Category: Class 9

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 3.3

9th Maths Algebra Exercise 3.3 Question 1.
Check whether p(x) is a multiple of g(x) or not.
p(x) = x³ – 5x² + 4x – 3, g(x) = x – 2
Solution:
p(x) = x³ – 5x² + 4x – 3; g(x) = x – 2
Let g(x) = 0
x – 2 = 0
x = 2
p(2) = 2³ – 5(2²) + 4(2) – 3
= 8 – 5 × 4 + 8 – 3 = 8 – 20 + 5 = -7 ≠ 0
⇒ p(x) is not a multiple of g(x)

9th Maths Exercise 3.3 Question 2.
By remainder theorem, find the remainder when, p(x) is divided by g(x) where,
(i) p(x) = x³ – 2x² – 4x – 1; g(x) = x + 1
(ii) p(x) = 4x³ – 12x² + 14x – 3; g(x) = 2x – 1
(iii) p(x) = x³ – 3x² + 4x + 50; g(x) = x – 3
Solution:
(i) p(x) = x³ – 2x² – 4x – 1; g(x) = x + 1
Let g(x) = x + 1
x + 1 = 0
x = -1
P(-1) = (-1)³ – 2(-1)² – 4(-1) – 1
= -1 -2 × 1 + 4 – 1
= -4 + 4 = 0
∴ Remainder = 0.

(ii) p(x) = 4x³ – 12x² + 14x – 3; g(x) = 2x – 1

(iii) p(x) = x³ – 3x² + 4x + 50 ; g(x) = x – 3
Let g(x) = x – 3
x – 3 = 0
x = 3
p(3) = 3³ – 3(3²) + 4(3) + 50
= 27 – 27 + 12 + 50
= 62
∴ Remainder = 62.

9th Maths 3.3 Question 3.
Find the remainder when 3x³ – 4x² + 7x – 5 is divided by (x + 3)
Solution:
(3x³ – 4x² + 7x – 5) + (x + 3)

The remainder is -143.

9th Class Maths Exercise 3.3 Solution Question 4.
What is the remainder when x²⁰¹⁸ + 2018 is divided by x – 1.
Solution:
x²⁰¹⁸ + 2018 is divided by x – 1
Let g(x) = x – 1 = 0
x = 1
p(x) = x²⁰¹⁸ + 2018
p(1)= 1²⁰¹⁸ + 2018
= 1 + 2018 = 2019

Samacheer Kalvi 9th Maths Chapter 3 Question 5.
For what value of k is the polynomial p(x) = 2x³ – kx² + 3x + 10 exactly divisible by (x – 2).
Solution:
Let g(x) = x – 2 = 0
x = 2
Since p(x) is exactly divisible by (x – 2)
p(2) = 2(2³) – k(2²) + 3(2)+ 10
= 16 – 4k + 6 + 10
= 32 – 4k = 0
= -k = -32
k= \(\frac{32}{4}\) = 8.

Ex 3.3 Class 9 Samacheer Question 6.
If two polynomials 2x³ + ax² + 4x – 12 and x³ + x² – 2x + a leave the same remainder when divided by (x – 3), find the value of a. and also find the remainder.
Solution:
Let f(x) = 2x³ + ax² + 4x – 12 and g(x) = x³ + x² – 2x + a
When f(x) is divided by x – 3, the remainder is f(3).
Now f(3) = 2(3)³ + a(3)² + 4(3) – 12 = 54 + 9a + 12 – 12
f(3) = 9a + 54 …………. (1)
When g(x) is divided by x – 3, the remainder is g(3).
Now g(3) = 3³ + 3² – 2(3) + a = 27 + 9 – 6 + a
g(3) = a + 30 ……….. (2)
Since, the remainder’s are same (1) = (2)
Given that f(3) = g(3)
That is 9a + 54 = a + 30
9a – a = 30 – 54 ⇒ 8a = -24 ∴ a = -3
Substituting a = -3 in f(3), we get
f(3) = 9(-3) + 54 = -27 + 54
f(3) = 27
∴ The remainder is 27.

9th Class Math 3.3 Exercise Solution Question 7.
Determine whether (x – 1) is a factor of the following polynomials:
(i) x³ + 5x² – 10x + 4
(ii) x⁴ + 5x² – 5x + 1
Solution:
(i) Let P(x) = x³ + 5x² – 10x + 4
By factor theorem (x – 1) is a factor of P(x), if P(1) = 0
P(1) = 1³ + 5(1²) – 10(1) + 4 = 1 + 5 – 10 + 4
P(1) = 0
∴ (x – 1) is a factor of x³ + 5x² – 10x + 4

(ii) Let P(x) = x⁴ + 5x² – 5x + 1
By/actor theorem, (x – 1) is a factor of P(x), if P( 1) = 0
P(1) = 1⁴ + 5 (1²) – 5(1) + 1 = 1 + 5 – 5 + 1 = 2 ≠ 0
∴ (x – 1) is not a factor of x⁴ + 5x² – 5x + 1

Class 9th Maths Exercise 3.3 Question 8.
Using factor theorem, show that (x – 5) is a factor of the polynomial 2x³ – 5x² – 28x + 15
Solution:
LetP(x) = 2x³ – 5x² – 28x + 15
By factor theorem, (x – 5) is a factor of P(x), if P(5) = 0
P(5) = 2 (5)² – 5 (5)² – 28 (5) + 15
= 2 × 125 – 5 × 25 – 140 + 15
= 250 – 125 – 140 + 15 = 265 – 265 = 0
∴ (x – 5) is a factor of 2x³ – 5x² – 28x + 15

Class 9 Maths Exercise 3.3 Solutions Question 9.
Determine the value of m, if (x + 3) is a factor of x³ – 3x² – mx + 24.
Solution:
Let P(x) = x³ – 3x² – mx + 24
By using factor theorem,
(x + 3) is a factor of P(x), then P (-3) = 0
P(-3) = (-3)³ -3 (-3)² – m (-3) + 24 = 0
⇒ -27 – 3 × 9 + 3m + 24 = 0 ⇒ 3m = 54 – 24
⇒ m = \(\frac{30}{3}\) = 10

Exercise 3.3 Class 9 Maths Question 10.
If both (x – 2) and (x – \(\frac{1}{2}\)) are the factors of ax² + 5x + b, then show that a = b.
Solution:
Let P(x) = ax² + 5x + b
(x – 2) is a factor of P(x), if P(2) = 0
P(2) = a(2)² + 5(2) + b = 0
4a + 10 + b = 0
4 a + b = – 10 …………….. (1)
(x – \(\frac{1}{2}\)) is a factor of P(x), P(\(\frac{1}{2}\)) = 0

2a + 8b = -20
a + 4b = – 10 ……………… (2)
From (1) and (2)
4a + b = – 10 …………. (1)
a + 4b = – 10 ………… (2)
(1) and (2) ⇒ 4a + b = a + 4b
3a = 3b
∴ a = b. Hence it is proved.

Ex 3.3 Class 9 Maths Solutions Question 11.
If (x – 1)divides the polynomial kx³ – 2x² + 25x – 26 without remainder, then find the value of k.
Solution:
Let P(x) = kx³ – 2x² + 25x – 26
By factor theorem, (x – 1) divides P(x) without remainder, P (1) = 0
P(1) = k(1)³ -2 (1)² + 25 (1) – 26 = 0
k – 2 + 25 – 26 = 0
k – 3 =0
k = 3

Class 9th Math Exercise 3.3 Question 12.
Check if (x + 2) and (x – 4) are the sides of a rectangle whose area is x² – 2x – 8 by using factor theorem.
Solution:
Let P(x) = x² – 2x² – 8
By using factor theorem,(x + 2) is a factor of P(x), if P (-2) = 0
P(-2) = (-2)² – 2 (-2) – 8 = 4 + 4 – 8 = 0
and also (x -4) is a factor of P (x), if P (4) = 0
p (4) = 4² – 2(4) – 8 = 16 – 8 – 8 = 0
∴ (x + 2), (x – 4) are the sides of a rectangle whose area is x² – 2x – 8.

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 3 Money and Credit

Money and Credit Textual Exercise

I. Choose the correct answer.

Money And Credit Class 9 Question 1.
Certain metals like ….. (gold/iron) were used as a medium of exchange in ancient times.
2. The Head Quarters of the RBI is at ….. (Chennai / Mumbai).
3. International trade is carried on in terms of …… (US Dollars / Pounds).
4. The currency of Japan is ……. (Yen/Yuan)
Answers:
1. gold
2. Mumbai
3. US Dollars
4. Yen

II. Fill in the blanks.
1. …… System can be considered as the first form of trade.
2. Money supply is divided into ……
3. The first printing press of the RBI was started at ………
4. …… act as a regulator of the circulation of money.
5. The thesis about money by B.R. Ambedkar is ……..
Answers:
1. Barter
2. four
3. Nasik, Maharashtra
4. The Reserve Bank of India
5. The Problem of the Rupee

III. Match the following:

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

IV. Give short answers.

9th Economics Question 1.
Why was money invented?
Answer:

1. If there were no money, we would be reduced to a barter economy.
2. In the market we don’t barter for individual goods.
3. Instead we exchange for goods (or) services for a common medium of exchange that is money.

Money Supply Is Divided Into Dash Question 2.
What is ancient money?
Answer:

1. Measuring the quantity and value of the goods exchanged were found very difficult. To solve these issues they fixed a common item with a standard value for the effective exchange of goods.
2. Gold, silver and copper were called ancient money.

Money And Credit Notes Question 3.
What were the items used as barter during olden days?
Answer:
Leather beads, shells, tobacco, salt, com and even slaves were the items used as barter during olden days.

Question 4.
What is spice route? Why was it called so?
Answer:

1. Pepper, spices, pearls, gems, rubies and muslin clothes were exported from the eastern sea of TamilNadu.
2. Pepper and spices took a major share of the exports. Hence this route was called the spice route.

Question 5.
What is natural money?
Answer:
The metals such as silver and gold gained importance gradually all over the world. So, these metals were used as standard value in the exchange of goods. This was called as natural money.

Question 6.
Why were coins of low value printed in large quantities?
Answer:

1. Mines had a limited reserve of the metals.
2. An alternative was found and coins were made using metals with lesser value.
3. These were used to buy and sell goods of lesser value.
4. It was used as the money of the poor people,

Hence the coins of low value were printed in large quantities.

Question 7.
What is meant by foreign exchange?
Answer:

1. It is the conversion of one country’s currency into another. A country’s currency value may also be set by the country’s government.
2. It is a system of trading in and converting the currency of one country into that of another.

V. Answer in Detail.

Question 1.
Explain how money is transacted in the digital world.
Answer:
Money has become an inseparable part of everyone’s life today. It has changed its form in the economic front. Money transactions are done through many ways in the electronic world. One has to visit the bank and fill in a challan or produce a cheque to withdraw money from his account.

Now this practice is gradually vanishing. Instead, one can easily withdraw the necessary amount from an Automated Teller Machine (ATM), with the help of an ATM debit card. One can easily withdraw the money needed at any time at ATMs located everywhere. A person can deposit money in their account without visiting the branch.

Similarly, credit cards are also available, through which things are bought on credit and the amount can be paid later.

Question 2.
Explain in detail about the role of RBI in the country.
Answer:
A government has the responsibility to regulate money supply and oversee the monetary policy. Hoarding of money must be avoided at all costs in a country’s economy. Only then money can be saved in banks.

A major portion of the savings in banks are used for the development of industries, economic growth and various development schemes for the welfare of the poor.
All the major and important banks were nationalised (1969) in India. The Reserve Bank of India (RBI) regulates the circulation of currency in India.

The Reserve Bank of India started its operations on 1st April 1935. It was permanently moved to Mumbai from the year 1937. RBI was nationalised in 1949. 85% of the printed currency is let for circulation. According to the statistics available as on August 2018, currency worth of 19 lakh crore are in circulation.

Question 3.
Write in detail about the various functions of money.
Answer:
When money replaced the barter system, a lot of practical issues were solved. Money acts a medium of exchange, a unit of measurement, a store of value and a standard of deferred payments. It plays an important role in transactions.

Medium of Exchange: Money should be accepted liberally in exchange of goods and services in a country.

Unit of Account: Money should be the common, standard unit of calculating a country’s total consumer goods, products, services etc. For example, if a book costs ₹ 50, it means that the price of the book is equale to 50 units of money. Money is used to measure and record financial transactions in a country.

A Store of Value: Money is used as a store of purchasing power. It can be used to finance future payments.

Question 4.
What are the divisions of money supply?
Answer:
Money supply is divided into four;
M₁ = Currency held with the public + cash Reserves in commercial and Co-operative banks + cash reserves in the RBI.
M₂ = M₁ + Money saved in Post office and bank savings Accounts
M₃ = M₁ + Time Deposits in Commercial and co-operative banks
M₄ = M₃ + Post office savings Money .

VI. Write the correct statement.

A.
1. The barter system flourished wherever civilizations thrived.
2. This was the initial form of trade.
(i) 1 is correct; 2 is wrong
(ii) Both 1 and 2 are correct
(iii) Both 1 and 2 are wrong
(iv) 1 is wrong; 2 is correct
Answer:
(ii) Both 1 and 2 are correct

B.
1. Most of the international trade transactions are carried out in US dollars.
2. No other country except the US carries out trade in the world.
(i) Both the statements are correct.
(ii) Both the statements are wrong.
(iii) 1 is correct; 2 is wrong
(iv) 1 is wrong; 2 is correct
Answer:
(iii) 1 is correct; 2 is wrong

VII. Project and activity.

Question 1.
Visit a local museum and collect information about the coins displayed there.
Answer:
You can do this activity under the guidance of your teacher.

Question 2.
Imagine you are going abroad for a Post Graduation course in architecture. Write a letter to the Branch Manager regarding an education loan.
Answer:
18.04.2019
Chennai
From
Deepa
18, Meenakshi Nagar
Nerkundram
To
The Branch Manager
HDFC Bank
T. Nagar
Chennai-600 017
Respected Sir,
Sub: Request for Educational Loan
I am Deepa, a student of Architecture living in Chennai. I have completed my degree course with 85% marks. I have got an opportunity to pursue a Post Graduation course in Architecture at King’s College, London. As I belong to an economically weaker section, I need your help in funding my studies. I am applying for an educational loan at your esteemed bank. I herewith enclose the copies of my marksheet and admission letter. Could you please consider my request for the loan. I shall be obliged for the same.
Thank you,
Yours sincerely,
Deepa
Enclosures:
1. B.Arch. marksheet
2. Admission Letter for Post Graduation in Architecture

To The Branch Manager HDFC Bank T. Nagar, Chennai – 600 017

VIII. Life skills – Student Activity.
Question 1.
Observe a 20 rupee note. What is written on it?
Answer:
• RESERVE BANK OF INDIA
• GUARANTEED BY THE CENTRAL GOVERNMENT
• I PROMISE TO PAY THE BEARER THE SUM OF TWENTY RUPEES
Students can write other words written in different languages:
• …………………………………………….
• …………………………………………….

Question 2.
Prepare a family budget for a month.
Answer:

1. The class will be divided into 4 groups.
2. They will be asked to prepare a family budget with the help of parents.
3. The report will be presented in the class by each group.

Money and Credit Additional Questions

I. Choose the correct answer.
1. ………….. (Ancient men/Modern men) hunted and gathered food.
2. …………. (Goods/Metals) be termed as the first form of money.
3. ……… (The later Cholas/The early Cholas) allowed the traders to have their own army.
4. All the major and important banks were nationalised in ……. (1969/1970) in India.
5. The currency of England is …………. (Pound/Dollar).
6. The currency of Saudi Arabia is ………. (Ringgit/Riyal).
Answers:
1. Ancient men
2. Metals
3. The later Cholas
4. 1969
5. Pound
6. Riyal

II. Fill in the blanks.

1. The …….. system was the initial form of international trade.
2. ……. plays a predominant and inseparable role in all our lives.
3. The first form of money is ……….
4. ………. issued a coin of silver weighing 178 grams which was termed as the Rupiya.
5. A government has the responsibility to regulate money supply and oversee the ……… policy.
6. ……….. attempts to meet the educational aspirations of the society.
7. There is no security required for the loan amount upto ₹ ………. lakhs.
8. The …… regulates the circulation of currency in India.
9. The Indian currency is called the ………
10. Till 1947, the currency notes with the image of …….. were in circulation.
Answers:
1. Barter
2. Money
3. metals
4. Sher Shah Suri
5. Monetary
6. Educational loan
7. 4 lakhs
8. Reserve Bank of India
9. Indian Rupee INR
10. King George VI

III. Match the following.

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

IV. Give short answers.

Question 1.
Give a short account of the life of ancient men.
Answer:
Ancient man hunted and gathered food. He lived in caves and forests. In later stages, he invented weapons for hunting and gathering food. Later, he invented fire and learnt to practise agriculture. He used mud to build houses and settle down in a place, and also to make earthenware. ”

Question 2.
How does money play a predominant and inseparable role in all our lives?
Answer:
The Government, as well as, private institutions and industries calculate their financial status through money. Thus, money plays a predominant and inseparable role in all our lives.

