Category: Class 9

AP State Syllabus AP Board 9th Class Physical Science Solutions Chapter 6 Chemical Reactions and Equations Textbook Questions and Answers.

AP State Syllabus 9th Class Physical Science Solutions 6th Lesson Chemical Reactions and Equations

9th Class Physical Science 6th Lesson Chemical Reactions and Equations Textbook Questions and Answers

Improve Your Learning

Question 1.
What is a balanced chemical equation? Why should chemical equations be balanced?
Answer:
1) A chemical equation in which the number of atoms of different elements on the reactants side (left side) are same as those on product side (right side) is called a balanced chemical equation.
Ex : Zn + 2HCl → ZnCl₂ + H₂ ↑

2) All the chemical equations must balance because atoms are neither created nor destroyed in chemical reactions.

3) The number of atoms of each element before and after reaction must be the same.

4) According to the law of conservation of mass, the total mass of the substances that are taking part in a chemical reaction must be the same before and after the reaction.

Question 2.
Balance the following chemical equations.
a) NaOH + H₂SO₄ → Na₂SO₄ + H₂O
b) Hg (NO₃)₂ + KI → Hgl₂ + KNO₃
c) H₂ + O₂ → H₂O
d) KClO₃ → KCl + O₂
e) C₃H₈ + O₂ → CO₂ + H₂O
Answer:
a) 2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O
b) Hg (NO₃)₂ + 2 KI → Hgl₂ + 2KNO₃
c) 2H₂ + O₂ → 2H₂O
d) 2KClO₃ → 2KCl + 3O₂
e) C₃Hg + 5O₂ → 3CO₂ + 4H₂O

Question 3.
Write the balanced chemical equations for the following reactions.
a) Zinc + Silver nitrate → Zinc nitrate + Silver
b) Aluminium + Copper chloride → Aluminium chloride + Copper
c) Hydrogen + Chlorine → Hydrogen chloride
d) Ammonium nitrate → Nitrous Oxide + Water
Answer:
a) Zn + 2AgNO₃ → Zn(NO₃)₂ + 2Ag
b) 2Al + 3CuCl₂ → 2AlCl₃ + 3Cu
c) H₂ + Cl₂ → 2HCl
d) NH₄NO₃ → N₂O + 2H₂O

Question 4.
Write the balanced chemical equations for the following and identify the type of reaction in each case.
a) Calcium hydroxide(aq) + Nitric acid(aq) → Water(l) + Calcium nitrate(aq)
b) Magnesium(sJ + Iodine → Magnesium Iodide(s)
c) Magnesium(s) + Hydrochloric acid(aq) → Magnesium chloride(aq) + Hydrogen^
d) Zinc(s) + Calcium chloride(aq) → Zinc Chloride(aq) + Calcium(s)
Answer:
a) Ca(OH₂) + HNO₃ → H₂O + Ca(NO₃)₂
This is double decomposition reaction.

b) Mg + I₂ → Mgl₂
This is chemical combination reaction.

c) Mg + 2HCl → MgCl₂ + H₂ ↑
This is chemical displacement reaction.

d) Zn + CaCl₂ → ZnCl₂ + Ca
This is chemical displacement reaction. This reaction is not possible, because calcium is more reactive than zinc.

Question 5.
Write an equation for decomposition reaction where energy is supplied in the form of heat / light / electricity.
Answer:
Chemical decomposition reaction : A chemical reaction in which a single substance splits into two or more substances is called chemical decomposition.
For decomposition reaction energy is supplied in the form of :

Question 6.
What do you mean by precipitation reaction?
Answer:
A reaction in which insoluble substance in water is formed as product is called precipitation reaction.

Question 7.
How does chemical displacement reactions differ from chemical decomposition reaction? Explain with an example for each.
Answer:

Question 8.
Name the reactions taking place in the presence of sunlight.
Answer:
1) In the presence of sunlight plants prepare their food by taking C02 from the air and H20 from the soil with their chloroplasts of the green leaves. This reaction is called photosynthesis.

Question 9.
Why does respiration considered as an exothermic reaction? Explain.
Answer:

• We need energy to stay alive.
• We get this energy from food we eat.
• During digestion, food is broken down into simpler substances.
• For example, rice and potato contains starch.
• The starch breaks down to form glucose.
• This glucose combines with oxygen in the cells of our body and releases energy, which helps to do the various works.
• During this process, energy is given out. Hence this reaction can be called exothermic reaction.
• The special name of this reaction is respiration.
• So respiration is considered as exothermic reaction.
• C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Q (Energy)

Question 10.
What is the difference between displacement and double displacement reactions? Write equations for these reactions.
Answer:

Question 11.
MnOz + 4HCl → MnCl₂ + 2H₂O + Cl₂ ↑
In the above equation, name the compound which is oxidized and which is reduced.
Answer:
In the above equation, HCl compound is oxidized and MnO₂ is reduced.

Question 12.
Give two examples for oxidation-reduction reaction.
Oxidation :
Oxidation is a reaction that involves the addition of oxygen or loss of hydrogen or electrons.

Reduction :
The process in which a substance loses oxygen or gains hydrogen or electrons is known as reduction.

Question 13.
In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal. Write the reaction involved.
Answer:

• Cu_(s) + 2 AgNO_3(aq) > Cu(NO₃)_2(aq) + 2Ag_(s)
• This is redox reaction, copper is the reducing agent and the silver is reduced.
• Electrons from the copper metal are transferred to the silver.
• This reaction can also be called a displacement reaction because copper displaces silver as it is more reactive.

Question 14.
What do you mean by corrosion? How can you prevent it?
Answer:

• When some metals are exposed to moisture, acids, etc. they tarnish due to the formation of respective metal oxide on their surface. This process is called “corrosion”.
• Corrosion can be prevented by painting, oiling, greasing, galvanizing, chrome plating or making alloys.
• Galvanizing is a method of protecting iron from rusting by coating them a thin layer of zinc.

Question 15.
Explain rancidity.
Answer:

• Oxidation reactions in food material that were left for a long period are responsible for spoiling of food. This process is called “rancidity”.
• When these processes occur in food, undesirable odours and flavours can result.
• Rancidity is an oxidation reaction.

Question 16.
Balance the following chemical equations including the physical states,
a) C₆H₁₂O₆ → C₂H₅OH + CO₂
b) Fe + O₂ → Fe₂O₃
c) NH₃ + Cl₂ → N₂H₄ + NH₄Cl
d) Na + H₂O → NaOH + H₂
Answer:
a) C₆H₁₂O_6(s) → C₂H₅OH_(l) + CO_2(g)
b) Fe_(s) + O_2(g) → Fe₂O_3(s)
c) NH_3(aq) + Cl_2(g) → N₂H_4(l) + NH₄Cl_(aq)
d) 2Na_(s) + 2H₂O_(l) → NaOH + H₂

Question 17.
Balance the chemical equation by including the physical states of the substances for the following reactions.
a) Barium chloride and Sodium sulphate aqueous solutions react to give insoluble Barium sulphate and aqueous solution of Sodium chloride.
b) Sodium hydroxide reacts with Hydrochloric acid to produce Sodium chloride and water.
c) Zinc pieces react with dilute Hydrochloric acid to liberate Hydrogen gas and forms Zinc chloride.
Answer:
a) BaCl_2(aq) + Na₂SO_4(aq) → BaSO_4(s)↓ + NaCl_(aq)
b) NaOH_(aq) + HCl_(aq) → NaCl_(aq) + H₂O_(l)
c) Zn_(s) + 2HCl_(aq) → ZnCl_2(aq) + H_2(g)

Question 18.
A shiny brown coloured element ‘X’ on heating in air becomes black in colour. Can you predict the element ‘X’ and the black coloured substance formed? How do you support your predictions?
Answer:
The brown coloured element is copper (Cu). On heating copper reacts with oxygen
present in the atmosphere to form copper oxide which is black in colour.
The reaction is shown below.

If we pass hydrogen gas over hot copper oxide we will notice that black coating on copper turns brown because copper oxide loses oxygen to form copper.
This will support our prediction.

Question 19.
Why do we apply paint on iron articles?
Answer:

• Ferrous reacts with oxygen in the air and form iron oxide.
  2 Fe + O₂ → 2 FeO
• This reaction is called corrosion. It spoils the iron articles by rusting.
• Corrosion of iron articles can be prevented or minimized by shielding the metal surface from oxygen and moisture.
• It can be prevented by applying paint on the articles.

Question 20.
What is the use of keeping food in air tight containers?
Answer:

• Oxidation is defined as the interaction of oxygen molecules with all the different substances from metal to living tissue which may come into contact with it.
• When fats and oils are oxidized they become rancid. Their smell and taste change.
• Keeping food in airtight containers helps to slow down oxidation process.
• So, manufacturers of potato chips usually flush bags of chips with gas such as nitrogen to prevent the chips from getting oxidized.

Fill in the Blanks

1. The decomposition of vegetable into compost is an example of ……………. reaction.
2. The chemical reaction in which energy is absorbed to form a new compound is called ………….
3. The reaction 2N₂O → 2N₂ + O₂ is an example for ………….. reaction.
4. The reaction Ca + 2H₂O → Ca(OH)₂ + H₂ ↑ is an example for ………….. reaction.
5. The substances that are present on left side of a chemical equation are called
6. The arrow mark between the products and reactants of a chemical equation shows of the reaction.
Answer:

1. oxidation
2. endothermic reaction
3. decomposition
4. displacement
5. reactants
6. direction

7. Match the following :

Answer:

Multiple Choice Questions:

1. Fe₂O₃ + 2Al → Al₂O₃ + 2Fe
The above reaction is an example of:
A) Combination reaction
B) Decomposition reaction
C) Displacement reaction
D) Double decomposition reaction
Answer:
C) Displacement reaction

2. What happens when dil. hydrochloric acid is added to iron filings? Choose the correct answer.
A) Hydrogen gas and iron chloride are produced.
B) Chlorine gas and iron hydroxide are produced.
C) No reaction takes place.
D) Iron salt and water are produced.
Answer:
A) Hydrogen gas and iron chloride are produced.

3. 2PbO_(s) + C_(s) → 2Pb_(s) + CO_2(g)
Which of the following statements are correct for the above chemical reaction?
i) Lead is reduced
ii) Carbon dioxide is oxidized
iii) Carbon is oxidized
iv) Lead oxide is reduced
A) (i) and (ii)
B) (i) and (iii)
C) (i), (ii) and (iii)
D) all
Answer:
B) (i) and (iii)

4. The chemical equation
BaCl₂ + Na₂SO₄ → BaSO₄ + 2NaCl represents following type of chemical reaction.
A) displacement
B) combination
C) decomposition
D) double-displacement
Answer:
D) double-displacement

5. The reaction of formation hydrogen chloride from hydrogen and chlorine repre¬sents following type of chemical reaction i
A) decomposition
B) displacement
C) combination
D) double-displacement
Answer:
C) combination

9th Class Physical Science 6th Lesson Chemical Reactions and Equations InText Questions and Answers

9th Class Physical Science Textbook Page No. 90

Question 1.
What changes do you notice generally?
Answer:
I noticed two types of changes generally. They are :

1. Physical change,
2. Chemical change.

Question 2.
“Coal is burnt”, “crackers are burnt” ………. changes Are they physical changes (or) chemical changes?
Answer:
They are all chemical changes.

Question 3.
Are they (coal, crackers) temporary changes or permanent changes?
Answer:
They are permanent changes.

Question 4.
How do we know a chemical reaction has taken place?
Answer:
While we observe the following things, we can conclude that a chemical reaction has taken place.

1. A change that changes state and colour of substance.
2. A change that releases heat energy.
3. A change which forms an insoluble substance as precipitate.
4. A change that liberates a gas.

9th Class Physical Science Textbook Page No. 92

Question 5.
Do the atoms of each element on left side equal to the atoms of the element on the right side of the equation?
Answer:
Yes. The atoms of each element in left side are equal to the atoms of their corresponding element.

9th Class Physical Science Textbook Page No. 94

Question 6.
Are the atoms of all elements of reactants present in products?
Answer:
Yes. The atoms of all elements of reactants are present in products.

Question 7.
2 C₃H₈ + 10 O₂ → 6 CO₂ + 8 H₂O.
Is it a well balanced equation as per rules ? How do you say?
Answer:
Yes, it is a balanced equation.

