new medicines
Answer:
(d) trying out new medicines

The Cat And The Painkiller Paragraph Question 3.
Tom used the pain-killer to __________________.
(a)take care of his health
(b) mend the crack on the sitting room floor
(c) cure Becky Thatcher
(d) help his aunt
Answer:
(b) mend the crack on the sitting room floor

9th English Unit 4 Supplementary Question 4.
Peter sprang a couple of yards in the air as __________________.
(a) he had a teaspoon of the pain-killer
(b) his tail was caught in the mouse trap
(c) Tom threw him out of the window
(d) Aunt gave him a push
Answer:
(a) he had a teaspoon of the pain-killer

The Cat And The Painkiller Summary In English Question 5.
Finally Aunt Polly said to Tom that he__________________  .
(a) need not take any more medicine
(b) has to go to school regularly
(c) should not meet any of his friends
(d) must take medicines every day
Answer:
(a) need not take any more medicine

Cat And The Painkiller Summary Additional Questions

1. Tom put his hoop away, ………………………… .
(a) and his belt
(b) and his scarf
(c) and his shoes
(d) and his bat
Answer:
(d) and his bat

2. Tom became fed up and …………………….. .
(a) planned various relief ideas
(b) became a nuisance
(c) started bothering his aunt
(d) pretended to be fond of pain-killer
Answer:
(d) pretended to be fond of pain-killer

3. One day Tom was ………………………….. .
(a) dreaming of Becky
(b) dosing the crack
(c) begging for a pain killer
(d) caressing Peter
Answer:
(b) dosing the crack

4. So Tom opened his mouth and poured ………………………… .
(a) a war-whoop
(b) the pain killer
(c) water all over
(d) out his frenzied enjoyment
Answer:
(b) the pain killer

5. Tom’s tone was ……………………. .
(a) apprehensive
(b) stand for his rights
(c) feel positive
(d) excited
Answer:
(a) apprehensive

B. Identify the character or speaker of the following lines.

1. He banged against furniture
2. She stood petrified with astonishment peering over her glasses.
3. ‘That is, I believe they do.’
4. ‘What has that got to do that with it?’
5. ‘I done it out of pity for him.’

Answers:

1. Peter, the cat
2. Aunt Polly Arts
3. Tom Sawyer
4. Aunt Polly
5. Tom Sawyer

The Cat And The Pain Killer Additional Questions:

1. Aunt Polly entered in time to see him throw summersets.
2. Next he rose on his hind feet and danced around.
3. He lay on the floor expiring with laughter.
4. She began to try all manners of remedies on Tom.
5. He banged against furniture, upsetting flower-pots.
6. ‘Don’t ask for it unless you want it, Peter.’
7. She added hot baths, sitz baths, shower baths, and plunges.
8. He looked up with just a twinkle peeping through his gravity.
9. He put his hoop away, and his bat.
10. He sprang a couple of yards in the air.
11. ‘Hadn’t any aunt! – you numbskull.’
12. ‘Cats always act so when they’re having good time.’

Answers:

1. Aunt Polly
2. Peter
3. Tom
4. Aunt Polly
5. Peter
6. Tom
7. Aunt Polly
8. Tom
9. Tom
10. Peter
11. Aunt Polly
12. Tom

C. Based on your reading, rearrange the following sentences in the correct sequence.

1. Since all her methods failed, finally she gave him a pain-killer.
2. He told his aunt that Peter had no aunt, so he gave him the medicine.
3. The pain-killer triggered adverse reactions on Peter.
4. It jumped out of the open window.
5. Tom was dull and depressed.
6. This incident upset Aunt Polly and she questioned him.
7. But, Tom gave that pain-killer to the cat Peter.
8. So, Aunt Polly tried different types of remedies on him.
Answers:
3, 8, 5, 6,1, 7, 4, 2

3. The pain-killer triggered adverse reactions on Peter.
8. So, Aunt Polly tried different types of remedies on him.
5. Tom was dull and depressed.
6. This incident upset Aunt Polly and she questioned him.
1. Since all her methods failed, finally she gave him a pain-killer.
7. But, Tom gave that pain-killer to the cat Peter.
4. It jumped out of the open window.
2. He told his aunt that Peter had no aunt, so he gave him the medicine.

D. Based on your understanding of the story, write the answers for the following questions in a sentence or two.

The Cat And The Painkiller Short Summary Question 1.
Why did Tom lose the charm of his life?
Answer:
Tom’s friend Becky Thatcher stopped coming to school. So he lost the charm of his life.

The Cat And The Painkiller Characters Question 2.
Why did Aunt Polly try different remedies on Tom?
Answer:
Tom’s aunt wanted to try new medicines of producing health. She was infatuated with patent medicines and an incurable experimenter. So, she tried different remedies on Tom.

The Cat And The Painkiller Moral Of The Story Question 3.
How did the medicine diminish
Answer:
Tom professed to be fond of pain-killer. So he asked for it often. He used to pour it into a crack in the sitting room floor. Thus the medicine diminished

The Cat And The Painkiller Moral Question 4.
Did Tom compel Peter to have the pain-killer?
Answer:
No. Tom did not compel Peter to have the pain-killer.

The Cat And The Painkiller Story Question 5.
Why did Peter wish to taste the pain-killer?
Answer:
Peter wished to taste the pain-killer because he wanted it.

The Cat And The Painkiller Mind Map Question 6.
How did Aunt Polly discover the reason for Peter’s absurd behaviour?
Answer:
Aunt found the teaspoon and held it out. Thus she discovered the reason for Peter’s absurd behaviour.

Question 7.
What was the reason given by Tom for giving the pain-killer to the cat?
Answer:
Tom said that the cat had no aunt. So he gave it the medicine.

Question 8.
Why did Aunt Polly’s eyes water?
Answer:
Aunt realized that the cruelty to the cat is cruelty to the little boy too. So her eyes watered.

E. Answer the following questions in about 80-100 words.

Question 1.
Describe the different types of remedies tried by Aunt Polly on Tom.
Answer:
Tom’s aunt was the type of person who was infatuated with patent medicines and new ways of producing health or mending it. The first remedy aunt Polly tried on Tom was the water treatment. She stood him up in the woodshed and drowned him with a deluge of cold water; then she scrubbed him down with a towel like a file; then she rolled him up in a wet sheet and put him under blankets till he sweated his soul clean.

The boy remained as dismal as a hearse. Aunt Polly began to assist the water with a slim oatmeal diet and blister plasters. When she heard of Pain-killer, she ordered a lot at once. She tasted it and it was simply fire in a liquid form. She gave Tom a teaspoonful pain-killer and watched with anxiety for the result.

Question 2.
Narrate the funny sequence between Tom Sawyer and Peter, the cat.
Answer:
The “Pain-killer” became a regular treatment, and to Tom Sawyer, it tasted like liquid fire. Tired of the daily doses, one day Tom feeds a spoonful to the cat Peter, which upon receiving the medicine begins to do somersaults in the air while “spreading chaos and destruction in his path.” When Aunt Polly leams that Tom has fed the cat the pain-killer, Tom explains for his actions by saying that he “done it out of pity for the cat because he (the cat) hadn’t any aunt” to “bum him out” and “roast his bowels.”

Additional Question:

Question 1.
Describe Peter’s reaction after having the medicine.
Answer:
Peter sprang a couple of yards in the air, and then delivered a war-whoop and set off round and round the room, banging against furniture, upsetting flower-pots, and making general confusion. Next he rose on his hind feet and danced around, in a frenzy of enjoyment, with his head over his shoulder and his voice proclaiming his happiness. Then he went tearing around the house again spreading chaos and destruction in his path.

F. Complete the summary of the extract using the appropriate words from the box below.

Tom Sawyer felt (1) ……………… as Becky Thatcher had stopped coming to (2) ……………… His Aunt Polly was very concerned about his (3) …………….. condition. So, she began to try various (4) …………….. on him. Tom became fed up with his Aunt’s brand of remedies and (5) to like the pain-killer. He started to ask for it very often. But, Tom used the medicine to mend the (6) ……………….. on the floor. One day, Tom gave the pain-killer to his Aunt’s cat, (7) …………… The (8) …………………. had an adverse effect on the cat and it started to jump around the room. Aunt Polly entered the room in time to see the cat throw a few (9) …………….. and sail through the open window. She found the (10) ……………… with a little pain-killer sticking to it and knew that Tom had treated the cat with it. She realised that, what was (11) ……………. to the cat should be the same to the boy too and (12) ………….. giving medicines to him.
Answers:

1. dejected
2. school
3. health
4. remedies
5. pretended
6. crack
7. Peter
8. pain-killer
9. summersets
10. teaspoon
11. cruelty
12. stopped.

G. In the story we find a lot of American slang usage of English. Complete the tabular column with standard English. One has been done for you.

Answer:

H. Complete the mind map based on the inputs from the extract.

Answer:

1. stopped
2. unhappy
3. was concerned
4. all manners of remedies on Tom
5. the pain-killer
6. Peter
7. petrified

Additional Question:

Answers:

1. hot baths, sitz baths, shower baths and plunges.
2. with a slim oatmeal diet and blister-plasters
3. She calculated his capacity
4. so he thought over
5. the idea of liking pain-killer

The Cat and the Pain-killer by Samuel Langhome Clemens About The Author:

Samuel Langhome Clemens (1835-1910), better known by his pen name Mark Twain, was an American writer, humourist, entrepreneur, publisher and lecturer. Twain grew up in Hannibal, Missouri, the influence of which can be seen in his novels. His wit and satire, in prose and in speech, earned praise from critics and peers, and he was a friend to presidents, artists, industrialists, and European royalty. His first success as a writer came when his humourous tall tale The Celebrated Jumping Frog of Calaveras County was published on November 18, 1865, in the New York weekly The Saturday Press, bringing him national attention. His famous works were The Adventures of Tom Sawyer and The Adventures of Huckleberry Finn.

The Cat and the Pain-killer Summary:

“The Cat and the Pain-killer” is one of the episodes from the novel “The Adventures of Tom Sawyer”. Tom Sawyer is a mischievous young boy growing up along the Mississippi river with his aunt Polly and brother Sid. He is up to all sorts of mischief, but somehow manages to escape from the punishments. Though he finds the school life miserable, the arrival of Becky Thatcher makes him happy. That happiness does not last long as Becky falls ill and stops coming to school.

At home, his Aunt notices that Tom is disturbed and uninterested in doing anything. So Aunt Polly, who is infatuated with patent medicines, tries them on Tom. She tries all kinds of treatments on Tom to make him cheerful again, but to no avail. Tom being fed up with Aunt Polly’s treatment says that he wants pain-killers. Aunt Polly notices that the medicines are diminishing, though she is not aware that Tom is using them to mend the crack in the sitting room floor.

One day while Tom is mending the crack with the pain-killer, the cat Peter arrives and almost begs to taste the medicine. Tom feeling pity towards the cat gives him a spoonful to taste, on which Peter springs up in the air and keeps jumping and dancing, disturbing the furniture and flower pots. Aunt Polly hearing weird noises enters just in time to see the cat perform summersets and carry some flower pots out the window. The old lady is petrified seeing all the mess and Tom’s uncontrollable laughter. Aunt Polly questions Tom regarding the cat’s behaviour. Tom replies that the cats act like this when they’re having a good time.

Aunt Polly finds the teaspoon and understands that Tom has fed the cat with the medicine. She scolds him for being so cruel to the cat, for which he answers that the cat doesn’t have an aunt like her to take care of it and that he has given the cat the medicine out of pity. Aunt Polly suddenly realizes that if the cat would feel so miserable after taking a small sip of the medicine, how the boy must be feeling. Then she puts her hand on Tom’s head saying that she was only trying to do the best for him. Tom replies that he too was only trying to do the best for the cat. Aunt Polly finally says that she wouldn’t try any more medicines on him.

The Cat and the Pain-killer Glossary:

You can Download Samacheer Kalvi 6th Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 6th Science Solutions Term 1 Chapter 2 Force and Motion

Samacheer Kalvi 6th Science Force and Motion Textual Evaluation

I. Choose the correct answer.

Force And Motion Class 6 Book Back Questions And Answers Question 1.
Unit of speed is
(a) m
(b) s
(c) kg
(d) m/s
Answer:
(d) m/s

Unit 2 Force And Motion Question 2.
Oscillatory motion among the following is
a. Rotation of the earth about its axis
b. Revolution of the moon about the earth
c. To and fro movement of a vibrating string
d. All of these.
Answer:
c. To and fro movement of a vibrating string

Force And Motion Class 6 Question 3.
The correct relation among the following is
(a) Speed = distance × time
(b) speed = distance / time
(c) Speed = time / distance
(d) speed = 1/ (distance × time)
Answer:
(b) speed = distance / time

Samacheer Kalvi Guru 6th Science Question 4.
Gita rides with her father’s bike to her uncle’s house which is 40 km away from her home. She takes 40 minutes to reach there.
Statement 1 : She travels with a speed of 1 km/minute
Statement 2: She travels with a speed of 1 km/hour
a. Statement 1 alone is correct.
b. Statement 2 alone is correct
c. Both statement 1 and 2 are correct.
d. Neither statement 1 nor statement 2 is correct.
Answer:
a. Statement 1 alone is correct.

II. Find whether the following statements are true or false. – if false give the correct answer.

Samacheerkalvi.Guru 6th Science Question 1.
To and fro motion is called oscillatory motion.
Answer:
True.

Samacheer Kalvi.Guru 6th Science Question 2.
Vibratory motion and rotatory motion are periodic motions.
Answer:
False. Vibratory motion and oscillatory motion are periodic motions.

Samacheer Kalvi Guru 6 Science Question 3.
Vehicles moving with varying speeds are said to be in uniform motion.
Answer:
False. Vehicles moving with varying speeds are said to be in ton-uniform motion.
(OR)
Vehicles moving with uniform speeds are said to be in uniform motion.

Samacheer Kalvi Guru 6th Standard Science Question 4.
Robots will replace human in future.
Answer:
False. Robots wili not replace human in future.

III. Fill in the blanks.

1. A bike moving on a straight road is an example of _______ motion.
2. Gravitational force is a _______ force.
3. Motion of a potter’s wheel is an example of _______ motion.
4. When an object covers equal distances in equal interval of time, it is said to be in _______ motion.

Answers:

1. Linear
2. Non Contact Force
3. rotatory
4. uniform

IV. Match the following


Answers:

1. c
2. d
3. b
4. a
5. e

V. Analogy

Samacheer Kalvi Guru 6th Science Guide Question 1.
kicking a ball: contact force :: falling of leaf: ________?
Answer:
Non contact force.

Samacheer Kalvi Guru 6th Science Book Back Answers Question 2.
Distance : metre :: speed : _______ ?
Answer:
metre/second.

6th Standard Choose The Correct Answer Question 3.
circulatory motion :: a spinning top :: oscillatory motion : _______ ?
Answer:
Swinging of a pendulum.

VI. Given below Is the distance-travelled by an elephant across a forest with uniform speed. Complete the data of the table given below with the idea of uniform speed.

Answer:

(i) Distance/Time = \(\frac { 4 }{ 2 } \) × 4 = \(\frac { 16 }{ 22 } \) = 8
(ii) Distance / Time = \(\frac { 4 }{ 2 } \) × 8 = \(\frac { 32 }{ 2 } \) = 16
(iii) Time/Distance = \(\frac{1 \emptyset}{2 \emptyset}\) × 12 = \(\frac { 12 }{ 2 } \) = 6

VII. Complete the web chart.

Answer:

VIII. Give one word for the following statements.

Question 1.
The force which acts on an object without physical contact with it.
Answer:
non-contact forces.