Question 3.
How were the later cholas treated the traders?
Answer:
The later Cholas allowed the traders to have their own army. Historical evidences state that during this period, small traders and producers gave credit to the Tamil traders to support their export needs.

Question 4.
Where were the barter system flourished?
Answer:
The barter system flourished wherever civilizations thrived. This system was active not only within a civilization, but also among civilizations. This was the initial form of international trade.

Question 5.
What is currency?
Answer:
Currency is the medium of exchange in a country. The Indian currency is called the Indian Rupee (INR). In a country the foreign currency is called foreign exchange.
Purchasing capacity of all currencies in the world are compared using the US dollar as the standard currency. This value differs from country to country.

Question 6.
What do the Government do with the savings in the banks?
Answer:
A major portion of the savings in banks are used for the development of industries, economic growth and various development schemes for the welfare of the poor.

Question 7.
What is Credit?
Answer:
Farmers avail credit during monsoons for buying seeds, agricultural input and other expenses. Traders and small entrepreneurs need credit for their needs. Even large industries receive credit to take up their new projects.

Question 8.
Give an account of Self Help Groups.
Answer:
People who live in a particular place or those who are involved in a certain work join together as a group and start saving. These are called as Self Help Groups. The nationalised banks provide help to these groups through micro-credit. Credit given though Self Help Groups for street vendors, fishermen, especially women and the poor really make a difference in their life.

V. Answer in detail.

Question 1.
How is currency printed in India?
Answer:
In 1925, the British government established a government press at Nasik in Maharashtra. Currencies were printed three years later. In 1974, a press was started in Dewas, Madhya Pradesh. (Security Printing and Minting Corporation of India Ltd.) In the 1990s. two more presses were started in Mysuru, Karnataka and Salboni in West Bengal to print bank notes. The Reserve Bank of India has the authority to decide the value of currency to be printed and how the amount should reach its destination safely. Around ten thousand workers are employed here. Countries like Sri Lanka, Bhutan, Iraq and Africa have drawn contracts for printing their currencies and sent to the respective countries.

Though the RBI has the power to print up to ten thousand rupee notes, at present a maximum of upto rupees two thousand is printed.

Question 2.
Write in detail the Foreign Exchange rate equivalent to US Dollars.
Answer:

VI. Write the correct statement.

A.
1. Money is recognized as a standard record for the payment of a thing or service.
2. Using this currency, people can purchase things, pay taxes and repay debts.
(i) Both 1 and 2 are correct
(ii) Both 1 and 2 are wrong
(iii) 1 is correct; 2 is wrong
(iv) 1 is wrong; 2 is correct
Answer:
(i) Both 1 and 2 are correct

B.
1. Paper money was introduced because metal supply was limited.
2. All the major and important banks were nationalised in 1964, in India.
(i) Both 1 and 2 are correct
(ii) Both 1 and 2 are wrong
(iii) 1 is correct; 2 is wrong (iv) 1 is wrong; 2 is correct
Answer:
(iii) 1 is correct; 2 is wrong

HOTS

Question 1.
How important is foreign exchange to one’s country?
Answer:

1. During any Crisis Foreign exchange reserves come to the rescue of any country. It absorbs the distress related to such crisis.
2. It increases the confidence in the monetary and exchange rate policies of the government.
3. Foreign exchange reserves are the foreign currencies held by the Country’s Central Bank. They are also called Foreign currency reserves (or) Foreign reserves. They manage their currencies.

Thus foreign exchange is important to any country.

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 5 Biosphere

Biosphere Textual Exercise

I. Fill in the blanks.

1. An area where animals, plants and micro organisms live and interact with one another is known as ………
2. ……… are also called Heterotrophs.
3. ……. is a system of interlocking and independent food chains.
4. ………. is an extensive large ecosystem.
5. The vegetative type commonly found in desert biomes is called …..
6. ……. is an aquatic biome that is found where fresh water and salt water mix.
Answers:
1. Habitat
2. Consumers
3. Food web
4. A biome
5. Xerophytes
6. Estuary

II. Choose the correct answer.

Biosphere Provides A Stable Ecosystem Give Reason Question 1.
The coldest biome on Earth is ……….
(a) Tundra
(b) Taiga
(c) Desert
(d) Oceans
Answer:
(a) Tundra

Biosphere Provides A Stable Ecosystem Question 2.
This is the smallest unit of biosphere.
(a) Ecosystems
(b) Biome
(c) Environment
(d) None of the above
Answer:
(a) Ecosystems

Biosphere 9th Class Social Question 3.
Nutrients are recycled in the atmosphere with the help of certain micro organisms, referred to as
(a) Producers
(b) Decomposers
(c) Consumers
(d) None of the above
Answer:
(b) Decomposers

Biosphere Lesson Class 9 Question 4.
To which climatic conditions are Xerophytic plants specifically adapted to?
(a) Saline and sandy
(b) Limited moisture availability
(c) Cold temperature
(d) Humid
Answer:
(a) Saline and sandy

Biosphere Class 9 Question 5.
Why is the usage of rainforest biomes for large scale agriculture unsustainable?
(a) because it is too wet
(b) because the temperature is too warm
(c) because the soil is too thin
(d) because the soil is poor
Answer:
(b) because the temperature is too warm

Questions 6-8 are assertion type questions.
Directions:
(A) Both assertion (A) and reason (R) are true; R explains A
(B) Both assertion (A) and reason (R) are true; R does not explain A
(C) A is true; R is false
(D) Both A and R are false
Answer:
(C) A is true; R is false

Biosphere Solutions Question 6.
(A): Heterotrophs do not produce their own food.
(R): They depend on autotrophs for their nourishment.
Answer:
(C) A is true; R is false

Biosphere Provides A Stable Ecosystem. Question 7.
(A): Hotspots are the regions characterised by numerous endemic plants and animal species
living in a vulnerable environment.
(R): To manage and focus on conservation work more effectively, researchers identified hotspots.
Answer:
(A) Both assertion (A) and reason (R) are true; R explains A

9th Class Social Biosphere Lesson Question 8.
(A): The number of gorillas in Africa has plummeted by 60% in the past twenty years.
(R): Non intervention of human beings in the forest areas.
Answer:
(D) Both A and R are false

III. Answer the following in brief:

9th Class Social Biosphere Question 1.
What is Biosphere?
Answer:
Biosphere is a life supporting layer that exists on the earth’s surface. This layer on earth encompasses the Lithosphere, Hydrosphere and Atmosphere. It includes flora and fauna that thrive on or near the earth’s surface.

Samacheer Kalvi 9th Social Science Geography Chapter 1 Question 2.
What is an ecosystem?
Answer:
The place on earth where living organisms live and interact with one another and with their physical environment is called an ecosystem.

Question 3.
What does the term ‘biodiversity’ meant
Answer:
Biodiversity or biological diversity refers to a wide variety of living organisms (plants, animals and other micro organisms) which live in a habitat. It is highly influenced by topography, climate as well as human activities.

Question 4.
What is meant by loss of biodiversity?
Answer:
The extinction of species (flora and fauna) due to human and natural influences is called loss of biodiversity. The biodiversity loss has a great impact on mankind and also affects land, water, air etc. Habitat destruction due to deforestation, population explosion, pollution and global warming are the major cause for loss of biodiversity.

Question 5.
Mention the various terrestrial biomes.
Answer:
The major terrestrial biomes of the world are:
A. Tropical Forest Biomes
B. Tropical Savanna Biomes
C. Desert Biomes
D. Temperate Grassland Biomes
E. Tundra Biomes

IV. Distinguish between the following:

Question 1.
Producers and Decomposers.
Answer:

S.No.	Producers	Decomposers
(i)	They are self nourishing components of the ecosystem.	They are organisms that are incapable of preparing its own food.
(ii)	Producers are called Autotrophs. e.g. Plants, Algae, Bacteria, etc.	Decomposers are organisms that are incapable of preparing its own food. They are called Saprotrophs. e.g. Fungus, Mushrooms.

Question 2.
Terrestrial biomes and Aquatic biomes
Answer:

S.No.	Terrestrial biomes	Aquatic biomes
(i)	It is a group of living organisms that live and interact with one another on land.	It is a group of living organisms that live and interact with one another for nutrients and shelter.
(ii)	They are determined by temperature and rainfall.	These are influenced by a series of abiotic factors.
(iii)	Terrestrial biomes are Tropical forest biomes, Tropical Savanna biomes, Desert biomes, Temperate Grassland biomes and Tundra biomes.	Aquatic biomes are Fresh water biomes and Marine biomes.

Question 3.
Tropical vegetation and Desert vegetation
Answer:

S.No.	Tropical vegetation	Desert vegetation
(i)	Half of the World’s Tropical forests are found in Central and South America.	Deserts are found in the Western Margin of the continents.
(ii)	This biome extends between 10°N and 10°S of the equator.	This extends between 20°N and 30°S latitudes.
(iii)	This weather condition favours thick vegetative cover.	They possess special type of vegetation called xerophytes.
(iv)	People in this region sustain their livelihood through food gathering.	People in this region sustain their life through food gathering and hunting.
(v)	High annual rainfall and relatively constant temperature is likely	Annual rainfall is less than 25 c.m in these regions.

Question 4.
Savannas and Tundra
Answer:

S.No.	Savannas	Tundras
(i)	Tropical grasslands are generally found between tropical forests.	These vast lowlands are found where the ground remains frozen.
(ii)	Generally hot climate and dry. They also experience moderate to low rainfall.	Generally long severe winter and short cool summer.
(iii)	Found in the Sahel, South of Sahara in East Africa and in Australia.	Found in Greenland Arctic and Antarctic regions and Northern parts of Asia, Canada and Europe.
(iv)	Chief occupation is herding.	Hunting and fishing are their main occupations.

V. Give reasons for the following:

Question 1.
Producers are also called autotrophs.
Answer:
Producers are self nourishing components of the ecosystem. Hence they are called Autotrophs. They are found both on land and water, e.g. Plants, Algae, Bacteria etc.

Question 2.
Biosphere provides a stable ecosystem.
Answer:

1. Biosphere extends from the deep ocean trenches to lush rain forests.
2. People play an important role in maintaining the flow of energy in the biosphere.
3. There are places on earth that are both biologically rich and deeply threatened.
4. Hence Biosphere provides a stable ecosystem.

VI. Answer the following in a paragraph:

Question 1.
Explain the various components of ecosystem.
Answer:
An ecosystem is a community, where all living organisms live and interact with one another and also with their non-living environment such as land, soil, air, water etc. Ecosystems range in size from the smallest units (e.g. bark of a tree) that can sustain life to the global ecosystem or ecosphere. (e.g. Cropland, Pond ecosystem, Forest ecosystem, Desert ecosystem etc.). Biosphere harbours all ecosystems on the earth and sustains life forms including mankind.
Components of ecosystem:
An ecosystem consists of three basic components, namely
(A) Abiotic components
(B) Biotic components and
(C) Energy component

A) Abiotic Components: Abiotic components include the non-living, inorganic, physical and chemical factors in the environment, e.g. Land, Air,Water, Calcium, Iron etc.

B) Biotic Components: Biotic components include plants, animals and micro organisms. Biotic components can be classified into three categories:

• Producers are self nourishing components of the ecosystem. Hence they are called Autotrophs. They are found both on land and water, e.g. Plants, Algae, Bacteria etc.
• Consumers are those that depend on producers, directly or indirectly. Hence they are called Heterotrophs.

C) Energy Components: All organisms in the biosphere use energy to work and convert one form of energy into another. The Sun is the ultimate source of energy for the biosphere as a whole. The solar energy gets transformed into other forms of energy through the various components in the ecosystem. The producers, consumers and the decomposers contribute a lot to the energy flow in an ecosystem.

Question 2.
Write a paragraph on the functions of an ecosystem.
Answer:
Functions of an ecosystem: The living organisms form an interacting set of flora and fauna which are organized into trophic levels, food chains and food webs. The functioning of an ecosystem depends on the pattern of the energy flow, as it helps in the distribution and circulation of the organic and inorganic matter within an ecosystem. Energy flow generally takes place in a hierarchical order in an ecosystem through various levels. These levels are called trophic levels. The chain of transformation of energy from one group of organisms to another, through various trophic levels is called a food chain. A system of interlocking and interdependent food chains is called a food web.

Question 3.
Explain about the aquatic biomes on Earth.
Answer:
Aquatic biome is a group of living organisms that live and interact with one another and its aquatic environment for nutrients and shelter. Like terrestrial biomes, aquatic biomes are influenced by a series of abiotic factors. It is broadly classified as fresh water biomes and marine biomes.

A. Fresh water Biomes: It comprises lakes, ponds, rivers, streams, wetlands etc. It is influenced by various abiotic components such as the volume of water, water flow, composition of oxygen, temperature, etc. Humans rely on freshwater biomes for drinking water, crop irrigation, sanitation and industry. Water lily, lotus, duck weeds etc. are the common plants found here. Trout, salmon, turtles, crocodiles etc. are the animals found here.

B. Marine Biomes: They are the largest aquatic biomes on earth. They are continuous bodies of salt water and provide a wide range of habitats for marine plants and animals. Coral reefs are a second kind of marine biomes within the ocean. Estuaries, coastal areas where salt water and fresh water mix, form a third unique marine biome. As water provides maximum mobility to marine organisms, nutrients are circulated more quickly and efficiently here than the terrestrial biomes. Apart from animals, plants such as kelp, algae, phytoplankton etc. also grow in water. Aquatic biomes are not only important for plants and animals, but also for humans. Humans use aquatic biomes for water, food and leisure activities. Some of the threats and issues to aquatic biomes are overfishing, pollution and rise in sea level.

VII. Find out the dates for the following:

1. World Wild Life Day – …………
2. International Day of Forest – ………..
3. World Water Day – ………..
4. Earth Day – ………….
5. World Environment Day – June 5th
6. World Oceans Day – …………
Answers:
1. March 3rd
2. March 21st
3. March 22nd
4. April 22nd
6. June 8th

VIII. Map Study

Locate the following on the world outline map.

1. Priairies
2. Downs
3. Tundra Biomes
4. Equatorial Biomes

You can identify and locate the above mentioned grasslands with the help of an atlas.
Hint: Temperate grasslands are called differently in different parts of the world.
Prairies – North America
Downs – Australia and New Zealand
Tundra – Greenland, Arctic and Antarctic regions and Northern parts of Asia, Canada and Europe
Equatorial Biomes – Near the equator in Central and South America, parts of Africa and Asia

IX. Picture Study

Narrate the given food web of Arctic Tundra in your own words.

1. The flow of energy from the sun through an eco system can be illustrated in a food chain.
2. Within a food Chain there are produces. e.g., grasses, lichens, Arctic wild flower, etc.
3. Life in any biome includes producers (plants) and consumers (energy obtained from producers)
4. These consumers may be further classified as herbivores (plant eater) carnivores(meat eaters) (or) anniores (feed on combination of both animals and plants).