9th Class Physical Science Textbook Page No. 105

Question 8.
Did you notice the colour coating on silver and copper articles?
Answer:
Yes. I noticed. To prevent from corrosion they are colour coated like that.

9th Class Physical Science Textbook Page No. 106

Question 9.
How can we prevent the spoiling of food?
Answer:
The spoilage of food can be prevented by adding preservatives like vitamin C and vitamin E.

9th Class Physical Science 6th Lesson Chemical Reactions and Equations Activities

Activity – 1

Question 1.
Write an activity when calcium oxide reacts with water.
What type of reaction is this ? Write balanced chemical equation.
Answer:

1. Take about 1 gm of quick lime (CaO) in a beaker.
2. Add 10 ml of water to this.
3. Touch the beaker with your finger.
4. The beaker is hot.
5. The reason is that the calcium oxide reacts with water and releases heat energy.
6. Calcium oxide dissolves in water producing colourless solution [Ca(OH)2],
7. Dip the red litmus paper in it.
8. Red litmus paper changes into blue colour.
9. We conclude that the solution obtained is a basic solution.
10. It is a chemical combination reaction.
    CaO_(s) + H₂O_(l) → Ca(OH)₂

Activity – 2

Question 2.
What change do you observe by mixing of sodium sulphate solution and barium chloride solution?
(OR)
Which type of reaction is this (mixing of sodium sulphate and barium chloride solutions)?
Answer:

• Take about 100 ml of water in a beaker.
• Dissolve a small quantity of sodium sulphate (Na₂SO₄) in it.
• Take about 100 ml of water in another beaker.
• Dissolve a small quantity of barium chloride (BaCl₂) in it.
• Add these (Na₂SO₄, BaCl₂) two solutions.
• We will get a white precipitate of barium sulphate.
  Na₂SO₄ + BaCl₂ → BaSO₄↓ + 2NaCl
• It is a double displacement reaction.

Activity – 3

Question 3.
Formation of H₂ gas by the action of dil. HCl and Zn pieces.
(OR)
What happens if dilute HCl is added to zinc granules. Explain the process with an experiment. What type of reaction is this? Write the balanced chemical equation for this process.
Answer:

Hydrogen gas experiment:

1. Take a few zinc granules in a conical flask.
2. Add about 5 ml of dilute hydrochloric acid to the conical flask.
3. Observe the changes in the conical flask.
4. Keep a burning matchstick near the mouth of the conical flask.
5. The light of burning matchstick is put off with ‘pop’ sound.
6. This indicates the H₂ gas has released in this reaction.
7. When we touch the bottom of the conical flask with our finger, we feel hot.
8. So, this reaction produces heat.
9. It is a displacement reaction
   Zn_(s) + 2HCl_(aq) → ZnCl_2(aq) + H_2(g)

Activity – 4 Chemical Combination

Question 4.
Write an activity on burning of magnesium ribbon in the presence of air.
(OR)
Write an activity which shows burning of magnesium ribbon is a chemical combination reaction.
Answer:

1) Take about 3 cm long piece of magnesium ribbon.
2) Rub the magnesium ribbon with sand paper.
3) Hold it with a pair of tongs.
4) Burn it with a spirit lamp or burner.
5) Magnesium burns in oxygen by producing dazzling white flame and changes into white powder (magnesium oxide).

7) In this reaction magnesium and oxygen combine to form a new substance magnesium oxide.
8) A reaction in which single product is formed from two or more reactants is known as chemical combination reaction.

Activity – 5 Decomposition Reaction

Question 5.
How can you prove that CO₂ is released on heating CaCO₃?
(OR)
When calcium carbonate is heated it releases certain gas. What is the gas that has been released? How do you identify that gas? Write the activity of this reaction.
Answer:

• Take a pinch of Calcium Carbonate (lime stone) in a boiling tube.
• Heat the boiling tube over the flame of spirit lamp or burner.
• Now take a burning matchstick near the mouth of delivery tube.

Heating of calcium carbonate and testing the gas evolved with burning matchstick

• We can observe that the matchstick kept near the mouth of the boiling tube will be put off.
• In the above activity, on heating CaC03, it decomposes to Calcium oxide (CaO) and Carbon dioxide (CO₂).
  
• When a decomposition reaction is carried out by heating, it is called thermal decomposition reaction.

Activity – 6

Question 6.
Write an activity to show that nitrogen dioxide (NO^ is released by heating of lead nitrate.
(OR)
Write an activity which shows thermal decomposition reaction.
Answer:

1. Take about 0.5 g of lead nitrate powder in a boiling test tube.
2. Hold the boiling tube with a test tube holder.
3. Heat the boiling tube over a flame.
4. We observe that on heating of lead nitrate brown fumes of nitrogen dioxide are released.
5. On heating lead nitrate, it decomposes and gives lead oxide, oxygen and nitrogen dioxide.

6) Reaction :

7) This is also an example for thermal decomposition reaction.

Activity – 7

Question 7.
Write an activity to show dissociate of water into hydrogen and oxygen.
(OR)
Write an activity showing decomposition of a compound in the presence of electricity.
(OR)
Draw a neat diagram representing electrolysis of water.
How do you prove that water contains hydrogen and oxygen in the ratio of 2 : 1?
(OR)
Explain electrolysis of water.
(OR)
What are the materials required for the experiment to show the chemical decomposition of water ? Write the procedure of the experiment. Name the products which we get in this reaction.
(OR)
Draw a neat diagram showing the electrolytic decomposition reaction of water. Write the balanced chemical equation of the above reaction.
Answer:

1. Take a plastic mug.
2. Drill two holes at its base.
3. Fit two ‘one holed rubber stoppers’ in these holes.
4. Insert two graphite electrodes in these rubber stoppers.
5. Connect the electrodes to 9V battery.
6. Fill the mug with water, so that the electrodes are immersed.
7. Add few drops of dilute sulphuric acid to water.
8. Take two test tubes filled with water and invert them over the two graphite electrodes.
9. Switch on the current and leave the apparatus undisturbed for sometime.
10. We will notice that the liberation of gas bubbles at both the electrodes.
11. These bubbles displace the water in the test tubes.
12. We also observe that the volume of gas collected in the both test tubes is different.
13. Once the test tubes are filled with gases take them out carefully.
14. Test both the gases separately by bringing a burning candle near the mouth of each test tube.
15. The gas which occupies high volume makes to burn with blue flame and put off candle flame with ‘puf sound is hydrogen gas.
16. The gas which occupies low volume and makes to burn candle brightly is oxygen gas.
17. In the above activity on passing the electricity, water dissociates to hydrogen and oxygen gases. This is called electrolytic composition reaction.
    

Activity – 8

Question 8.
Write an activity to observe silver bromide decomposes in the presence of sunlight.
(OR)
Write an activity for photochemical reaction.
Answer:

• Take some quantity of silver bromide on a watch glass.
• When we observe the colour of silver bromide it is light yellow in colour.
• Place the watch glass in sunlight for sometime.
• Silver bromide decomposes to silver and bromine in sunlight.
• After sometime we observe that the colour of silver bromide changes into grey colour.

• Light yellow coloured AgBr changes into Ag and Br.
• This decomposition reaction occurs in the presence of sunlight and such reactions are called photochemical reactions.
• The above decomposition reactions require some energy to convert reactants to products.
• This type of reactions are called endothermic reactions.
• 

Activity – 9

Question 9.
Write an activity to show that zinc displaces hydrogen from dil. hydrochloric acid.
Answer:

1. Take a small quantity of zinc dust in a conical flask.
2. Add dilute hydrochloric acid slowly.
3. Now take a balloon and tie it to the mouth of the conical flask.
4. We can observe that the gas bubbles coming out from the solution and the balloon bulges out.
5. Zinc pieces react with dilute hydrochloric acid and liberate hydrogen gas.
6. The element zinc has displaced hydrogen from dilute hydrochloric acid. This is one of the examples for displacement reaction.
7. Equation : Zn_(s) + 2 HCl_(aq) → ZnCl_2(aq) + H_2(g) ↑

Activity – 10

Question 10.
Write an activity to show that iron displaces copper from copper sulphate.
(OR)
Write an activity about how you conduct an experiment to show that more reactive metals replace less reactive metals from their compounds. (OR)
Why is an iron nail kept in a solution brownish? Explain the activity.
Answer:

1. Take two iron nails and clean them by rubbing with sand paper.
2. Take two test tubes and mark them as A and B.
3. Take about 10 ml of copper sulphate solution in each test tube.
4. Dip one iron nail in copper sulphate solution of test tube A.
5. Keep the test tube with iron nail undisturbed for 20 minutes.
6. Keep the other iron nail and test tube aside. ;
7. Compare the colours of the solutions in the test tubes.
8. Now take out the iron nail from copper sulphate solution.
9. Keep the iron nail and test tubes A and B side by side.
10. Compare with the other iron nail that has been kept aside.
11. We will observe that the iron nail dipped in copper sulphate solution becomes brownish.
12. Blue colour of copper sulphate solution in test tube ‘A’ fades.
13. Iron is more reactive than copper, so it displaces copper from copper sulphate.
14. This is one of the examples for displacement reaction.
15. Equation : Fe_(s) + CuSO_4(aq) → FeSO_4(aq) + Cu_(s)

Activity – 11 Double displacement reaction

Question 11.
Write an activity for the formation of lead iodide and potassium nitrate.
(OR)
Your friend has a doubt about chemical double displacement reaction. How can you clarify his/her doubt by showing an experiment? Explain.
(OR)
What happens if lead nitrate solution is added to potassium iodide solution? Explain the activity.
Answer:

It forms yellow precipitate of lead iodide.

1. Take a pinch of lead nitrate and dissolve in 5.0 ml of distilled water in a test tube.
2. Take a pinch of potassium iodide in another test tube and dissolve in distilled water.
3. Mix lead nitrate solution with potassium iodide solution.
4. We observe that a yellow coloured substance which is insoluble in water, is formed.
5. This insoluble substance is known as precipitate.
6. The precipitate is Lead Iodide.
7. Equation : Fb(NO₃)_2(aq) + 2 KI_(aq) → Pbl_2(s) + 2KNO_3(aq)
8. In the above reaction, lead ion and potassium ion exchange their places each other.
9. Lead ion combines with iodide ion and forms Pbl2 as precipitate and KN03 remains in the solution.
10. Such reaction is double displacement reaction.

Activity – 12

Question 12.
Write an activity to show that the oxidation of copper to copper oxide.
(OR)
Write an activity for example of oxidation and reduction.
Answer:

• Take about 1.0 gram of copper powder in a China dish.
• Keep the China dish on a tripod stand containing wire gauze.
• Heat it with a bunsen burner or with a spirit lamp.
• We can find that the surface layer of copper becomes black.
• On heating copper reacts with oxygen present in the atmosphere to form copper oxide.

•  Here copper combines with oxygen to form copper oxide.
• Here oxygen is gained and the process is called oxidation.
• Now pass hydrogen gas over hot copper oxide.

• We can observe that the black coating on copper turns brown because copper oxide loSes oxygen to form copper.
• In this process oxygen is lost and the process is called ”Reduction”.

SCERT AP Board 9th Class Social Solutions 15th Lesson Industrialisation and Social Change Textbook Questions and Answers.

AP State Syllabus 9th Class Social Studies Solutions 15th Industrialisation and Social Change

9th Class Social Studies 15th Lesson Industrialisation and Social Change Textbook Questions and Answers

Improve Your Learning

Fill in the blanks with correct options :
Question 1.
Britain did not depend on different parts of the world for ________ and ________ (labourers; raw material; capital; inventions)
Answer:
labourers, capital

Question 2.
Two important types of transport during the Industrial revolution were ________ and ________ (road, air, water, rail)
Answer:
water, rail

Question 3.
Write two sentences each on following aspects in the context of Industrial revolution:
a) Technology
b) Financing and money
c) Agriculture revolution
d) Transport systems
Answer:
a) Technology :
The commencement of industrial revolution is closely linked to a small number of innovations, beginning in the second half of the 18th century. By the 1830s the following gains had been made in important technologies, e.g. : Textiles, steam power and iron making.

b) Financing and money:
The whole industrial revolution got founded by a few people who held power to issue essentially infinite credit. Most new industries were financed by small investors, merchants, shopkeepers and farmers.

c) Agriculture Revolution :
The Agriculture Revolution was period of agriculture development between 18th and the end of 19th century, which saw a massive and rapid increase in agricultural productivity and vast improvement in farm technology. Many inventions were created and improved during this revolution.

d) Transport Systems :
The growth of industrial revolution developed on the ability to transport raw materials and finished goods over long distances. These facilities were of three main types – Water ways, Roadways and Rail roads.
Out of these three, water transportation was the cheapest.