Question 2.
A change in the position of an object with time.
Answer:
Motion.

Question 3.
The motion which repeats itself after a fixed interval of time.
Answer:
Oscillatory motion.

Question 4.
The motion of an object travels equal distances in equal intervals of time.
Answer:
Uniform motion.

Question 5.
A machine capable of carrying out a complex series of actions automatically.
Answer:
Artificial intelligence.

IX. Answer the following in a sentence or two.

Question 1.
Define force.
Answer:
Forces are push or pull by an animate or inanimate agency.

Question 2.
Name different types of motion based on the path.
Answer:

1. Linear motion;
2. Curvilinear;
3. Circular motion;
4. Rotatory motion;
5. Oscillatory motion
6. Irregular motion.

Question 3.
If you are sitting in a moving car, will you be at rest or motion with respect your friend sitting next to you?
Answer:
I am in rest with respect to my friend, sitting inside the car.

Question 4.
Rotation of the earth is a periodic motion. Justify
Answer:
Rotation of the earth is a periodic motion because it takes equal interval of time for all rotations.

Question 5.
Differentiate between rotational and curvilinear motion.
Answer:
Rotational motion:

1. A body moves along a circular path.
2. Without changing its position, about its own (fixed) axis.
3. Eg. Rotation of a spinning top.

Curvilinear motion:

1. A body moves along a curved path.
2. Changes its position with motion.
3. Eg. Throwing paper airplanes or paper darts.

X. Calculate

Question 1.
A vehicle covers a distance of 400 km in 5 hour. Calculate its average speed.
Answer:
Distance covered by the vehicle = 400 km
Time taken = 5 hour

XI. Answer in detail.

Question 1.
What is motion? Classify different types of motion with examples.
Answer:
Motion :
Change of position of an object with respect to time is known as motion.

1. Based on Path :

1. Linear motion. – Ex.: Parade of the soldiers.
2. Curvilinear motion. – Ex.: Paper flight moving.
3. Circular motion. – Ex.: Swirling stone tied to the rope.
4. Rotatory motion. – Ex.: Rotating top.
5. Oscillatory motion. – Ex.: Clock pendulum.
6. Zigzag (irregular) motion. – Ex.: Motion of a bee.

2. Based on Duration :

1. Periodic motion. – Ex.: Motion of a bob of simple Pendulum.
2. Non periodic motion. – Ex.: Swaying of the branches of a tree.

3. Based on Speed:

1. Uniform motion. – Ex.: Elour hand of a clock.
2. Non – uniform motion. – Ex.: Motion of a train, as it leaves a station.

XII. Fill with examples.

Answer:

Samacheer Kalvi 6th Science Force and Motion Intext Activities

Activity – 1

Can you identify whether it is push or pull that results in motion in the following cases?

Event 2:
The girl on the swing is moving with respect to the seat of the swing.
She is at rest with respect to the garden.

Event 3:
Nisha is going to her grandmother’s house by bicycle The girl on the bicycle is moving with respect to the road.
She is at rest with respect to the bicycle.

Activity – 2

Moon or Cloud?
Observe the moon on a windy night with a fair bit of cloud cover in the sky. As a cloud passes in front of the moon you sometimes think it is the moon which is moving behind the cloud. What would you think if you were to observe a tree at the same time?

Answer:
Activity to be done by the students themselves

Activity – 3

Fill in the empty spaces.

Answer:

Can you give example for contact and non-contact forces?

Answer:

Activity – 4
Play with pencil
Please do what Shanthi did…

1. Shanthi took a pencil and sharpened it with a sharpener.
2. Then she drew a circle using the pencil and a compass.
3. Later she took her ruler (scale) and drew a straight line in another paper.
4. Then she kept the pencil between her finger and moved it back and forth.

Now, look at the motion of the pencil in all these four cases. How was it?

1. In the first case, the pencil rotated in its axis.
2. In the second case, it went in a circle.
3. In the third case, the pencil travelled in a straight line.
4. Fourth case, the pencil tip moved back and forth, that is it oscillated like a swing.

Activity – 5

Activity – 6
Classify the following according to the path it takes.

Linear, Curvilinear, Circular, Rotatory, Oscillatory, Zigzag (irregular)

• A sprinter running a 100 m race – Linear Motion
• A coconut falling from a tree – Linear Motion
• striking a coin in a carom board game – Zigzag Motion
• Motion of flies and mosquitoes – Zigzag Motion
• Beating of heart – Oscillatory Motion
• Children playing in a swing – Oscillatory Motion
• The tip of hands of a clock – Rotatory Motion
• Flapping of elephant’s ears – Oscillatory Motion
• A stone thrown into the air at an angle – Curvilinear Motion
• Movement of people in a bazaar – Zigzag Motion
• Athlete running around a track – Circular Motion
• Revolution of the moon around the earth – Circular Motion
• The movement of a ball kicked in a football match – Curvilinear Motion
• Motion of a spinning top – Rotatory Motion
• Revolution of the earth around the sun – Circular Motion
• Swinging of a pendulum – Oscillatory Motion
• Children skidding on a sliding board – Linear Motion
• Skidding down a playground slide – Zigzag Motion
• Wagging tail of a dog – Oscillatory Motion
• Flapping of a flag in wind – Oscillatory Motion
• A car driving around a curve – Circular Motion
• Woodcutter cutting with a saw – Linear Motion
• Motion of water wave – Oscillatory Motion
• Motion of piston inside a syringe – Linear Motion
• Bouncing ball – Oscillatory Motion

add five motions you observe to this list :

• Falling fruits from the tree – Linear Motion
• Ceiling fan running – Rotatory Motion
• Car running on the straight road – Linear Motion
• Swirling stone tied to the rope – Circular Motion
• Motion of sewing machine needle – Oscillatory Motion

Activity

Answer:
The Taxi driver travelled with highest speed.

How do we say? Let us calculate how long they travelled in One Hour?
Distance travelled by the Car in One Hour = 80 km (160 ÷ 2)
Distance travelled by the Bus in One Hour = 50 km (200 ÷ 4)
Distance travelled by the Truck in One Hour = 60 km (300 ÷ 5)

Have you found out? say now.
Fastest Taxi, Slowest Bus.

Our speed…

Let us play a small game. Go to the playground with your friends. Mark 100 metre distance for a race. Conduct a friendly running race and calculate the time they taken to complete the distance by stopwatch. Now fill up the following table.

Compute the following Numerical Problems.

1. If you travel 10 kilometres in 2 hours, your speed is 5 km per hour. (10 km/2 hours)
2. If you travel 15 kilometres in 1/2 hour, you would travel 30 km in one hour, and your speed is 30 km per hour. (15 km × 2/1 hours)
3. If you run fast at 20 kilometres per hour for 2 hours, you will cover 40 km. (20 km × 2 hours)

Activity

Multiple Motion to a Sewing Machine

Motion of the needle
Periodic (or) Oscillatory motion

Motion of the wheel
Rotatory motion

Motion of footrest
Oscillatory motion

Activity – 7

Simple Spinner

Let us enjoy by making a simple spinner. Make it by the following instruction.

Cut a 2cm long piece from an old ball-pen refill and make a hole in its center with a divider point (Fig 1).

Take a thin wire of length 9cm and fold it into a U-shape (Fig 2).

Weave the refill spinner in the U-shaped wire (Fig 3).

Wrap the two ends of the wire on the plastic refill, leaving enough clearance for the spinner to rotate (Fig 4).

On blowing through the refill, the spinner rotates (Fig 5).

For obtaining maximum speed – adjust the wires so that air is directed towards the ends of the spinner.

Have you enjoyed with simple spinner. Do you observe the motions in the toy. Can you answer the following question?

1. Motion of the air in tube is _____________ motion.
2. Motion of the refill stick _____________ motion.
3. The toy converts _____________ motion into _____________ motion.

Answers:

1. Linear
2. Rotatory
3. Linear, Rotatory

Samacheer Kalvi 6th Science Force and Motion Additional Questions

I. Choose the correct answer:

Question 1.
_______ is an ancient Indian astronomer.
(a) C.V. Raman
(b) Aryabhata
(c) Usain Bolt
(d) Edison
Answer:
(b) Aryabhata

Question 2.
What is the path of the housefly buzzing around the room?
(a) Periodic motion
(b) Non- Periodic motion
(c) circular motion
(d) None of the above
Answer:
(b) Non- Periodic motion

Question 3.
Identify the Periodic motion among the following :
(a) a horse running in a race
(b) revolution of the moon around the earth
(c) a coconut falling from a tree
(d) paper flight moving
Answer:
(b) revolution of the moon around the earth

Question 4.
The cheetah the fastest animal among terrestrial animals run with the average speed of
(a) 100 km /hr
(b) 200 km/hr
(c) 112 km/hr
(d) 10 km /hr.
Answer:
(c) 112 km/hr

Question 5.
_______ are robots scaled down to microscopic size in order to put them into very small spaces to perform a function.
(a) Car robots
(b) Home robots
(c) Game robots
(d) Nanobots
Answer:
(d) Nanobots

Question 6.
A _______ is the fastest land animal.
(a) Horse
(b) Lion
(c) Cheetah
(d) Tiger
Answer:
(c) Cheetah

Question 7.
A cheetah can run with an average speed of _______
(a) 112 km/h
(b) 121 km/h
(c) 211 km/h
(d) 122 km/h
Answer:
(a) 112 km/h

II. Find whether the following sentences are true or false. If false Correct the statement.

Question 1.
Motion occurs when the object is pulled or pushed by an agency.
Answer:
True.

Question 2.
Force executed by touching the body is called non – contact force.
Answer:
False. Force executed by touching the body is called contact force.

Question 3.
Gravity pushes the ripen coconut from the tree to the ground.
Answer:
False. Gravity pulls the ripen coconut from the tree to the ground.

Question 4.
Throwing paper aeroplane is the best example of linear motion.
Answer:
False. Throwing paper aeroplane is the best example ofcurvilinear motion.

Question 5.
The movement of a body about its own axis like a rotating top is liner motion.
Answer:
False. The movement of a body about its own axis like a rotating top is Rotatory

Question 6.
Motion repeated in equal intervals of time is called as periodic motion.
Answer:
True.

III. Fill in the blanks.

1. _________ are push or pull by an animate or inanimate agency.
2. Application of force in an object results in motion from a state of _________
3. Fast oscillations are referred to as _________
4. Motion repeated in equal intervals of time is called _________
5. _________ are automatic machines.
6. The term Robots comes from a czech word _________
7. _________ is die study of robots in science.

Answers:

1. Forces
2. rest
3. vibrations
4. periodic motion
5. Robots
6. robota
7. Robotics

IV. Complete the web chart.

Answer:

• A – In animate factors,
• B – Contact forces.

V. Answer the following in one or two sentences.

Question 1.
What is meant by the State of Rest?
Answer:
When there is no change of position of an object with respect to time and if it remains stationary it is called rest.

Question 2.
What is a non-contact force?
Answer:
The force applied without touching the object is known as non-contact force.

Question 3.
What is the contact force?
Answer:
When the force is in contact with the object then it is known as contact force.

Question 4.
Give the properties of force.
Answer:

1. Forces can change the state of a body from rest to motion or motion to rest.
2. Forces can change the shape of the body.

Question 5.
A bus moves with a speed of 40 km and crosses 200 km and then how many hours has that bus taken to travel?
Answer:
Time (t) = \(\frac{distence}{AverageSpeed}\)
Time (t) = \(\frac{200 km}{400 km/h}\) = 5 hours

Question 6.
Define Average speed.
Answer:
The distance travelled by an object in unit time is called average speed.

Question 7.
List out the types of motion on the basis of speed.
Answer:
There are two types:

1. Uniform motion,
2. Non-uniform motion.

Question 8.
Define uniform motion.
Answer:
If an object covers uniform distances in uniform intervals, then the motion of the object is called uniform motion.

Question 9.
Why robots are used in many places?
Answer:
Robots can perform mechanical and repetitive jobs faster, more accurately than human beings. It can also handle dangerous materials and explore distant planets.

Question 10.
What are the important parts of a robot?
Answer:
Electronic sensors are a robot’s eyes and ears. These are the important parts.

Question 11.
What is nanobots?
Answer:
Nanobots are robots scaled down to microscopic size in order to put them into very small places to perform a function.

Question 12.
What are the uses of future robots?
Answer:

1. It could be placed in the bloodstream to perform surgical procedures.
2. It could target cancer cells and destroy them without touching healthy cells nearby.

VI. Answer in Detail.

Question 1.
Classify the following motions according to the path it takes.
(a) A coconut falling from a tree
(b) Heart beat
(c) A stone thrown into the air at an angle
(d) Movement of people in a bazzar
(e) Motion of a spinning top
Answers:
(a) A coconut falling from a tree – Linear Motion
(b) Heart beat – Oscillatory Motion
(c) A stone thrown into the air at an angle – Curvilinear Motion
(d) Movement of people in a bazar – Zigzag Motion
(e) Motion of a spinning top – Rotatory Motion

Question 2.
Classify the following motions based on duration and speed.
(a) Coconut falls to the ground
(b) A cart pulled by a bullock
(c) Train journey
(d) A bouncing ball
(e) Revolution of Moon around the earth
Answers:
(a) Non-periodic Motion
(b) Non-periodic Motion
(c) Non-uniform Motion
(d) Periodic Motion
(e) Uniform Motion

You can Download Samacheer Kalvi 9th Maths Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 9th Maths Solutions Chapter 3 Algebra Ex 3.4

9th Maths Exercise 3.4 Question 1.
Expand the following :
(i) (2x + 3y + 4z)²
(ii) (-p + 2q + 3r)²
(iii) (2p + 3)(2p – 4)(2p – 5)
(iv) (3a + 1)(3a – 2)(3a + 4)
Solution:
(i) (2x + 3y + 4z)²
(a + b + c)² ≡ a² + b² + c² + 2ab + 2bc + 2ca
∴ (2x + 3y + 4z)² = (2x)² + (3y)² + (4z)² + 2 (2x) (3y) + 2 (3y) (4z) + 2 (4z) (2x)
= 4x² + 9y² + 16z² + 12xy + 24yz + 16zx

(ii) (-p + 2q + 3r)²
(a + b + c)² ≡ a² + b² + c² + 2ab + 2bc + 2ca
(-p + 2q + 3r)² = (-p)² + (2q)² + (3r)² + 2(-p) (2q) + 2(2q) (3r) + 2 (-p) (3r)
= p² + 4q² + 9r² – 4pq +12qr – 6rp

(iii) (2p + 3)(2p – 4)(2p – 5)
(x + a) (x + b) (x + c) ≡ x³ + (a + b + c) x² + (ab + be + ca) x + abc
(2p + 3)(2p – 4)(2p – 5) = (2p)³ + (3 – 4 – 5) (2p)² + [(3 × – 4)² + (-4 × -5) + (-5 × 3)] 2p + 3 × – 4 × – 5
= 8p³ + (-6) (4p²) + [-12 + 20 + (-15)] 2p + 60
= 8p³ – 24p² + (-7)2p + 60
(2p + 3)(2p – 4)(2p – 5) = 8p³ – 24p² – 14p + 60

(iv) (3a + 1)(3a – 2)(3a + 4)
(x + a) (x + b) (x + c) ≡ x³ + (a + b + c) x² + (ab + bc + ca) x + abc
(3a + 1)(3a – 2)(3a + 4) = (3a)³ + (1 – 2 + 4) (3a)² + [1 × (- 2) + (-2 × 4) + 4 × 1] (3a) + 1 × -2 × 4
= 27a³ + 3 (9a²) + (-2 – 8 + 4)3a – 8
= 27a³ + 27a² – 8a – 8