Biosphere Additional Questions

I. Fill in the blanks.

1. ……… are self nourishing components of the ecosystem.
2. All living things, large or small are grouped into ………
3. The ……. is the ultimate source of energy for the biosphere as a whole.
4. Decomposers live on dead and decaying plants and animals and are called ………
5. The extinction of species (flora and fauna) due to human and natural influences is called ………
6. The branch of science that deals with ecosystem is called ………
7. The temperate grasslands are called …… in North America.
8. ……….. is a fertile fresh water source found in deserts and semi-arid regions.
Answers:
1. Producers
2. species
3. sun
4. Saprotrophs
5. Lass of biodiversity
6. Ecology
7. Prairies
8. An Oasis

II. Choose the correct answer.

Question 1.
……….. the fourth sphere of the Earth.
(a) Lithosphere
(b) Hydrosphere
(c) Biosphere
(d) Atmosphere
Answer:
(c) Biosphere

Question 2.
………. are found both on land and water.
(a) Autotrophs
(b) Heterotrophs
(c) Saprotrophs
(d) None of the above
Answer:
(a) Autotrophs

Question 3.
Consumers are those that depend on directly (or) indirectly are called ………..
(a) Saprotrophs
(b) Heterotrophs
(c) Autotrophs
(d) None of the above
Answer:
(b) Heterotrophs

Question 4.
A group of living organisms that live and interact with One another on land is ………
(a) Tropical Savanna Biomes
(b) Tropical Forest Biomes
(c) Desert Biomes
(d) Terrestrial Biomes
Answer:
(d) Terrestrial Biomes

Question 5.
The chain of transformation of energy from one group of organisms to another through various trophic levels is called as ……….
(a) Food chain
(b) Food web
(c) Trophic level
(d) None of the above
Answer:
(a) Food chain

Questions 6-8 are Assertion (A) Reason (R) type.
(A) Both Assertion (A) and Reason (R) are true. (R) explains (A).
(B) Both Assertion (A) and Reason (R) are true. (R) does not explain (A).
(C) (A) is true; (R) is false.
(D) Both (A) and (R) are false.

Question 6.
Assertion (A): In Biodiversity each species, no matter how big of small has an important role to play in the ecosystem.
Reason (R): It maintains the ecological balance.
Answer:
(A) Both Assertion (A) and Reason (R) are true. (R) explains (A).

Question 7.
Assertion (A): As the soil is sandy and saline deserts remain agriculturally unproductive. Reason (R): Tribal people who live in deserts practice food gathering and hunting.
Answer:
(B) Both Assertion (A) and Reason (R) are true. (R) does not explain (A).

Question 8.
Assertion (A): Aquatic animals use 10% energy to obtain oxygen.
Reason (R): Terrestrial animals use only 2-4% of energy to obtain oxygen.
Answer:
(D) Both (A) and (R) are false.

III. Answer the following in brief.

Question 1.
What does an ecosystem consists of?
Answer:
An ecosystem consists of three basic components, namely
(A) Abiotic components
(B) Biotic components and
(C) Energy component.

Question 2.
Define Abiotic Components.
Answer:
Abiotic components include the non-living, in-organic, physical and chemical factors in the environment, e.g., Land, Air, Water, Calcium, Iron, etc.

Question 3.
What are energy components?
Answer:
All organisms in the biosphere use energy to work and convert one form of energy into another. The Sun is the ultimate source of energy for the biosphere as a whole. The solar energy gets transformed into other forms of energy through the various components in the ecosystem. The producers, consumers and the decomposers contribute a lot to the energy flow in an ecosystem.

Question 4.
State the unique weather condition that favours thick vegetative cover in the Tropical Forest Biomes.
Answer:
The climate in these biomes shows little seasonal variation with high annual rainfall and relatively constant, high temperature. This unique weather condition favours thick vegetative cover.

Question 5.
How do the people live Desert Biomes?
Answer:
People who live here practice food gathering and hunting. They move their temporary settlements frequently in search of pastures. Transportation becomes very difficult here and is carried on by camels. Reptiles like snakes, lizards, scorpions etc., are most commonly found here.

Question 6.
Mention the Temperate Grasslands in different parts of the world.
Answer:
Temperate grasslands are called differently in different parts of the world.
Prairies – North America
Steppes – Eurasia
Pampas – Argentina and Uruguay
Veld – South Africa
Downs – Australia and Newzealand.

Question 7.
What is an oasis?
Answer:
An oasis is a fertile fresh water source found in deserts and semi-arid regions. Oases are fed by springs. Crops like date palms, figs, citrus fruits, maize etc. are cultivated near these oases.

Question 8.
What is a Biosphere Reserve?
Answer:
A Biosphere Reserve is a special ecosystem or specialized environment with flora and fauna that require protection and nurturing. There are 18 Bioshpere Reserves in India.

IV. Distinguish the following.

Question 1.
Producers Consumers
Answer:

Producers	Consumers
Producers are self nourishing components of the ecosystem. Hence they are called Autotrophs. They are found both on land and water, e.g. Plants, Algae, Bacteria etc.	Consumers are those that depend on producers, directly or indirectly. Hence they are called Heterotrophs.

Question 2.
Abiotic components Biotic components
Answer:

Abiotic components	Biotic Components
Abiotic components include the non-living, inorganic, physical and chemical factors in the environment, e g. Land, Air, Water, Calcium, Iron etc.	Biotic components include plants, animals and micro organisms. Biotic components can be classified into three categories.

Question 3.
Mention any 3 points between Aquatic ecosystem and Terrestrial ecosystem.
Answer:

S.No.	Aquatic Ecosystem	Terrestrial Ecosystem
(i)	Aquatic ecosystem exists on water covering 71% of the earth surface.	Terrestrial ecosystem exists on land covering 29% of the earth surface.
(ii)	Aquatic animals use 20% of energy to obtain oxygen.	Terrestrial animals use only 1-2% of energy to obtain oxygen.
(iii)	In this ecosystem there is abundant of water with limited oxygen supply.	In this ecosystem there is less availability of water, greater availability of gases and temperature fluctuation.

V. Give reasons for the following.

Question 1.
Stable biosphere has to be conserved.
Answer:
A healthy eco system provides clean water, pure water, enriched soil, food, raw materials, medicines etc. Hence stable biosphere has to be conserved.

Question 2.
The Primary cause of today’s loss of biodiversity.
Answer:
The primary cause of today’s loss of biodiversity is habitat alteration caused by human activities. The ever increasing population results in over exploitation of biological resources. This has an adverse impact, on flora and fauna on earth. There are places on earth that are both biologically rich and deeply threatened.

Question 3.
The Net Primary productivity is low in Tundra.
Answer:
This biome experiences long severe winter and short cool summer. Due to the prevailing of low temperature and short growing seasons, the net primary productivity is very low in tundra.

VI. Answer in a paragraph.

Question 1.
Write down the differences between the Aquatic Ecosystem and Terrestrial Ecosystem.
Answer:

S.No.	Aquatic Ecosystem	Terrestrial Ecosystem
(i)	Aquatic ecosystem exists on water covering 71 % of the earth surface.	Terrestrial ecosystem exists on land covering 29% of the earth surface.
(ii)	Aquatic animals use 20% of energy to obtain oxygen.	Terrestrial animals use only 1-2% of energy to obtain oxygen.
(iii)	In this ecosystem there is abundant of Water with limited oxygen supply.	In this ecosystem there is less availability of water, greater availability of gases and temperature fluctuation.
(iv)	The small drifting photosynthetic organisms of the ocean called photo phytoplankton are regarded as the major primary producer.	The primary producer is the plant that produce food through photosynthetic process.
(v)	Aquatic environment is more stable with smaller fluctuation in temperature and other variable.	Terrestrial environment is quite unstable as the land surface is affected by great risks from external impacts.

Question 2.
Desert Biomes.
Answer:
Deserts are usually found on the western margins of the continents between 20° and 30° N and S latitudes. The annual rainfall is less than 25 cm in these regions. Due to the lack of rainfall and arid conditions, these regions do not possess any vegetation but have special vegetation type called Xerophytes. As the soil is sandy and saline, deserts remain agriculturally unproductive. Drought resistant thorny scrubs and bushes, palms are found here.

Tribal people who live here practice food gathering and hunting. They move their temporary settlements frequently in search of pastures. Transportation becomes very difficult here and is carried on by camels. Reptiles like snakes, lizards, scorpions etc., are most commonly found here.

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 2 Employment in India and Tamilnadu

Employment in India and Tamilnadu Textual Exercise

I. Choose the correct answer.

Employment In India And Tamilnadu Question 1.
We take age group …….. years for computation of the workforce.
(a) 12 – 60
(b) 15 – 60
(c) 21 – 65
(d) 5 – 14
Answer:
(b) 15 – 60

Employment Pattern Changes Due To Answer Question 2.
Which is the correct sequence of various sectors in GDP of India in the descending order?
(a) Primary sector, Secondary sector, Tertiary sector
(b) Primary sector, Tertiary sector, Secondary sector
(c) Tertiary sector, Secondary sector, Primary sector
(d) Secondary sector, Tertiary sector, Primary sector
Answer:
(a) Primary sector, Secondary sector, Tertiary sector

Employment Pattern Changes Due To Question 3.
Which one of the following sectors is the largest employer in India?
(a) Primary Sector
(b) Secondary Sector
(c) Tertiary Sector
(d) Public sector
Answer:
(a) Primary Sector

Employment Pattern Changes Due To Dash Question 4.
Which one of the following is not in Primary Sector?
(a) Agriculture
(b) Manufacturing
(c) Mining
(d) Fishery
Answer:
(b) Manufacturing

Question 5.
Which one of the following is not in the Secondary Sector?
(a) Construction
(b) Manufacturing
(c) Small Scale Industry
(d) Forestry
Answer:
(d) Forestry

Question 6.
Tertiary Sector include/s …..
(a) Transport
(b) Insurance
(c) Banking
(d) All of these
Answer:
(d) All of these

Question 7.
Match the List I with List II using the codes given below:

Answer:
(b) 4, 3, 2, 1

Question 8.
Which sector is not included in the occupational pattern?
(a) Primary sector
(b) Secondary sector
(c) Tertiary sector
(d) Private sector
Answer:
(d) Private sector

Question 9.
Which Delhi Sultan of medieval India formed ‘Employment Bureau’ to solve the un-employment problem?
(a) Muhamad Bin Tugluq
(b) Allauddin Khilji
(c) Feroz Shah Tugluq
(d) Balban
Answer:
(c) Feroz Shah Tugluq

Question 10.
…….. sector is registered and follows government rules.
(a) Agriculture
(b) Organised
(c) Unorganised
(d) Private
Answer:
(b) Organised

Question 11.
……. sector provides j.ob security and higher wages
(a) Public sector
(b) Organised sector
(c) Unorganised sector
(d) Private sector
Answer:
(b) Organised sector

Question 12.
Find the odd one.
(a) Banking
(b) Railways
(c) Insurance
(d) Small Scale Industry
Answer:
(b) Railways

Question 13.
The sectors are classified into Public and Private sectors on the basis of …
(a) number of workers employed
(b) nature of economic activity
(c) ownership of enterprises
(d) employment conditions
Answer:
(c) ownership of enterprises

Question 14.
Assertion (A): The unorganised sector of the economy characterised by the household manufacturing activity and small-scale industry.
Reason (R): Jobs here are low paid and often not regular
(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 15.
People who employ workers and pay rewards for their work is termed as ……
(a) employee
(b) employer
(c) labour
(d) caretaker
Answer:
(b) employer

Question 16.
……. continues to be the largest employer in Tamil Nadu.
(a) Agriculture
(b) Manufacturing
(c) Banking
(d) Small Scale Industry
Answer:
(a) Agriculture

II. Fill in the blanks.

1. In ……. sector, the employment terms are not fixed and regular.
2. Economic activities are classified into ……….. and …… sectors.
3. ……… has always featured as an important element of development policy in India.
4. Employment pattern changes due to …….
5. The nature of employment in India is ………
6. ……. of the economy is the number of people in the country, who work and also
capable of working.
7. Public sector means ……… .
Answers:
1. unorganised
2. Public and Private
3. Employment
4. life style of the people
5. multi-dimensional
6. Labour force
7. Government undertaking

III. Match the following.

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

IV. Give short answers.

Question 1.
What is labour force of the economy?
Answer:
Labour force of the economy is the number of people in the country who work and also capable of working.

Question 2.
Why are children and old age (above 60 years) are not considered for computation of workforce?
Answer:
We take the age group of 15-60 years for the computation of work force. Persons who are less than 15 years are considered as children and person who have crossed 60 years of age are excluded as they are not physically fit to undertake productive occupation. Hence they are not considered for computation of work force.

Question 3.
What are the three sectors of an economy?
Answer:
The economy is classified into three sectors. Primary (or) Agriculture sector, Secondary (or) Industrial sector and Tertiary (or) Service sector.

Question 4.
Agriculture, despite a sharp decline in Gross Domestic Product, continues to be the largest employer in Tamil Nadu. Give reason.
Answer:
Agriculture, despite a sharp decline in gross domestic product, continues to be the largest employer in Tamil Nadu. This is because the non-agriculture sectors are yet to generate enough employment to affect a shift of labour force.

V. Answer in detail.

Question 1.
Explain:
(a) primary sector;
(b) secondary sector;
(c) tertiary sector.
Answer:
The structure of employment denotes the number of workers engaged in different sectors of the economy.
Primary Sector: Agriculture, forestry, animal husbandry, poultry, dairy farming, fishing, etc. Secondary Section: Manufacturing, small and large scale industries and constructional activities. .
Tertiary Sector: Transport insurance banking, trade, communication, real estate, government and non-government services.
In developing countries like India that a large work force will be engaged in Primary Sector, while a small proportion in Secondary and Tertiary sectors.

Question 2.
Explain the employment structure of India.
Answer:

1. The nature of employment in India is multi-dimensional. Some get employment throughout the year; some others get employed for only a few months in a year.
2. The economy is classified into three sectors: primary or agriculture sector, secondary or industrial sector and tertiary or service sector.
3. The structure of employment denotes the number of workers engaged in different sectors of the economy.
4. Though the occupational pattern varies from one country to another, one can find in developing countries like India that a large work force will be engaged in primary sector, while a small proportion in secondary and tertiary sectors.
5. Whereas, in well-developed countries, the proportion of workforce engaged in agriculture will be very small and a majority of labour force will be in the industrial and tertiary sectors.
6. Employment has always featured as an important element of development policy in India.
7. Employment growth has increased at an average rate of 2% during the past four decades since 1972 – 73.

Question 3.
Compare the employment conditions prevailing in the organised and unorganised
sectors.
Answer:

Question 4.
Distinguish between the Public sector and the Private sector.
Answer:

VI. Projects and Activities.

Question 1.
Make a long list of all kinds of work that you find for adults around you. In what way can you classify them?
Answer:
(a) Agriculture, Food & Natural resources.
(b) Business, Management & Administration.
(c) Communication & Information Systems.
(d) Engineering, Manufacturing & Technology.
(e) Health Science Technology.
(f) Human Services.

Question 2.
A research scholar looked at the working people in the city of Chennai and found the following:
Answer:

Question 3.
Classify the following list of occupations under primary, secondary and tertiary sectors. Milk vendor, tailor, teacher, doctor, farmer, postman, engineer, potter, fisherman, artisans, policeman, banker, driver, carpenter.
Answer:

VII. HOTS.

Tertiary sector is in top position in the world now. Justify
Answer:

1. In a direct sense, the tertiary sector is mostly independent.
2. This sector primarily includes those activities that help in the development of the primary and secondary sector.
3. They aid and support the production process.
   e.g., The transport sector, that uses trucks to transport finished products from factory to the retail stores.
4. Service sector also includes some essential services that may not directly help in the production of goods.
   e.g., Teachers, doctors, washermen, barbers, etc.
5. Tertiary sector actually caters to the excess income in a person’s hand after he is successful in acquiring his basic needs.

This sector will remain a chief engine for future growth.

VIII. Life Skill.

Question 1.
Discuss the sectors of your village economy.
Answer:

1. The teacher will make the students to gain knowledge of Primary, Secondary and Tertiary sector.
2. The students will be asked to collect information regarding the three sectors.
3. The students will be advised to classify the jobs available under Primary, Secondary and Tertiary sectors in their village.

Employment in India and Tamilnadu Additional Questions

I. Choose the correct answer.

Question 1.
The nature of employment in India is
(a) Two-dimensional
(b) Three dimensional
(c) Multi-dimensional
(d) All the above
Answer:
(c) Multi-dimensional

Question 2.
This is Primary Sector.
(a) Agriculture
(b) Manufacturing
(c) Small scale Industries
(d) Banking
Answer:
(a) Agriculture

Question 3.
This sector do not enjoy any special benefit.
(a) Organised Sector
(b) Unorganised Sector
(c) Public Sector
(d) Private Sector
Answer:
(b) Unorganised Sector

Question 4.
Assertion (A): Unorganised sector jobs are low paid.
Reason (R): These employees have no job-security.
(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:
(b) Both (A) and (R) are true and (R) does not explain (A).