Question 4.
What do you think is special about inventions happening during the industrial revolution ?
Answer:

• Most inventions were more the product of determination, interest, curiosity, even luck, than the application of scientific knowledge.
• Some inventors in the cotton industry, like John Kay and James Hargreaves, were familiar with the skills of weaving and carpentry.
• Richard Arkwright, however, was a barber and wig-maker, Samuel Crompton was not technically skilled and Edmund Cartwright studied literature, medicine and agriculture, initially wished to become a clergyman and knew little of mechanics.
• By contrast, in the area of steam engines, Thomas Savery, an army officer, Thomas Newcomen, a blacksmith and locksmith, and James Watt, with a strong mechanical bent, all had some knowledge relevant to their inventions.
• The road-builder John Metcalf, who personally surveyed surfaces for roads and planned them, was blind.
• The canal builder James Brindley was almost illiterate, with such poor spelling that he could never spell the word ‘navigation’, but he had tremendous powers of memory, imagination and concentration.

Question 5.
How were the lives of different classes of British women affected by the Industrial revolution?
(OR)
“All classes of British women were affected by the industrial revolution” Write your comments.
Answer:

• The Industrial Revolution was a time of important changes in the way that women worked.
• The village women were actively involved in farm work, they reared livestock, gathered firewood and spun yarn on spinning wheels in their homes.
• Their earnings were necessary to supplement men’s meagre wages.
• Women were the main workers in the silk, lace making and knitting industries, as well as in the metal industries of Birmingham.
• Women may well have gained increased financial independence and self-esteem from their jobs; but this was more than offset by the humiliating terms of work they endured.
• Most classes eventually benfited in some way from the huge profits.
  Thus the lives of different classes of British women were affected by the industrial revolution.

Question 6.
What were the relative advantages of canal and railway transportation?
Answer:

• It is easy to shipping goods.
• Both are cheap means of transport when compared to roadways.
• Bulk quantity of goods can be transhipped.

Question 7.
Locate the places where iron and textile Industries are mainly concentrated in England during Industrial revolution.
Answer:

Question 8.
Prepare a table on invention during the time of Industrial Revolution.
Answer:

Question 9.
Read the para under the title “The workers” of Page No. 192 and comment on it.

(OR)

Q: “What were the problem faced by workers in those days”. Comment it.
Answer:

• The life of the workers was hard.
• Multiple families were living in one apartment.
• Very poor sanitary conditions in the factories and in houses.
• Not enough earning to buy basic needs.
• Poor living standards.
• The short span of lives.
• Lack of medical facilities.
• Epidemic diseases.
  It was miserable to lead life.

Question 10.
Mention the consequences of the Industrial Revolution in the Economic field. Write a report and present in your class.
Answer:
Some 20th century historians argued that the process of economic change took place gradually.

1. GDP, per capita income was broadly stable before the industrial revolution and the emergence of the modern capitalist economy.
2. The Industrial Revolution began an era of per capita economic growth in capitalist economies.
3. Economic historians are in agreement that the onset of the industrial revolution is the most important event in the history of humanity.
4. Rapid increase in technology which affects production.
5. Standardisation of production process and parts.
6. Substantially lower transportation costs and development of improved transportation systems.
7. Better and cheaper intermediate good production and
8. Vast increase in global trade.

9th Class Social Studies 15th Lesson Industrialisation and Social Change InText Questions and Answers

Question 1.
Write two important inventions which revolutionised the textile industry. (Text Book Page No. 188)
Answer:

1. Water powered loom – Edmund Cartwright.
2. Spinning Jenney – James Hargreaves.

Question 2.
Mention two important industrialisation effects on women and children’s life. (Text Book Page No. 193)
Answer:

• Women lost their family life and children their childhood.
• Women had gained increased financial independence and self-esteem. Children worked in factories and stayed away from education.

Question 3.
Compare the industrialisation in Germany and France. Identify similarities and differences. (Text Book Page No. 195)
Answer:
Similarities :

• Germany and France lacked colonial resources.
• In both the countries industrialisation received a boost by the introduction of.railways in 1830s.
• Railways stimulated trade, communication and economic growth.

Differences :

Question 4.
Discuss the developments in Britain and in other parts of the world in 18th entury that encouraged British Industrialisation. (Text Book Page No. 187)
Answer:

• The Industrial Revolution took place in Great Britain almost a century before any other country.
• At that time Great Britain was a very powerful country that controlled many colonies.
• The country gained abundant useful resources from these colonies that aided its growth.
• The country had also just experienced an Agriculture Revolution.
• The country could support the demand for workers in factories. It has many natural resources.
• During the Industrial Revolution, the government of Britain was stable, wealthy and supportive of economy growth. So the Industrial Revolution was emerged first in Great Britain.
• The Industrial Revolution on continental Europe came a little later than in Great Britain, this involved the application of technology developed in Great Britain in new places. Often the technology was purchased from Britain or British engineers and entrepreneurs moved in search of new opportunities.
• The German, Russian and Belgian governments also provided state funding to the new industries.
• France’s economic growth industrialisation process was slow and steady along the 18^th and 19^th centuries.
• U.S. also supported Industrial Revolution and provided fuels for economic and industrial growth.
• Japan : There Industrial Revolution began about 1870 as Meiji period leaders decided to catch up with the west.

Question 5.
Discuss the effects of early industrialisation on British towns and villagesandcompare these with similar situation in India. (Text Book Page No. 194)
Answer:
New technology and techniques in agriculture paved the way for change. As surplus of cheap agriculture labour led to serve unemployment and rising poverty in many rural areas. As a result, many people left the countryside to find work in towns and cities. So the scene was set for a large scale labour intensive factory system. It led to urbanization.

In India during colonial rule, the British exported all the raw material to Britain. They did not establish or develop any industry here. They did not encourage the agriculture. They imported the finished goods. Both the agriculture and cottage industries were disturbed. As the agriculture is the backbone of India, the dependants suffered a lot. The dependants on agriculture became cheap labour.

Question 6.
What factors enabled Germany to outstrip England and France in industrialisation? (Text Book Page No. 195)
Answer:
The factors that enabled Germany to outstrip England and France in industrialisation:

1. Its government assistance.
2. Transport facilities.
3. The governments’s control over working class, movement with a heavy hand.
4. The government provided for many social benefits and insurance for the workers.
5. Benefit from the technical developments achieved by Britain and U.S.A.
6. Heavy capital investment facilities from large banks.
7. A great proportion of Germany’s industrial production was used to build up Germany’s military and naval power.

Question 7.
Why is high quality steel and iron necessary for industrialisation? Discuss in the class. (Text Book Page No. 188)
Answer:
Throughout the 18 and 19 centuries the English steel and iron makers produced blister and crucible steel and iron. In the 18th century innovations like steam boats, rail road and guns increased the demand for fine iron and steel.

Question 8.
Why do you think the mining of iron ore and coal received equal importance? (Text Book Page No. 188)
Answer:
I think coal is used for smelting iron. So the mining of iron ore and coal received equal importance.

Question 9.
Why do you think the early industrial centres were situated near the iron and coal mines? (Text Book Page No. 188)
Answer:
I think there were no proper transportation facilities to transport the coal and iron. And it is very difficult also to transport such heavy things from one place to another place. Later the canal and rail road transports were introduced and developed. So the early industrial centres were situated near the iron and coal mines.

Question 10.
Why do you think France lagged behind in industrial development? (Text Book Page No. 195)
Answer:
France was slow in industrialising. Even by the end of 19^th century she remained a rural country with a large majority of people cultivating small plots of land. Manufacturers found it more profitable to give out work to rural workers who worked at home rather than to set up factories in towns. Such rural domestic production began to decline after 1850 resulting in economic adversity for the people. Machines in towns began to take over much of the work and only delicate hand work was given out to rural workers. Much of French industrialisation was a result of the spread of railway and road networks after 1860 which created a wide market for its industrial goods.

France also did not develop Banks which could mobilise large amount of capital and lend them to industrialists. As a result most of French manufacturers depended upon family resources. They remained small companies as a result. It also made them slow in adopting new ideas and technologies.

Heavy industry based on iron and coal was slow to develop in France as she did not have good reserves of coal and depended upon expensive imports. Thus French industrialisation remained focused on consumer products like textiles, which were basically small scale enterprises. This was in contrast to the German and British Industrial situation where heavy industries predominated.

So France lagged behind industrial development.

Question 11.
What were the difficulties faced by women and children during industrial revolution? (Text Book Page No. 186)
(OR)
What are the difficulties faced by Women and Children during industrial revolution? What is your reaction towards this?
Answer:
The following selections are testimonies from England and Wales collected by Parliamentary Commission who began to investigate the industrial employment of women and children in the early 1840s.

1. Working conditions were unsanitary and the work was dangerous.
2. Education of the children suffered because of the demands of work.
3. Home life suffered as women were faced with the double burden of factory work formed by domestic chores and child care.
4. Men assumed supervisory roles over women and received higher wages.
5. Unsupervised young women away from home generated societal fears over their fate.
6. As a result of the need for wages in the growing cash economy, families became dependent on the wages of women and children.
7. There was some worker opposition to propagate that child and female labour should be abolished from certain jobs.
8. Children as young as 5 years old worked hard hours for little or no pay (sometimes 19 hours a day)
9. Large, heavy and dangerous equipment was very common for children to be using or working near.
10. Many accidents occurred injuring or killing children on the job.

My reaction :
This is very cruel and inhuman treatment. If it is there now-a-days the factory owners should be punished by govt severely.

AP State Syllabus AP Board 9th Class Physical Science Important Questions Chapter 2 Laws of Motion

AP State Syllabus 9th Class Physical Science Important Questions 2nd Lesson Laws of Motion

9th Class Physical Science 2nd Lesson Laws of Motion 1 Mark Important Questions and Answers

Question 1.
Calculate the momentum of a fast moving ball with a velocity 2.2 m/s of mass 6 kg.
Answer:
mass (m) = 6 kg
velocity (v) = 2.2 m/s
momentum = mv = 6 × 2.2 = 13.2 kg.m.s^-1
The momentum of a fast moving ball is 13.2 kg ms^-1.

Question 2.
What is Newton’s first law of motion?
Answer:
Every object will remains at rest or in a state of uniform motion, unless compelled to change its state by the action of a net force.

Question 3.
From a fixed height, two eggs are dropped such that one falls on a concrete floor and the other on a cushioned pillow. The egg falling on the concrete floor breaks and the one falling on the pillow does not break. Explain why in terms of momentum.
Answer:

• The change of momentum of an egg takes place in shorter time in case of concrete surface.
• The change of momentum of the egg takes place in longer time in case of cushioned pillow.
• Hence, egg does not break on cushioned pillow.

9th Class Physical Science 2nd Lesson Laws of Motion 2 Marks Important Questions and Answers

Question 1.
A vehicle of mass 300 kg travels at a velocity of 90 km/h. Find its momentum.
Answer:
Mass of the vehicle (m) = 300 kg
Velocity of the vehicle (v) = 90 km/h = 90 × \(\frac{5}{18}\) m/s = 25 m/s
Momentum = mv = 300 × 25 = 7500 kg.m.s^-1

Question 2.
“With our day to day experience, we must exert some force on an object to keep it moving”.
i) By which law, you can support the above lines?
ii) Which act on the body ? Either force or net force?
Answer:
i) Newtons first law of motion.
ii) Net force. The position of object is changed due to net force only.

9th Class Physical Science 2nd Lesson Laws of Motion 4 Marks Important Questions and Answers

Question 1.
Fill the following table.

Answer:

Question 2.
What is impulse? Derive the formula for impulse.
Answer:
Impulse :
The change of momentum of an object is called impulse.
Formulae for impulse ⇒ ∆p = F_net∆t.