9th Maths Algebra Exercise 3.4 Question 2.
Using algebraic identity, find the coefficients of x2, x and constant term without actual expansion.
(i) (x + 5)(x + 6)(x + 7)
(ii) (2x + 3)(2x – 5)(2x – 6)
Solution:
(i) (x + 5)(x + 6)(x + 7)
(x + a) (x + b) (x + c) ≡ x³ + (a + b + c) x² + (ab + bc + ca) x + abc
Co-efficient of x² = a + b + c = 5 + 6 + 7 = 18
Co-efficient of x² = ab + bc + ca = (5 × 6) + (6 × 7) + (7 × 5)
= 30 + 42 + 35 = 107
Constant term = abc = 5 × 6 × 7
Co-efficient of constant term = 210

(ii) (2x + 3)(2x – 5)(2x — 6)
∴ Co-efficient of x² = 4 (a + b + c) = 4 (3 + (-5) + (-6))
= 4 × (-8) = -32
Co-efficient of x = 2 (ab + bc + ca)
= 2 [3 × (-5) + (-5) (-6) + (-6) (3)]
= 2[-15 + 30- 18] = 2 × (-3) = -6
Constant term = abc = 3 × (-5) × (-6) = 90

9th Maths 3.4 Question 3.
If (x + a)(x + b)(x + c) = x³ + 14x² + 59x + 70, find the value of
(i) a + b + c
(ii) \(\frac{1}{a}+\frac{1}{b}+\frac{1}{c}\)
(iii) a² + b² + c²
(iv) \(\frac{a}{b c}+\frac{b}{a c}+\frac{c}{a b}\)
Solution:
(x + a)(x + b)(x + c) = x³ + 14x² + 59x + 70 …………….. (1)
(x + a) (x + b) (x + c) ≡ x³ + (a + b + c) x² + (ab + bc + ca) x + abc …………. (2)
(i) Comparing (1) & (2)
We get, a + b + c = 14
(ii) \(\frac{1}{a}+\frac{1}{b}+\frac{1}{c}=\frac{b c+a c+a b}{a b c}=\frac{59}{70}\)
(iii) (a + b + c)² = a² + b² + c² + 2ab + 2bc + 2ca
(a + b + c)² = a² + b² + c² + 2(ab + bc + ca)
= 14² – 2 (59) = 196 – 118 = 78
(iv) \(\frac{a}{b c}+\frac{b}{a c}+\frac{c}{a b}=\frac{a^{2}+b^{2}+c^{2}}{a b c}=\frac{78}{70}=\frac{39}{35}\)

Exercise 3.4 Class 9 Question 4.
Expand
(i) (3a – 4b)³
(ii) (x + \(\frac{1}{y}\))³
Solution:
(i) (3a – 4b)³ We know that
(x – y)³ = x³ – 3x²y + 3xy² – y³
(3a-4b)³ = (3a)³ – 3 (3a)² (4b) + 3 (3a) (4b)² – (4b)³
= 27a³ – 108a²b + 144 ab² – 64b³

(ii) (x + \(\frac{1}{y}\))³
(x + y)³ ≡ x³ + 3x²y + 3xy² + y³
\(\left(x+\frac{1}{y}\right)^{3}=x^{3}+\frac{3 x^{2}}{y}+\frac{3 x}{y^{2}}+\frac{1}{y^{3}}\)

9th Maths Exercise 3.4 In Tamil Question 5.
Evaluate the following by using identities:
(i) 98³
(ii) 1001³
Solution:
(i) 98² = (100 – 2)³
(a – b)³ ≡ a³ – 3a²b + 3ab² – b³
98³ = (100 – 2)³ = 100³ – 3 × 100² × + 3 × 100 × 2² – 2³
= 1000000 – 3 × 10000 × 2 + 300 × 4 – 8
= 1000000 – 60000 + 1200 – 8 = 1001200 – 60008 = 941192

(ii) 1001³ = (1000 + 1)³
(a + b)³ ≡ a³ + 3a²b + 3ab² + b³
(1000 + 1)³ = 1000³ + 3(1000²) × 1 + 3 × 1000 × 1² + 1³
= 1000,000,000 + 3,000,000 + 3000 + 1 = 1,003,003,001

Ex 3.4 Class 9 Question 6.
If (x + y + z) = 9 and (xy + yz + zx) = 26 then find the value of x² + y² + z².
Solution:
(x + y + z) = 9 and(xy + yz + zx) = 26
x² + y² + z² = (x + y + z)² – 2 (xy + yz + zx)
= 9² – 2 × 26 = 81 – 52 = 29

9th Standard Maths Exercise 3.4 Question 7.
Find 27a³ + 64b³, if 3a + 4b = 10 and ab = 2.
Solution:
3a + 4b = 10, ab = 2
(3a + 4b)³ = (3a)³ + 3 (3a)² (4b) + 3 (3a) (4b)² + (4b)³
(27a³ + 64b³) = (3a + 4b)³ – 3 (3a) (4b) (3a + 4b)
∵ x³ + y³ = (x + y)³ – 3xy – (x + y)
= 10³ – 36 ab (10)= 1000 – 36 × 2 × 10
= 1000 – 720 = 280

Exercise 3.4 Class 9 Maths Solution Question 8.
Find x³ – y³, if x – y = 5 and xy = 14.
Solution:
x – y = 5, xy = 14
x³ – y³ = (x – y)³ + 3xy (x – y) = 5³ + 3 × 14 × 5
= 125 + 210 = 335

Class 9 Maths Exercise 3.4 Solutions Question 9.
If a + \(\frac{1}{a}\) = 6, then find the value of a³ + \(\frac{1}{a^{3}}\)
Solution:
a³ + b³ = (a + b)³ – 3ab (a + b)

9th Math 3.4 Solution Question 10.
If x² + \(\frac{1}{x^{2}}\) = 23, then find the value of x + \(\frac{1}{x}\) and x³ + \(\frac{1}{x^{3}}\)
Solution:

Maths Exercise 3.4 Class 9 Question 11.
If (y – \(\frac{1}{y}\))³ = 27, then find the value of y³ – \(\frac{1}{y^{3}}\)
Solution:

9th Class Maths Exercise 3.4 Solution Question 12.
Simplify : (i) (2a + 36 + 4c)(4a² + 9b² + 16c² – 6ab – 12bc – 12bc – 8ca)
(ii) (x – 2y + 3z) (x² + 4y² + 9z² + 2xy + 6yz – 3xz)
Solution:
(i) (2a + 36 + 4c)(4a² + 9b² + 16c² – 6ab – 12bc – 12bc – 8ca)
We know that
(a + b + c) (a² + b² + c² – ab – bc – ca) = a³ + b³ + c³ × 3 abc
∴ (2a + 36 + 4c) (4a² + 9b² + 16 c² – 6 ab – 12 bc – 8 ca)
= (2a)³ + (3b)³ + (4c)³ – 3 × 2a × 36 × 4c
= 8a³ + 27b³ + 64c³ – 72 abc

(ii) (x – 2,y + 3z) (x² + 4y² + 9z² + 2xy + 6yz – 3xz)
(a + b + c) (a² + b² + c² – ab – bc – ca) = a³ + b³ + c³ – 3abc .
∴ (x – 2y + 3z) (x² + 4y² + 9z² + 2xy + 6yz – 3xz)
= x³ + (-2y)³ + (3z)³ – 3 × x × (-2y) (3z)
= x³ – 8y³ + 27z³ + 18 xyz

9th Maths Exercise 3.4 Samacheer Kalvi Question 13.
By using identity evaluate the following:
(i) 7³ – 10³ + 3³
(ii) 1 + \(\frac{1}{8}-\frac{27}{8}\)
Solution:
(i) 7³ – 10³ + 3³
(a + b + c) (a² + b² + c² – ab – bc – ca) = a³ + b³ + c³ – 3 abc
If a + b + c = 0, then a³ + b³ + c³ = 3 abc
∴ 7 – 10 + 3 = 0
⇒ 7³ – 10³ + 3³ = 3 × 7 × – 10 × 3
= 9 × -70 = -630

9th Class Math Exercise 3.4 Solution Question 14.
If 2x – 3y – 4z = 0, then find 8x³ – 27y³ – 64z³.
Solution:
If 2x – 3y – 4z = 0 then 8x³ – 27y³ – 64z³ = ?
If x + y + z = 0 then x³ + y³ + z³ = 3xyz
8x³ – 21 y³ – 64z³ = (2x)³ + (-3y)³ + (-4z)³
= 3 × 2x × -3y × – 4z = 72 xyz

You can Download Water – The Elixir of Life Questions and Answers, Summary, Activity, Notes, Samacheer Kalvi 9th English Book Solutions Guide Pdf Prose Chapter 5 help you to revise complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 9th English Solutions Prose Chapter 5 Water – The Elixir of Life

Water – The Elixir of Life Warm Up:

Water The Elixir Of Life Questions And Answers Question 1.
Do you think the living organisms in this planet can survive without water? Why?
Answer:
No, because water is required by all living organisms in various processes for their survival.

Water The Elixir Of Life Question 2.
Where do you get your drinking water from?
Answer:
I get drinking water from borewell and corporation pumps.

Water The Elixir Of Life Summary Question 3.
Is the drinking water you use in your home treated?
Answer:
No, the drinking water we use is not treated.

Water The Elixir Of Life Book Back Answers Question 4.
If not, how do you purify it?
Answer:
Water is purified by filtration.

Water – The Elixir of Life Intext Questions

Water The Elixir Of Life 9th Std Question 1.
What is the imaginary elixir of life?
Answer:
The divine Amrita is the imaginary elixir of life.

Water The Elixir Of Life Reading Answers Question 2.
What according to the writer is the real elixir of life?
Answer:
According to the writer, water is the real elixir of life.

9th English Water The Elixir Of Life Question 3.
What is the ‘wonderful difference’ the writer talks about in the passage?
Answer:
On one side, was the visible sea of billowing sand without a speck of green or a single living thing anywhere on it. On the other side lay one of the greatest, most fertile and densely populated areas to be found anywhere on the earth, teeming with life and vegetation. This is the ‘wonderful difference’ that the writer talks about in the passage.

Water The Elixir Of Life Summary Pdf Question 4.
What is the ‘cheering sight’ mentioned in the paragraph?
Answer:
The rain fed tanks that are so common in South India are a cheering sight when they are full.

Water – The Elixir Of Life Question 5.
What does the writer compare water in a landscape to?
Answer:
The writer compares the water in a landscape to the eyes in a human face.

Water-The Elixir Of Life Question 6.
How does the water in rainfed tanks get its colour?
Answer:
The water in the rain fed tank carry slit or finely divided soil in suspension. This is the origin of the characteristic colour of the water in the rain fed tanks.

Water Elixir Of Life Summary Question 7.
What is the main cause of soil erosion?
Answer:
The sudden burst of excessively heavy rain resulting in a large run of surplus water is the main cause of soil erosion.

Water The Elixir Of Life Pdf Question 8.
What other factors add to the erosion of precious soil?
Answer:
The slope of land, removal of natural protective coat of vegetation, the existence of ruts along which the water can flow with rapidly gathering momentum and the absence of any checks of such flow are the other factors that add to the erosion of precious soil.

Water, The Elixir Of Life Notes Of Lesson Question 9.
How can soil erosion be prevented?
Answer:
The terracing of land, construction of bunds to check the flow of water, the practice of contour cultivation and the planting of appropriate types of vegetation are the measures that can prevent soil erosion.

The Elixir Of Life Question And Answers Pdf Question 10.
How does prevention of soil erosion serve a double purpose?
Answer:
The prevention of soil erosion would help to conserve and keep the water where it is wanted, in other words, on and in the soil. Thus it serves a double purpose.

The Elixir Of Life Question And Answer Question 11.
What are the two sources of water?
Answer:
The two sources of water are rain and snowfall.

Question 12.
What happens to the rain water?
Answer:
The rain water flows down into the streams and rivers and ultimately finds its way to the sea.

Question 13.
What is the idea of civilized forest?
Answer:
The civilized forests would directly and indirectly prove a source of untold wealth to the country. They would check soil erosion and conserve the rainfall of the country from flowing away to waste and would provide the necessary supplies of cheap fuel, and thus render unnecessary the wasteful conversion of farmyard manure into a form of fuel.

Question 14.
How can you check soil erosion?
Answer:
The terracing of the land, the construction of bunds, the practice of contour cultivation and the planting of some types of vegetation are the measures that can be used to check soil erosion.

Question 15.
What is the cheapest means of transport?
Answer:
The cheapest means of transport is by boats and barges through canals and rivers.

Question 16.
How can you make a difference in the countryside?
Answer:
The availability of electric power would make a tremendous difference to the life of the countryside and enable rural economy to be improved in various directions.

Water – The Elixir of Life Textual Questions

A. Answer the following questions briefly in one or two sentences.

Question 1.
What makes water one of the most powerful and wonderful things on earth?
Answer:
Water played a role of vast significance in shaping the course of the earth’s history and continues to play the leading role in the drama of life on the surface of our planet.

Question 2.
How does water help in the formation of fertile lands?
Answer:
The water has its power to carry slit or finely divided soil in suspension. The great tracts of land formed by slit thus deposited is evident on an examination of the soil in alluvial areas. Thus, water helps in the formation of fertile lands.

Question 3.
How does soil erosion happen and what are its main causes?
Answer:
The flow of water under certain conditions causes soil erosion. Sudden bursts of excessively heavy rain resulting in large run of surplus water are the principal factors in causing soil erosion.

Question 4.
What are some measures that are used to prevent soil erosion?
Answer:
The terracing of land and construction of bunds to check the flow of water, the practice of contour cultivation and the planting of appropriate types of vegetation are few measures to check erosion.

Question 5.
How, according to Sir C. V. Raman, can rainwater as well as the water of rivers be, prevented from going to waste?
Answer:
The systematic planting of suitable trees can prevent rainwater going to waste.

Additional Questions

Question 1.
How will development of hydro-electric power be a resource?
Answer:
Development of hydro-electric power will enable tapping of underground water which requires electricity and thus overcome the inadequacies of other sources of water.

Question 2.
What is far from an exhausted field of research?
Answer:
The investigation of nature and properties of water is considered the highest scientific interest and is far from an exhausted field of research.

Question 3.
When and where did the author notice not a single living being?
Answer:
The author noticed not a single living being while standing on the line which separated the Libyan Desert from the Valley of the Nile in Egypt. The desert was without a speck of green.

Question 4.
How is the Nile valley soil created?
Answer:
Nile valley soil is created by the river itself. It is brought down as the finest silt in its flood waters, from the highlands of Abyssinia and from remote Central Africa. It is laid down through the ages in the trough through which the Nile flows into the sea.

Question 5.
How is the great tracts of land formed by deposition of silt evident on an examination of the soil in alluvial areas?
Answer:
Great tracts of land formed by silt deposition is evident on an examination of the soil in alluvial areas. When silt-laden water mixes with the salt water of the sea, there is rapid precipitation of the suspended matter. The colour of the water changes successively from red or brown shades of silt through varying shades of yellow and green before it becomes blue of the deep sea.

Question 6.
Why is physiological activity impossible where fluid does not play an important role?
Answer:
Water is the elixir of all life. Even fauna and flora contains a considerable proportion of free or combined water in its body. Hence, physiological activity is impossible where the fluid does not play an important role.

Question 7.
State the national problem which must be considered and dealt with on national lines.
Answer:
Water conservation is the national problem which must be considered and dealt with on national lines. Unbelievably, large quantities of the precious fluid are not conserved. Our rivers, mostly run to waste and harnessing it is vital.