Question 5.
Find the odd one.
(a) Transport
(b) Insurance
(c) Banking
(d) Poultry
Answer:
(d) Poultry

Question 6.
This is Private Sector.
(a) TVS Motors
(b) NLC
(c) SAIL
(d) BSNL
Answer:
(a) TVS Motors

II. Fill in the blanks.

1. To survive in the world we all need …… to earn money.
2. In well developed countries the proportion of work force engaged in ……. will be very smart.
3. …….. sector has some formal processes and procedures.
4. …….. are not registered with the government.
5. Most of the …….. in Tamil Nadu has been contributed by the unorganised and informal sectors.
Answers:
1. employment
2. Agriculture
3. Organized
4. Unorganised Sectors
5. employment growth

III. Match the following.

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

IV. Give short answers.

Question 1.
Who are called employees ?
Answer:
Those who are engaged in economic activities, in whatever capacity – high (or) low are called employees.

Question 2.
What is the nature of employment in India?
Answer:
The nature of employment in India is multi-dimensional. Some get employment throughout the year. Some others get employed for only a few months in a year.

Question 3.
Mention the recent trends in the working pattern of the employees.
Answer:
The trends are
(a) Increasing self-employment.
(b) Firms using fewer full-time employees and tending to offer more short-term contracts.
(c) There has been a growth in part-time employment.

Question 4.
What does structure of employment denote?
Answer:
Structure of employment denotes number of workers engaged in different sectors of the economy.

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 History Solutions Chapter 4 Intellectual Awakening and Socio-Political Changes

Intellectual Awakening and Socio-Political Changes Textual Exercise

I. Choose the correct answer.

Intellectual Awakening And Socio Political Changes Question 1.
Identify the founder of a new sect who exemplified simplicity and self-denial.
(a) Buddha
(b) Lao-tze
(c) Confucius
(d) Zoroaster
Answer:
(a) Buddha

Samacheer Kalvi Guru 9th Social Science Question 2.
The Magadha king influenced by the teachings of Mahavira.
(a) Dhananandha
(b) Chandragupta
(c) Bimbisara
(d) Shishunaga
Answer:
(b) Chandragupta

Intellectual Awakening Meaning In Tamil Question 3.
The northern India extended from the Kabul Valley in the north to the Godavari in the south witnessed the rise of Sixteen States.
(a) Mahajanapadas
(b) Gana-sanghas
(c) Dravida
(d) Dakshinapatha
Answer:
(a) Mahajanapadas

Samacheer Kalvi 9th Social Science Question 4.
Tri-ratnas are the three priniciples taught by ……………..
(a) Buddha
(b) Mahavira
(c) Lao-tze
(d) Confucius
Answer:
(b) Mahavira

Samacheer Guru 9th Social Question 5.
The account which throws light on Mauryan polity and society …………..
(a) Marco Polo
(b) Fahien
(c) Megasthanes
(d) Seleucus
Answer:
(c) Megasthanes

Samacheer Kalvi 9th History Book Question 6.
(i) Under the Magadha king the mahamatriyas functioned as secretaries to the ministers.
(ii) Accounts of Megasthanes titled Indica is a useful record about Mauryan polity and society.
(iii) Nanda’s attempt to build an imperial structure was cut short by Ashoka who founded the Mauryan kingdom.
(iv) According to tradition, towards the end of his life Chandragupta became an ardent follower of Buddhism.
(a) (i) is correct
(b) (ii) is correct
(c) (i) and (ii) is correct
(d) (iii) and (iv) is correct
Answer:
(i), (ii), (iii) and (iv) are correct

II. Fill in the blanks.

1. ………….. is a collection of sacred literature of different epochs, containing prayers, confessions and myths.
2. In the Gangetic plain …………… agriculture required the use of bullocks.
3. Jains believe that …………….. came in a long line of Tirthankaras and he was the twenty – fourth and the last.
4. The place where Buddha attained enlightenment has been built into the Mahabodhi temple that still exists in ……………..
5. The rock edicts form the reliable source to know about the Mauryan empire in particular the Dharmic rule of ……………….
Answer:
1. ZendAvesta
2. Iron plough
3. Mahavira
4. Bodh Gaya
5. Ashoka

III. Find out the correct statement.

9th Social Science Samacheer Kalvi Question 1.
(a) The introduction of Bronze tools made easy the removal of dense forest cover from the banks of the Ganges.
(b) Ajivikas had a small presence in western India.
(c) The clusters where particular clansmen were dominant came to be known were Pre-Maury an states.
(d) Of the kingdoms mentioned in the literature .of the period Kashi, Kosala and Magadha are considered to be powerful.
Answer:
(a) incorrect
(b) incorrect
(c) incorrect
(d) correct

Samacheer Kalvi Guru 9th Social Question 2.
(a) Ajatashatru was the first important king of Magadha.
(b) Bimbisara succeeded in establishing a comprehensive structure of administration.
(c) The Mauryas were the first of non-Kshatriya dynasties to rule in northern India.
(d) Nanda’s attempt to build an imperial structure was cut short by Ashoka.
Answer:
(a) incorrect
(b) correct
(c) incorrect
(d) incorrect

IV. Match the following.

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

V. Answer the following briefly.

Samacheer Kalvi 9th Social Question 1.
The invention of smelting of Iron transformed both production and warfare. Justify.
Answer:

1. The invention of smelting of iron transformed both production and warfare.
2. Before iron, copper and its alloy, bronze which were expensive were employed in production.
3. The weapons (or) ploughs made of copper (of) bronze edges became blunt quickly.
   1. Iron ore in contrast was available in abundance.
4. The “weapons made of iron was in usage.
5. The iron axe enabled cultivators to clear the jungles and the iron plough was used to’ break the hardest soil.

Question 2.
Elaborate the term “Tri-ratnas”.
Answer:
The three principles of Jainism also known as Tri-ratnas are the following.

1. Right faith: Belief in the teachings and wisdom of Mahavira.
2. Right knowledge: Acceptance of the theory that there is no God and that the world existed without a creator.
3. Right Action: It refers to the Mahavira’s observance of the five great vows.
   (a) ahimsa (b) honesty (c) kindness (d) truthfulness and (e) not coveting (or) desiring things belonging to others.

Question 3.
What do you know of Ajatasatru?
Answer:

• Ajatashatru, the son of Bimbisara is said to have murdered his father and ascended the throne in 493 BCE.
• He continued his father’s policy of expansion through military conquests.
• He strengthened the Rajagriha fort and also built another fort at Pataligrama on the Ganges. It served as the exchange centre for the local produce and late became Mauryan capital of Pataliputra.
• Ajatasatru died in 461 BCE.

Question 4.
What does the Edict of Kalinga convey?
Answer:

• In one of his Kalinga edicts, he tells his horror and sorrow over the deaths which the war and conquest caused.
• In yet another edict, he makes it known that Ashoka would not tolerate any longer the death (or) captivity of even hundredth (or) thousandth part of the number killed and captive in Kalinga.

Question 5.
Highlight the steps taken by Ashoka to spread Buddhism.
Answer:
Steps taken by Ashoka to spread Buddhism:

1. Ashoka became an ardent Buddhist after meeting the Buddhist monk Upagupta and propounded his Dharma.
2. He issued edicts, which were carved out in the rock.
3. He protected the animals.
4. Hospitals were constructed for them and animal sacrifice was forbidden.
5. Ashoka sent his son Mahendra and his daughter Sanghamitra to Ceylon to spread his message of Dharma there. Ashoka died after ruling for 38 years.

VI. Answer all the questions given under each caption.

Question 1.
Zoroastrianism
(a) Who was the founder?
Answer:
Zoroaster of Persia is the founder of Zoroastrianism.

(b) Name the God he proclaimed.
Answer:
Ahura Mazda (the Lord of lights)

(c) What did Zoroaster teach?
Answer:
Zoroaster taught that the great object of religion state or society is the cultivation of morality.

(d) What was the highest form of worship?
Answer:
Fire was worshipped as a symbol of the deity and considered the highest form of worship.

Question 2.
Gautama Buddha
(a) What was the original name of Buddha?
Answer:
The original name of Buddha was Siddhartha.

(b) Name the birth place of Buddha.
Answer:
The birth place of Buddha is Lumbini Garden near Kapilavasthu in 567 BCE.

(c) Where did he get enlightenment?
Answer:
He got enlightenment in the Mahabodhi temple, still exists in Bodh Gaya (Bihar).

(d) Mention the place of his first sermon.
Answer:
The place of his first sermon was Samath.

VII. Answer the following in detail.

Question 1.
Discuss the five cardinal principles of Confucius.
Answer:
Five Cardinal Principles of Confucius’ Ethics
1. Humaneness
2. Righteousness
3. Propriety;
4. Wisdom
5. Trustworthiness
(i) Confucius said that wisdom grows from the family, and that the foundation of society is the disciplined individual in an orderly family.

(ii) The superior man, according to him, is not merely intelligent or scholarly, but his character should be exemplary.

(iii) The superior man of Confucius possesses three virtues: intelligence, courage and goodwill

(iv) Though Confucius insisted on children obeying parents and wife her husband, he also clearly proposed that “when the command is wrong a son should resist his father and a minister should resist the prince.’’

(v) When asked about government, he said that there are three requisites for it: “That there should be sufficiency of food, sufficiency of military equipment and confidence of the people in their ruler.”

(vi) The philosophy of Confucius gave the Chinese people an awareness about their political rights. ‘

(vii) It also clearly listed the government’s duty towards the people. Confucius felt that the government should work with an ideal.

(viii) In matters of national life, Confucius felt that the people in the nation are the actual and proper source of political sovereignty. He advised that the ruler must appoint persons of character in the government to govern the people impartially.

(ix) Confucianism is often characterized as a system of social and ethical philosophy rather than as a religion.

Question 2.
Compare and contrast the principles of Jainism and Buddhism.
Answer:

1. The founders of Jainism and Buddhism did not prescribe killing as a religious rite.
2. They secured their livelihood mostly by alms. Celibacy and abstinence from holding property made the new teachers much more acceptable than the Brahman priests.
3. The people’s resentment about the expensive and elaborate Vedic rituals, animal sacrifice and the desire for wealth eventually took them towards Jainism and Buddhism.
4. Mahavira and Buddha lived a life of purity and exemplified simplicity and self-denial. They lived in the times of Bimbisara and Ajatashatru, the famous kings of Magadha.
5. The commercial development of the northern cities like Kaushambi, Kushinagar, Benaras, Vaishali and Rajgir added importance to the Vaishyas who turned to Buddhism and Jainism in their eagerness to improve their social status.

Student Activities

Question 1.
Prepare a case study of Asoka’s Edicts.
Answer:
“There are 33 edicts, including 14 Major Rock edicts, 7 Pillar edicts and 2 Kalinga edicts apart from Minor Rock edicts and Minor Pillar inscriptions”.
(i) The students can be divided into three groups in the class. Each group will be assigned a particular work, such as Major Rock Edicts, Pillar Edicts and Kalinga Edicts.
(ii) They can refer History Books, from the library (or) download from the Internet.
(iii) The teacher will be there to motivate the students.

Question 2.
Enact a drama about the life and teachings of Buddha.
Answer:
(i) You can prepare the script with the assistance of your teacher.
(ii) The drama can be enacted as a recreational activity in the class.

Assignment with teacher’s guidance

(i) List out the countries where Buddhism exists in the world and mark on the world map. Some of the Buddhist countries are: Cambodia, Thailand, Myanmar, Bhutan, Sri Lanka, Laos, Mongolia, Japan, Taiwan, Singapore, South Korea, Malaysia, China and Vietnam. The students can mark these places on the world map.
(ii) Prepare a clay model of Sjanchi Stupa, Darmachakra.
You can do this activity in groups with the help of your teacher.

Intellectual Awakening and Socio-Political Changes Additional Questions

I. Choose the correct answer.

Question 1.
The discovery of ………….. marked the beginning of the second phase in the history of civilisations.
(a) Iron
(b) Gold
(c) Copper
(d) Bronze
Answer:
(a) Iron

Question 2.
…………… said that wisdom grows from the family.
(a) Lao-Tse
(b) Zoroaster
(c) Confucius
(d) Buddha
Answer:
(c) Confucius

Question 3.
The doctrines and rituals of the Zoroastrians have much similarity to those of the ……………
(a) Buddhism
(b) Vedas
(c) Jainism
(d) Taoism
Answer:
(b) Vedas

Question 4.
Buddhism was preached in people’s language ……………….
(a) Pali
(b) Sanskrit
(c) Hindi
(d) Chinese
Answer:
(a) Pali

Question 5.
Chandragupta’s son was ……………
(a) Bimbisara
(b) Bindusara
(c) Ajatasatru
(d) None of the above
Answer:
(b) Bindusara

Question 6.
(i) Monastries and temples served the purpose imparting education.
(ii) Nalanda was a great monastry built by the Magadha empire.
(iii) Nalanda became the most renowned seat of learning.
(iv) Fees were charged to the students.
(a) (i) is correct
(b) (ii) is correct
(c) (iii) is correct
(d) (i), (ii), (iii) are correct (iv) is incorrect
Answer:
(d) (i), (ii), (iii) are correct (iv) is incorrect

II. Fill in the blanks.

1. The philosophy of confucius gave the Chinese people an awareness about their ……………..
2. ………….. was pained to find his people worshipping primitive deities.
3. Mahavira and Buddha lived a life of purity and exemplified …………… and …………….
4. The statue of Bahubali at …………… in Karnataka is the tallest jain statue ever carved out in India.
5. Buddha belonged to the Sakya class he was also known as ……………….
6. Buddhism was split into two as ………….. and ……………
7. …………… succeeded in establishing a comprehensive structure of administration.
8. Alexander’s death, however, cleared the way for the founding of a great empire …………….. empire in India.
9. The envoy of Seleucus’s was …………….
10. Chandragupta’s minister Chanakya is credited with a book titled …………..
Answer:
1. Political rights
2. Zoroaster
3. Simplicity, Self-denial
4. Shravanabelgola
5. Sakya Muni
6. Hinayana & Mahayana
7. Bimbisara
8. Mauryan
9. Megasthenes
10. Arthasastra

III. Match the following.

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

IV. Answer the following questions briefly.

Question 1.
Who were the two great thinkers in the sixth century BCE?
Answer:
Confucius and Lao-Tse were the two great thinkers in the sixth century BCE.

Question 2.
Mention the five important works of Confucius.
Answer:

1. The Book of Records
2. The Book of odes
3. The Book of changes
4. The spring and Autumn Annals
5. The Book of History.

Question 3.
Name the seven qualities of Ahura Mazda.
Answer:

1. light
2. good mind
3. right
4. dominion
5. piety
6. well-being
7. immortality.

Question 4.
What kind of life Mahavira and Buddha live?
Answer:
Mahavira and Buddha lived a life of purity and exemplified simplicity and self-denial.

Question 5.
Write a short note on “split in Jainism”.
Answer:

• In course of time, Jainism split into two branches namely the Digambaras (Sky-clad) and the Svetambaras (White-clad)
• The Digambaras were the Orthodox followers of Mahavira. They rejected clothes altogether. The Svetambaras wore a white dress from head to toe.

Question 6.
What did Buddha do to establish Buddhism?
Answer:

• Buddha in order to carry his message to different parts of India, established the Buddhist Sangha (or) the Holy order of Monks.
• The bikshus (monks) and the bikshunis (nuns) were enlisted for spreading the faith and they were required to lead a life of purity and poverty.

Question 7.
What do you know about Nanda dynasty?
Answer:

1. Mahapadma Nanda founded the Nanda dynasty.
2. The Nandas were the first of non-Kshatriya dynasties to rule in North India.
3. Nandas gave importance to irrigation with the canals, they built touching even the Kalinga kingdom.

Question 8.
Mention the Educational centres of Mauryan Administration.
Answer:

1. Monastries and temples served the purpose of imparting education.
2. Nalanda was a great monastry built by the Magadha Empire.
3. Educational centres offered Buddhist and Vedic literature, logic, grammar, medicine, philosophy and astronomy.
4. Even the science of war was taught.
5. Nalanda became the most renowned seat of learning in course of time.

V. Answer all the questions given under each caption.

Question 1.
Confucius.
(a) When was confucius born?
Answer:
Confucius was bom in the Shantung province of China in 551 BCE.

(b) Mention the five important works of Confucius.
Answer:

1. The Book of Records
2. The Book of odes
3. The Book of changes
4. The spring and Autumn Annals
5. The Book of History.