Derivation :
We can express the second law of motion as

From the above equation we know that the product of net force and interaction time is called impulse of net force (∆p).

Question 3.
State and prove the law of conservation of linear momentum.
Answer:
Law of conservation of momentum : Law of conservation of momentum states, in the absence of a net external force on the system, the momentum of the system remains unchanged.
Explanation :

• Let two marbles with masses nij and m2 travel with different velocities ut and u2 in the same direction along a straight line.
• If u₁ > u₂, they collide each other and the collision lasts for time’t’.
• During collision, each marble exerts force on other marble. [F₁₂ and F₂₁]
• Let v₁ and v₂ be the velocities of the marbles after collision.

Now look at the table.

• The total momentum before collision is equal to total momentum after collision.
• Hence, the total momentum remains unchanged before and after collision.

Question 4.
a) Name the ‘machine’ use to prove Newton’s laws of motion. Draw a neat diagram of it.
(OR)
The masses ‘m ‘ and ‘m2’ are attached to a string and roll over a pully, which is attached to a rigid support. Identify the machine and draw the neat diagram of it.
Answer:
a) Atwood machine.
Answer:

b) Draw FBD of both, masses on it.
Answer:

9th Class Physical Science 2nd Lesson Laws of Motion 1 Mark Important Questions and Answers

Question 1.
Newton’s first law of motion is also called
Answer:
Law of inertia.

Question 2.
State Newton’s second law of motion.
Answer:
The rate of change of momentum of a body directly proportional to the net force acting on it and it takes place in the direction of net force.

Question 3.
What is inertia?
Answer:
The natural tendency of objects to resist a change in their state of rest or of uniform motion is called inertia.

Question 4.
What is momentum?
Answer:
Linear momentum of a body is the product of its mass and velocity.
Momentum (p) = mass (m) × velocity (v)

Question 5.
State Newton’s third law of motion.
Answer:
When an object exerts a force on the other object, the second object exerts a force on the first one with equal magnitude and in opposite direction.

Question 6.
Write the law of conservation of momentum.
ANswer:
The law of conservation of momentum states that in the absence of net external force on the system, the momentum of the system remains unchanged.
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂

Question 7.
What is an impulse?
Answer:
The product of net force and interaction time of a system is called impulse of net force.
Impulse ∆p = F_net. ∆t.

Question 8.
What is the Aristotle’s conclusion about the natural state of an object?
Answer:
Aristotle concluded that the natural state of an earthly object is to be at rest. Hence the object at rest requires no explanation as any moving object naturally comes to rest.

Question 9.
What is the Galileo’s conclusion on the motion of an object?
Answer:
Galileo gave birth to modern science by stating that an object in motion will remain in same motion as long as no external force is applied on it.

Question 10.
What is the effect of mass on inertia?
Answer:
As mass increases, inertia increases.
Mass is a property of an object that specifies how much inertia the object has.

Question 11.
Who proposed laws of motion?
Answer:
Sir Isaac Newton proposed the laws of motion.

Question 12.
Give two daily life examples where you experience inertia.
Answer:

• When the bus which is at rest begins to move suddenly, the person standing in the bus falls backward.
• When you are travelling in a bus the sudden stop of the bus makes you fall forward.

Question 13.
If action is always equal to the reaction, explain how a horse can pull a cart.
Answer:
Horse and cart constitutes a single system. So they cannot form action-reaction pair. Therefore, horse can pull the cart.

9th Class Physical Science 2nd Lesson Laws of Motion 2 Marks Important Questions and Answers

Question 1.
What is momentum? What are its units in S.I. system?
Answer:
Momentum (p) of a body is defined as the product of its mass (m) and velocity (v).
Momentum (p) = mass (m) × velocity (v)
p = mv
S.I. units of momentum are kg. m /sec (or) N – sec.

Question 2.
A mass of 0.5 kg has been suspended to a roof as shown in the figure. What is the force exerted by the rope on the object?

Answer:
The forces acting on the object of mass 0.5 kg are
i) gravitational force (downward) = 0.5 x 9.8 = 4.9 N
ii) Tension in the string T (upward).
The object is at rest. Hence the two forces are equal.
∴ The force exerted by the string on the object is 4.9 N (upwards).

Question 3.
Write few incidents if there were no friction.
(OR)
What happens when there were no friction in this world?
Answer:
If there were no friction,

1. we could not be able to walk on ground.
2. we would not be able to stop a fast moving car.
3. any object could not be able to stay on the ground.

Question 4.
What are the factors influencing acceleration? Explain.
Answer:
Factors influencing acceleration are force and mass.
Force :
As the net force increases, the acceleration increases when mass remains constant.

Mass :
When force is constant, as the mass increases, the acceleration decreases.

Question 5.
Why does a fielder catch a fast moving cricket ball by pulling back his arms while catching it?
(OR)
Why does a cricketer move his hands backwards while catching a fast moving cricket ball?
Answer:

• When he pulls back his arms he experiences a smaller force for a longer time.
• The ball stops only when your arms stop.
• This is to avoid a large impulse.
• If he doesn’t pull his arms back, the ball will hurt him.
• This is due to a larger force for a smaller time.

Question 6.
What is the state of an object when no net force is acting on an object?
Answer:
If the net force acting on an object is zero, the object which is at rest remains at rest or if the object is already moving with a certain velocity it continue to move with same velocity.

Question 7.
Which of the following has more inertia?
a) A rubber ball and a stone of the same size.
b) A bicycle and a train.
c) A five rupees coin and a one-rupee coin.
Answer:
As the mass of the object increases the inertia of the object increases.
a) Stone has more mass than rubber ball. So stone has more inertia.
b) Train has more inertia.
c) 5 rupee coin has more inertia.

Question 8.
Explain why some of the leaves may get detached from a tree, if we vigorously shake its branch?
Answer:
The leaves are at the state of rest. When the tree is vigorously shaken the state of rest is disturbed. So the leaves are detached from the tree due to inertia of rest.

Question 9.
Which would require a greater force – accelerating a 2 kg mass at 5 ms^-2 or a 4 kg mass at 2 ms^-2?
Answer:
Force F = ma
Here we have m₁ = 2kg, a₁ = 5 ms^-2 and m₂ = 4 kg, a₂ = 2ms^-2.
Thus F₁ = m₁a₁
Thus accelerating a 2 kg mass at 5 ms^-2 would require a greater force.

Question 10.
A motor car is moving with a velocity of 108 km/h and it takes 4s to stop after the brakes are applied. Calculate the force exerted by the brakes on the motor car if its mass along with the passengers is 1000 Kg.
Answer:

Question 11.
Explain why is it difficult for a fireman to hold a hose, which ejects large amounts of water at a high velocity.
AnswerL
It is difficult for a fireman to hold a hose which ejects large amounts of water at a high velocity because due to high velocity of water the hose moves backward directiondue to Newton’s third law.

Question 12.
From a rifle of mass 4 kg, a bullet of mass 50 g is fired with an initial velocity of 35 ms^-1. Calculate the initial recoil velocity of the rifle.
Answer:
Mass of rifle m₁ = 4 kg
Mass of bullet m₂ = 50 g = \(\frac{50}{1000}\) = 0.05 kg
Initial velocity of rifle u₁ = 0
Initial velocity of bullet u₂ = 0
Final velocity of rifle (recoil velocity) v₁ = v
Final velocity of bullet v₂ = 35 ms^-1
According to law of conservation of momentum
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂.
4(0) + 0.05 (0) = 4v + 0.05 × 35
4v = – 1.75
v = – 0.44 m/s

Question 13.
An automobile vehicle has a mass of 1500 kg. What must the force between the vehicle and road if the vehicle is to be stopped with a negative acceleration of 1.7 ms^-2?
Answer:
m = 1500 kg ;
a = – 1.7 ms^-2
F = ma = 1500 ×- 1.7 = -2550 N
Negative sign indicates that it is a retarding force.

Question 14.
What happens to a person standing in a bus when the bus which is at rest begins to move suddenly?
(OR)
Explain static inertia with an example.
Answer:

• The property of an object at rest will try to remain at rest is called “static inertia”.
• For example, when the bus which is at rest begins to move suddenly, the person standing in the bus falls backward because of static inertia of the body.
• Bus pulls the legs forward while body is in the rest position (static inertia).

Question 15.
Observe the given figure.
a) What happens to the coin, when we pull the paper with a jerk of force?
b) Why?
Answer:

1. The coin falls inside the glass.
2. This is due to static inertia of the coin.
3. This means coin in the state of ‘rest’ before and after pulling the paper. It falls down due to gravity only.

9th Class Physical Science 2nd Lesson Laws of Motion 4 Marks Important Questions and Answers

Question 1.
Give some examples for Newton’s third law of motion from your day-to-day observations.
Answer:
1) Flying of birds :
a) When birds fly, they push the air downward with their wings.
b) The air pushes back the bird in opposite upward direction.
c) These two forces are equal in magnitude and opposite in direction. Hence the bird can fly.

2) Swimming of fish :
a) When a fish swims in water, it pushes back the water.
b) The water pushes the fish with equal but in opposite direction.
c) Hence the fish moves forward.

3) Launching of a rocket:
a) A rocket accelerates by expelling gas at high velocity.
b) The reaction force of the gas on the rocket accelerates the rocket in a direction opposite to the expelled gases.

Question 2.
Derive F = ma.
Answer:
1) Newton’s second law of motion states that the rate of change of momentum of an object is proportional to the net force applied on the object in the direction of net force.

Question 3.
How did Galileo differ the statement of Aristotle ‘The natural state of an earthy object is to be at rest?
(OR)
Write the great experiments of Galileo on inclined planes.
(OR)
How do you appreciate Galileo, the father of modern science?
Answer:

• Galileo came up with two ingenious thought experiments.
• He did his experiments on inclined planes with smooth surfaces.
• He observed that the smoother the surface the farther the ball travelled.
• He extended this ajgument and concluded that if the surface was perfectly smooth, the ball will travel indefinitely until encountered by another object.

• As shown in the figure 1 (a) he observed that when a marble rolls down a slope it picks up speed due to the force of gravity of the earth.
• As shown in the figure 1(b) when the object rolls up an inclined plane, its speed decreases.
• Now let us assume that a marble is moving on a level surface as shown in the figure 1(C), it has no reason to speed up or slow down.
• So, it will continue to move with constant velocity.
• By this experiment, Galileo came to a conclusion which was in contrast to Aristotle’s belief that the state of an earthy object is to be at rest.

Question 4.
Explain Newton’s third Law of motion with an activity.
(OR)
Take two spring balances of equal calibrations. Connect the two spring balances and pull them in opposite direction. Does they show different readings? Why?
Answer:
Newton’s third law of motion : When an object exerts a force on an other object, the second object also exerts a force on the first one which is equal in magnitude but opposite in direction.

Activity:

1. Let us take two spring balances of equal calibrations.
2. Connect the two springs balances as shown in the figure.
3. Pull the balances in opposite direction.
4. Observation : Spring balances shows same readings.
5. Here, one spring balance shows reading of ‘action’ force, and other spring balance shows reading of ‘reaction’ force.
6. Forces are equal, direction are opposite.
7. This shows Newton’s third law of motion.

Question 5.
Take two marbles of m₁, m₂ mass respectively. Make a collision in one second with marbles using u₁, u₂ initial velocities respectively. Take the final velocities as v₁, v₂ You observed the following in the experiment.
m₁ = 10 kg u₁ = 5 m/s v₁ = 15 m/s
m₂ = 100 kg u₂ = 2 m/s -v₂ = 1 m/s
t = 1 sec
Fill the table with suitable answers and write the conclusion from it.

Answer:

Conclusion :

1. The table momentum is unchanged before and after collision.
2. We can say that the momentum is conserved.

Question 6.
How do you appreciate ‘Laws of motion’.
(OR)
How do you appreciate Newton, the great scientist.
Answer:

1. Built upon ideas primarily developed by Aristotle and Galileo, Sir Isaac Newton proposed his three fundamental Laws.
2. These Laws explain the connection between force and a change in motion.
3. These Laws are popularly known as Newton’s Law of motion.
4. Newton’s first law of motion : A body continuous its state of rest or of uniform motion unless a net force acts on it.
5. This law is very useful to study about inertia, mass, weight of an object.
6. This law is used to prepare cranes, machines, vehicles, etc.
7. Newton’s second Law of motion : The rate of change of memontum of a body is directly proportional to the net force acting on it and it takes place in the direction of net force.
8. This law is useful to find the attraction between two objects.
9. It is very useful to study the behaviour of substances like velocity, acceleration, force, momentum, etc.
10. Newton third law of motion : If an object exerts a force on an other object, the second object also exerts a force on the first one which is equal magnitude but opposite in direction.
11. This law is used to prepare rockets.
12. In this way Newtons Law’s are very useful in the fields of automobiles space centres and various industries.
13. In this way Newton laws changed the life of human beings.
14. So, I am appreciating the laws of motion and Newton for his great service to us.