B. Answer the following in about 80-100 words.

Question 1.
How does C.V. Raman show that water Is the real elixir of life?
Answer:
Raman tries to bring about the importance of water, which has a unique power of maintaining animal and plant life. Water, the elixir of life, is the commonest of all liquids. Without water the land will be barren like the deserts in Egypt. On one side it is a sea of sand. On the other side laid one of the greatest, most fertile, densely populated areas the valley of Nile.

It is separated by the river Nile flowing down thousands of miles away. The entire soil is the creation of river Nile. Egypt, in fact was made by its river. Water is the basis of all life. Every animal and plant contains water in its body. Water is essential for the body, moisture in the soil is equally important for the life and growth of plants and trees. The conservation and utilization of water is fundamental for human welfare.

Question 2.
Water exists in all plant and animal forms – Explain.
Answer:
If there is plenty of water and abundant rainfall, there will be good growth of plants. The population of animals depending on these plants will increase. On the other hand, if there is a drought, there will be a smaller supply of plants. The animals depending on these plants will decrease in population as a result of the decrease in the plant population. Water is the fundamental necessity for both animal and plant forms.

Question 3.
Life cannot exist on earth without water – Explain.
Answer:
Water is the basis of all life. Every animal and plant contains water in its body. Water is essential for the body, moisture in the soil is equally important for the life and growth of plants and trees. The conservation and utilization of water is fundamental for human welfare. Much of Indian agriculture depends on monsoon.

It is clear that the adoption of techniques preventing soil erosion would help to conserve and keep the water where it is wanted. Without water, nothing is possible on earth. The collection of rain water and utilizing them is very important. Vast areas of land which at present are scrub jungle could be turned into fertile and prosperous country by courageous and well-planned action.

Additional:

Question 1.
How is Artesian Water Created?
Answer:
Springs become artesian when the water flows to the surface under natural pressure without pumping. Water flows down a decline into a porous substance such as rock, sand or gravel. The hard rock surrounding the porous substance prevents water to escape through it. In some places the overlying impermeable rocks are broken by joints or faults. A pressure starts building up between two impermeable surfaces. The water underneath is forced out by this pressure and it may escape through the faults to rise to the surface. Most of the times the escape is a well, which becomes the source of the artesian water.

C. Given below are some idioms related to water. Match the idioms with its meaning.

Answers:
1. (d), 2. (i), 3. (f), 4. (b), 5. (j), 6. (h), 7. (a), 8. (c), 9. (g), 10. (e).

D. Water is a scarce resource. Discuss the causes, problems and solutions to water scarcity and write them below.

Causes :
Conflict: A conflict over an area of land may make it difficult to access the water located there.
Distance: Many areas face water scarcity because they aren’t close to any source of water.
Drought: Some areas do not get enough rainfall to be able to sustain life.
Overuse of Water: The overuse of water on people, animals, land, or recreational activities can cause water scarcity.
Pollution: Water might get polluted by anything from oil, to carcasses, to chemicals, and to fecal matter.

Problems:
Diseases: If we don’t have clean water access, we will be more likely to get diseases.
Hunger: Due to shortage of water, agricultural lands will not be watered properly. This may cause crop deficiency and people and animals will have to go hungry.
Lack of Drinking Water: The worst outcome of water scarcity is non-availability of clean drinking water.
Lack of Education: Children might be too sick to even go to school.
Sanitation Issues: Absence of clean water makes it difficult to clean food, dishes, or even to take a bath.

Solutions:
Technology: New and modem methods of water conservation can be applied.
Education: By educating people about water scarcity, we can prevent the problem from becoming worse in the future.
Improved Farming: We must think of farming and irrigation techniques that don’t use much water.
Recycle Water: We can recycle rainwater and use it in factories and homes.
Support Clean Water Initiatives: We can fund such organizations which bring clean water to areas that don’t have it.

Listening:

E. On the basis of the listening passage, choose the correct answer from the given options.

Question 1.
Severn Suzuki represents an organization called ECO which stands for _________.
(a) Ecological Cooperation.
(b) Environmental Coordinating Organization.
(c) Environmental Children’s Organization.
(d) Ecological Children’s Organization.
Answer:
(c) Environmental Children’s Organization

Question 2.
“I am fighting for my future.” The ‘fight’ refers to her ________.
(a) fight to win an election.
(b) fight to gain a few points in share market.
(c) fight against corruption.
(d) fight against environmental pollution.
Answer:
(d) fight against environmental pollution

Question 3.
Animals and fish are becoming extinct because ___________.
(a) they have no place to go.
(b) they die of diseases.
(c) their food and habitat are polluted.
(d) all the above.
Answer:
(d) all the above.

Question 4.
It is evident that Severn Suzuki is concerned about all other species too as,____________.
(a) she considers them all belonging to one world.
(b) they have nobody except her to speak for.
(c) they belong to her.
(d) they are all children.
Answer:
(a) she considers them all belonging to one world

Question 5.
Severn Suzuki condemns the people of her country for ____________.
(a) contributing large amounts of waste and not sharing the excess with the needy.
(b) being afraid of the poor.
(c) being angry with the poor belonging to other countries.
(d) being wealthy.
Answer:
(a) contributing large amounts of waste and not sharing the excess with the needy

Question 6.
Which of the following statements is not true? __________________.
(a) Canada is a rich country and people have in plenty.
(b) Canadian children are privileged.
(c) A Brazilian child was willing to share because she was rich.
(d) Northern countries will not share with the needy
Answer:
(c) Canada is a rich country and people have in plenty

F. Answer the following questions briefly.

Question 1.
What is the humb

le request of the twelve- year -old to the elders?
Answer:
She requests adults to change their ways and save nature for the future.

Question 2.
The dream of Severn Suzuki is
Answer:
She has dreamt of seeing the great herds of wild animals, jungles and rain forests, full of birds and butterflies.

Question 3.
The fear and agony of Severn Suzuki is
Answer:
We make so much waste.

Question 4.
How does she proclaim that she represents the future generation?
Answer:
She calls herself as one of the children starving in Somalia or a victim of war in the Middle East or a beggar in India.

Question 5.
The duties and responsibilities of the parents are
(a) to comfort their children saying that everything will be all right.
(b) _____________.
(c) _____________.
Answer:
(b) To teach children to respect others.
(c) To clean up their mess and not to hurt other creatures.

Speaking:

G. You are the President of CO GREEN, the Environment Club of your school. On the occasion of World Environment Day, you have been asked to address the school on the topic, ‘The Nature of Our Future Depends on the Future of Our Nature’
Answer:

Good morning, esteemed Chief Guest, the Head Master, teachers, dear friends and invitees. I am Shobha, Secretary of GO GREEN, the Environment Club of our school. Today, I stand before you to share my views on the topic “Stopping pollution is the best solution”. We humans have always deceived ourselves by thinking that someone else will save our planet.

Can you imagine… for the past 200 years we have been conquering nature, and now we are beating it to death by constantly polluting it. The Earth is not dying, it is being killed and the people who are killing it have names and addresses. All the human actions in this modem world directly impact the whole ecosystem. Industrial emissions, poor disposal of wastes, mining, deforestation, use of fossil fuels and agricultural activities, ultimately harm the nature which is the sole provider of pure oxygen, food and other requirements of man and animal.

Animals are becoming extinct. There are newer diseases evolving for which diagnosis has become impossible and so takes longer time to find a cure. Due to pollution, the number of various chemical elements is increasing in the atmosphere which ultimately causes irregular rainfall and global warming. Who is responsible? It is time we start thinking and doing our bit to be conservative and eco-friendly.

Let us walk or cycle to our work places/school. Let us not use plastic bags. Let us all keep our surroundings clean and plant at least one tree. As quoted by Lady Bird Johnson, “The Environment is Where we all meet; Where we all have a Mutual Interest; It is the one thing we all Share”. So, let’s be eco-friendly and go green. Thank you. Have a good day.

H. A class of super heroes:

‘CHANGE IS NEEDED, AND IT IS NEEDED NOW’. Let’s meet a class of superheroes who have taken simple sustainability projects upon themsleves to trackles the envirionmental problems in their campus.

Grammar:
Simple present tense

A. Choose the correct form of the present tense verb from the options given.

1. All children something new every day. (learn / learns / learned)
2. A good student always hard, (work / works / worked)
3. Engineers bridges, (build / builds / built)
4. My sister is an architect. She skyscrapers. (design / designs / designed)
5. The Himalayas India from the cold winds. (protect / protects / protected)
6. It always here in the afternoon, (drizzle / drizzles / drizzled)
7. My mother in a factory, (work / works / worked)
8. Chella English very well, but she doesn’t understand Hindi. (speak / speaks / spoke)
9. Cows us milk, (give / gives/ gave)
10. The trains to Chennai always on time, (run / runs / ran)

Answer:

1. learn
2. works
3. build
4. designs
5. protect
6. drizzles
7. works
8. speaks
9. give
10. run

Present Continuous Tense:

B. Make sentences in the present continuous tense using the verb given in brackets.

1. Who is that boy _________ on the table? (stand)
2. What are you _______? (do) I ________ (listen) to music.
3. My brother _________ (work) in London now.
4. I ________ (wait) for my mother.
5. It is better not to disturb her, she ___________ (work).

Answer:

1. standing
2. doing, am listening
3. is working
4. am waiting
5. is working

C. What are they doing? Use the verbs below and write sentences.
eat, cry, play, read, sing, watch.
Answer:

1. Anu is singing.
2. Peter is watching.
3. Sudhan is playing.
4. Velu is reading.
5. Kalai is crying.

D. Look at the picture again and answer the questions.

1. Is Tom reading? __________.
2. Is Velu eating? _____________.
3. Is Kalai dancing? _____________.
4. Is Peter watching TV? _____________.
5. Is Anu crying? _____________.

Answer:

1. No, Tom is eating
2. No, Velu is reading
3. No, Kalai is crying
4. No, Peter is watching through a telescope
5. No, Anu is singing

E. Write the -ing form of the verbs.

1. Come _____________.
2. Take _____________.
3. Fly _____________.
4. Swim _____________.
5. Study _____________.
6. Read _____________.

Answer:

1. Coming
2. Taking
3. Flying
4. Swimming
5. Studying
6. Reading

F. Write negative sentences.

1. He is learning to read.
2. I am having a bath.
3. I’m reading a fantastic book.
4. Raja is driving a new car.
5. I’m looking for my bag.

Answer:

1. No, he isn’t learning to read.
2. No, I am not having a bath.
3. No, I am not reading a fantastic book.
4. No, Raju isn’t driving a new car.
5. No, I am not looking for my bag.

G. Write questions for the answers.

1. _________________?
No, they aren’t singing.
Answer:
Are they singing?

2. _________________?
Yes, She is writing a new book.
Answer:
Is she writing a new book?

3. _________________?
Yes, It is working.
Answer:
Is it working?

4. _________________?
No, he isn’t doing the project.
Answer:
Is he doing the project?

5. _________________?
Yes, We are planning to go.
Answer:
Are we planning to go?

H. Fill in the blanks with verbs in the present continuous.

1. You (listen) to the music.
2. He (cry).
3. I (swim) in the pool.
4. Latha (wait) for her daughter.
5. she (watch) TV?
6. Who he (help)?
7. Her father (not / cook) dinner.
8. Akila Y, (not /sing) a song.
9. My brother (not / do) his homework.
10. your mother (work) today?
11. Amutha and Praba (play) tennis.
12. Amith and Ravi (not / swim) in the lake.

Answer:

1. are listening
2. is crying
3. am swimming
4. is waiting
5. is, watching
6. is, helping
7. is not cooking the
8. is not singing
9. is not doing
10. is, working
11. are playing
12. are not swimming

Present Perfect Tense:

I. Make sentences in the present perfect tense using the verbs in brackets.

1. She to _______________ anybody, (never apologized, has never apologized, have never apologized)
Answer:
has never apologized

2. My mother to _______________ London, (has been, being in, have been)
Answer:
has been

3. I _______________ all the plays of Shakespeare, (read, had read, have read)
Answer:
have read

4. Have you _______________ your lunch? (finish, finished, had finished)
Answer:
finished

5. _______________ he brought his bike? (Had, Has, Have)
Answer:
has

Present perfect with “ever and never”

J. Have you ever…?
Question:
Have you ever eaten a kiwi fruit?
Answer:
Yes, I have eaten a kiwi fruit.
Or No, I have never eaten a kiwi fruit.

Answer:

Present perfect continuous tense:

K. Make sentences in the present perfect continuous tense using the verbs in brackets.

1. How long _______________ ? (are you waiting, have you been waiting, have you waited)
Answer:
have you been waiting

2. She _______________ in the garden since morning, (is working, has been working, work)
Answer:
has been working

3. I _______________ this mobile for three years, (am using, has used, have been using)
Answer:
have been using

4. The children _______________ in the park, (has been playing, have been playing, had been playing)
Answer:
have been playing

5. The workers _______________ higher wages for a long time, (has been demanding, have been demanding, demand)
Answer:
have been demanding

Simple Past Tense:

L. Complete the story using the past tense of the verbs.

Answer:

1. Knew
2. could
3. was
4. said
5. had
6. found
7. told
8. hid
9. began
10. ran
11. was
12. thought
13. decided
14. fell
15. woke up
16. saw
17. was
18. was
19. ran
20. couldn’t
21. sat
22. got up
23. turned
24. won

M. Finish each clue by changing the verb within brackets to an irregular past-tense verb.Then complete the crossword puzzle.

Across:

1. The lake (freeze) ………. overnight.
2. Hema (buy) ………. a new bicycle.
3. Aravind (give) ………. me a slice of pizza.
4. We (drink) ……….. milk.
5. The dog (sleep) ………… on the sofa.
6. He (write) …………… a letter to his cousin in America.

Down:

1. I (find) ………… a coin on the ground.
2. Tony (teach) …………. his cat to use the litter box.
3. Selvi (blow) ……….. out the candle.

Answers:

Past Continuous Tense:

N. Make sentences in the past continuous tense using the verb in brackets.

1. The children _________ (wait) for the bus.
Answer:
were waiting

2. The girls __________ (leam) their lessons.
Answer:
were learning

3. I ____________ (play) in the rain all evening.
Answer:
was playing

4. Vijay ____________. (repair) his car.
Answer:
was repairing

5. Hari ____________ (work) hard to pass the entrance
Answer:
was working

Past Perfect Tense:

O. Complete the sentences using the past perfect tense.

1. Kalai didn’t complete his homework because ……………… .
2. By the time Sundar got up ………….. .
3. When we reached the park,…………. .
4. Saralah didn’t want to see her …………. .
5. Manohar was laughing because ………….. .

Answers:

1. he had slept
2. his brother had gone for work
3. our friend had already reached
4. brother, though her brother had hoped the same
5. he had smelt the laughing gas

Past Perfect Continuous Tense:

P. Circle the correct verb form in each of the following sentences.

1. Ezhil baked / had been baking a cake when they came.
2. Veeran cleaned/ had been cleaning the room since morning.
3. We worked / had been working in the city for ten years before we moved to the village.
4. The cat had been waiting/was waiting for the mice to come out of its hole.
5. Kannan had been looking/ have been looking for a job for a long time.

Answers:

1. had been baking
2. had been cleaning
3. had been working
4. had been waiting
5. had been looking

Simple Future Tense:

Q. Complete the sentences using the correct form of the verbs in brackets.

1. We hope you …………. (have) a great time in Ooty.
2. I think Manju ……………. (visit) her grandparents during the vacation.
3. Be careful, that mirror ……………. (fall) on the floor.
4. As soon as my father arrives, we …………….(go) to watch the film.
5. When your train arrives, I …………….. (wait) for you at the station.