(c) What are the five cardinal principles of “Confucius” Ethics?
Answer:

1. Humaneness
2. Righteousness
3. Propriety
4. Wisdom
5. Trustworthiness.

(d) Mention the three virtues to be possessed by a superior man.
Answer:
Intelligence, courage and good will.

Question 2.
Jainism.
(a) When was Mahavira born?
Answer:
Vardhamana Mahavira was bom in 599 BCE at Kundagrama near Vaishali.

(b) Mention the three principles of Jainism.
Answer:

1. Right faith
2. Right knowledge
3. Right Action.

(c) Name the rulers who patronised Jainism.
Answer:
Dhana Nanda, Chandra Gupta Maurya and Kharavela.

(d) What are the two branches of Jainism?
Answer:
The two branches are Digambaras and Svetambaras.

VI. Answer the following in detail.

Question 1.
Explain the teachings of Lao-Tse (Taoism).
Answer:

1. The cause of human unhappiness in the world is human selfishness. Selfishness creates unlimited human desires, which can never be satisfied.
2. In nature, all the things act in a natural way. The law of human conduct must correspond . with nature.
3. Humans live a life under the regulation of someone. This is because they have acquired knowledge and have not remained innocent. On the basis of their acquired knowledge, they have built up an urban civilisation and have made themselves unhappy.

Question 2.
Give reasons for the decline of Buddhism.
Answer:
Buddhism declined in India due to the following reasons:

1. Buddhism was popular in the beginning because it was preached in people’s language (Pali). The later texts were written in Sanskrit, which was difficult for the common people to understand.
2. The split in Buddhism into Hinayana and Mahayana was another vital reason. Image worship in Mahayana made no difference between Hinduism and Buddhism.
3. Buddhism lost its royal patronage during the reign of Guptas.
4. Further, the invasions of Huns and Turks almost wiped out Buddhism.

You can Download Mother’s Voice Questions and Answers, Summary, Activity, Notes, Samacheer Kalvi 9th English Book Solutions Guide Pdf Supplementary Chapter 6 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 6 Mother’s Voice

Mother’s Voice Supplementary In English

Mother’s Voice Warm Up:

If you are given an opportunity to go on a one-way trip to Mars, will you accept it? Discuss.
If given an opportunity to go on a one-way trip to Mars, I will not take it up since I am basically a timid person. When I am so frightened to travel by airplane, how will I travel to outer space!

Mother’s Voice Textual Questions

A. Choose the correct answer.

Mother’s Voice Summary Question 1.
Mother was excited because __________.
(a) her son would be home in the spring
(b) her son was coming back to earth
(c) it was her first visit to the moon
(d) her son was going to another galaxy
Answer:
(c) it was her first visit to the moon

Mother’s Voice Supplementary Paragraph Question 2.
On weekdays, as Mother went about the chores __________.
(a) she constantly thought of her son
(b) she was always tired
(c) her singing would be soft and almost inaudible
(d) her singing was muted and a little sad
Answer:
(d) her singing was muted and a little sad

Mother’s Voice Questions And Answers Question 3.
__________ occupies more than a hundred square kilometers on the moon.
(a) Selenopolis
(b) Metropolis
(c) Astrodrome
(d) Orchards
Answer:
(a) Selenopolis

Mother’s Voice Question 4.
The Community of Nations Square is where people __________.
(a) live on the moon
(b) work on the moon.
(c) walk on the moon
(d) of different nationalities come after work
Answer:
(d) of different nationalities come after work

Mother’s Voice Supplementary Summary Question 5.
They are planning an expedition to a neighbouring __________.
(a) galaxy
(b) country
(c) planet
(d) star
Answer:
(a) galaxy

Mother Voice Summary Question 6.
The mother was not able to understand why people wanted to leave the moon because __________.
(a) it was better to remain as a part of solar-system
(b) it was better to remain on the earth
(c) it was not possible to come back
(d) it was a place to enjoy life
Answer:
(a) it was better to remain as a part of the solar system.

Summary Of Mother’s Voice Additional Questions

Mothers Voice Question 1.
The mother wanted to know if her son would come during ………………. .
(a) Summer
(b) Autumn
(c) Winter
(d) Spring
Answer:
(b) Autumn

Mother’s Voice Supplementary Question 2.
His mother looked at the enormous lily-shaped tent over a ……………….. .
(a) Plate
(b) crater
(c) sheet of ice
(d) galaxy
Answer:
(b) crater

Mother’s Voice Lesson Plan Question 3.
His mom preferred River ……………………… than Selenopolis.
(a) Dnieper
(b) Pluto
(c) Ganges
(d) Miami
Answer:
(a) Dnieper

Mother’s Voice Book Back Answers Question 4.
Since the pond is deepend, there will be a lot of …………….. .
(a) fresh water
(b) moss
(c) mosquitoes
(d) fish
Answer:
(d) fish

Mother’s Voice By Vasil Summary Question 5.
The spaceships on the moon were readied for ……………….. .
(a) the scientists to travel.
(b) an expedition to the nearby galaxy
(c) the school students to explore
(d) a voyage around’ the moon.
Answer:
(b) an expedition to the nearby galaxy

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

1. It’s so easy to walk here, son!
2. They’re planning an expedition to a neighboring galaxy.
3. Why should people go off into the unknown?
4. I don’t know when we’ll see each other again.
5. Operator on duty, ………. report to the office.

Answers:

1. Mother
2. Son
3. Mother
4. Son
5. A voice from the loud Speaker

Mother’s Voice Summary By Vasil Berezhnoy Additional Questions:

Identify the character or speaker of the following lines.

Astronaut’s Mom to Son:

1. I never realized it was such a beautiful place.
2. Back home the orchards are in bloom.
3. Will you come for a holiday in the summer?
4. I’m sure it’s better in the river Dnieper.
5. What are these?
6. Of course, you will walk on the dewy grass.
7. Why should people go off into the unknown?
8. Do you know why people settle down on the Moon so easily?
9. There will be a lot of fruits this year if only the frosts don’t strike.
10. Why ask for trouble?
11. These are very reliable spaceships.
12. At least try to come in the autumn.
13. They have deepened the pond.
14. You could visit your friends and relatives.
15. It’s full of fish now, you like fishing.

The young astronaut to his mother:

1. That’s why I asked you to come.
2. It’s easy to walk here but the distances are long.
3. People of different nationalities who work in Selenopolis come here after work.
4. Let’s ride for a bit.
5. The Community of Nations Square.
6. It’s quite an exotic experience to have a swim on the moon.
7. Long-range spaceships They’re planning an expedition to a neighboring galaxy.
8. You may be right, but
9. How do I know?
10. You think I don’t want to walk barefoot on the dewy grass?
11. Coming
12. These are very reliable spaceships.
13. There are some tourists.
14. Selenopolis occupies more than a hundred square kilometers.
15. They are walking towards the lake.

C. Answer the following questions in about 100 -120 words.

Mother’s Voice Supplementary Story In Tamil Question 1.
Write a paragraph listing all the sentimental and the scientific reasons given by the mother against the expedition to the neighbouring galaxy.
Answer:
The mother’s sentimental and scientific reasons against the expedition to the neighboring galaxies are that the moon is a beautiful place, easy to walk on. There are lots of fruits on earth. The river Dnieper is better to swim. She asked her son why people should go off into the unknown and ask for trouble. She also suggested that it is advisable for people to settle on the moon first and then on the planets in the solar system.

She philosophized that the moon has the same gravitational field of their native earth, under the native sun. She sentimentally invited her son to come in the autumn for the apples, pears and the watermelons. She persuaded him to come to their deepened pond to fish and indicated that the pond was now full of fish.

Mother’s Voice Supplementary Theme Additional Questions:

Mother’s Voice 9th Supplementary Question 1.
Describe Selenopolis.
Answer:
Selenopolis is much easier to walk through though the distances are long. It occupies more than a hundred square kilometers. It’s a moving pavement covered with green plastic strips. These are rushed through echoing tunnels and spacious caves with walls sparkling in the light of the quartz lamps. There is a large lily-shaped tent over a crater, at least a kilometer in diameter. This was called, ‘The community of Nations Square.’ ‘People of different nationalities who work in Selenopolis and tourists go there to relax.

D. Think and answer.

“The explorer in this story is traveling to another galaxy. The final destination is an unknown ‘ planet in another galaxy. The travel will take many years”. What qualities and life skills do you think an explorer-like him must possess? Why? Do you have any of these skills and qualities? Explain.
Answer:
Space explorers work either as pilots who fly spacecraft or as mission specialists who conduct experiments. Regardless of their position, they need certain qualities to survive both NASA’s selection process and space travel itself. The qualities and life- skills needed are intelligence, adaptability, good physique, mental endurance and good ‘ knowledge. I have all these skills except the educational level which I would study as I grow up. ‘

Intelligence:
Astronauts need above-average intelligence and need quick thinking to A handle unexpected problems. They also need the intellectual creativity to dream up new avenues of space-based research into medicine, materials and processes for use N on Earth and in space. Curiosity is key, as are people skills and communication skills.

Adaptability:
Astronauts have many responsibilities in space. They need the flexibility to move from one task to another, different task. They also work on teams with astronauts from other countries and cultures, so they must be open-minded to diversity. They must be willing to change routines to accommodate new procedures.

Physical Condition:
The rigors of space travel are just about as intense as the rigors of space training. Astronauts need eyesight of20/100 or better uncorrected, correctable to 20/20 in each eye. Their blood pressure can’t be above 140/90. Candidates also must meet military water survival standards, which test for the ability to swim without stopping and to swim and tread water clothed in flight gear.

Astronauts also must be SCUBA-qualified to prepare for spacewalk training. Their bodies must respond well to high and low atmospheric pressures. They also must be prepared for the physical effects of zero gravity training up to 40 times a day. Space travel can last for months, during which the human body must function amid physical stress.

Mental Endurance:
Astronauts who make it through the physical demands of space travel must also grapple with isolation, fear and separation from loved ones. It’s not easy to live in close quarters with virtual strangers for three to six months or more. Astronauts must begin to cope with those long periods away from home during training, which takes two to three years and requires heavy travel to practice with international mission partners.

Education:
Astronauts need a bachelor’s degree from an accredited university in engineering, biological science, physical science and maths.

E. Based on the understanding of the story, discuss in groups and make a note of the following.

Mother’s Voice by Vasil Berezhnoy About The Author:

In 1972, a group of authors were awarded the Rudaki Prize of the Tajik SSR, which shows the importance of Soviet Literature and the role played by Science fiction. Vasil Berezhnoy was surely one among the group of authors.

Mother’s Voice Supplementary Summary:

This story revolves around the feeling of a young astronaut who has volunteered to explore the 1 galaxy beyond the one he lived in. The entire conversation between the mother and son is the recording that he hears now and then. The beginning of the story sees him taking his mother to the moon. He shows her around. They walk through the Selenopolis, seeing tall structures that have propped up the star-studded sky. The son listens to his mother’s voice that is so dear to him. She talks to her son about the orchards, the river Dnieper where he used to go for fishing, the apples, pears and melons, the walk on the dewy grasses, their relatives whom he may never meet if he goes for this expedition.

Yet she hopes that he will come and visit her during his vacation. She tells how the planet earth is so rich and beautiful with snow-covered peaks, that there can never be a place like the planet earth. This makes the son look at the earth with a newer vision and he understands that his mother is right. It is never going to be the same in another galaxy far away from home and his mother.

But, now he is helpless and cannot change his decision of coming back to earth. He goes on explaining the things happening on the moon; how people come to the ‘Community of Nations Square’ after work for relaxation. He tells about the spaceships which is fully equipped for this major expedition. The mother watches the rockets with people assembling for a take off, and asks her son why someone yearns to leave their home and go to another galaxy instead of being happy with their own.

She tries to pursue her son to quit from this mission even though she knew she may never see her son again. Just then a voice from the loudspeaker asks the astronaut to report to duty and he turns off the button and the screen becomes blank. He often plays this recording to be in that moment with his mother. This kind of expedition is the result of young curious minds and humanity.

Mother’s Voice 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 5 Magnetism and Electromagnetism

Samacheer Kalvi 9th Science Magnetism and Electromagnetism Textbook Exercises

I. Choose the correct answer.

9th Science Magnetism And Electromagnetism Question 1.
Which of the following converts electrical energy into mechanical energy?
(a) motor
(b) battery
(c) generator
(d) switch
Answer:
(a) motor

Magnetism And Electromagnetism Samacheer Kalvi Question 2.
The part of the AC generator that passes the current from the armature coil to the external circuit is
(a) field magnet
(b) split rings
(c) slip rings
(d) brushes
Answer:
(d) brushes

Chapter 5 Magnetism And Electromagnetism Question 3.
Transformer works on
(a) AC only
(b) DC only
(c) both AC and DC
(d) AC nor effectively than DC
Answer:
(a) AC only

Magnetism And Electromagnetism Questions And Answers Pdf Question 4.
The unit of magnetic flux density is
(a) Weber
(b) weber/meter
(c) weber/meter²
(d) weber.meter²
Answer:
weber/meter²

II. Fill in the blanks.

1. The SI Unit of magnetic field induction is ……………………..
2. Devices which is used to convert high alternating current to low alternating current is …………………..
3. An electric motor converts …………………..
4. A device for producing electric current is ……………………..

Answer:

1. Tesla
2. Step down transformer
3. Electrical energy into mechanical energy
4. Generator

III. Match the following.

Column – I	Column – II
1. Magnetic material	(a) Oersted
2. Non-magnetic material	(b) iron
3. Current and magnetism	(c) induction
4. Electromagnetic induction	(d) wood
5. Electric generator	(e) Faraday

Answer:

1. (b) iron
2. (d) wood
3. (a) Oersted
4. (e) Faraday
5. (c) induction

IV. True or False.

1. A generator converts mechanical energy into electrical energy – True
2. Magnetic field lines always repel each other and do not intersect – True
3. Fleming’s Left hand rule is also known as Dynamo rule – True
4. The speed of rotation of an electric motor can be increased by decreasing the area of the coil – False
   Correct Statement: The speed of rotation of coil can be increased by increasing the area of the coil.
5. A transformer can step up direct current – False
   Correct Statement: A transformer can step up alternating current.
6. In a step down transformer the number of turns in primary coil is greater than that of the number of turns in the secondary coil – True

V. Answer in brief.

Magnetism And Electromagnetism Pdf Question 1.
State Fleming’s Left Hand Rule.
Answer:
It states that while stretching the three fingers of left hand in perpendicular manner with each other, if the direction of the current is denoted by middle finger of the left hand and the second finger is for direction of the magnetic field then the thumb of the left hand denotes the direction of the force or movement of the conductor.

Electromagnetism Exercises And Solutions Pdf Question 2.
Define magnetic flux density.
Answer:
The number of magnetic field lines crossing unit area kept normal to the direction of field lines is called magnetic flux density. Its unit is Wb/m²

9th Class Science Chapter 5 Question Answer Question 3.
List the main parts of an electric motor.
Answer:
Main parts of an electric motor are:

1.  Shaft,
2. Primary and Secondary windings,
3. Ball bearings,
4. Armature,
5. Stator,
6. Commutator,
7. Brushes,
8. Terminals

Magnetism And Electromagnetism Question 4.
Draw and label the diagram of an AC generator.
Answer:

Electromagnetism Exercises Question 5.
State the advantages of AC over DC.
Answer:
Advantages of AC over DC:

• The Voltage of AC can be varied easily using a device called transformer. The AC can be carried over long distances using step up transformers. The loss of energy while distributing current in the form of AC is negligible.
• Direct current cannot be transmitted as such. The AC can be easily converted into DC. Generating AC is easier than DC. The AC can produce electromagnetic induction which is useful in several ways.

Magnetism Notes Class 9 Question 6.
Differentiate step up and step down transformer.
Answer:

Step up transformer	Step down transformer
The transformer used to change a low alternative voltage to a high alternating voltage is called a step up transformer, i.e. (Vs>Vp).	The transformer used to change a high alternating voltage to a low alternating voltage is called a step down transformer (Vs <Vp).
In a step up transformer, the number of turns in the secondary coil is more than the number of turns in the primary coil (Ns > Np)	In a step down transformer, the number of turns in the secondary coils are less than the number of turns in the primary coil (Ns < Np)

Question 7.
A portable radio has a built in transformer so that it can work from the mains instead of batteries. Is this a step up or step down transformer?
Answer:
A step-down transformer is used in a portable radio in order to reduce the voltage.