Question 7.
Write suitable law and concept to the given situation or vice versa in the given table.

Answer:
A = Newton’s first law of motion
B = Static inertia
C = Newton’s third law of motion
D = Force of action = force of reaction
E = Newton’s second law of motion
F = Less impulse of net force
G = Newton’s third law of motion
H = Force of action = force of reaction
I = Fish swims in water
J = Force of action = force of reaction
K = Dropping egg on a cushion
L = Object thrown in universe (No external forces acts)
M = Newton’s first Law of motion
N = Bullet hurts
O = Newton’s second law of motion
P = Less impulse of net force
Q = Newton’s Second law of motion
R = Less momentum

SCERT AP Board 9th Class Social Solutions 20th Lesson Democracy: An Evolving Idea Textbook Questions and Answers.

AP State Syllabus 9th Class Social Studies Solutions 20th Democracy: An Evolving Idea

9th Class Social Studies 20th Lesson Democracy: An Evolving Idea Textbook Questions and Answers

Improve Your Learning

Question 1.
How does democracy produce an accountable, responsive, and legitimate government?
Answer:
1. Accountable :
Democracy produces a government which is accountable to all people, it is the basic outcome of democracy. It will produce a government which responds to people.

2. Legitimate :
In democracy, elections are conducted through which people select their representatives. If they do not react for their demands, they choose another representative in the next elections.

3. Responsive :
Democracy produces a government which responds to all the demands and needs of different people.

Question 2.
What are the conditions under which democracies accommodate social diversity?
Answer:

• In every society, there are people belonging to different religions, income groups, and using different languages.
• Democracy means that equal treatment is given to all the individual and that there should not be any discrimination on the basis of caste, gender, race, religion, or region.
• It accommodates all the social diversity by giving equal rights and freedoms to the people.
• In a democratic set up, people from socially weaker sections of the society are allowed to vote and choose their representatives in the government, and no particular religion or language is given any special preference.
• Also, women are given equal rights as men in the society.
• It also ensured that the rule of the majority is not by those who are in majority just in number. The majority group needs to work in harmony with the minority group such that interests and concerns of every group are respected.

Question 3.
Give arguments to support or oppose the following assertions :
A) Industrialised countries can afford democracy but poor countries need dictatorship to become rich.
Answer:
No, we do not agree with the statement, because the nature and scope of democracy is not confined or limited to rich or industrialised countries only. Democracy is the government of modern era which provides accountable, representative, responsible and legitimate government to the people. It also tries to accommodate social differences and promote economic growth which a dictatorship cannot. Hence, a poor country can also afford democracy for popular government and economic growth.

B) Democracy can’t reduce inequality of incomes between different citizens.
Answer:
We do not agree with the statement. Democracy can’t reduce inequality of incomes between different citizens. But democracy can reduce the economic inequality by providing equal distribution of wealth and equal opportunities to all.

C) Government in poor countries should spend less on poverty reduction, health, education, and spend more on industries and infrastructure.
Answer:
We do not agree with this statement. Poverty is one of the social challenges which democracy has to accommodate, so poor countries should spend more to check poverty.

Besides food, clothing, health and education are the basic needs of the people and it is the duty of the government to provide these facilities to the people.

D) In democracy, all citizens have one vote, which means that there is absence of any domination and conflict.
Answer:
Yes, we do agree with the statement. Democracy stands for political equality and guarantees Universal Adult Franschise. Universal Adult Franchise gives right to vote to every adult citizen of the country. Hence there is no chance of political domination and conflict.

Question 4.
In the context of assessing democracy, which among the following is odd one out? Democracies need to ensure :
A) free and fair elections
B) dignity of the individual
C) majority rule
D) equal treatment before law
Answer:
(C) Reason : Majority rule is odd one out because democracy ensures people’s rule based on popular consensus.

Question 5.
Studies on political and social inequalities in democracy show that:
A) democracy and development go together.
B) inequalities exist in democracies.
C) inequalities do not exist under dictatorship.
D) dictatorship is better than democracy.
Answer:
(B) Inequalities exist in democracies

Question 6.
Here is some information about six countries. Based on this information, how would you classify each of these countries? Write ‘democratic’, ‘undemocratic’ or ‘not sure’ against each of these.
i) Country A : People who do not accept the country’s official religion do not have a right to vote
ii) Country B : The same party has been winning elections for the last twenty years
iii) Country C : Ruling party has lost in the last elections
iv) Country D : The parliament cannot pass a law about the army without the consent of the Chief of Army
v) Country E : The parliament cannot pass a law reducing the powers of the judiciary
vi) Country F : All the major economic decisions about the country are taken by officials of the central bank which the ministers cannot change,
Answer:

i) Undemocratic
ii) Not sure (More details are needed)
iii) Democratic
iv) Undemocratic
v) Democratic
vi) Undemocratic

Question 7.
Each of these statements contains a democratic and an undemocratic element. Write out the two separately for each statement.
A) A minister said that some laws have to be passed by the parliament in order to confirm to the regulations decided by the World Trade Organisation.
Answer:
Passing laws by the parliament is democratic whereas passing it in confirmity to the regulations decided by WTO is undemocratic.

B) The Election Commission ordered re-polling in a constituency where large scale rigging was reported.
Answer:
To order repoll in a constituency by the Election Commission is democratic whereas rigging is undemocratic.

C) Women’s representation in the parliament has never reached 10 per cent. This led women’s organisations to demand one-third seats for women.
Answer:
Demand by women’s organisation to reserve 1/3 seats for women is democratic whereas less 10% women’s representation in the parliament is undemocratic.

Question 8.
Write a response to the following arguments against democracy :
A) Army is the most disciplined and corruption-free organisation in the country. Therefore army should rule the country.
Answer:
Army rule is always undemocratic. Under this system, people do not enjoy freedom of speech and expression and are not allowed to criticise the government. Military rule is another name for dictatorship. Moreover, many army men are not disciplined and are corrupt.

B) Rule of the majority means the rule of ignorant people. What we need is the rule of the wise, even if they are in small numbers.
Answer:
Rule of majority is democratic as it represents the views of all sections of the people.

C) If we want religious leaders to guide us in spiritual matters, why not invite them to guide us in politics as well. The country should be ruled by religious leaders.
Answer:
Rule by religious leaders is not democractic. It arouses communal feeling among the people which sometimes lead to communal riots. Besides many religious leaders do not have any experience of administration.

Question 9.
Locate the following countries in the world map.
1. Sri Lanka
2. Belgium
3. Russia
4. America (USA)
Answer:

Question 10.
Read the first two paragraphs under the subheading ‘Dignity and freedom of the citizens’ and answer the following question.

Democracy stands much superior to any other form of government in promoting dignity and freedom of the individual. Every individual wants to receive respect from fellow beings. Often conflicts arise among individuals because some feel that they are not treated with due respect. The passion for respect and freedom are the basis of democracy. Democracies throughout the world have recognised this, at least in principle. This has been achieved in various degrees in various democracies. For societies which have been built for long on the basis of subordination and domination, it is not a simple matter to recognise that all individuals are equal.

Take the case of dignity of women. Most societies across the world were historically male-dominated societies. Long struggles by women have created some sensitivity today that respect to and equal treatment of women are necessary ingredients of a democratic society. That does not mean that women are actually always treated with respect. But once the principle is recognised, it becomes easier for women to wage a struggle against what is now unacceptable legally and morally. In a non-democratic set up, this unacceptability would not have legal basis because the principle of individual freedom . and dignity would not have the legal and moral force there. The same is true of caste inequalities. Democracy in India has strengthened the claims of the disadvantaged and discriminated castes for equal status and equal opportunity. There are instances still of caste-based inequalities and atrocities, but these lack the moral and legal foundations. Perhaps it is this recognition that makes ordinary citizens value their democratic rights.

Write about the dignity and freedom of the citizens in a democratic country in your own words.
Answer:

• In a democratic country people have freedom to choose their representatives on the basis of universal adult franchise.
• Most societies across the world are male dominated. Equal treatment of women became the necessary requirement of a democratic society. Thus their status in democratic countries improved.
• In a non-democratic set up, there is no legal basis for freedom and dignity of individuals.
• Democracy in India has strengthened the claims of the disadvantaged and discriminated castes for equal status and equal opportunity.
• Democracy transforms people from the status of subjects under a king or a dictator to the status of citizens with rights and duties.
• Many fundamental rights are granted to citizens in a democratic country. One such right is to travel anywhere, freedom to any profession, to choose any religion, etc.

Question 11.
What are the reasons for the people to fight for democracy?
Answer:
Reasons:

1. A democracy is the best form of government.
2. Democracy promotes equality.
3. It promotes dignity and freedom of the individual.
4. It improves the quality of decision making.
5. People can elect the leaders of their choice.
6. People have the right to get the information about the public administration.

Question 12.
Give some examples which prove that democracy is practised in our schools.
Answer:

1. Admissions to the students without any differences of caste/creed / religion.
2. Elections to elect SPL / CPL
3. Parents, teachers, associations
4. Social clubs
5. Community participation
6. Equality in teaching etc.

Question 13.
Conduct elections in your class to elect class representative with the help of your teacher.
Answer:
Note : ‘Mock poll’ should be conducted in the class with the help of the teacher.

9th Class Social Studies 20th Lesson Democracy: An Evolving Idea InText Questions and Answers

Question 1.
Discuss the solutions given in both the countries to accomodate social, religious, and linguistics diversity in them. (Text Book Page No. 254)
Answer:
Both are democracies. Yet, they dealt with the question of power sharing differently. In Belgium, the leaders have realised that the unity of the country is possible only by respecting the feelings and interests of different communities and regions. Such a realisation resulted in mutually acceptable arrangements for sharing power. Sri Lanka shows us a contrasting example. It shows us that if a majority community wants to force its dominance over others and refuses to share power, it can undermine the unity of the country and force the country back several hundred years with internal conflicts and civil wars.

Question 2.
How will this chess board change? (Text Book Page No. 247)

Answer:
If the inequalities are vanished, the chess board will change.

Question 3.
If a party is repeatedly voted to power, does it mean that people really want it to come to power, or that there is no alternative or that people are not allowed to vote for any alternative? Answer on the basis of the following three case studies: (Text Book Page No. 249)
a. Since its independence in 1930, Mexico holds elections after every six years to elect its President. The country has never been under a military or dictator’s rule.But, until 2000, every election was won by a party called PRI (Institutional Revolutionary Party). Opposition parties did contest elections, but never managed to win. The PRI was known to use many unfair means to win elections. Teachers of government schools used to force parents to vote for the PRI.

b. Zimbabwe attained independence from White minority rule in 1980. Since then, the country has been ruled by ZANU-PF, the party that led the freedom struggle.Its leader, Robert Mugabe, has been ruling the country since independence. Elections have been held regularly and always won by ZANU-PF. President Mugabe is popular but also uses unfair practices in elections. His government has changed the Constitution several times to increase the powers of the President and make him less accountable. Opposition party workers are harassed and their meetings disrupted. There is a law that limits the right to criticise the President. Television and radio are controlled by the government and give only the ruling party’s version.

c. In China, elections are regularly held after every five years for electing the country’s parliament, called Quanguo Renmin Daibiao Oahui (National People’s Congress). The National People’s Congress has the power to appoint the President of the country. It has nearly 3,000 members elected from all over China. Some members are elected by the army. Before contesting elections, a candidate needs the approval of the Chinese Communist Party. Only those who are members of the Chinese Communist Party or eight smaller parties allied to it were allowed to contest elections held in 2002-03. The government is always formed by the Communist Party.
Answer:

1. Democracy requires free and fair elections.
2. People should have choice to vote.
3. People should not be forced by the government.
4. Electoral rolls should maintained in a right way.