Answers:

1. will have
2. will visit
3. will fall
4. will go
5. will wait

Future Continuous Tense:

R. Make sentences in the future continuous tense using the verb in brackets.

1. Ashwin …………. (complete) M.B.A.in another two years.
2. I …………….. (go) to Thanjavur by this time tomorrow.
3. Prabha ……………(receive) the best student award in six months’ time.
4. The plane ……………… (leave) at 3 o’clock.
5. He …………… (attend) the conference.

Answers:

1. will be completing
2. will be going
3. will be receiving
4. will be leaving
5. will be attending

S. What is Amala going to do? Given below is Amala’s schedule for next week. Read it and answer the questions using the future continuous tense.

Amala’s Schedule

Question 1.
What will Amala do on Sunday morning?
Answer:
She will be visiting her grand mother.

Question 2.
What is Amala planning to do on Saturday afternoon?
Answer:
She will be preparing sweets.

Question 3.
Where is Amala going on Wednesday morning?
Answer:
Amala will be going to the library to return the books.

Question 4.
Who is Amala meeting on Tuesday morning?
Answer:
Amala will be meeting her friends.

Question 5.
What will she buy on Monday afternoon?
Answer:
Amala will be buying groceries for the week.

Future Perfect Tense:

T. Match words from the different columns to make reasonable predictions. Then write them down in the space below. One has been done as an example.

Write the sentences:

1. In 50 years the ice cap will have melted.
2. …………………………………………………………
3. …………………………………………………………
4. …………………………………………………………
5. …………………………………………………………
6. …………………………………………………………
7. …………………………………………………………

Answers:

1.  In 50 years the ice cap will have melted.
2. In 10 years, the world’s population will have reached 10 billion
3. In 50 years, India will have become the world’s richest country.
4. In 10 years, women will have obtained equal rights with men.
5. In 10 years, Scientists will have discovered a complete cure for cancer.
6. In 50 years, India will have launched a space centre in moon.
7. In 50 years, U.K. will have become one country.

Water – The Elixir of Life About The Author:

Sir Chandrasekhara Venkata Raman (1888-1970) was an Indian physicist bom in Tiruchirappalli. In 1904, he stood first and won the gold medal in physics in the Bachelor of Arts examination of University of Madras. He carried out ground-breaking work in the field of light scattering, which earned him the 1930 Nobel Prize for Physics. He discovered changes in wavelength of some of the deflected light when light traverses a transparent material. This phenomenon, subsequently known as Raman Scattering, results from the Raman effect. To commemorate it, February 28th is celebrated as the National Science Day. In 1954, India honoured him with its highest civilian award, the Bharat Ratna.

Water – The Elixir of Life Summary:

Since ages man has sought in vain for an imaginery elixir of life – the divine Amrita which confers immortality. But in reality the true elixir is the water that is freely available. The author remembers once standing on the line that separates Libyan Desert from the valley of the Nile. He could observe a wonderful difference between the desert where there was no life to be seen. On the other side, due to the presence of river Nile the valley has become the most fertile and densely populated land on earth. Geologists explain that this fertility is totally attributed to the river Nile, which flows from the highlands and from remote Central Africa. The Egyptian civilization is sustained by the waters that flow from Nile river.

Water, which we take for granted in our everyday lives, has played a vital role in shaping the course of Earth’s history and continues to do so. Moreover, it adds so much to the beauty of the countryside, such as the streams or ponds and so on. The rainfed tanks are so common in South India and its sad to see its neglected maintenance, though it is a cheering site when they are full. South Indian agriculture is completely dependent on these tanks. Some of these tanks are large enough so that the sun rise or set can be seen over one of them. Water in a landscape may be compared to the eyes in a human face, which reflects the mood of the hour, being bright and gay during the day and turns dark and gloomy when the sky is overcast.

Water has the remarkable feature of carrying silt or finely divided soil in suspension which contributes to the characteristic colour of the water in rainfed tanks. Swiftly flowing water can carry fairly large and heavy particles. These particles are deposited on the areas they flow and settle. The variation in the different layers of soil can be seen in alluvial areas. Such lands are usually very fertile. The flow of water thus has played an important role in shaping the earth. On the contrary it has led to soil erosion which led to heavy loss in agriculture especially in many parts of India.

Soil erosion occurs in successive steps being unnoticed in,the early stages and later forming deep gullies and ravines which make all agriculture impossible. Heavy rains are the prime reason for soil erosion, others include; slope of the land, removal of the natural protective coat of vegetation, the existence of ruts. It calls for urgent prevention measures which includes; terracing of land, construction of bunds, practice of contour cultivation and the planting of appropriate types of vegetation.

In a country like India, such measures has to be taken as they completely depend on seasonal rainfall. Water forms the basis of all life. Every animal or plant requires water for all kinds of physiological activities. In India, afforestation has to be checked and planting of suitable trees in every possible area, and the development of what one can call civilized forests, as distinguished from wild and untamed jungle should be carried out. Such plantation would directly and indirectly prove a source of untold wealth to the country.

Water – The Elixir of Life Glossary:

You can Download Samacheer Kalvi 9th Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 9th Science Solutions Chapter 22 World of Microbes

Samacheer Kalvi 9th Science World of Microbes Textbook Exercises

I. Choose the correct answer.

World Of Microbes Class 9 Question 1.
Which of the following is transmitted through air?
(a) Tuberculosis
(b) Meningitis
(c) Typhoid
(d) Cholera
Answer:
(a) Tuberculosis

Chapter 22 World Of Microbes Question 2.
One of the means of indirect transmission of disease is ………………….
(a) sneezing
(b) coughing
(c) vectors
(d) droplet infection
Answer:
(c) vectors

9th Science World Of Microbes Question 3.
Diptheria affects the ………………………
(a) Lungs
(b) Throat
(c) Blood
(d) Liver
Answer:
(b) Throat

World Of Microbes Class 9 Pdf Question 4.
The primary organ infected during tuberculosis is …………………..
(a) bone marrow
(b) intestine
(c) spleen
(d) lungs
Answer:
(d) lungs

Science Solution Class 9 Samacheer Kalvi Question 5.
Microbes that generally enter the body through nose are likely to affect …………………….
(a) gut
(b) lungs
(c) liver
(d) lymph nodes
Answer:
(b) lungs

9 Samacheer Kalvi Science Question 6.
The organ affected by jaundice is …………………
(a) liver
(b) lungs
(c) kidney
(d) brain
Answer:
(a) liver

Samacheer Kalvi Guru 9th Science Question 7.
Poliomyelitis virus enters the body through ……………………..
(a) skin
(b) mouth and nose
(c) ears
(d) eye
Answer:
(b) mouth and nose

II. Fill in the blanks.

1. ………….. break down organic matter and animal waste into ammonia.
2. Typhoid fever is caused by ………………
3. H1N1 virus causes ……………..
4. ……………… is a vector of viral disease dengue.
5. ……………. vaccine gives considerable protection against tuberculosis.
6. Cholera is caused by …………… and malaria is caused by ……………..

Answer:

1. Nitrification
2. Salmonella typhi
3. Swine Flu
4. Aedes aegypti mosquito
5. BCG (Bacillus Calmette Guerin)
6. Vibrio cholerae, Plasmodium

III. Expand the following

1. ORS – Oral Rehydration Solution.
2. HIV – Human Immunodeficiency Virus
3. DPT – Dipetheria, Pertussis (whooping cough) and Tetanus.
4. WHO – World Health Organization.
5. BCG – Bacillus Calmette Guerin

IV. Pick out the odd one.

1. AIDS, Retrovirus, Lymphocytes, BCG,
2. Bacterial disease, Rabies, Cholera, Common cold and Influenza

Answer:

1. BCG
2. Rabies

V. State whether True or False. If false write the correct statement.

1. Rhizobium, associated with root nodules of leguminous plants fixes atmospheric nitrogen – True.
2. Non- infectious diseases remain confined to the person who develops the disease and do not spread to others – True.
3. The process of vaccination was developed by Jenner – True.
4. Hepatitis B is more dangerous than Hepatitis A – True.

VI. Match column A with column B.

	Column A	Column B
1.	Swine flu	(a) Human Papilloma virus
2.	Genital warts	(b) Human Immunodeficiency Virus
3.	AIDS	(c) Mycobacterium
4.	Tuberculosis	(d) Influeuza virus HIN 1

Answer:

1. (d) Influenza virus H1N1
2. (a) Human Papillomavirus
3. (b) Human Immunodeficiency Virus
4. (c) Mycobacterium

VII. Define the following.

Samacheer Kalvi 9th Science Question 1.
Pathogen
Answer:
A pathogen is a biological agent that causes disease to its host. e.g. bacteria, virus, etc.

Samacheer Kalvi Guru 9th Question 2.
Bacteriophages
Answer:
Bacteriophages are virus that infect bacterial cells, e.g. T4 bacteriophage.

Samacheer Kalvi Class 9 Science Solutions Question 3.
Vaccines
Answer:
Preparation of antigenic proteins of pathogens (weakened or killed) which on inoculation into a healthy person provides temporary/permanent immunity against a particular disease.

Samacheerkalvi.Guru 9th Science Question 4.
Prions
Answer:
Viral particles which contain only protein. They do not contain nucleic acid.

VIII. Answer the following in brief.

9th Samacheer Kalvi Science Question 1.
Distinguish between Virion and Viroid.
Answer:

Virion	Viroid
Virion is a simple virus particle and can grow and multiply in living cells only	Viroid is a free pathogenic RNA of virus.
They are the smallest infecting agents and can live on plants, animals, human beings and bacteria	They are found in plant cells and causes diseases only in plants.

9th Science Samacheer Kalvi Question 2.
Name the vector of the malarial parasite. Mention the species of malarial parasite which cause malignant and fatal malaria.
Answer:
The vector of the malarial parasite is the female Anopheles mosquito. Malaria caused by Plasmodium falciparum is malignant and fatal.

Samacheer Kalvi 9th Standard Science Question 3.
What is triple antigen? Mention the disease which can be prevented by using the antigen.
Answer:
DPT is called triple antigen vaccine as it is a combined vaccine for protection against Diptheria, Pertusis and Tetanus.

Samacheer Kalvi 9th Science Guide Question 4.
Name the chronic diseases associated with respiratory system.
Answer:
Chronic diseases associated with respiratory system are; Diptheria, Whooping Cough, Tuberculosis.

Samacheer Kalvi 9th Science Solutions Question 5.
Name the organism causing diarrhoel disease and give one precaution against it.
Answer:
Cholera (Acute diarrhoeal disease) is caused by Vibrio cholerae through contaminated food, water, oral route and through houseflies. It can be prevented by hygienic sanitary condition, intake of Oral Rehydration Solution (ORS).

Science 9th Samacheer Kalvi Question 6.
Name two common mosquitoes and the diseases they transmit.
Answer:
Anopheles mosquito and Aedes aegypti mosquito are common mosquitoes that transmit malaria, Chikungunya and Dengue.

IX. Answer in detail.

Science Class 9 Samacheer Kalvi Question 1.
Give an account of classification of bacteria based on the shape.
Answer:
Bacteria are microscopic, single celled prokaryotic organisms without nucleus and other cell organelles. Although majority of bacterial species exist as single celled forms, some appear to be filaments of loosely joined cells. The size varies from less than 1 to 10 µm in length and 0.2 to 1 µm micrometer in width.
Based on the shapes, bacteria are grouped as:

1. Spherical shaped bacteria called as cocci (or coccus for a single cell).
2. Rod-shaped bacteria called as bacilli (or bacillus for a single cell).
3. Spiral shaped bacteria called as spirilla (or spirillum for single cell)

Samacheer Kalvi.Guru 9th Question 2.
Describe the role of microbes in agriculture and industries.
Answer:
Microbes play an important role in agriculture as biocontrol agents and biofertilizers. Microbes play a vital role in the cycling of elements like carbon, nitrogen, oxygen, sulphur and phosphorus.

1. Microbes as biocontrol agents
   Microorganisms used for controlling harmful or pathogenic organisms and pests of plants are called as biocontrol agents (Biopesticides). Bacillus thuringiensis (Bt) is a species of bacteria that produces a protein called as ‘cry’ protein. This protein is toxic to the insect larva and kills them.
2. Microbes as biofertilizers
   Microorganisms which enrich the soil with nutrients are called as biofertilizers. Bacteria, cyanobacteria and fungi are the main sources of biofertilizers. This is done by microbes either in free living conditions or by having symbiotic relationship with the plants, e.g. Nitrosomonas, Nostoc (free living), symbiotic microbes like Rhizobium, Frankia, mycorrhizae.

Microbes in Industries
Microorganisms play an important role in the production of wide variety of valuable products for the welfare of human beings.

1. Production of fermented beverages:
   Beverages like wine are produced by fermentation of malted cereals and fruits by Saccharomyces cerevisiae.
2. Curing of coffee beans, tea leaves and tobacco leaves: Beans of coffee and cocoa, leaves of tea and tobacco are fermented by the bacteria Bacillus megaterium. This gives the special aroma.
3. Production of curd: Lactobacillus sp. converts milk to curd. .
4. Production of organic acids, enzymes and vitamins: Oxalic acid, acetic acid and citric acid are produced by fungus Aspergillus niger. Enzymes like lipases, invertase, proteases, and glucose oxidase are derived from microbes. Yeasts are rich source of vitamin-B complex.

Samacheer Kalvi 9th Science Solution Question 3.
Explain the various types of viruses with examples.
Answer:
Viruses are categorized as:
i. Plant virus: Virus that infect plants, e.g. Tobacco mosaic virus, Cauliflower mosaic virus, Potato virus.

ii. Animal virus: Virus that infect animals, e.g. Adenovirus, Retrovirus(HIV), Influenza virus, Poliovirus.

iii. Bacteriophages: Virus that infect bacterial cells, e.g. T4 bacteriophage.

Science Samacheer Kalvi 9th Question 4.
Suggest the immunization schedule for a newborn baby till 12 months of age. Why it is necessary to follow the schedule?
Answer:

Age	Vaccine	Dosage
New bom	BCG	1st dose
15 days	Oral Polio	1st dose
6th week	DPT and Polio	1st dose
10th week	DPT and Polio	1st dose
14th week	DPT and Polio	1st dose
9-12 months	Measles	1st dose

The immunization schedule must be followed so that the vaccines administered will protect the children in future from infectious and life-threatening diseases.

X. Assertion and Reason.

Mark the correct statement as.
(a) If both A and R are true and R is correct explanation of A.
(b) If both A and R are true but R is not the correct explanation of A.
(c) If A is true but R is false.
(d) If both A and R are false.
Samacheer Kalvi.Guru 9th Science Question 1.
Assertion: Chickenpox is a disease indicated by scars and marks in the body.
Reason: Chickenpox causes rashes on face and further spreads throughout the body.
Answer:
(a) If both A and R are true and R is a correct explanation of A.

9th Science Solutions Samacheer Kalvi Question 2.
Assertion: Dengue can be treated by intake of antibiotics.
Reason: Antibiotics blocks the multiplication of viruses.
Answer:
(d) If both A and R are false.

XI. Questions based on thinking skills.

Samacheer Kalvi Science 9th Question 1.
Suggest precautionary measures you can take in your school to reduce the incidence of infectious disease.
Answer:
Precautionary measures that can be taken are;

1. The sick student or staff can be asked to stay at home.
2. Clean and disinfect classroom materials and surfaces.
3. Adopt healthy practices such as safe handling of food and usage of toilets.
4. Provide awareness in daily announcements about preventing spread of germs and illnesses.

Question 2.
Tejas suffered from typhoid while, Sachin suffered from tuberculosis. Which disease could have caused more damage and why?
Answer:
Typhoid is a food and water-borne disease which affects the intestines. There are good drugs available for its treatment. If the patient reports to the doctor on time, it can be treated safely. Typhoid vaccine is also available that can protect against further attacks.