Question 8.
State Faraday’s laws of electromagnetic induction.
Answer:
Whenever there is a change in the magnetic flux linked with a closed-circuit an emf is produced and the amount of emf induced varies directly as the rate at which the flux changes. This emf is known as induced emf and the phenomenon of producing an induced emf due to change in the magnetic flux linked with a closed circuit is known as electromagnetic induction.

VI. Answer in detail.

Question 1.
Explain the principle, construction and working of a DC motor.
Answer:
A motor is an electrical machine which converts electrical energy into mechanical energy. The principle of working of a DC motor according to Faraday’s laws of electromagnetic induction is that “whenever a current carrying conductor is placed in a magnetic field, it experiences a mechanical force”. The various parts of a DC motor are; Permanent magnets on both sides of a coil which consists of carbon brush and commutator as shown in

Working of electric motor is primarily dependent upon the interaction between magnetic field and current. The direction of this force is given by Fleming’s left hand rule and it’s magnitude is given by F = BIL. Where, B = magnetic flux density, I = current and L = length of the conductor within the magnetic field.

Question 2.
Explain two types of transformer.
Answer:
Transformer is a device used for converting low voltage into high voltage and high voltage into low voltage. It works on the principle of electromagnetic induction. It consists of primary and secondary coil insulated from each other. Depending upon the number of turns in the primary and secondary coils, the two types of transformers are; step-up or step-down transformers.

Step up transformer:
The transformer used to change a low alternative voltage to a high alternating voltage is called a step up transformer, ie (Vs > Vp) . In a step up transformer, the number of turns in the secondary coil is more than the number of turns in the primary coil (Ns > Np).

Step down transformer:
The transformer used to change a high alternating voltage to a low alternating voltage is called a step down transformer (Vs < Vp). In a step down transformer, the number of turns in the secondary coils are less than the number of turns in the primary
coil (Ns < Np).
The formulae pertaining to the transformers are given in the following equations.

• • The number of primary turns N_p / The number of secondary turns N_s = The primary voltage V_p/ The secondary voltage V_s
  • The number of secondary turns N_s / The number of primary turns N_p – The primary current I_p/ The secondary current I_s

Question 3.
Draw a neat diagram of an AC generator and explain its working.
Answer:
An alternating current (AC) generator, consists of a rotating rectangular coil ABCD called armature placed between the two poles of a permanent magnet. The two ends of this coil are connected to the two slip rings S₁ and S₂. The inner sides of these rings are insulated. Two conducting stationary brushes B₁ and B₂ are kept separately on the rings S₁ and S₂ respectively. The two rings S₁ and S₂ are internally attached to an axle. The axle may be mechanically rotated from outside to rotate the coil inside the magnetic field. Outer ends of the two brushes are connected to the external circuit.

When the coil is rotated, the magnetic flux linked with the coil changes. This change in magnetic flux will lead to generation of induced current. The direction of the induced current, as given by Fleming’s Right Fland Rule, is along ABCD in the coil and in the outer circuit it flows from B₂ to B₁. During the second half of rotation, the direction of current is along DCBA in the coil and in the outer circuit it flows from B₁ to B₇. As the rotation of the coil continues, the induced current in the external circuit is changing its direction for every half a rotation of the coil.

ACTIVITY

Question 1.
Put a magnet on a table and place some paper clips nearby. If you push the magnet slowly towards the paper clips, there will be a point at which the paper clips jump across and stick to the magnet. What do you understand from this?
Answer:

The invisible magnetic field that surrounds the magnet acts at a particular distance. This magnetic field attracts the paper clip which is made of steel.

Samacheer Kalvi 9th Science Magnetism and Electromagnetism In Text Problems.

Question 1.
A conductor of length 50 cm carrying a current of 5 A is placed perpendicular to a magnetic field of induction 2 × 10^{– 3} T. Find the force on the conductor.
Solution:
Force on the conductor = ILB
= 5 × 50 × 10^{– 2} × 2 × 10^{– 3}
= – 5 × 10^{– 3} N

Question 2.
A current carrying conductor of certain length, kept perpendicular to the magnetic field experiences a force F. What will be the force if the current is increased four times, length is halved and magnetic field is tripled?
Solution:
F = ILB = (4I) × ( L / 2) × (3 B) = 6 F
Therefore, the force increases six times.

Question 3.
The primary coil of a transformer has 800 turns and the secondary coil has 8 turns. It is connected to a 220 V ac supply. What will be the output voltage?
Solution:
In a transformer, E_s / E_p = N_s / N_p
E_s = N_s / N_p × E_p
= \(\frac { 8 }{ 800 }\) × 220 = \(\frac { 220 }{ 100 }\) = 2.2 volt

Samacheer Kalvi 9th Science Magnetism and Electromagnetism Additional Questions

I. Short answers questions.

Question 1.
What are natural magnets?
Answer:
Natural magnets exists in the nature and can be found in rocks and sandy deposits in various parts of the world.

Question 2.
How can the speed of rotation of a coil be increased? Write at least three methods.
Answer:
The speed of rotation of a coil can be increased by;

• increasing the strength of the Current in the coil
• increasing the area of the coil
• increasing the strength of the magnetic field.

Question 3.
What is the connection between electricity and magnetism?
Answer:
Electricity and magnetism are closely related to each other. The current flowing through the wire produces a circular magnetic field outside the wire. The direction of this magnetic field depends on the electric current.

Similarly, a changing magnetic field produces an electric current in a wire or conductor. The relationship between electricity arid magnetism is called electromagnetism.

Question 4.
What are the factors that determine the strength of the magnet?
Answer:
The strength of the magnetic field at a point due to current carrying wire depends on:

• the current in the wire
• distance of the point from the wire
• the orientation of the point from the wire and
• the magnetic nature of the medium.

Question 5.
Name some equipmetns that use electromagnetism for functioning.
Answer:
Many of the medical equipments such as scanners, x-ray equipments and other equipments also use principle of electromagnetism for their functioning.

Question 6.
Explain why the ozone layer is not affected by the solar wind.
Answer:
Magnetic field can penetrate through all kinds of materials. The Earth produces its own magnetic field, which shields the earht’s ozone layer from the solar wind.

Question 7.
Write the properties of magnetic lines of force.

• Magnetic lines of force are closed continuous curves, extending through the body of the magnet.
• Magnetic lines of force start from the North Pole and end at the South Pole.
• Magnetic lines of force never intersect.
• They will be maximum at the poles than at the equator.
• The tangent drawn at any point on the curved line gives the direction of magnetic field.

II. Long answers questions.

Question 1.
What do you know about Michael Faraday?
Answer:
Michael Faraday discovered that a current carrying conductor also gets deflected when it is placed in a magnetic field. Michael Faraday was a British Scientist who contributed to the study of electromagnetism and electrochemistry. His main discoveries include the principles underlying electromagnetic induction, diamagnetism and electrolysis. Although Faraday received little formal education, he was one of the most influential scientists in history. Faraday was an excellent experimentalist who conveyed his ideas in clear and simple language.

The SI unit of capacitance is named in his honour: the farad. Albert Einstein kept a picture of Faraday on his study wall, alongside pictures of Isaac Newton and James Clerk Maxwell. Faraday is one of the greatest scientific discoverers of all time.

Question 2.
Explain in detail about the application of electromagnets.
Answer:
Applications of electromagnets – Electromagnetism has caused a great impact on various fields such as medicine, industries, space, etc. In our day to day life, it finds application in;
(a) Speakers – In a speaker the electromagnet is placed in front of a permanent magnet. The permanent magnet is fixed whereas the electromagnet is mobile. As pulses of electricity pass through the coil of the electromagnet, the direction of its magnetic field rapidly changes. This causes it to get attached to and repelled from the permanent magnet, thereby causing vibration. The electromagnet is attached to a cone made of plastic or paper which amplifies the sound and the waves reaching our ears.

(b) Maglev – Magnetic levitation trains are suspended with no support other than magnetic fields. In maglev trains two sets of magnets are used. One set to repel and push the train up off the track, and another to move the floating train ahead at a great speed without friction. The train travels along a guideway of magnets which controls the tram’s stability and speed using the basic principles of magnets.

(c) MRI Scanner – Magnetic resonance imaging is a procedure using sophisticated instruments that work on the principle of electromagnetism that can scan minute details of the human body. Other medical equipment such as X-rays etc., also use this principle for their functioning.

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 Civics Solutions Chapter 3 Human Rights

Human Rights Textual Exercise

I. Choose the correct answer.

Human Rights Class 9 Question 1.
‘Apartheid’ was followed by
(a) South Sudan
(b) South Africa
(c) Nigeria
(d) Egypt
Answer:
(b) South Africa

Samacheer Kalvi 9th Social Question 2.
…….. right exercises in the formation and administration of a government.
(a) Social
(b) Economic
(c) Political
(d) Cultural
Answer:
(c) Political

Samacheer Kalvi Guru 9th Social Question 3.
A 10 year old boy is working in a shop. Which right can you use to recover him?
(a) Right to equality
(b) Right to freedom
(c) Right against child labour exploitation
(d) Right to freedom of Religion
Answer:
(c) Right against child labour exploitation

Samacheer Kalvi Guru 9th Social Science Question 4.
Which one of the following rights has increased the influence of the people over bureaucracy?
(a) Right to equality
(b) Right to information
(c) Right to education
(d) Right to freedom
Answer:
(b) Right to information

Samacheerkalvi.Guru 9th Social Question 5.
What is the time limit to get the information from RTI Act 2005?
(a) 20 days
(b) 25 days
(c) 30 days
(d) 35 days
Answer:
(c) 30 days

9th Samacheer Kalvi Social Science Civics Solutions Chapter 3 Human Rights Question 6.
…….. right was removed from the fundamental Rights by the 44^th Amendment.
(a) Right to own (or) sell property
(b) Right to freedom of religion
(c) Child labour and right against exploitation
(d) None of the above
Answer:
(c) Child labour and right against exploitation

9th Social Samacheer Kalvi Question 7.
Which of the following statements are true?
(i) The state Human Rights commission was established in 1993.
(ii) It has the power of a civil count.
(iii) It’s power extend beyond the state.
(iv) It can also recommend compensation to victims.
(a) (i) and (ii) are true
(b) (i) and (iii) are true
(c) (i), (ii) and (iii) are true
(d) (i), (ii) and (iv) are true
Answer:
(d) (i), (ii) and (iv) are true

Samacheer Kalvi 9th Social Solutions Question 8.
Consider the following statements.
Assertions (A): Rights and duties are the two sides of the same coin.
Reason (R): We have a right to freedom of religions. We have to promote harmony and the spirit of the people of other religions.
(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
Answer:
(a) both A and R are correct and R explains A

9th Samacheer Kalvi Social Science Question 9.
According to the UNO a child is a person who has not completed the age of …….. years.
(a) 12
(b) 14
(c) 16
(d) 18
Answer:
(d) 18

9th Standard Samacheer Kalvi Social Science Question 10.
Kailash Satyarthi and Malala have been awarded Nobel Prize for
(a) Literature
(b) Peace
(c) Physics
(d) Economics
Answer:
(b) Peace

II. Fill in the blanks.

1. The Universal Declaration of Human Rights (UDHR) was adopted on ……….
2. The Universal Declaration of Human Rights Contains …….. articles.
3. The fundamental Duties were incorporated in the Constitution by ……… Amendment Act.
4. The National Human Rights commission was established on ………..
5. ………. Act came into effect on 1st April 2010.
6. Indian state to implement women ancestral property Act in 1989 was ………..
7. The Civil Rights movement in the United State was initiated by ……….
Answers:
1. 10^th December 1948
2. 30
3. 42^nd
4. 12^th October 1993
5. Right to Education
6. Hindu Succession Act
7. Rosa Parks

III. Match the following:

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

IV. Give short answers.

Samacheer Kalvi 9th Social Science Civics Book Solutions Question 1.
What is Human Right?
Answer:
The U.N.O defines Human rights as “The right inherent to all human beings, regardless of race, gender, nationality, ethnicity, language, religion or any other status. Every one is entitled to these rights without discrimination”.

Samacheer Kalvi Social 9th Question 2.
What are the fundamental rights?
Answer:

• Right to Equality
• Right to Freedom
• Right against Exploitation
• Right to Freedom of Conscience and Religion
• Cultural and Educational Rights for minorities
• Right to Constitutional Remedies

Question 3.
What are the Child Rights define by the UNO?
Answer:

• Right to life
• Right to family environment
• Right to Education
• Right to benefit from Social security
• Right against sexual exploitation
• Right against sale or trafficking
• Right against other forms of exploitation like Child labour.

Question 4.
Write a short note on the Right to Constitutional Remedies.
Answer:
Fundamental Rights are guaranteed by the Constitution. By this right, a person can adopt Constitutional means and approach a court if he is denied the Fundamental Rights. The court then issues orders which are called ‘Writs’ to the government to restore the rights to the citizen. The Constitutional Remedies put to right anything which may be wrong in terms of the Constitution. This right therefore protects and safeguards all other rights.

Question 5.
Define: POCSO
Answer:

1. The state should protect children from sexual exploitation and abuse, when they are forced or persuaded to take part in sexual activities physically or mentally.
2. The Protection of Children from Sexual Offences Act, 2012.
3. Regards the best interest of the child as being of paramount importance at every stage.

Question 6.
Why do children need special attention?
Answer:

1. Children are considered to be the future citizens and an asset to a nation.
2. They should be brought up with warmth and by nurturing their interest.
3. The children when loved and appreciated, realizes their value.
4. This makes the child feel secured and develops self-esteem.
5. Eventually, the child is ready to face challenge in life with positive attitude.

Question 7.
What are the contributions to labourers by B.R. Ambedkar?
Answer:
Dr. B.R. Ambedkar’s contribution to labourers.

• Reduction in Factory Working Hours (8 hours a day)
• Compulsory Recognition of Trade Unions
• Employment Exchange in India
• Employees State Insurance (ESI)
• Minimum Wages
• Coal and Mica Mines Provident Fund

Question 8.
‘All are equal before law’. But we have enacted a separate law for women – Justify.
Answer:

1. The National Commission for Women (NCW) is constituted in India to review the Constitutional and legal safeguards for women.
2. Recommends remedial measures.
3. Advises the government on all matters of policy affecting the welfare and development of women in the country.
4. Women’s rights under the Constitution of India mainly include equality, dignity, and freedom from discrimination.

Question 9.
Write about the Right against exploitation.
Answer:
It is against the law of employ children below 14 years of age in mines, factories or other occupations. Neither contractor nor an employer can force a worker to do a job against the their will.

Question 10.
Differentiate: Fundamental Rights and Human Rights.
Answer:

Fundamental Rights	Human Rights
The elemental rights of the citizens of a country, which are listed in the constitution and enforceable under the law is known as fundamental rights.	The rights that a human being deserves to survive with respect and freedoms.
Fundamental rights includes only those rights which are basic to a normal life.	Human rights include those rights which are basic to a real life and are absolute, i.e. it cannot be taken away.
Fundamental rights are guaranteed under the constitution of the country.	Human rights are recognised at international level.

V. Answer in Detail.

Question 1.
Write a paragraph about UDHR.
Answer:

1. The Universal Declaration of Human Rights is a milestone document in the history of human rights.
2. The Declaration was proclaimed by the United Nations General Assembly in Paris on 10th December 1948.
3. The first time it sets out the fundamental human rights to be universally protected and the UDHR has been translated into many languages.
4. There are 30 articles in the Universal Declaration of Human Rights and it guarantees freedom of expression as well as civil, political, social, economic and cultural rights. These rights apply to all people, irrespective of their race, gender and nationality, as all people are born free and equal.

Question 2.
What are fundamental duties? How would you follow these in your school premises?
Answer:
These were incorporated in the Constitution by the 42^nd Amendment Act in 1976. The
Constitution states eleven Fundamental Duties as given below:

1. Respect for the Constitution and its ideals and institutions, the National Flag and the
   National Anthem.
2. To follow and cherish the noble ideals which inspired our National Struggle for freedom.
3. To uphold and protect the sovereignty, unity and integrity of India.
4. To defend the country and render national service when called upon to do so.
5. To promote harmony and spirit of common brotherhood amongst all the people of India, transcending religious, linguistic, regional or sectional diversities, to renounce practices derogatory to the dignity of women.
6. To value and preserve the rich heritage of our composite culture.
7. To protect and improve the natural environment including forests, lakes, rivers and wildlife and have compassion on living creatures.
8. To develop the scientific temper, humanism and the spirit of inquiry and reform.
9. To safeguard public property and to abjure from violence.
10. To strive towards excellence in all spheres of individual and collective activity, so that the nation constantly rises to higher levels of endeavour and achievements.
11. To provide opportunities for education by the parent and guardian to their child or ward upto the age of 14 years.