In these 3 cases, these conditions are not fulfilled. So we can say that the elections are conducted in an undemocratic way.

Question 4.
Let us take the example of an election in India. Of all the residents in a region, let us assume that 1000 have right to vote. In any typical election about 60% people go to cast their votes. Thus, we have 600 people voting in an election. Let us assume that there are ten candidates in the election and of these the winning candidate gets about 250 votes, the second candidate gets 200 votes and the other candidates between them get about 150 votes. We declare the one with 250 votes the winner. Does he or she really represent the views and interests of the residents of the locality? Actually, he or she only represents one fourth of the voters. Is this a fair democratic arrangement ? Can there be better ways of representing the people in decision making bodies? (Text Book Page No. 250)
Answer:
He or she really represents the views and interests of the majority people of the locality. This may not be a fair democratic arrangement.

This controversial new look at democracy in a multicultural society considers the ideas of political inclusion and exclusion and recommends ways to engage in democratic politics in a more inclusive way. Processes of debate and decision making often marginalize individuals and groups because the norms of political discussion are biased against some forces of expression. Inclusion and democracy broadens our understanding of democratic communication by reflecting on the positive political function. It reconstructs concepts of civil society and public sphere.

Question 5.
Do the millions of poor people really have any control over the functioning of the elected functionaries? (Text Book Page No. 246)
Answer:
In a democracy, every citizen has certain basic rights that anyone cannot take away from them. I think people are using this during the time of elections.

Question 6.
Does democracy mean rule by people or merely rule by elected persons? (Text Book Page No. 246)
Answer:
Literally, democracy means rule by people only. But in practice, it is rule by elected persons.

Question 7.
How can people really participate in government on a day to day basis? (Text Book Page No. 246)
Answer:
This is possible when all policies and laws are made after extensive public discussions, in which people participate and openly state their needs and views. It also requires that people be involved in effective implementation of the policies and laws – by forming independent citizens committees.

Question 8.
Why do people not want to participate in governance? Is it because of poor knowledge or lack of interest or a feeling that they don’t have a real say in things? (Text Book Page No. 247)
Answer:
The people remain apathetic and they lose their interest in politics. Fore.g. : whoever may be the elected representative, he tries to save his position and wealth, etc.
So they do not want to participate in governance.

Question 9.
Why do you think does such high level of inequality persist even where the countries are democratic and government works in the interest of all people? (Text Book Page No. 248)
Answer:
In many countries like the USA, most of the media are owned by very rich corporate houses or media barons. They effectively manipulate and influence public opinion by what they high light and what they black out. The rich and powerful also have immediate access to members of the legislature and the ministers, and are in a position to influence their policies and programmes.

On the other hand, the poor and illiterate people have no such access to the government circles. Thus the government of many of these countries follow policies which seem to be contradictory to the interests of the poor and in favour of the rich.

So the high level of inequality persists even where the countries are democratic and government works in the interest of all people.

Question 10.
Even today, most countries do not give voting powers to people who have migrated from other countries. Actually, millions of people across the world live without these democratic rights simply because the countries they live in treat them as illegal immigrants. This is the plight of South American immigrants in the US or Turkish immigrants in France or Germany. Such immigrants and refugees are found all over the world including India. Should they not be part of democratic governance? (Text Book Page No. 247)
Think of some reasons for your answer.
Answer:
Democracy is based on the fundamental principle of political equality and inclusiveness. In a democracy, each adult citizen must have one vote and each vote must have one value. So they should also be a part of democratic governance.

Question 11.
Many governments give people the civil liberties. But they keep a careful watch on the activities of the citizens by tapping their telephones and letters, spying on them etc. Do you think this is justified? (Text Book Page No. 248)
Answer:
Today the conditions in the world are so. All the countries are in the shadow of terrorism. So the governments are supposed to do like that. But the government should not disclose the secrecy of the individuals. Then only I think this is justified.

AP State Syllabus AP Board 9th Class Physical Science Solutions Chapter 10 Work and Energy Textbook Questions and Answers.

AP State Syllabus 9th Class Physical Science Solutions 10th Lesson Work and Energy

9th Class Physical Science 10th Lesson Work and Energy Textbook Questions and Answers

Improve Your Learning

Question 1.
Define work and write its units. (AS 1)
Answer:
Work : Work can be defined as the product of the force (F) and the distance (s) moved along the direction of the force.
Work done = Force × displacement = F × s
[This formula is used in only translatory motion of the object]

1. Work is a scalar quantity.
2. Unit of work is ‘N – m’ or ‘Joule’ (J).

Question 2.
Give few examples where displacement of an object is in the direction opposite to the force acting on the object. (AS 1)
Answer:

• When a ball is thrown up, the motion is in upward direction, whereas the force due to earth’s gravity is in downward direction.
• If a ball is moving on plain ground, will get stopped after sometime, due to frictional force acting on it in opposite direction.

Question 3.
Identify the wrong statement among the following. Rewrite them by making necessary corrections. (AS 1)
a) Work and energy have different units.
Answer:
Correction :
Work and energy have same units.

b) When an aeroplane takes off, the work done by its weight is positive.
Answr:
Correction : When an aeroplane takes off, the work done by its weight is negative.

c) The potential energy of spring increases when it is extended and decreases when it is compressed.
Answer:
Correct.

d) If the work done by external forces on a system is negative then the energy of the system decreases.
Answer:
Correct.

e) When a body is falling freely from a height, its kinetic energy remains constant.
Answer:
Correction : When a body is falling freely from a height, its K.E. increases and P.E. decreases, but the total energy of the body remains constant.

f) The unit of power is watt.
Answer:
Correct.

Question 4.
What is mechanical energy? (AS 1)
Answer:
The sum of the kinetic energy and the potential energy of an object is called its mechanical energy.

Question 5.
State the principle of conservation of energy. (AS 1)
Answer:
Energy can neither be created nor destroyed. It can only be changed from one form to another.

Question 6.
When you lift a box from the floor and put it on an almirah the potential energy of the box increases but there is no change in its kinetic energy. Is it violation of conservation of energy? Explain. (AS 7)
Answer:

• When the box is on the floor, it has no K.E., but has some P.E.
• Its P.E. increases as it is lifted and put on an almirah.
• In this event, the energy produced by the person converts into K.E. and the total M.E. remains same.
• Hence it is not the violation of conservation of energy.

Question 7.
One person says that potential energy of a particular book kept in an almirah is 20 J and other says it is 30 J. Is one of them necessarily wrong? Give reasons. (AS 2, AS 1)
Answer:
Two cases will arise in this situation.
Case – I :
One of them will be wrong, if both of them kept the book in the same shelf of the almirah.

Case – II :
Both of them will be correct, if the first person keeps the book in lower shelf and the second one keeps the book in upper shelf of the almirah.

Question 8.
In which of the following cases is the work done positive or zero or negative? (AS 1)
a) Work done by the porter on a suitcase in lifting it from the platform on to his head.
Answer:
Positive

b) Work done by the force of gravity on suitcase as the suitcase falls from porter’s head.
Answer:
Positive

c) Work done by the porter standing on platform with suitcase on his head.
Answer:
Zero

d) Work done by force of gravity on a ball thrown up vertically up into the sky.
Answer:
Negative

e) Work done by force applied by hands of a man swimming in a pond.
Answer:
Negative

Question 9.
What is potential energy? Derive an equation for gravitational potential energy of a body of mass ‘m’ at a height ‘h’. (AS 1)
Answer:
Potential energy:
The energy possessed by an object because of its position or shape is called its potential energy.

Potential energy of a body at height (Or) Gravitational potential energy :

1. The gravitational potential energy of an object at a point above the ground is defined as the work done in raising it from the ground to that point against gravity.
2. Consider an object of mass ‘m’ raised to height ’h’ from the ground.
3. A force is required to do this.
4. The minimum force required to raise the object is equal to the weight of the object (mg).
5. The object gains energy equal to the work done on it.
6. Let the work done on the object against gravity be ‘W’.
   ∴ W = Force × displacement
   = mg × h
   W = mgh
7. The object gains the energy equal to the mgh’ units.
8. This energy is the potential energy of the object at a height ‘h’.
   ∴ P.E. = mgh

Question 10.
When an apple falls from a tree what happens to its gravitational potential energy just as it reaches the ground? After it strikes the ground? (AS 7)
Answer:

• Let us imagine an apple of mass ‘m’ falls from a height h.
• Before starting to fall down, its velocity is zero. Hence its energy is purely potential.
• When it falls down, its gravitational potential energy gradually converts into kinetic energy, but the entire energy in the system remains same.
• When it strikes the ground, its energy is fully kinetic, till its velocity becomes zero.

Question 11.
Let us assume that you have lifted a suitcase and kept it on a table. On which of the following does the work done by you depend or not depend? Why?
a) The path taken by the suitcase
b) The time taken by you in doing so
c) The weight of the suitcase
d) Your weight
Answer:
We know that P.E. = mgh
a) The work done by you does not depend on the path taken by the suitcase, because the height from the ground to the top of the table is fixed in this case, (h constant)

b) The work done by you does not depend the time taken, in doing so, because the work done is same. If you take less time your power will be more otherwise the power is less.

c) The work done by you depends on the weight of the suitcase. As the weight of the suitcase increases, the work done will also increase (See the formula P.E. = mgh).

d) The work done by you depends on your weight, we know that a person with more weight can Mft the suitcase easily.

Question 12.
When you push your bicycle up an incline, the potential energy of the bicycle and yourself increase. Where does this energy come from? (AS 7)
Answer:
The energy inside our body causes increase in the P.E. of the bicycle and ourself.

As we are pushing the bicycle upon incline, the work done by the gravitational force is negative. Hence the energy loses.

Question 13.
Why does a person standing for a long time get tired when he does not appear to be doing any work? (AS 7)
Answer:
1) A person standing for a long time, does not appear to be doing any work, because there is no displacement.
2) Eventhough work has not been done, the person gets tired.
3) This is due to the utilization of energy produced in his body.

Question 14.
What is kinetic energy? Derive an expression for the kinetic energy of a body of mass ‘m’ moving at a speed ‘v’. (AS 1)
Answer:
Kinetic energy :
The energy possessed by an object due to its motion is called kinetic energy.

Numerical expression for K.E.:
1) Let us assume that an object of mass (m) is at rest on a smooth horizontal plane as shown in figure.

2) Let be displaced through a distence ‘s’ from the point A to B by a force (F) acting upon it in the direction of the displacement.
3) In the horizontal direction the net force ‘F_net‘ is equal to the force applied ‘F’.
∴ W = F_net.s = F.s …………. (1)
4) Let the work done on the object cause a change in its velocity from ‘u’ to ‘v’ anr the ‘acceleration produced be ‘a’.

8) As we Have assumed that object is at rest, then the initial velocity u = 0.
∴ W = \(\frac{1}{2}\) mv²

9) We know that K.E. of a body moving with certain velocity is equal to work done on the object to acquire that velocity from rest.

10) Thus the K.E. of an object of mass’m’ and moving with velocity V is equal to
K.E = \(\frac{1}{2}\) mv²

Question 15.
A free-fall object eventually stops on reaching the ground. What happens to its kinetic energy? (AS 1)
Answer:

• Its kinetic energy becomes ‘zero’.
• As the ball stops on reaching the ground, its final velocity ‘v’ becomes zero.
• Hence the K.E. = \(\frac{1}{2}\) mv² = \(\frac{1}{2}\).m.0 = 0

Question 16.
A man carrying a bag of total mass 25 kg climbs up to a height of 10 m in 50 seconds. Calculate the power delivered by him on the bag. (AS 1)
Answer:
Mass of the bag = 25 kg ; Height ‘h’ = 10 m
Acceleration due to gravity g = 9.8 m/s²
The P.E. of the man = mgh = 25 × 9.8 × 10 = 2450 J
The work done by the man is equal to the P.E. possessed by the man.
∴ The work done by the man (W) = 2450 J ; Time (t) = 50 sec.
∴ Power delivered by the man on the bag = \(\frac{\mathrm{W}}{\mathrm{t}}=\frac{2450 \mathrm{~J}}{50 \mathrm{sec}}\) = 49 watts

Question 17.
A 10 kg ball is dropped from a height of 10 m. Find (a) the initial potential energy of the ball, (b) the kinetic energy just before it reaches the ground and (c) the speed just before it reaches the ground.
Answer:
Mass of the ball = 10 kg ; It is dropped from a height h = 10 m
Acceleration due to gravity g = 9.8 m/sec²
a) The initial P.E. of the ball = mgh = 10 × 9.8 × 10 = 980 J
b) We know that the energy is conserved in a freely falling object at anywhere in its journey.
∴ The K.E. just before it reaches the ground = 980 J

c) K.E. just before it reaches the ground = 980 J ;
Speed = v m/s

Question 18.
Calculate the work done by a person in lifting a load of 20 kg from the ground and placing it 1 m high on a table. (AS 1)
Answer:
Mass of a load = 20 kg ; Height h = 1 m
Acceleration due to gravity = 9.8 m/s²
The work done by a person in lifting the load is equal to the P.E.
P.E. = mgh = 20 × 9.8 × 1 = 196 J

Question 19.
Find the mass of a body which has 5 J of kinetic energy while moving at a speed of 2 m/s. (AS 1)
Answer:
KE = 5 J
Speed v = 2 m/sec
Mass of the body = m kg.