Whereas, Tuberculosis is a very tricky disease. Though it basically infects the lungs, it can spread to other parts of the body such as bones, intestines, etc. Another complication of TB is that, once infected, the Mycobacterium remains dormant in the body even after adequate treatment. Whenever the immunity of the patient goes down, TB can resurface again. Therefore, Tuberculosis causes more damage when compared to Typhoid.

Activity

Question 1.
Observe the mosquitoes that are active during the day time. Catch them using an insect net and observe their bodies and legs. What do you observe? Why are cases of Dengue reported in large numbers during the post-monsoon season?
Answer:
Mosquitoes of Aedes sp. are active during day time. The special features that can be observed in this mosquito is white bands on its legs and a silver-white pattern of scales on its body.

The female mosquitoes lay their eggs above the water line inside containers that hold water. These containers include tires, buckets, birdbaths, water storage jars, and flower pots which are filled with water due to rains. After the mosquitoes lay their eggs, the mosquito larvae hatch which are aquatic and feed on the microorganisms that is found in water necessary for its growth. Hence, Dengue is reported largely during the post-monsoon season.

Question 2.
Recently in 2018, Nipah virus was in the headlines of the daily newspaper. Collect the following information.

1. What is Nipah virus?
2. How it gets transmitted?
3. Mention the preventive measures taken by the government to check the disease.

Answer:

1. Nipah virus is a zoonotic virus.
2. It is transmitted from animals to humans when humans are exposed to secretions from the pigs, or unprotected contact with the tissue of a sick animal.
3. Nipah virus infection can be prevented by avoiding exposure to sick pigs and bats in endemic areas and not drinking raw date palm sap.
   Routine and thorough cleaning and disinfection of pig farms with appropriate detergents. The infected animals should be slaughtered – with close supervision of burial or incineration of carcasses – may be necessary to reduce the risk of transmission to people.

Samacheer Kalvi 9th Science World of Microbes Additional Questions

I. Choose the correct answer.

Question 1.
…………… can multiply only inside the living cells.
(a) Bacteria
(b) fungi
(c) worm
(d) Virus
Answer:
(d) Virus

Question 2.
Bacterial cell membranes covered by strong rigid cell wall are made up of ……………….
(a) peptidoglycan
(b) glycogen
(c) polysaccharides
(d) lipopolysaccharides
Answer:
(a) peptidoglycan

Question 3.
…………….. depend on other organisms or dead organic matter for food.
(a) Parasites
(b) Saprophytes
(c) Heterotrophic bacteria
(d) Symbionts
Answer:
(c) Heterotrophic bacteria

Question 4.
……………. are the site of protein synthesis
(a) Plasmid
(b) Mitochondria
(c) Cell
(d) Ribosome
Answer:
(d) Ribosome

Question 5.
Bacteria are ………………… single-celled prokaryotic organisms without a nucleus and other cell organelles.
(a) motile
(b) non-motile
(c) microscopic
(d) anaerobic
Answer:
(c) microscopic

Question 6.
……………… are either a single or cluster of flagella at both the cell poles.
(a) Lophotrichous
(b) Amphitrichous
(c) Monotrichous
(d) Peritrichous
Answer:
(b) Amphitrichous

Question 7.
The body of the fungus is called ………………………
(a) thallus
(b) hyphae
(c) mycelium
(d) filament
Answer:
(a) thallus

Question 8.
…………….. is a complex of several thin filaments called hyphae.
(a) Thallus
(b) Mycelium
(c) Cellulose
(d) Hemicellulose
Answer:
(b) Mycelium

Question 9.
Typhoid disease is common in children of age group ……………….. years
(a) 2-16
(b) 3-17
(c) 1-15
(d) 4-18
Answer:
(c) 1-15

Question 10.
Measles is caused by …………………..
(a) Varicella virus
(b) Rhinovirus
(c) Myxovirus parotitis
(d) Rubeola virus
Answer:
(d) Rubeola virus

II. Fill in the blanks.

1. ………………. rely on chemical compounds for their energy.
2. ……………… means proteinaceous infective particle.
3. ………………. are metabolic products of microorganisms, which in very low concentration are inhibitory or detrimental to other microbes.
4. Tuberculosis is caused by …………………
5. ……………….. affects the respiratory tract and causes mild fever, severe cough ending in whoop.
6. Cholera and typhoid are examples of …………….. disease.

Answer:

1. Chemotrophs
2. Prion
3. Antibiotics
4. Mycobacterium tuberculosis
5. Bordetella pertussis
6. waterborne

III. Expand the following

1. AIDS – Acquired Immuno Deficiency Syndrome
2. TT – Tetanus Toxoid.
3. DT – Diphtheria and Tetanus

IV. State whether true or false

1. Microorganisms that are killed by heat or chemicals are live vaccines – False
   Correct Statement: Microorganisms that are killed by heat or chemicals are killed vaccines.
2. DT is a dual or combined antigen – True
3. Poliovirus is also called enterovirus – True
4. Malaria is caused by bacteria – False
   Correct Statement: Malaria is vector-borne disease caused by Plasmodium sp. a protozoan.
5. Dengue is also known as break-bone fever – True

V. Match column A with column B.

Question 1.

S.No.	Column A		Column C
1.	Genital Herpes	a.	Neisseria gonorrhoea
2.	Gonorrhoea	b	Treponema pallidum
3.	Syphilis	c	Plasmodium sp.
4	Malaria	d	Herpes Simplex Virus

Answer:

S.No.	Column A		Column C
1.	Genital Herpes	a.	Herpes Simplex Virus
2.	Gonorrhoea	b	Neisseria gonorrhoea
3.	Syphilis	c	Treponema pallidum
4	Malaria	d	Plasmodium sp.

VI. Analyze the table and select the option given below that correctly fills the blank

Disease	Causative organism	Symptoms
Swine flu		Fever, cough, headache
Filaria	Nematode
Chikungunya	RNA virus
Cholera		vomiting, nausea, and dehydration

(Joint pain, body rashes, headache, Vibrio cholerae, Fever, Inilueuza virus H1N1)

Disease	Causative organism	Symptoms
Swine flu	Influenza virus H1N1	Fever, cough, headache
Filaria	Nematode	Fever
Chikungunya	RNA virus	Joint pain, body rashes, headache
Cholera	Vibrio cholerae	vomiting, nausea and dehydration

VII. Define the following.

Question 1.
Vector
Answer:
Pathogens of certain diseases reach the human body through intermediate agents which act as carrier or vector, (eg) Housefly, Mosquito.

Question 2.
Sporozoites
Answer:
Infective stage of Plasmodium (Malarial parasite) which infect man and transmitted from salivary gland of mosquito.

Question 3.
Peptidoglycan
Answer:
Peptidoglycan is a combination of sugars and amino acids that forms the cell wall of most bacteria.

VIII. Answer in brief.

Question 1.
Write a short note on Fungi.
Answer:
Fungi are larger than bacteria. They lack chlorophyll, hence depend on living or dead host for their nutritional needs. They are spherical in shape.

Question 2.
What is Creutzfeldt-Jakob disease?
Answer:
Creutzfeldt-Jakob disease is a neurodegenerative disease. As a result of this disease cerebral cortex is affected and it is characterised by progressive dementia, memory loss, behavioral changes, poor coordination and visual disturbances.

Question 3.
What are the disease categories based on microbes?
Answer:
Microbial Disease can be categorized based on:

1. The extent of occurrence (endemic, epidemic, pandemic or sporadic).
2. Whether infectious or non-infectious.
3. Types of pathogen – whether caused by bacterial, viral, fungal or protozoan infections.
4. Transmitting agent – whether airborne, waterborne or vector-borne.

Question 4.
Define the incubation period.
Answer:
The interval between infection and the first appearance of a disease is called incubation period. It may vary from few hours to several days.

Question 5.
What is Diptheria?
Answer:
Diptheria is caused by Corynebacterium diphtheriae. It generally affects the upper respiratory tract (nose and throat) and causes fever, sore throat and choking of air passage.

Question 6.
Write about Dengue.
Answer:
Dengue is known as break-bone fever. The name break bone fever was given because of the contortions caused due to the intense joint and muscle pain. Dengue haemorrhagic fever is a more severe form and can be life threatening or fatal.

Question 7.
What is immunization?
Answer:
Immunization is a process of developing resistance to infections by the administration of antigens or antibodies. It is an effective way of controlling the spread of infection by strengthening the host defenses.

IX. Answer in detail.

Question 1.
Explain vector borne diseases.
Answer:
Vector is an agent that acts as an intermediate carrier of the pathogen. Many insects and animals acts as vectors. Diseases transmitted by vectors are called vector borne diseases. These vectors can transfer infecting agents from an infected person to another healthy person. Some of the insect vector borne diseases are Malaria, Filaria, Chikungunya, Dengue, and the diseases which are transmitted through animals are Bird flu and Swine flu.

• Malaria continues to be one of the major health problems of developing countries. Malaria is caused by protozoan parasite Plasmodium. Four different species of Plasmodium namely, P. vivax, P. malariae, P. falciparum and P. ovale cause malaria. Malaria caused by Plasmodium falciparum is malignant and fatal.
• Chikungunya, which is caused by single stranded RNA vims, is transmitted in humans by the bite of infected Aedes aegypti mosquito during the day time. It causes severe and persistent joint pain, body rashes, headache and fever. Joint pains can last for a very long time.
• Dengue is known as break bone fever. The name break bone fever was given because of the contortions caused due to the intense joint and muscle pain. It is transmitted by Aedes aegypti mosquito that has previously bitten an infected person.

Question 2.
Write in detail about the diseases transmitted by animals.
Answer:
Diseases Transmitted by Animals:
Swine Flu is so termed because the virus that first caused the disease had originated from pigs. People with weak immune system are at high risk of contracting swine flu. It is an acute respiratory virus which is contagious and spreads through air. Swine flu is caused by virus that affects pigs and has started infecting humans as well. Influeuza virus FI1N1 has been identified as the cause of this disease.

Avian influenza is a contagious bird disease caused by a number of viruses. Birds that can carry and spread an avian influenza virus include poultry (like chickens, turkeys or ducks), wild birds and even pet birds.

Question 3.
Explain about the waterborne diseases.
Answer:
Microbes present in the contaminated water cause various infectious diseases. Some of the water borne diseases are cholera, typhoid, infectious hepatitis, poliomyelitis, diarrhoea, etc.

• Cholera is an epidemic disease and in the earlier days many people died due to this. It is caused by Vibrio cholerae mostly due to contaminated food and water. Acute diarrhoea with watery stool, vomiting, nausea and dehydration are the symptoms of this disease.
• Typhoid is common in children of age group 1-15 years. Nearly 2.5 million people suffer from typhoid disease every year. This is caused by the bacteria Salmonella typhi. Food and water contaminated by the faeces of infected person causes this disease. Infected persons show symptoms of fever, weakness and vomiting.
• Poliomyelitis is caused by polio virus and spreads from person to person. This virus gets into the blood and enters into the brain or spinal cord and affects the central nervous system. Muscles get paralysed and result in difficulty in walking.
• Hepatitis A or Infectious Hepatitis is caused by Hepatitis A virus (HAV). It is transmitted through contaminated water and food and through oral route. It causes inflammation of liver resulting in jaundice (Yellow fever).
• Acute diarrhea is commonly caused by infection of intestine. It is caused by Rotavirus and results in sudden onset of frequent stools, three or more in a day. It is transmitted through contaminated water and food. Increased fluidity and the volume of bowel movements result in excessive loss of fluid and electrolytes from the intestine.

Question 4.
Write short notes on antibiotics and vaccines.
Answer:
Antibiotics are metabolic products of microorganisms, which in very low concentration are inhibitory or detrimental to other microbes. In 1929, Alexander Fleming produced the first antibiotic pencillin. In human beings antibiotics are used to control infectious diseases like cholera, diptheria, pneumonia, typhoid, etc.

Class of Microorganisms	Type of Microorganism	Antibiotic produced
	Streptomyces griseus	Streptomycin
Bacteria	Streptomyces erythreus	Erythromycin
	Bacillus subtilis	Bacitracin
Fungi	Penicillium notatum	Penicillin
	Cephalosporium acremonium	Cephalosporin

Vaccines are prepared by killing or making the microbes inactive (attenuated). These inactive microbes are unable to cause the disease, but stimulate the body to produce antibodies against the antigen in the microbes.

Type of Vaccine	Name of the vaccine	Disease
Live attenuated	MMR	Measles, Mumps and Rubella
	BCG (Bacillus Calmette Guerin)	Tuberculosis
Inactivated (Killed antigen)	Inactivated polio virus (IPV)	Polio
Subunit vaccines (Purified antigens)	Hepatitis B vaccine	Hepatitis B
Toxoid (Inactivated antigen)	Tetanus toxoid (TT)	Tetanus
	Ditpheria toxoid	Diptheria

You can Download Earthquake Questions and Answers, Summary, Activity, Notes, Samacheer Kalvi 9th English Book Solutions Guide Pdf Supplementary Chapter 3 help you to revise complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 9th English Solutions Supplementary Chapter 3 Earthquake

Earthquake Warm Up:

When was the last time you helped someone? Write a few instances of your act of kindness.
Answer:
I had helped a blind person cross the road few months ago. I have helped my friends who had been absent in class due to illness to complete the notes. I had given money to people who asked they needed it to buy bus tickets.

Earthquake Textual Questions

A. Fill in the blanks with words from the text.

1. The name of the narrator is _________________ .
2. There were _________________ villages in the valley.
3. Brij went to Pauri to buy his _________________ .
4. The soldiers had set up a _________________
5. Bhuli had been buried under the debris for _________________  hours.

Answers:

1. Brij
2. six hundred and seventy
3. school books
4. makeshift hospital
5. hundred and sixteen

Additional Questions

Fill in the blanks with words from the text.

1. Are you waiting for the bus to …………………. ?
2. In ……………… minutes, Brij will have the fire going in his tea shop.
3. Brij is a young boy aged ……………………. .
4. Brij’s ancestral home was in ………………. village.
5. The earthquake occured in the month of ………………. four years ago.
6. The earthquake was felt as far as ……………. and ……………… .
7. ………………… days were gonne by before the help arrived.
8. Brij had a brother named ……………… and a baby sister named
9. A ………………. camp was set up by the soldiers.
10. ……………….. survived a hundred and sixteen hours under the debris after the earthquake.

Answers:

1. Badrinath
2. ten
3. seventeen
4. Molthi
5. October
6. Delhi, Lucknow
7. Four
8. Nilu, Bhuli
9. makeshift
10. Bhuli

B. Based on your understanding of the story, choose the right answers from the options.

Earthquake 9th Standard Supplementary Question 1.
Brij started a tea shop because he wanted to _________________ .
(a) start a company.
(b) serve the people.
(c) go on a pilgrimage.
(d) become a tour guide.
Answer:
(b) serve the people

Earthquake Lesson For 9th Class In English Question 2.
Molthi was completely devastated because of _________________ .
(a) a high intensity earthquake.
(b) thunder and hail storm!
(c) drought and famine.
(d) flash floods
Answer:
a high intensity earthquake.

Earthquake Supplementary Theme Question 3.
The brother searched everywhere and looked dejected because _________________ .
(a) he couldn’t find his house.
(b) he couldn’t locate his sister.
(c) he was hungry and didn’t eat for a few days.
(d) he lost his school books.
Answer:
he couldn’t locate his sister.