Question 3.
How does the National Human Rights Commission protect our rights?
Answer:

• To inquire into the violation of human rights or negligence in the prevention of such violation by a public servant
• To intervene in court proceedings relating to human rights
• To undertake and promote research in the field of human rights
• To engage in human rights education among various sections of society
• To encourage the effects of NGOs and institutions working in the field of human rights.

Question 4.
What are the benefits for workers provided by labour law?
Answer:

• Reduction in Factory Working Hours (8 hours a day)
• Compulsory Recognition of Trade Unions
• Employment Exchange in India
• Employees State Insurance (ESI)
• Minimum Wages
• Coal and Mica Mines Provident Fund

Women Labourers’ Welfare and Ambedkar Dr. B.R. Ambedkar framed many laws for women workers in India such as the ‘Mines Maternity Benefit Act’, ‘Women Labour Welfare Fund’, ‘Women and Child Labour Protection Act’, ‘Maternity Benefit for Women Labour’, and ‘Restoration of Ban on Employment of Women . on Underground Work in Coal Mines’.

Question 5.
How do you enjoy the fundamental rights in your life?
Answer:
Right to Equality before law and equal protection of law. Prohibition or discrimination on the grounds of religion, caste, races, gender or place of birth is offensive and one can seek justice from court.
Right to Freedom: Six different types of freedom are mentioned in the Constitution. They are:
(a) Freedom of speech and expression.
(b) Freedom to assemble peacefully without arms.
(c) Freedom to form associations and unions.
(d) Freedom to reside and settle in any part of India.
(e) Freedom to move freely throughout the territory of India.
(f) Freedom to practice any profession and carry on any occupation, trade or business.

Right against Exploitation

It is against the law to employ children below 14 years of age in mines, factories or other occupations. Neither contractor nor an employer can force a worker to do a job against the their will.

VI. Project and Activity

Question 1.
How do you protect yourself from child abuse/sexual exploitation and trafficking.
Answer:
You can do this activity under the guidance of your teacher.

Question 2.
Write an article titled “My country, My Rights”.
Answer:
You can do this activity under the guidance of your teacher.

Human Rights Additional Questions

I. Choose the correct answer.

Question 1.
UDHR has played a crucial role in promoting
(a) Individual Rights
(b) Human Rights
(c) Fundamental Rights
(d) None of the above
Answer:
(b) Human Rights

Question 2.
NCW was constituted to safeguard
(a) Students
(b) Women
(c) Labourers
(d) Children
Answer:
(b) Women

Question 3.
Fundamental duties were incorporated in the Indian Constitution in the year
(a) 1976
(b) 1980
(c) 1975
(d) 1950
Answer:
(a) 1976

Question 4.
Which of the following statements are true?
Answer:
(i) The general explanations of Human Rights by UDHR is not a legally binding document.
(ii) UDHR has a political and moral importance.
(a) (i) is correct (ii) is wrong
(b) (i) is wrong (ii) is correct
(c) (i), (ii) and (iii) are wrong
(d) Both (i) and (ii) are correct
Answer:
(d) Both (i) and (ii) are correct

II. Fill in the blanks.

1. In 1994 ……… became the President of South Africa.
2. UNO was established in the year ……
3. Political rights are given to the citizens by ………. .
4. Protection and promotion of human rights is India in the responsibility of ……….
5. The written order from the court or other legal authority is called a ………..
Answers:
1. Nelson Mandela
2. 1945
3. Law
4. NHRC
5. Writ

III. Match the following

Answers:
1. (b)
2. (e)
3. (a)
4. (b)

IV. Give short answers.

Question 1.
What are Extended rights?
Answer:
The Child rights, SC and ST rights, Women rights, Right to information Act (RTI) and Labour laws come under Extended rights.

Question 2.
What is Apartheid?
Answer:
Apartheid means social discrimination. Apartheid was the highest form of discrimination that existed in South Africa. Places of residences were determined by racial classification. It was the governing policy in the country by the minority whites over the majority non-whites. The people of South Africa protested against racial discrimination.

Question 3.
Write a note on Nelson Mandela.
Answer:
Nelson Mandela raised his voice against Apartheid. When he organised defiant campaigns against the government, he was imprisoned. He was released in 1990 by the President F. W. de Klerk: The efforts taken by Mandela and de Klerk put an end to apartheid. In 1994, general election was held and Nelson Mandela, the leader of the African National Congress, became President.

Question 4.
What does the term Civil rights refer to?
Answer:
The term ‘ Civil rights’ refers to the basic rights afforded by laws of the government.
It is guaranteed to every person regardless of race, nationality, colour, gender, age, religion etc.

Question 5.
What is NHRC?
Answer:
The National Human Right Commission (NHRC) is an autonomous body constituted on 12th October 1993 under the protection of Human Rights Act, 1993. It consists of a chairman and few other members. NHRC is responsible for the protection and promotion of human rights in India. The Act defines the right relating to life, liberty, equality and dignity of the individual guaranteed by the Constitution or embodied in the international covenants.

V. Answer in detail.

Question 1.
What are the functions of SHRC?
Answer:
The functions of SHRC are,

1. The SHRC shall enquire into violation of human rights in respect of matters specified in the state and concurrent lists.
2. Its objectives and duties are the same as NHRC, but confined only to the state. It has a chairman and two members.
3. It has the power of a civil court, and can take cognizance of cases if received.
4. It can also recommend compensation to victims.

Question 2.
Explain Child Rights.
Answer:
Child Rights are,

(a) Right to life:

1. A child has the right to survive even before its birth.
2. The right to survival also includes the right to be born, the right to basic needs of food, shelter and clothing and a dignified living.

(b) Right to Family Environment:

1. A child has the right to live a normal childhood in a family environment.
2. Children who have been left destitute, abandoned or orphaned also have the right to live.
3. These children can be given for adoption to caring families.

(c) Right to Education:
Right to Education Act is an Act of the Parliament of India enacted in 2009 for free and compulsory education for children from 6 to 14 years of age as under Article 21 A of the Constitution.

(d) Right against sale or trafficking:

1. Children should be treated as individuals with fundamental human rights.
2. Children are subj eCted to sale or trafficking for various reasons like economic exploitation, sexual exploitation, sexual abuse, drug trafficking and child labour.

(e) Right against sexual exploitation:

1. The state should protect children from sexual exploitation and abuse.
2. POCSO Act- Protection of Children from Sexual Offences Act in 2012.

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 14 Acids, Bases and Salts

Samacheer Kalvi 9th Science Acids, Bases and Salts Textbook Exercises

I. Choose the correct answer.

Chapter 14 Acids, Bases And Salts Question 1.
Zn + 2HCl ➝ ZnCl₂ + ………….. ↑
(a) H₂
(b) O₂
(c) CO₂
Answer:
(a) H₂

Acids Bases And Salts Class 9 Samacheer Kalvi Question 2.
Apple contains malic acid. Orange contains ……………….
(a) citric acid
(b) ascorbic acid
Answer:
(b) ascorbic acid

9th Class Science Acids Bases And Salts Question 3.
Acids in plants and animals are organic acids. Whereas Acids in rocks and minerals are ………………..
(a) Inorganic acids
(b) Weak acids
Answer:
(a) Inorganic acids

Acids Bases And Salts Samacheer Kalvi Question 4.
Acids turn blue litmus paper to …………………
(a) Green
(b) Red
(c) Orange
Answer:
(b) Red

9th Acid Base And Salt Question 5.
Since metal carbonate and metal bicarbonate are basic they react with acids to give salt and water with the liberation of ………………
(a) NO₂
(b) SO₂
(c) CO₂
Answer:
(c) CO₂

Acid Base And Salt 9th Class Exercise Question 6.
The hydrated salt of copper sulphate has …………….. colour
(a) Red
(b) White
(c) Blue
Answer:
(c) Blue

II. Answer in brief.

Acids, Bases And Salts Samacheer Kalvi Question 1.
Name any two metals which do not react with sodium hydroxide.
Answer:
Few metals do not react with sodium hydroxide. For example: Cu, Ag, Cr.

9th Class Science Acids, Bases And Salts Question Answer Question 2.
Write any four uses of acids.

• Sulphuric acid is called King of Chemicals because it is used in the preparation of many other compounds. It is used in car batteries also.
• Hydrochloric acid is used as a cleansing agent in toilets.
• Citric acid is used in the preparation of effervescent salts and as a food preservative.
• Nitric acid is used in the manufacture of fertilizers, dyes, paints and drugs.

Acid Base And Salts Exercise 9th Class Question 3.
Give the significance of pH of soil in agriculture.
Answer:
In agriculture, the pH of soil is very important. Citrus fruits require slightly alkaline soil, while rice requires acidic soil and sugarcane requires neutral soil.

Acid Base And Salts Book Back Answers Question 4.
When does the acid rain occur?
Answer:
The pH of rain water is approximately 7 which means that it is neutral and also represents its high purity. If the atmospheric air is polluted with oxide gases of sulphur and nitrogen, they get dissolved in rainwater and make its pH less than 7. Thus, if the pH of rain water is less than 7, then it is called acid rain.

Acids, Bases And Salts Class 9 Pdf Question 5.
What are the uses of Plaster of Paris?
Answer:

1. It is used for plastering bones
2. It is used for making casts for statues.

Acid Base And Salts Class 9 Question 6.
Two adds ‘A’ and ‘B’ are given. Acid A gives one hydrogen ion per molecule of the acid in solution. Acid B gives two hydrogen ions per molecule of the acid in solution.

1. Find out acid A and acid B.
2. Which acid is called the King of Chemicals?

Answer:

1. Acid A is HCl and Acid B is H₂SO₄
2. Sulphuric acid is called the King of Chemicals.

Acids Bases And Salts Question Bank Question 7.
Define aquaregia.
Answer:
Metals like gold and silver are not reactive with either HCl or HNO₃. But the mixture of these two acids can dissolve gold. This mixture is called Aquaregia. It is a mixture of hydrochloric acid and nitric acid prepared optimally in a molar ratio of 3:1. It is a yellow- orange fuming liquid. It is a highly corrosive liquid, able to attack gold and other resistant substances.

Acids Bases And Salts Class 9 Questions And Answers Question 8.
Correct the mistakes:

1. Washing soda is used for making cakes and bread soft, spongy.
2. Calcium sulphate hemihydrate is used in textile industry.

Answer:

1. Baking soda is used for making cakes and bread soft, spongy.
2. Calcium Oxychloride hemihydrate is used in textile industry.

Acids Bases And Salts Solutions Question 9.
What is neutralization reaction? Give an example.
Acids and bases neutralize each other to form corresponding salts and water.
Example: Bases react with acids to form salt and water.
KOH + HCl ➝ KCl + H₂O
The above reaction between a base and an acid is known as Neutralisation reaction.

III. Answer in detail.

Class 9 Science Chapter 5 Acids Bases And Salts Question 1.
Why does distilled water not conduct electricity whereas rain water does?
Answer:
Distilled water is created through the process of distillation.

In this process, the pure water (H₂O) is boiled to remove contaminants. This is done by the capturing of steam that rises after boiling of water followed by cooling. This is distilled water and is free of ions that are required for the conduction of electricity. Whereas, the pollutants present in the atmospheric air gets dissolved in rainwater which provides necessary ions for the conduction of electricity.

Question 2.
Plaster of Paris should be stored in a moisture proof container. Why?
Answer:
The Plaster of Paris .should be stored in a moisture-proof container as it turns into a hard substance known as gypsum on absorption of water from moisture.

Question 3.
Write any four uses of bases.
Answer:

1. Sodium hydroxide is used in the manufacture of soap.
2. Calcium hydroxide is used in white washing of building.
3. Magnesium hydroxide is used as a medicine for stomach disorder.
4. Ammonium hydroxide is used to remove grease stains from cloths

Question 4.
Write any five uses of salts.
Answer:
Common Salt (NaCl): It is used in our daily food and used as a preservative.

1. Washing Soda (Sodium Carbonate):
   • It is used in softening hard water.
   • It is used in glass, soap and paper industries.
2. Baking Soda (Sodium bicarbonate -NaHC0₃):
   • It is used in making of baking powder which is a mixture of baking soda and tartaric acid.
   • It is used in soda-acid fire extinguishers.
   • Baking powder is used to make cakes and bread, soft and spongy.
   • It neutralizes excess acid in the stomach and provides relief.
3. Bleaching powder (Calcium Oxychloride – CaOCl₂)
   • It is used as disinfectant.
   • It is used in textile industry for bleaching cotton and linen.
4. Plaster of Paris (Calcium Sulphate Hemihydrate – CaS0₄ . \(\frac { 1 }{ 2 }\)H20)
   • It is used for plastering bones
   • It is used for making casts for statues

Question 5.
Sulphuric acid is called King of Chemicals. Why is it called so?
Answer:
Sulphuric acid is called King of Chemicals because it is used in the preparation of many Other compounds. It is used in car batteries also.
Acids react with metallic oxides to give salt and water.
CaO + H₂S0₄ CaS0₄ + H₂0

Activity

Question 1.
Take about 10 ml of dilute hydrochloric acid in a test tube and add a few pieces of zinc granules into it. What do you observe? Why are bubbles formed in the solution?
Answer:
Take a burning candle near a bubble containing hydrogen gas, the flame goes off with a ‘Popping’ sound. This confirms that metal displaces hydrogen gas from the dilute acid.
Bubbles are formed as Zinc reacts with HCl to form ZnCl and Hydrogen gas is released.

Question 2.

• Take solutions of hydrochloric acid or sulphuric acid.
• Fix two nails on a cork and place the cork in a 100 ml beaker.
• Connect the nails to the two terminals of a 6V battery through a bulb and a switch as shown in Figure.
• Now pour some dilute HCl in the beaker and switch on the current.
• Repeat the activity with dilute sulphuric acid, glucose and alcohol solutions. What do you observe now?
• Does the bulb glow in all cases?

Answer:
The bulb glows when the solution in the beaker is hydrochloric acid or sulphuric acid as they ionise into H⁺ ions thus facilitating the flow of current.
Both hydrochloric acid and sulphuric acid readily ionise to H⁺, Cl^– and 2H⁺ and SO^4- in solution and thus conduct electricity letting the bulb glow. Whereas glucose and alcohol do not ionise and hence the bulb doesn’t glow.

Question 3.
Collect the following samples from the science laboratory – Hydrochloric acid, sulphuric acid and Nitric acid, Sodium hydroxide, Potassium hydroxide. Take 2 ml of each solution in a test tube and test with a litmus paper and indicators phenolphthalein and Methyl orange. Tabulate your observations.

Sample Solutions	Litmus Paper		Indicators
	Blue	Red	Phenolphthalein	Methyl Orange
Hydrochloric acid		✓	Colourless	Pink
Sulphuric acid		✓	Colourless	Pink
Nitric acid		✓	Colourless	Pink
Sodium hydroxide	✓		Pink	Yellow
Potassium hydroxide	✓		Pink	Yellow

Question 4.
Fill in the blanks in the following table based on the concept of water of crystallisation.

Salt	Formula of an hydrous salt	Formula of hydrated salt	Name of hydrated salt
Zinc sulphate	ZnSO4	ZnSO4.7H2O
Magnesium chloride	MgCl2		Magnesium chloride hexahydrate
Iron (II) sulphate		FeSO4.7H20	Iron (II) sulphate heptahydrate
Calcium chloride	CaCl2	CaCl2.2H2O
Sodium thiosulphate	Na2S2O3		Sodium thiosulphate pentahydrate

Answer:

Salt	Formula of an hydrous salt	Formula of hydrated salt	Name of hydrated salt
Zinc sulphate	ZnSO4	ZnSO4.7H2O	Zinc sulphate heptahydrate
Magnesium chloride	MgCl2	MgCl2. 6H2O	Magnesium chloride hexahydrate
Iron (II) sulphate	FeSO4	FeSO4.7H20	Iron (II) sulphate heptahydrate
Calcium chloride	CaCl2	CaCl2.2H2O	Calcium chloride dihydrate
Sodium thiosulphate	Na2S2O3	Na2S2O3.5H2O	Sodium thiosulphate pentahydrate

Question 5.
Boil about 100 ml of ground water in a vessel to dryness. After all the water get evaporated observe the inner wall of the vessel. Can you observe any deposits?
Answer:
Yes, this is the deposit of dissolved salts present in water.