Question 20.
A cycle together with its rider weighs 100 kg. How much work is needed to set it moving at 3 m/s?
Answer:
Mass of the bicycle with its rider = 100 kg ; Speed = 3 m/s Amount of work needed to set it moving is equal to its K.E.
K.E. = \(\frac{1}{2}\)mv² = \(\frac{1}{2}\) × 100 × 3 × 3 = 450 J
∴ 450 J work is needed.

Question 21.
When the speed of a ball is doubled its kinetic energy (AS 1)
A) remains same
B) gets doubled
C) becomes half
D) becomes 4 times
Answer:
D) becomes 4 time

Question 22.
Two bodies of unequal masses are dropped from the top of a building. Which of the following is equal for both bodies at any instant?
A) Speed
B) Force of gravity
C) Potential energy
D) Kinetic energy
Answer:
B) Force of gravity

Question 23.
A man with a box on his head is climbing up a ladder. The work done by the man on the box is ……….
A) Positive
B) Negative
C) Zero
D) Undefined
Answer:
A) Positive

Question 24.
A porter with a suitcase on his head is climbing up steps with uniform speed. The work done by the “weight of the suitcase” on the suitcase is ……
A) Positive
B) Negative
C) Zero
D) Undefined
Answer:
B) Negative

Question 25.
How will the increasing energy needs and conservation of energy influence international peace, cooperation and security? Discuss.
Answer:
1) The increasing energy needs and conservation of energy influence international peace, co-operation and security.

2) For example, many great nations depend on the gulf countries and many countries for fuel (Petrol, diesel, etc.). The need of fuel brings co-operation among the countries. Also the need of energy (electricity, fuel, etc.) link all nations to a small circle so that there comes the peace, co-operation and security.

3) Atomic energy, thermal energy, chemical energy, etc. bring unity among all nations.

Question 26.
How would you assess the role of energy conversion occurring naturally in maintaining ecological balance of nature?
Answer:

• The chemical changes in the sun is providing us the heat energy and light energy to the earth.
• The heat energy of the sun evaporates the water into water vapour. This helps us to get heavy rainfall.
• The solar energy is taken by the plant to change CO₂, water and chloroplast into starch which is the food of the plant. This process is called photosvnthesis.
• In the photosynthesis process the plant releases O₂ (oxygen).
• The leguminous (Pea plants) plants help the bacteria present at their roots. In return they help the plants to fix nitrogen in them The nitrogen cycle is maintained.
• From the above examples we can understand that the energy conversion is helpful in maintaining ecological balance of nature.

Question 27.
Collect pictures showing various situation where potential energy possessed by an object depends on its shape and position. Prepare a scrap book.
Answer:
Note : Students can collect pictures of different objects at different heights, with different shapes.
e.g.: 1) A stone on a hill.
2) A book on a table and a pen on a table, etc.
Paste these pictures in your scrap book.

Question 28.
Draw a diagram to show conservation of mechanical energy in case of free falling body.
Answer:

9th Class Physical Science 10th Lesson Work and Energy InText Questions and Answers

9th Class Physical Science Textbook Page No. 161

Question 1.
How are these works being done?
Answer:
All the works mentioned above are being done by utilizing human muscular energy or electrical energy.

Question 2.
What do you need to do these works?
Answer:
Both human beings or machines need energy to do work.

Question 3.
Where does the energy spent go ultimately?
Answer:
The energy spent will be converted into another form to complete the task.

Question 4.
Is there any transfer of energy while work is being done?
Answer:
Yes. We can observe the transfer of energy while work is being done. For example, in fan, electrical energy is converted into mechanical energy. In heater, electrical energy is converted into heat energy, etc.

Question 5.
Can we do any work without transfer of energy?
Answer:
No, we cannot do any work without transfer of energy.

9th Class Physical Science Textbook Page No. 162

Question 6.
What is work?
Answer:
When a force is applied on an object and a displacement is observed, the work is said to be done.

Question 7.
Why is there difference between general view of work and scientific view of work?
Answer:
In general view, work is said to be done while reading, writing, eating or even standing for some time. We cannot observe any displacement in these cases. But in scientific view, work is said to be done when there is a displacement in the direction of force applied.

9th Class Physical Science Textbook Page No. 163

Question 8.
Observe the following examples.
 
a) Are all the people mentioned in the above examples doing work ?
Answer:
No.
In example (1) and (2) there is displacement. Hence they are doing work.
In example (3) and (4) there is no displacement. Hence they are not doing any work.

b) How do you define work?
Answer:
Work is defined as the product of force and displacement.
W = F × s

9th Class Physical Science Textbook Page No. 165

Question 9.
What would be the work done when the force on the object is zero?
Answer:
We know work done W = F × s
Here F = 0
⇒ W = 0 × s = 0
∴ The work done is zero.

Question 10.
What would be the work done when the displacement of the object is zero?
Answer:
Work done W = F × s
Here s = 0
⇒ W = F × 0 = 0
∴ The work done is zero.

Question 11.
Can you give some examples, where the displacement of the object is zero?
Answer:

• When a boy pushes a wall, the displacement in the wall is zero.
• When a boy stands for some time at one place, then there is no displacement in the boy.
• Wind causes the swing in trees, but the tree does not have any displacement.

9th Class Physical Science Textbook Page No. 166

Question 12.
What happens to the speed of the ball while it moves up?
Answer:
The speed of the ball while it moves up decreases gradually, due to negative gravitational force acting on it.

Question 13.
What is the speed at its maximum height?
Answer:
The speed of the ball at its maximum height is zero.

Question 14.
What happens to the speed of the ball during its downward motion?
Answer:
During its downward motion, the ball starts from zero velocity*and its velocity gradually increases due to the positive gravitational force acting on it.

9th Class Physical Science Textbook Page No. 167

Question 15.
What is energy?
Answer:
Energy is the capability to do work.

Question 16.
How can we decide that an object possess energy or not?
Answer:
The capacity of doing work by an object on another object depends on position and state of the object which is doing work.

Question 17.
What will happen to the plate? Why?
Answer:
The plate breaks into pieces, because of the potential energy of the metal ball.

Question 18.
What changes do you notice? Why?
Answer:
The toy car is at rest before winding the key but the same toy gets energy to move when the key attached to it is wound up.

9th Class Physical Science Textbook Page No. 168

Question 19.
What could be the reason?
Answer:

• The reason for breaking up of the plate is the potential energy of the metal ball.
• The reason for moving the toy car is the potential energy of the spring in the toy.

Question 20.
Where does this energy go?
Answer:
The energy is transferred from one object to another.

Question 21.
Is there any energy transfer between the object doing the work and the object on which work has been done?
Answer:
Yes. In case of the toy car, the potential energy of the wounded spring is transferred to car and made the toy car to move.

Question 22.
Can any force do work without energy transfer?
Answer:
No.

9th Class Physical Science Textbook Page No. 169

Question 23.
Where do we get energy from?
Answer:
The Sun is the biggest natural and primary source of energy for us. Many other secondary sources are derived from the sun. We can also get energy from the interior of the earth and from tides of the sea.

Question 24.
Can you think of other sources of energy?
Answer:
The other natural sources of energy are wind energy, tidal energy, gravitational energy, etc. The artificial sources of energy are electrical energy, heat energy, muscular energy, etc.

Question 25.
Are there sources of energy which are not dependent on the Sun?
Answer:
Energy can exists in several forms like mechanical energy, light energy, thermal energy, sound energy, electrical energy, magnetic energy, etc. These energies, though they are artificial, they ultimately depend on the Sun.

Question 26.
Do you know why a person gets tired standing at a place for long time?
Answer:
Though the person standing is not doing any work externally, a lot of work is being done inside the body.

The muscles of the body become stretched when he stands for long time and heart has to pump more blood to muscles. This leads to loss of energy inside the body and hence he gets tired.

9th Class Physical Science Textbook Page No. 176

Question 27.
How do green plants produce food?
Answer:
Green plants produce food from sunlight, by means of photosynthesis.

Question 28.
How are fuels like coal and petroleum formed?
Answer:
Dead plants hurried deep below the earth’s surface for millions of years get converted to fuels like petroleum and coal which have chemical energy stored in them.

Question 29.
What kind of energy conversions sustain the water cycle in nature?
Answer:
Water cycle and conversation of energies :
1) The Sun heats water in oceans and seas. Then water evaporates as water vapour into the air.
Here potential energy converts into kinetic energy.

2) Rising air currents take the vapour up into the atmosphere. There cooler temperatures cause it to condense into clouds.
Here kinetic energy converts into potential energy.

3) Air currents move water vapour around the globe, cloud particles collide, grow and fall out as rain.
Here potential energy converts into kinetic energy.

4) Run off and ground water are stored as fresh water in lakes. Some precipitation falls as snow or hail.
Here kinetic energy converts into potential energy.

9th Class Physical Science Textbook Page No. 178

Question 30.
Do all of us do the work at the same rate?
Answer:
The rate of work done by all of us will not same, because the capacity to do work differs from person to person depending on the weight, nature of work, etc.

Question 31.
Is the energy spent by the force doing work the same every time?
Answer:
No. The energy spent by the force doing work depends on the capacity of the machine or the capacity of a person.

Question 32.
Do the machines consume or transfer energy at same rate every time while doing a particular work?
Answer:
No. For example, consider two grinders of different wattages. The grinder with high wattage can perform fast. In this the energy transfer is faster. The grinder with less wattage can perform slowly. In this the energy transfer is slow.

9th Class Physical Science Textbook Page No. 179

Question 33.
Whose argument is correct?
Answr:
Raheem’s argument is correct, in view of work done.
Second labourer’s argument is correct in view of working hours.

Question 34.
Is work done in two cases same?
Answer:
The work done in two cases is same.

Question 35.
Why is there a change in rate of doing work?
Answer:
The rate of doing work is different, as the two labourers completed in different times.

9th Class Physical Science Textbook Page No. 165

Question 37.
A wooden chair is dragged on the level floor and brought to the same place. Let the distance covered be ‘s’ and frictional force acted on the chair by the floor be T. What is the work done by the frictional force?
Answer:
The displacement of the chair is zero. Hence the work done is zero.

9th Class Physical Science Textbook Page No. 166

Question 38.
Lift an object up from the ground. Work done by the force exerted by you on the object moves it in upward direction. Thus the force applied is in the direction of displacement. However there exists a force of gravitation on the object at the same time
• Which one of these forces is doing positive work?
• Which one is doing negative work?
• Give reasons.
Answer:

• Force applied by us on the object, because the object moves in the direction of force applied.
• Force of gravitation on the object is doing negative work. Here the object is moving against to gravitational force.

9th Class Physical Science Textbook Page No. 169

Question 39.
What would happen if nature does not allow the transfer of energy? Discuss with few examples.
Answer:
If nature could not allow the transfer of energy, the normal life is not possible, e.g.:
1) If the solar energy is not transferred into chemical energy, in which plants prepare their food, we cannot find any plant on the earth. Life without plants is impossible. We can not get food, cloth, shelter and fresh air for our survival.

2) Water cycle is also an example of transfer of energy in nature. If this does not take place, ground water cannot be recharged, we cannot find any water further.