Earthquake 9th Standard Supplementary Summary Question 4.
The boy had great reverence and respect for Army officers as they _________________ .
(a) were brave and courageous,
(b) worked day and night
(c) saved his sister from death.
(d) all the above.
Answer:
saved his sister from death

Earthquake 9th Standard Supplementary Ppt Question 5.
Brij finally offered the traveller a _________________ .
(a) cup of milk
(b) cup of tea
(c) glass of water
(d) cup of coffee
Answer:
cup of tea

C. Identify the character or speaker of the following lines.

1. Greetings, traveller. You looked tired and cold.
2. Tomorrow, we will go back to Pauri.
3. Whom are you looking for?
4. My men have been on their feet for days.
5. May God be with you!

Answers:

1. Brij
2. Uncle
3. Army officer
4. Army officer
5. Brij

Additional Questions

1. Perhaps, you are a pilgrim or a visitor to the Valley of Flowers?
2. It was sheer chance that I was away that night.
3. We feared the worst.
4. When they began to clear the debris.
5. Come, you must perform the last rites before sunset.
6. They stood at the doorway and waved.
7. They have not found her.
8. But we must find her.
9. Boy, it is no use.
10. Whom are you looking for?
11. All I want is to give her a proper cremation.
12. I could see that he was bonetired.
13. My men have been on their feet for days
14. A terrible despair engulfed me.
15. They laboured doggedly.
16. He stood in the middle of a small hollow.
17. Then, they lifted the door.
18. She is alive!
19. My sister and I went on to live with my uncle.
20. And one day, I did find him.

Answers:
1. Brij, 2. Brij, 3. Brij and uncle, 4. Soldier, 5. Uncle, 6. Ma, grandma, Nilu and Bhuli, 7. Soldiers, 8. Brij, 9. Uncle, 10. Army officer, 11. Brij, 12. Brij, 13. Army officer, 14. Brij, 15. The soldiers, 16. The soldiers, 17. The soldier, 18. The soldiers, 19. Brij and Bhuli, 20. Brij, the army officer.

D. Answer the following questions in a paragraph of about 80 to 100 words.

Earthquake Supplementary Summary In English Question 1.
Explain the efforts taken by the Army Officer to save the baby.
Answer:
The officer came with three soldiers armed with spades and crowbars. Without a word, the men began to remove the debris. They laboured doggedly. When it was completely dark, some one brought a few lit petromax lamps. Two hours r later, a soldier called out, “ Sir”. He stood in the middle of a small hollow. The wall had caved in at that spot. Brij recognised a part of the door. Beneath it, was a little foot. Feverishly, the soldiers began to clear the hollow. Then they lifted the door. It was a miracle. They rescued the baby alive after a hundred and sixteen hours. A ragged cheer went up and she was carried to a make-shift hospital.

Earthquake Chapter For Class 9 English Question 2.
Brij has become a symbol of love and humanity. Explain.
Answer:
Brij was happy to have Bhuli after a tough rescue operation. The officer who helped him was never seen again. He wanted to thank that Army officer. He hoped that one day he would run into him again. So Bhuj offered special tea with love and care to all tired travellers, army officers and soon every person who went that way. He felt a surge of sheer joy. He considered it as a humble service. Brij has become an epitome of love and a symbol of humanity.

E. Answer the following questions based on the reading of the story. Do not forget to go back to the passage whenever necessary to find and confirm the answers.

Answer:

Additional Questions:

Earthquake Supplementary Summary Question 1.
Where did Brij work first?
Answer:
Brij worked in a roadside shop outside Panipat.

9th English Earthquake Summary Question 2.
Where was the Molthi village loacted?
Answer:
Molthi village was located near a valley that consisted of the epicentre.

Earthquake Supplementary Reader Question 3.
Where did Brij go on the night the earthquake occured?
Answer:
Brij had gone to Pauri to buy his school books.

Earthquake Lesson Summary Question 4.
When Brij was going to perform the last rites, who was missing?
Answer:
When Brij was going to perform the last rites his two-year old sister Bhuli was missing.

9th English Earthquake Question 5.
Did Brij find the officer who had saved his sister?
Answer:
No, Brij did not find the officer who saved his sister.

Earthquake 9th Supplementary Lesson Plan Question 6.
Who built the house Brij was living in before the earthquake?
Answer:
Brij was living in the house his great grandfather had built in Molthi.

Earthquake Summary:

Bnj is a young boy having his own tea shop by the roadside. He meets a traveler and invites him to his shop and starts telling the incidences that took place in his life. He used to stay in Molthi village with his grandmother, mother, brother and a baby sister. Their village was not far from the epicenter and hence used to experience frequent tremors. One day he happened to go to the village Pauri, to buy his school books.

As it had become late he stayed in his uncle’s house. That night they were experiencing frequent tremors because of which they could not sleep that night. This resulted in numerous landslides and it took four days for the army officers to arrive at . Molthi. Brij and his uncle were the first to arrive after the army officers. They weren’t prepared for what they had seen that day, every single house had been brought down to the ground.

The soldiers began to clear the debris and not until that evening did they find the bodies. His uncle asked him to perform the last rite, that’s when he saw that his baby sister was missing. Hoping to find her, he ran to the place where his house stood once and started clearing the debris and searching for his sister.

One officer, seeing this said that there is no point in searching anymore since they have done their maximum and that there is no hope to find anyone alive. Brij did not pay heed to him and continued his search, but the officer left. He came after ten minutes along with three more officers and started to clear the debris. On clearing the debris, after two hours they realized to be standing in the middle of a hollow and Brij could instantly see the foot of his sister.

The soldier exclaimed, saying the little girl-was alive. He immediately wrapped her and carried her to the nearby makeshift hospital. The next day, when he had gone to thank the army officer, he had already left. He was very disappointed at this and whenever he used to see an army officer or a tired traveler, he remembered the officer who saved his sister’s life and would serve him tea for free as this made him very happy. In the same way, he offers this traveler also with a cup of tea and when his bus arrives wishes him a safe journey.

Earthquake Glossary:

You can Download Samacheer Kalvi 9th Social Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 9th Social Science Geography Solutions Chapter 2 Lithosphere – II Exogenetic Processes

Lithosphere – II Exogenetic Processes Textual Exercise

I. Choose the correct answer.

Lithosphere 2 Exogenetic Processes Question 1.
The disintegration or decomposition of rocks is generally called as …………………
(a) weathering
(b) erosion
(c) transportation
(d) deposition
Answer:
(a) weathering

Lithosphere 2 Exogenic Processes Question 2.
The process of the levelling up of land by means of natural agents.
(a) aggradation
(b) degradation
(c) gradation
(d) none
Answer:
(c) gradation

Lithosphere 2 Exogenic Processes Book Back Answers Question 3.
……………. is seen in the lower course of the river.
(a) Rapids
(b) Alluvial fan
(c) Delta
(d) Gorges
Answer:
(c) Delta

9th Social Guide Question 4.
Karst topography is formed due to the action of ………………
(a) Glacier
(b) Wind
(c) Sea waves
(d) Ground water
Answer:
(d) Ground water

9th Std Social Science Guide Pdf English Medium Question 5.
Which one of the following is not a depositional feature of a glacier?
(a) cirque
(b) Moraines
(c) Drurrtlins
(d) Eskers
Answer:
(a) cirque

Chapter 2 Lithosphere – Ii Exogenetic Processes Question 6.
Deposits of fine silt blown by wind is called as …………….
(a) Loess
(b) Barchans
(c) Hamada
(d) Ripples
Answer:
(a) Loess

Samacheer Kalvi 9th Social Book Answers Question 7.
Stacks are formed by …………….
(a) Wave erosion
(b) River erosion
(c) Glacial erosion
(d) Wind deposion
Answer:
(a) Wave erosion

Social Guide For Class 9 Question 8.
……………… erosion is responsible for the formation of cirque.
(a) wind
(b) glacial
(c) river
(d) underground water
Answer:
(b) glacial

9th Std Social Science Guide Pdf Question 9.
Which one of the following is a second order land form?
(a) Asia
(b) Deccan Plateau
(c) Kulu valley
(d) Marina Beach
Answer:
(b) Deccan Plateau

II. Match the following.

Answer:
1. (c)
2. (d)
3. (a)
4. (e)
5. (b)

III. Answer in brief.

9th Social Science Guide Pdf Download Question 1.
Define weathering.
Answer:
Weathering is the disintegration and decomposition of materials of the earth’s crust by their exposure to the atmosphere.

Samacheer Kalvi 9th Social Book Solutions Question 2.
What do you mean by biological weathering?
Answer:
Biological weathering occurs due to the penetration and expansion of plant roofs, earth worms, burrowing animals (rabbits, rats) and same human activities.

9th Standard Social Book Question 3.
Mention the three courses of a river with any two land forms associated to each course.
Answer:
The course of a river is divided into

1. The Upper course – V shaped valleys, gorges
2. The middle course – Alluvial fans, flood plains
3. The lower course – Delta and Estuary.

Samacheer Kalvi 9th Social Book Question 4.
What are Ox-bow lakes?
Answer:

1. Meanders in due course of time become almost a complete circle with narrow necks.
2. This in turn gets abandoned and forms a lake. This is called an Ox-bow lake.

Class 9 Social Science Guide Question 5.
How does a cave differ from a sea arch?
Answer:

Sea cave	Sea Arch
Prolonged wave attack on the base of a cliff erodes rock materials which result in the formation of caves.	When two caves approach one another from either side of a headland and Unite, they form an arch, e.g., Neil Island, Andaman & Nicobar.

Samcheer Kalvi.Guru 9th Social Question 6.
List out any four karst topographical areas found in India.
Answer:

1. Guptadham caves – Western Bihar
2. Pandav caves Pachmuri – Madhya Pradesh
3. Kutumsar – Bastar district in Chattisgarh
4. Borra caves of Visakhapatnam – Andhra Pradesh

9th Geography Guide Question 7.
What do you mean by a hanging valley?
Answer:
These are valleys eroded by tributary glacier and that hangs over the main valley.

9th Standard Social Science Guide Pdf Question 8.
Define: (a) Moraine (b) Drumlin (c) Esker.
Answer:
(a) Moraine:

• Landforms formed by the glacial deposits of valley (or) continental glaciers are termed as moraines.
• They are of various shapes and sizes, like ground, terminal and lateral moraines, etc.

(b) Drumlin: Drumlins are deposits of glacial moraines that resemble giant inverted teaspoons (or) half cut eggs.
(c) Esker: Long narrow ridges composed of boulders gravel and sand deposited by streams of melting water which run parallel to a glacier are called eskers.

9th Std Social Science Question 9.
Mention the various features formed by wind erosion.
Answer:

• The erosional landforms of wind: Mushroom rocks, Inselbergs and Yardangs
• The Depositional Landforms of wind: Sand dunes, Barchans and loess.

Exogenetic Processes Part 2 9th Std Question 10.
What are wave cuLplatforms?
Answer:
Flat surface found at the foot of the sea cliffs are called as wave cut platforms, wave cut platform is also referred as beach, shelf, terrace and plain.

IV. Distinguish between:

Question 1.
Physical and chemical weathering
Answer:

S.No.	Physical weathering	Chemical weathering
(i)	It is the breakdown of rocks without changing their chemical composition through the action of physical forces.	Disintegration and. decomposition of rocks due to chemical reactions is called Chemical weathering.
(ii)	Cracks are formed and disintegration occurs eventually.	Chemical weathering takes place through the processes of oxidation, carbonation solution and hydration.
(iii)	Exfoliation, block disintegration, granular disintegration, etc., are the different types of weathering.	The agents of Chemical weathering are oxygen, CO2 and Hydrogen.

Question 2.
Delta and Estuary
Answer:

S.No.	Delta	Estuary
(i)	A triangular shaped low lying area formed by the river at its mouth is called Delta.	Deltas have fine deposits of sediments enriched with minerals.
(ii)	Estuary is formed where the rivers meet the sea.	Deposition of silt by the river is not possible in the estuaries like Delta as if the waves keep on eroding the deposits e.g. River Narmada, River Tapti.

Question 3.
Stalactite and stalagmite
Answer:

Stalactite	Stalagmite
When the water containing dissolved calcite gradually drips from the ceiling of the caves, water evaporates and the remaining calcite hangs from the ceiling and thus Stalactites are formed.	When the calcite deposits rises upward like a pillar Stalagmites are formed.

Question 4.
Longitudinal and Transverse sand dunes
Answer:

Longitudinal	Transverse sand dunes.
Longitudinal dunes are long narrow ridges of sand, which extend in a direction parallel to the prevailing winds. These dunes are called Seifs in Sahara.	Transverse dunes are asymmetrical in shape. They are formed by alternate slow and fast winds that blow from the same direction.

Question 5.
Inselbergs and yardangs
Answer:

S.No.	Inselbergs	Yardangs
(i)	Certain hard rocks like igneous rocks are more resistant to wind action.	In arid regions, certain rocks .have hard and soft layers arranged vertically.
(ii)	Isolated residual hills rising abruptly from their surroundings are termed as inselbergs. e.g., Uluru (or) Ayers Rock – Australia.	When winds blow over these rocks, the soft layers get eroded leaving irregular crests. These are called Yardangs.

Question 6.
Spit and bar
Answer:

Spit	Bar
A spit is a ridge (or) embankment of sediment, attached to the land on one end and terminating in open water on the other end. Spits are common at the mouth of estuaries, e.g., Kakinada Spit.	A bar is an elongated deposit of sand, shingle (or) mud found in the sea almost parallel to the shoreline.

V. Give Reasons.

Question 1.
Chemical weathering is predominant in hot and humid zones.
Answer:

1. Chemical is predominant in hot and humid zones because the warm temperature and rainfall increases the chemical weathering.
2. It encourages the decomposition of plant matter to produce chemicals such as humic acids and CO₂
   These chemicals increases the rate of weathering.

Question 2.
Slit deposits are less at estuaries than deltas.
Answer:
Silt deposits are less at estuaries than deltas because the waves keep on eroding the deposits e.g., River Narmada & Tapti.

Question 3.
The snow line is at the sea level in Polar regions.
Answer:
The snow line is at the sea level in Polar regions because higher the latitude lower the snow line from sea level. –

Question 4.
Wind can possibly erode the rocks from aO sides.
Answer:

• Wind erosion can occur in any area where the Soil (or) Sand is not compacted (or) if it is finely granulated in nature.
• Wind can loosen the materials and send it in all directions.

Question 5.
In limestone regions, surface drainage is rarely found.
Answer:

• The rain water mixes with CO₂ and enters into limestone region it dissolves and destroys much of the lime stone.
• Subterranean drainage may limit surface water with few to no rivers.
• The ability of water to penetrate the rock lowers. Joints and bedding planes make the rock permeable.
  So surface drainage is rarely found.

VI. Answer in Paragraph.

Question 1.
Write a note on weathering classify and explain.
Answer:
Weathering is the disintegration and decomposition of materials of the earth’s crust by their
exposure to atmosphere. There are three types of weathering,
(a) Physical weathering, (b) Chemical weathering (c) Biological weathering
Physical weathering: It is the breakdown of rocks without changing their chemical composition, through the action of physical forces. The constant freezing and thawing of rocks during the night and day leads to the expansion and contraction of rocks. Cracks are formed and disintegration occurs eventually. Exfoliation, block disintegration, granular disintegration etc., are the different types of weathering.

Chemical weathering: Disintegration and decomposition of rocks due to chemical reactions is called Chemical Weathering. This is predominantly high in the hot and humid regions such as the equatorial, tropical and sub tropical zones. Chemical weathering takes place through the processes of oxidation, carbonation, solution, and hydfation. The agents of Chemical weathering are Oxygen, Carbon-dioxide and Hydrogen.

Biological weathering: Biological weathering occurs due to the penetration and expansion of plant roots, earthworms, burrowing animals (rabbits, rats) and some human activities.