Samacheer Kalvi 9th Science Acids, Bases and Salts Additional Questions

I. Short answers questions.

Question 1.
What are acids?
Answer:
Acids are those with chemical properties that includes; turning litmus red, neutralizing alkalis, and dissolving some metals; typically, a corrosive or sour-tasting liquid present in curd, fruit juices, vinegar, etc. The word ‘acid’ is derived from the Latin name “acidus” which means sour taste.

Question 2.
Why is the term basicity is used for acids?
Answer:
The term basicity is used for acids since they have replaceable hydrogen atoms in a molecule.

Question 3.
What are bases?
Answer:
According to Arrhenius theory, bases are substances that ionise in water to form hydroxyl ions (OH^–). Bases that are soluble in water are called alkalis.

Question 4.
“All alkalis are bases, but not all bases are alkalis”. Justify this statement.
Answer:
Bases react with acids to neutralise them. Some are insoluble. Soluble bases are called Alkalis. For example CuO (copper oxide) does not dissolve in water, therefore it’s a base. Generally hydroxides of alkali metals and alkaline earth metals are called alkalis.

Question 5.
What is the correct procedure of mixing an acid and water? Why?
Answer:
One has to be cautious while mixing’a concentrated inorganic acid with water. Always the acid must be added to water gently. While adding acid to water, one has to keep stirring the mixture simultaneously. Water should never be added to an acid as it generates huge amount of heat and the mixture can splash out of the container and cause harm to the person handling it, causing bums.

Question 6.
“All acids contain one or more hydrogen atoms, but not all substances containing hydrogen are acids.” Support this statement with examples.
Answer:
HCl (hydrochloric acid), H₂SO₄ (sulphuric acid) and HNO₃ (Nitric acid) are all examples of inorganic acids. They all have the hydrogen atom in common. Most acids essentially contain one or more hydrogen atoms. Whereas water (H₂0) also contains hydrogen, but it is not an acid. Similarly molecule of methane and ammonia also contain hydrogen, but all these do not produce H⁺ ions in aqueous solutions. Therefore it can be said that “all acids contain hydrogen, but all substances containing hydrogen are not acids.”

Question 7.
Explain the role of pH in our digestive system.
Answer:
The pH of saliva is usually between 6.5 – 7.5.
pH of stomach fluid is approximately 2.0. This is because it produces hydrochloric acid which helps in the digestion of food without harming the stomach. pH in the small and large intestine ranges from 4.0 to 7.0.

II. Long answers questions.

Question 1.
Explain water of crystallisation.
Answer:
Many salts are found as crystals with water molecules they contain. These water molecules are known as water of crystallisation. Salts that contain water of crystallisation are called ‘ hydrated salts. The number of molecules of water hydrated to a salt is indicated after the dot in its chemical formula. For example, copper sulphate crystal have five molecules of water for each molecule of copper sulphate. It is written as CuS0₄.5H₂0 and named as copper sulphate pentahydrate. This water of crystallisation makes the copper sulphate blue.

When it is heated, it loses its water molecules and becomes white. Salts that do not contain water of crystallisation is called anhydrous salt.

Question 2.
What are four types of salts?
Answer:
Types of Salts

1. Normal Salts
   A normal salt is obtained by complete neutralization of an acid by a base.
   NaOH + HCl ➝ NaCl + H₂O
2. Acid Salts
   It is derived from the partial replacement of hydrogen ions of an acid by a metal. When a calculated amount of a base is added to a polybasic acid, acid salt is obtained.
   NaOH + H₂S0₂ ➝ NaHS0₄ + H₂0
3. Basic Salts
   Basic salts are formed by the partial replacement of hydroxide ions of a diacidic or triacidic base with an acid radical.
   Pb(OH)₂ + HCl ➝ Pb(OH)Cl + H₂O
4. Double Salts
   Double salts are formed by the combination of the saturated solution of two simple salts in equimolar ratio followed by crystallization. For example, Potash alum is a mixture of potassium sulphate and aluminium sulphate.
   KAI(SO₄)_2·12H₂O

Question 3.
Classify acids based on their sources and basicity.
Answer:
Acids are classified in different ways as follows:
Based on their sources:

1. Organic acids: Acids present in plants and animals (living things) are organic acids. Example: HCOOH, CH₃COOH
2. Inorganic acids: Acids prepared from rocks and minerals are inorganic acids or mineral acids. Example: HCl, HNO₃, H₂SO₄

Based on their Basicity:

1. Monobasic Acid: Acid that contain only one replaceable hydrogen atom per molecule is called monobasic acid. It gives one hydrogen ion per molecule of the acid in solution. Example: HCl, HNO₃
2. Dibasic Acid: An acid which gives two hydrogen ions per molecule of the acid in solution. Example: H₃SO₄, H₂CO₃
3. Tribasic Acid: An acid which gives three hydrogen ions per molecule of the acid in solution. Example: H₃P0₄

Question 4.
Name the acid present in the given table.
Answer:
Acid and its source

SOURCE	ACID PRESENT
Apple	Malic acid
Lemon	Citric acid
Grape	Tartaric acid
Tomato	Oxalic acid
Vinegar	Acetic acid
Curd	Lactic acid
Orange	Ascorbic acid
Tea	Tannic acid
Ant, Bee	Formic acid
Stomach juice	Hydrochloric acid

Question 5.
Describe the tests used to determine acids and bases.
Answer:
Take 10 ml of solution in a test tube and test with a litmus paper or indicators like phenolphthalein and methyl orange.

1. Test with a litmus paper: An acid turns blue litmus paper into red. A base turns red litmus paper into blue.
2. Test with an indicator Phenolphthalein: In acid medium, phenolphthalein is colourless.
   In basic medium, phenolphthalein is pink in colour.
3. Test with an indicator Methyl orange: In acid medium, methyl orange is pink in colour. In basic medium, methyl orange is yellow in colour.

Question 6.
Differentiate between Acids and Bases.
Answer:

Acids	Bases
Acids are proton donors or electron acceptors	Bases are proton acceptor or electron donors
Acids are able to increase the H<sup>+</sup> ion concentration in aqueous solution.	Bases are able to increase the OH” ion concentration in an aqueous solution
Acids have a pH value < 7.	Bases have a pH value > 7.
Acids turn blue litmus paper red.	Bases turn red litmus paper blue.
Acids react with bases to form salts in an aqueous medium.	Bases react with acids to form salts.
Acids are sour to taste.	Bases are soapy to touch.

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 12 Periodic Classification of Elements

Samacheer Kalvi 9th Science Periodic Classification of Elements Textbook Exercises

I. Choose the correct answer.

Periodic Classification Of Elements Book Back Answers Question 1.
If Dobereiner is related with ‘law of triads’, then Newlands is related with ……………………
(a) Modern periodic law
(b) Hund’s rule
(c) Law of octaves
(d) Pauli’s Exclusion principle
Answer:
(c) Law of octaves

Periodic Classification Of Elements Class 9 Question 2.
Modem periodic law states that the physical and chemical properties of elements are the periodic functions of their ……………
(a) atomic numbers
(b) atomic masses
(c) similarities
(d) anomalies
Answer:
(a) atomic numbers

9th Science Periodic Classification Of Elements Question 3.
Elements in the modem periodic table are arranged in …………. groups and ………. periods.
(a) 7, 18
(b) 18,7
(c) 17,8
(d) 8, 17
Answer:
(b) 18,7

II. Fill in the blanks.

1. In Dobereiner’s triads, the atomic weight of the middle element is the ……………….. of the atomic masses of 1st and 3rd elements.
2. Noble gases belong to ……………….. group of the periodic table.
3. The basis of the classifications proposed by Dobereiner, Newlands and Mendeleev was …………………..
4. Example for liquid metal is …………………..

Answer:

1. average
2. 18th
3. atomic masses
4. Mercury

III. Match the following.

Column – I	Column – II
1. Traids	(a) Newlands
2. Alkali metal	(b) Calcium
3. Law of octaves	(c) Henry Moseley
4. Alkali earth metal	(d) Sodium
5. Modem Periodic Law	(e) Dobereiner

Answer:

1. (e) Dobereiner
2. (d) Sodium
3. (a) Newlands
4. (b) Calcium
5. (c) Henry Moseley

IV. State whether True or False.

1. Newlands’ periodic table is based on atomic masses of elements and modem periodic table is based on atomic number of elements – True
2. Metals can gain electrons – False.
   Correct Statement: Metals tend to lose electrons to attain Noble Gas electron configuration.
3. Alloys bear the characteristics of both metals and nonmetals – False
   Correct Statement: An alloy is a mixture of metals or a mixture of a metal and another element.
4. Lanthanides and actinides are kept at the bottom of the periodic table because they resemble each other but they do not resemble with any other group elements – True
5. Group 17 elements are named as Halogens – True

V. Assertion and Reason

Statement: Elements in a group generally possess similar properties but elements along a period have different properties.
Reason: The difference in electronic configuration makes the element differ in their chemical properties along a period.
(a) Statement is true and reason explains the statement.
(b) Statement is false but the reason is correct.
Answer:
(a) Statement is tme and reason explains the statement.

VI. Answer the following.

Chapter 12 Periodic Classification Of Elements Question 1.
State modern periodic law.
Answer:
The modem periodic law states that:
“The Chemical and Physical properties of elements are periodic functions of their atomic numbers”.

Periodic Classification Of Elements 9th Class Question 2.
What are groups and periods in the modern periodic table?
Answer:

• The horizontal rows are called periods. There are seven periods in the periodic table.
• Vertical columns in the periodic table starting from top to bottom are called groups. There are 18 groups in the periodic table.

9th Periodic Table Question 3.
What are the limitations of Mendeleev’s periodic table?
Limitations of Mendeleev’s periodic table:
Answer:

• Elements with large difference in properties were included in the same group. Eg: Hard metals like copper (Cu) and silver (Ag) were included along with soft metals like sodium (Na) and potassium (K).
• No proper position could be given to the element hydrogen. Non-metallic hydrogen was placed along with metals like lithium (Li), sodium (Na) and potassium (K).
• The increasing order of atomic mass was not strictly followed throughout. Eg. Co & Ni, Te &I.
• No place for isotopes in the periodic table.

Science Lesson 12 Class 9 Question 4.
State any five features of modern periodic table.
Answer:

• All the elements are arranged in the increasing order of their atomic number
• The horizontal rows are called periods. There are seven periods in the periodic table.
• The elements are placed in periods based on the number of shells in their atoms
• Vertical columns in the periodic table starting from top to bottom are called groups. There are 18 groups in the periodic table
• Based on the physical and chemical properties of elements, they are grouped into various families.

Periodic Classification Of Elements Activity

Classification Of Elements Question 1.
Find the pair of elements having similar properties by applying Newlands law of Octaves (Example: Mg & Ca):
Set I: F, Mg, C, O, B
Set II: Al, Si, S, Cl, Ca
Answer:

Set I:	F	Mg	C	0	B
Set II:	Cl	Ca	Si	s	Al

Samacheer Kalvi 9th Science Periodic Classification of Elements Additional Questions

I. Short answers questions.

Question 1.
Why did the classification of elements evolve?
Answer:
Scientists found it difficult to organize all that was known about the elements. Therefore they started looking for some pattern in their properties, and the concepts of classification of elements were proposed by various scientists. This led to the evolution of classification of elements from early to modem period.

Question 2.
What is a triads group?
Answer:
Johann Wolfgang Dobereiner arranged the elements into groups containing three elements each based on their relative,atomic masses. He called these groups as ‘triads’ also known as Dobereiner’s Triads.

Question 3.
Explain law of octaves.
Answer:
John Newlands arranged 56 known elements in the increasing order of their atomic mass. He observed that every eighth element had properties similar to those of the first element like the eighth note in an octave of music is similar to the first and this arrangement was known as “law’ of octaves”.

Question 4.
What is a periodic table?
Answer:
Dmitri Mendeleev proposed the law of periodicity which states that “the physical and chemical properties of elements are the periodic functions of their atomic masses”. He arranged 56 elements known at that time according to his law of periodicity. This was best known as the short form of periodic table.

Question 5.
What is IUPAC? Where is it located? Give examples of few elements named by IUPAC.
Answer:
IUPAC stands for-The International Union of Pure and Applied Chemistry. It is an international organization that represents Chemists from various countries. IUPAC is registered in Zurich, Switzerland and has its.secretarate in United States.

Question 6.
How are metals classified in the periodic table?
Answer:
Metals occupy a larger area in the periodic table and are categorized as follows –

• Alkali metals eg. – Sodium and Potassium
• Alkaline earth metals eg. – Calcium and Magnesium
• Transition metals eg. – Iron and Nickel
• Other metals eg. – Aluminium and Tin

Question 7.
What are alkali metals?
Answer:
The elements of group 1 (except hydrogen) are metals. They react with water to form solutions that are highly alkaline or basic. Hence they are called alkali metals.

Question 8.
Though they are found rare, they have many uses. Justify this statement.
Answer:
Helium, Neon, Argon, Krypton, Xenon and Radon are called the Noble or rare gases and are placed in group 18 in the periodic table. They are monoatomic and do not react with other substances easily. Though these gases are chemically inert, they have stable electronic . structures which are difficult to change. Their uses are as follows –

1. Helium has a very low density and used for filling weather ballon.
2. Neon gas is used in discharge lamps.
3. Argon is filled in electrical bulbs to prevent evaporation of the filament.
4. Radon is a radioactive gas.

II. Long answers questions.

Question 1.
Write any five advantages of modern periodic law.
Answer:

• The table is based on a more fundamental property i.e., atomic number.
• It correlates the position of the element with its electronic configuration more clearly.
• The completion of each period is more logical. In a period, as the atomic number increases, the energy shells are gradually filled up until an inert gas configuration is reached.
• Each group is an independent group and the idea of subgroups has been discarded.
• One position for all isotopes of an element is justified, since the isotopes have the same atomic number.

Question 2.
Explain limitations of Mendelev’s periodic table and why is the modern periodic table considered an extension of Mendelev’s periodic table.
Limitations of Mendelev’s periodic table –
(a) Elements with large difference in properties were included in the same group. Eg. Elard metals like copper (Cu) and silver (Ag) were included along with soft metals like sodium and potassium
(b) No proper position could be given to the element hydrogen. Non-metallic Hydrogen was placed along with metals like lithium, sodium and potassium.
(c) The increasing order of atomic mass was not strictly followed throughout. Eg. – Co & Ni, te & I.
(d) No place for isotopes in the periodic table.
The modem periodic table is an extension of the original Mendeleev’s periodic table and is known as the long form of periodic table. Mendeleev’s initial table had 63 elements, modem table has 109 elements. It is also known important to note how the modem periodic table is arranged.

Although the columns which reflect a natural order have been retained, the row’s of the modem table show elements in the order of Mendeleev’s columns. In other words the elements of what we now call ‘a period’ were listed vertically by Mendeleev. ‘Groups are now shown vertically in contrast to their horizontal format in Mendeleev’s table.

Question 3.
What are the advantages of alloys?

• Alloys do not get corroded or get corroded to very less extent.
• They are harder and stronger than pure metals (example: gold is mixed with copper and it is harder than pure gold).
• They have less conductance than pure metals (example: copper is good conductor of heat and electricity whereas brass and bronze are not good conductors).
• Some alloys have lower melting point than pure metals (example: solder is an alloy of lead and tin which has lower melting point than each of the metals).
• When metal is alloyed with mercury, it is called amalgam.

Question 4.
Explain the uniqueness of Hydrogen.
Answer:
Hydrogen is the lightest, smallest and first element of the periodic table. Its electronic configuration (Is1) is the simplest of all the elements. It occupies a unique position in the periodic table. It behaves like alkali metals as well as halogens in its properties. In the periodic table, it is placed at the top of the alkali metals.

1. Hydrogen can lose its only electron to form a hydrogen ion (H+) like alkali metals.
2. It can also gain one electron to form the hydride ion (H-) like halogens.
3. Alkali metals are solids while hydrogen is a gas.