Question 2.
Explain the erosional landformsformed by underground water.
Answer:
Most erosion takes plaice due to the process of solution. When rain water mixes with carbon- di-oxide and enters into a limestone region, it dissolves and destroys much of the limestone. As a result, landforms suph as Terra rossa, Lappies, sinkholes, swallow holes, dolines, uvalas, poljes, caves and caverns are formed.

Terra Rossa (Italian term for Red soil): Deposition of red clay soil on the surface of the Earth is due to the dissolution of limestone content in rocks. The redness of the soil is due to the presence of iron oxide.

Lappies: When the joints of limestone rocks are corrugated by groundwater, long furrows are formed and these are called LAPPIES.

Sinkhole: A funnel shaped depressions formed due to dissolution of limestone rock is called sinkholes. Their average depth ranges between three and nine meters.

Caves and Caverns: Caves and caverns are subterranean features of karst topography. Caves are hollows that are formed by the dissolution of limestone rocks when carbon di oxide in air turns into carbonic acid after its reaction with water. They vary in size and shape. Caverns are the caves with irregular floors, e.g., Guptadham caves in Western Bihar.
All types of deposits in the caves and caverns are collectively called speleothems which includes travertines, tufa, dripstones.
Swallow Holes, Uvalas, Dolines, Poljis are other erossional Features of karst regions predominant in other parts of the world.

Question 3.
What is a glacier? Explain its types.
Answer:
A Glacier is a large mass of ice that moves slowly over the land, from its place of accumulation. It is also known as ‘River of ice’. The place of accumulation is called snowfield. The height above which there is a permanent snow cover in the higher altitude or latitude is called snowline. Higher the latitude, lower the snowline from sea level.

The gradual transformation of snow into granular ice is called ‘firn’ or ‘ neve’ and finally it becomes solid glacial ice.
Movement of Glacier: The large mass of ice creates pressure at its bottom and generates heat. Due to this, the glacier melts a little and starts to move The rate of movement of a glacier varies from a few centimetres to several hundred meters a day. The movement of glaciers depends on slope, volume of the glacier, thickness, roughness at the bottom (friction) etc., and Temperature. Like the rivers, glaciers also carry out erosion, transportation and deposition.

Types of Glacier: Glaciers are broadly divided into two types based on the place of occurrence, such as Continental glacier and valley glacier.

Question 4.
Describe the depositional work of winds.
Deposition occurs when the speed of wind is reduced by the presence of obstacles like bushes, forests and rock structures. The sediments carried by wind get deposited on both the wind ward and leeward sides of these obstacles.
Some of the depositional landforms are sand dunes, barchans and loess.

Sand Dune: In deserts, during sandstorms, wind carries loads of sand. When the speed of wind decreases, huge amount of sand gets deposited. These mounds or hills of sand are called sand dunes. There are different types of sand dunes.

Barchan: Barchans are isolated, crescent shaped sand dunes. They have gentle slopes on the windward side and steep slopes on the leeward side.
Transverse Dunes: Transverse dunes are asymmetrical in shape. They are formed by alternate slow and fast winds that blow from the same direction.

Longitudinal Dunes: Longitudinal dunes are long narrow ridges of sand, which extend in a direction parallel to the prevailing winds. These dunes are called Seifs in Sahara.

Loess: The term loess refers to the deposits of fine silt and porous sand over a vast region. Extensive loess deposits are found in Northern and Western China, the Pampas of Argentina, in Ukraine and in the Mississippi Valley of the United States.

Question 5.
Give a detailed account on the three orders of land forms.
Answer:
Major land forms:
(i) First order landforms : Continents & Oceans
(ii) Second order landforms : Mountains, Plateaus, and plains minor land forests
(iii) Third order landforms : Deltas, Fjords coasts, Sand dimes, Beaches, Valleys, Cirques, Mushroom rocks, Limestone rocks.

First order land forms:

1. Continents: (i) It is a very large area of land.
   (ii) One of the seven large land masses on the earth’s surface, surrounded by sea.
   Asia, Africa, Europe, North America, South America, Australia and Antarctica.
2. Oceans: A very large expanse of sea, Atlantic ocean, Arctic ocean, Pacific ocean, Indian ocean and Antarctic ocean.

Second order land forms: Mountains, Plateaus and Plains.

1. Mountains: A large natural elevation of the earth’s surface, rising abruptly from the surrounding level, e.g., Himalayas.
2. Plateaus: An area of fairly level high ground, e.g., Tibetean plateau.
3. Plains: A large area of flat land, e.g., Coastal plains.

Third order land forms: Deltas, Fjords, Sand dunes, Beaches, Valleys, Cirques, Mushroom rocks, Limestone rocks.

1. Deltas: A triangular shaped low lying area formed by the river at its mouth is called Delta. Fjords: These are glacial valleys that are partly submerged in the sea.
2. Sand Dunes: In deserts, huge amount of sand gets deposited. These mounds (or) hills of sand are called sand dunes.
3. Beaches: Sand and gravel are moved and deposited by waves along the shore to form Beaches. Valleys: A low area of land between hills (or) mountains typically with a river (or) stream flowing through it.
4. Cirques: The glacier erodes the steep side walls of the mountain and farms bowl shaped arm chair. It is termed as cirque.
5. Mushroom rocks: By the constant wearing down action of wind the bottom of the rock gets eroded away to form a mushroom like structure. ,
   This is called Mushroom rock (or) Pedestal rock.
6. Limestone rocks: The underground water creates distinct landforms in limestone regions called Karst Topography. It consists of calcite, argonite.

VII. Consider the given statements and choose the right option given below.

Question (i).
1. ‘I’ shaped valley is an erosional feature of the river.
2. ‘U’ shaped valley is an erosional feature of the glacier.
3. ‘V’ shaped valley is an erosional feature of the glacier.
(a) (i), (ii) and (iii) are right
(b) (i) and (ii) are right
(c) (i) and (iii) are right
(d) only (i) is right
Answer:
(d) only (ii) is right

Question (ii).
Statement I: Running water is an important agent of gradation.
Statement II: The work of the river depends on the slope of land on which-it flows.
(a) Statement I is false II is true
(b) Statement I and II are false
(c) Statement I is true II is false
(d) Statement I and II are true
Answer:
(a) Statement I is false II is true

Question (iii).
Statement: Limestone regions have less underground water.
Reason : Water does not percolate through limestone.
(a) The statement is right reason is wrong.
(b) The statement is wrong Reason is right.
(c) The statement and reason are wrong.
(d) The statement and reason are right.
Answer:
(d) The statement and reason are right.

VIII. HOTS

Question 1.
Is wind the only gradational agent in the desert?
Answer:
Yes, wind is the only gradational agent in the desert.
e.g., Erosional activity: Yardung
Depositional activity: Sand Dimes.

Question 2.
Underground water is more common in limestone areas than surface run off. Why?
Answer:
The chief constituent of limestone is calcium carbonate which is soluble in pure water and easily soluble in carbonate water.

Question 3.
The river channels in the lower course are wider than the upper course.
Answer:
The reasons are,

1. The river splits into a number of channels called distributaries.
2. The river brings down loads of debris from its upper and middle.
3. The river deposits and develop typical landforms like Delta and Estuary.

In-text HOTs Questions

Question 1.
Is weathering a pre-requisite in the formation of soil?
Answer:

1. Yes, weathering a pre-requisite in the formation of soil.
2. The rock materials in due course of time are weathered further to form soil.
3. Soil is a mixture of disintegrated rock material.

Question 2.
Snowline of Alps’is 2700 metre where as the snowline of Greenland is just 600 mts. Find out the reason.
Answer:
On tropical mountains the snowline may be as high as 500 mts, but when traced poleward it descends to 2700 mts in the European Alps to 600 meters in Greenland and just to se-a level near the poles. –

IX. Map Skill.

Question 1.
On the given outline map of the world, mark the following.
1. Any two deltas
2. A Karst region
3. Any two hot and cold deserts
Answer:
1. Any two deltas – Euphrates & Tigris Delta and Amazon river Delta

2. A Karst region – China

3. Any two hot and cold desets

X. Give geographical terms for the following:

Question 1.
(a) Chemical alternation of carbonate rocks on lime stone region.
(b) Flat surfaces near cliffs.
(c) Erosion + Transportation + Deposition =
(d) The bottom line of a snow field.
Answers:
(a) Carbonation
(b) Plateau
(c) Gradation
(d) The snowline

Lithosphere – I Endogenetic Processes Additional Questions

I. Choose the correct answer.

Question 1.
The process of dissolution of rock substances in water is …………….
(a) oxidation
(b) solution
(c) gradation
(d) hydration
Answer:
(b) solution

Question 2.
This generally originate from mountains.
(a) lake
(b) sea
(c) river
(d) ocean
Answer:
(c) river

Question 3.
The cylindrical holes drilled vertically in the river bed are …………….
(a) Pot holes
(b) canyons
(c) rapid
(d) Gorge
Answer:
(a) Pot holes

Question 4.
The largest Delta in the world is …………….
(a) The Nile River Delta
(b) The Ganga – Brahmaputra Delta
(c) The Yellow river Delta
(d) The Indus Delta
Answer:
(b) The Ganga – Brahmaputra Delta

Question 5.
The redness of the red clay soil is due to. the presence of ……………
(a) iron oxide
(b) carbon
(c) copper
(d) magnesium
Answer:
(a) iron oxide

Question 6.
The most powerful agents of gradation are ……………
(a) Rivers
(b) Glaciers
(c) Sea waves
(d) Streams
Answer:
(c) Sea waves

II. Match the following.

Answer:
1. (e)
2. (a)
3. (d)
4. (b)
5. (a)

III. Answer in brief.

Question 1.
Define Granular Disintegration.
Answer:
Granular disintegration takes place in crystalline rocks where the grains of the rocks become loose and fall out. This is due to the action of temperature & frost.

Question 2.
Mention the land features carved by a river in its upper course.
Answer:
‘V’ shaped valleys, Gorges, Canyons, rapids, pot holes, spurs and waterfalls.

Question 3.
What are “Pot Holes”?
Answer:
Due to the river action, cylindrical holes are drilled vertically in the river bed with varying depth and diametre.

Question 4.
State the other erosional features of Karst regions in other parts of the world.
Answer:
Swallow Holes, Uvalas, Dolines, Poljis are the other erosional features.

Question 5.
What are Transverse Dunes?
Answer:

1. Transverse Dunes are asymmetrical in shape.
2. They are formed by alternate slow and fast winds that blow from the same direction.

Question 6.
What are wave cut Platforms?
Answer:
Flat surface found at the foot of the sea cliffs are called as wave Cut platform. It is also referred as Beach, shelf, terrace and plain.

IV. Distinguish between.

Question 1.
Oxidation and Carbonation.
Answer:

S.No.	Oxidation	Carbonation
(i)	Oxygen in the atmosphere reacts with the Iron found in rocks thus leading to the formation of Iron oxide. This process is known as oxidation.	Carbonation is the mixing of water with the atmospheric CO2 forming carbonic acid.
(ii)	Oxidation weakens the rocks.	It is important in the formation of caves, in limestone region.

Question 2.
Alluvial Plain and Flood Plain.
Answer:

S.No.	Alluvial Plain	Flood Plain
(i)	A fan shaped deposition made by the river at the foothills is called an alluvial plain.	Fine sediments are deposited on river banks when a river floods and is called flood plain.
(ii)	These deposits are rich and fertile useful for cultivation.	These sediments make the region rich and fertile.

Question 3.
Arete and Matterhorn.
Answer:

Arete	Matterhorn
Aretes are narrow ridges formed when two cirque walls joined together back to back and forms narrow knife like ridges.	The pyramidal peaks formed when three (or) more cirques meet together are referred as matterhoms.

Question 4.
Sea Cave and Sea Arch.
Answer:

Sea Cave	Arch
Prolonged wave attack on the base of a cliff erodes rock materials which result in the formation of caves.	When two caves approach one another from either side of a headland and Unite, they form an arch, e.g., Neil Island, Andaman Nicobar.

V. Give reasons.

Question 1.
Why do the Biological weathering occur?
Answer:
Biological weathering occurs due to the penetration and expansion of plant roots, earth worms, burrowing animals (rabbits and rats) and some human activities.

Question 2.
Why is Karst Topography formed?
Answer:
Karst Topography is formed due to the dissolution of soluble rocks such as limestone, dolomite and Gypsum.

Question 3.
Why do the Pedestal rock look like mushroom?
Answer:
By the constant wearing down action of wind, the bottom gets eroded away to form a mushroom like structure. So the Pedestal rock looks like mushroom.

VI. Answer in a Paragraph.

Question 1.
Explain the origin of the river and its course.
Answer:
Rivers generally originate from mountains and end in a sea or lake. The whole path that a river flows through is called its course. The course of a river is divided into:
(i) The upper course
(ii) The middle course and
(iii) The lower course
(i) The Upper Course: Erosion is the most dominant action of river in the upper course. In this course, a river usually tumbles down the steep mountain slopes. The steep gradient increases the velocity and the river channel performs erosion with great force to widen and deepen its valley. The land features carved by a river in its upper course are V-shaped valleys, gorges, canyons, rapids, pot holes, spurs, and waterfalls.

(ii) The Middle Course: The river enters the plain in its middle course. The volume of water increases with the confluence of many tributaries and thus increases the load of the river. Thus, the predominant action of a river is transportation. The deposition also occurs due to the sudden decrease in velocity. The river in the middle course develops some typical landforms like alluvial fans, flood plains, meanders, ox-bow lakes etc.,

(iii) The Lower course: The river, moving downstream across a broad, level plain is loaded with debris, brought down from its upper and middle courses. Large deposits of sediments are found at the level bed and the river, splits into a number of channels called distributaries. The main work of the river here is deposition and it develops typical landforms like delta and estuary.

Question 2.
Describe the Erosional landforms of Sea.
Answer:
Some of the erosional landforms of sea waves are sea cliff, sea cave, arch, stack, beach, bar and spit and wave cut platform.

• Sea Cave: Prolonged wave attack on the base of a cliff erodes rock materials, which result in the formation of caves.
• Sea Arch: When two caves approach one another from either side of a headland and unite, they form an arch, e.g., Neil Island, Andaman and Nicobar.
• Sea Stack: Further erosion by waves ultimately leads to the total collapse of the arch. The seaward portion of the headland will remain as a pillar of rock known as stack. Eg the Old man of Hoy in Scotland.
• Sea Cliffs: Sea cliffs are steep rock faces formed when sea waves dash against them. The rocks get eroded to form steep vertical walls.
• Wave Cut Platforms: Flat surface found at the foot of sea cliffs are called as wave cut platforms. Wave cut platform is also referred as beach, shelf, terrace and plain.

VII. Consider the given statements and choose the right option given below.

Question 1.
(i) The nature and magnitude of weathering differs from place to place and region to region.
(ii) Granular disintegration takes place due to the action of volcanoes.
(iii) Weathering is a pre-requisite in the formation of soil.
Which of the above statement is/are the right statement.
(a) (i), (ii) and (iii) are right
(b) (i) & (ii) are right
(c) (i) & (iii) are right
(d) only (i) is right.
Answer:
(c) is right

Question 2.
(i) Small streams that join the main river is tributary.
(ii) River Gangas is a tributary.
Which of the above statement is/are the right statement.
(a) The statement is right reason is wrong
(b) The statement is wrong reason is right
(c) The statement & reason are wrong
(d) The statement & reason are right
Answer:
(a) is right.

VIII. Map Skill.

Question 1.
Indus and Ganga Brahmaputra Delta
Answer:

2. Sri Lanka & Myanmar