9th Class Physical Science Textbook Page No. 172

Question 40.
a) Why is it easier to stop a lightly loaded truck than heavier one that has equal speed?
Answer:
Due to its light weight, the truck with lighter load is easy to stop.

b) Does the kinetic energy of a car change more when it goes from 10 m/s to 20 m/s or when it goes from 20 m/s to 30 m/s?
Answer:
Case – I :
K.E._(I) = \(\frac{1}{2}\) × m × 10 × 10 = 50m J
K.E._(F) = \(\frac{1}{2}\) × m × 20 × 20 = 200m J
Difference in K.E. = 200m – 50m = 150m J

Case – II :
K.E._(I) = \(\frac{1}{2}\) × m × 20 × 20 = 200m J
K.E._(F) = \(\frac{1}{2}\) × m × 30 × 30 = 450m J
Difference in K.E. = 450m – 200m = 250m J

c) A person starts from rest and begins to run. The runner puts a certain momentum into himself. What is the momentum of ground? And the runner puts a certain amount of kinetic energy into himself. What is the kinetic energy of the ground?
Answer:
Here two cases arise.
Case – I :
In view of the observer, ground has no velocity. Hence the momentum and kinetic energy of the ground will be zero.

Case – II :
In view of the runner, ground has a velocity equal to the velocity of the runner.

1. The momentum of ground is equal to the momentum of the runner in magnitude but opposite in direction.
2. The K.E. of ground is also equal to the K.E of the runner in magnitude but opposite in direction.

9th Class Physical Science Textbook Page No. 175

Question 41.
Does the international space station have gravitational potential energy?
Answer:
International space station is situated in space where the gravitational force is zero. Hence the gravitational potential energy is zero.

9th Class Physical Science Textbook Page No. 178

Question 42.
a) Someone wanting to sell you a super ball claims’ that it will bounce to a height greater than the height from which it is dropped. Would you buy this ball? If yes explain, if not explain.
Answer:
Yes. I will buy this ball. When the applied force is more, the ball bounce to a height greater than the hefght from which it is dropped.

b) A ball, initially at the top of the inclined hill, is allowed to roll down: At the bottom its speed is 4 m/s. Next, the ball is again rolled down the hill, but this time it does not start from rest. It has an initial speed of 3 m/s. How fast is it going when it gets to the bottom?
Answer:
A ball start from the top of an inclined plane u} = 0 m/s; v, = 4 m/s.
Let the acceleration a’ and distance ’s’.
v₁² – u₁² = 2as …………. (1)
Now the ball is rolled down from the top of an inclined plane with a velocity 3 m/s.
∴ u₂ = 3 m/s; v₂ =?
Here the acceleration of the inclined plane is ‘a’ and the distance is ‘s’.

9th Class Physical Science Textbook Page No. 179

Question 43.
The work done by a force F₁ is larger than the work done by another force F₂. Is it necessary that power delivered by F₁ is also larger than that of F₂? Why?
Answer:
Power delivered by F₁ is may or may not be larger than F₂.
Two cases arise.
Case – I :
If the displacement is same, as F₁ > F₂, the power delivered by F₁ is larger than F₂.

Case – II :
If the displacement is different, power delivered by F₁ may not be larger than F₂.

9th Class Physical Science 10th Lesson Work and Energy Activities

Activity – 1

Question 1.
Read Ex : 1, 2, 3, and 4 from page 162 and 163. Now fill the following table.
Answer:

Activity – 2

Question 2.
Explain the relation between work done on an object and energy of the object with an activity.
Answer:

1. Take a hard spring and keep it on the table as shown in the figure.
2. Now compress the spring with your palm and release it after few seconds.
3. We will notice that when a spring is being compressed there is a change in its size.
4. When it is released it gains some energy and may even jump from the table.
5. The work done by your palm on the spring increases its energy and makes it to jump.
6. Thus we can conclude that the object which does work loses energy and the object on which work has been done gains energy.

Activity – 3

Question 3.
List the energy sources.
Answer:
The main source of energy is the sun. Many other secondary sources of energy are electrical energy, magnetic energy, chemical energy, muscular energy, geothermal energy, energy from fossil fuels, etc.

Activity – 4

Question 4.
Explain the energy of moving objects with an activity.
Answer:

1. Consider a metal ball and a hollow plastic block which are kept on a table side by side.
2. Now, suppose that the ball is separated from the block and brought to one end of the table and pushed to roll on the table with speed ‘v’.
3. We may notice that, the ball hits the plastic block and displaces it from point A to B.
4. Thus a moving ball is more energetic than the ball at rest.
5. We can conclude that a body possesses more energy when it is moving than when it is at rest.

Activity – 5

Question 5.
Explain potential energy with the help of a bow.
Answer:

1. Take a bamboo stick and make a bow as shown in figure.
2. Place an arrow made of a light stick on it with one end supported by the string of the bow and stretch the string gently and release the arrow.
3. We notice that the arrow gets separated from the bow and falls down on the ground.
4. Now place the arrow on the bow with one end supported by the string, applying more force and release the arrow.
5. We observe that the arrow flies with great speed into the air.
6. From this we can conclude that the bow in normal shape is not able to push the arrow, but when we stretch the string, it acquires energy to throw the arrow into air with great speed.
7. The energy acquired by the bow due to change in its shape is known as its potential energy.

Activity – 6

Question 6.
Write an activity to show the energy in stretched rubber band.
Answer:
Take a rubber band hold it at one end and pull it from the other end. Then release the rubber band at one of the ends.

When we release the rubber band, it strikes our hand with great force. This force is due to the energy acquired by the rubber band by stretching it.

Activity – 7

Question 7.
Show that the object at some height possesses energy.
Answer:

1. Take a heavy ball.
2. Drop it on a thick bed of wet sand from different heights from 25 cm to 1.5 m.
3. Observe the depression created by the ball on die bed of sand. Compare the depths of these depressions.
4. When the ball is dropped from different heights, the depressions created by the ball on the bed of sand will be different. ‘
5. As the height from which the ball was dropped increases, the depth of depression also increases.
6. Thus we can conclude that a body at some height possesses energy.

Activity – 8

Question 8.
List out the energy conversions in nature and in day to day life.
Answer:
Discuss various ways of energy conversions in nature as well as in our day to day activities and make a separate list of situations for natural conversions of energy and energy conversions in day to day life and write them in the given tables.
Table

Table

Activity – 9

Question 9.
Write an activity which shows the conservation of mechanical energy.
Answer:

1. Take a long thread say 50-60 cm long.
2. Attach a small heavy object like a metal ball at one end.
3. Tie other end to a nail fixed to the wall as shown in figure.
4. Now pull the bob of the pendulum to one side to the position A₁ and release it.
5. The bob swings towards opposite side and reaches the point A₂. It repeats the motion over and over again.
6. The potential energy of the bob is minimum at A and reaches maximum at A₁ because the height of the bob is maximum at that position.
7. When the bob is released from this point (A₁), its P.E. decreases and K.E. starts increasing slowly.
8. When the bob reaches the position A, its K.E. reaches maximum, and P.E. becomes minimum.
9. As the bob proceeds from A to A₂, its P.E. increases slowly and becomes maximum at A₂.
10. The total P.E. and K.E. at any point on the path of motion during the oscillation of the pendulum.
11. Thus the total mechanical energy in the system of pendulum remains constant.

Activity – 10

Question 10.
Calculate the total energy of free-fall at different heights.
An object of mass 20 kg is dropped from a height of 4 m. Compute the potential and kinetic energy in each case and write the values in the table. (Take g = 10 ms-2)

a) What do you say about total energy of system of freely falling body?
Answer:
In a freely falling body, the total energy of system (i.e. the sum of potential energy and kinetic energy) is same at any instance of its travel.

b) Is the mechanical energy conserved in the system?
Answer:
The sum of potential energy and kinetic energy at any instance of its travel is same. Hence we can say that the mechanical energy is conserved in the system.

AP State Syllabus AP Board 9th Class Physical Science Important Questions Chapter 3 Is Matter Pure?

AP State Syllabus 9th Class Physical Science Important Questions 3rd Lesson Is Matter Pure?

9th Class Physical Science 3rd Lesson Is Matter Pure? 1 Mark Important Questions and Answers

Question 1.
There is a mixture with sand and iron filings. Write an activity for the separation of iron filings from sand.
Answer:

1. Take mixture of sand and iron filing in a tub.
2. Take a magnet and move over the mixture.
3. Iron filings are separated by sticking to the magnet.

9th Class Physical Science 3rd Lesson Is Matter Pure? 2 Marks Important Questions and Answers

Question 1.
Frame two questions to understand “Homogeneous mixture”.
Answer:

• Can you see components in homogenous mixture?
• In which mixture components are uniformly distributed, heterogeneous or homogeneous?

Question 2.
How can you use milk to show Tyndall effect?
Answer:

1. Take milk in a glass.
2. Pass light through the milk.
3. Milk particles shine due to scattering of light.
4. This is the Tyndall effect.
5. Milk is a colloidal solution.

9th Class Physical Science 3rd Lesson Is Matter Pure? 4 Marks Important Questions and Answers

Question 1.
Draw the arrangement of apparatus of fractional distillation experiment. What is the advantage of using the fractionating column?
Answer:

1. Fractional distillation column contains glass beads.
2. These glass beads in fractional distillation column provide maximum possible surface area for the vapours to cool and condense repeatedly.

Question 2.
Draw and label the apparatus set up for the separation of a mixture by sublimation.
Answer:

Question 3.
Draw and label the apparatus set up for the separation of a mixture by evaporation.
Answer:

Question 4.
Explain how two miscible liquids can be separated if their boiling points are close to each other.
Answer:

To separate two or more miscible liquids when the difference in their boiling points is less than 25°C, fractional distillation process is used.

Aim :
To separate two miscible liquids (water and acetone) by fractional distillation.

Materials required :
Stand, distillation flask, thermometer, condenser, beaker, acetone and water, one holed rubber cork.

Procedure:

1. Take a mixture of acetone and water in a distillation flask.
2. Fix a thermometer as shown in the figure and clamp to the stand.
3. Attach condenser to the flask.
4. Keep a beaker to collect distillate at the end of condenser.
5. Heat the mixture slowly.
6. Observe the reading of thermometer.
7. The acetone (low boiling point) vapourises and condenses.
8. It can be collected from the condenser outlet.
9. Water remains in the distillation flask. ,

Question 5.
800 ml of solution contains 20 grams of solute. Calculate the concentration in terms of mass by volume percentage of the solution.
Answer:

Question 6.
a) Diagram shows one of the process of separation by mixtures. Based on the diagram answer the following questions.
i) Identify the process involved in the diagram.
Answer:
Sublimation.

ii) Is something missing in the diagram. If so what is that?
Answer:
Stove is missed for heating.

iii) If ‘B’ represent ammonium chloride, then what is ‘A’ represent?
Answer:
Mixture of ammonium chloride and salt.

iv) Give one more example for separation of mixture using above process?

Answer:
Camphor and salt.

Question 7.
Name the instrument used to separate immiscible liquids. Draw a neat diagram of it taking kerosene and water as immiscible liquids.
Answer:
The instrument used to separate immiscible liquids is separating funnel.

9th Class Physical Science 3rd Lesson Is Matter Pure? Important Questions and Answers

9th Class Physical Science 3rd Lesson Is Matter Pure? 1 Mark Important Questions and Answers

Question 1.
What is meant by ‘Pure substance’?
Answer:
In our day to day language, ‘pure’ means something with no adulteration. A substance is said to be pure i.e., homogeneous when the composition doesn’t change, no matter which part of the substance you take for examination.

Question 2.
What is a mixture?
Answer:
A mixture is generally made of two or more components that are not chemically combined.

Question 3.
What is a homogeneous mixture? Give examples.
In a homogeneous mixture the components of the mixture of uniformly distributed throughout it.
Ex : Lemonade, sugar solution, air, etc.

Question 4.
What is a heterogeneous mixture? Give examples.
Answer:
A heterogeneous mixture is a mixture made up of different substances or the same substance in different states which are not uniformly distributed in it.
Ex : Mixture of oil and water; water and naphthalene, etc.

Question 5.
What are the factors affecting rate of dissolving?
Answer:
The factors affecting rate of dissolving are
i) Temperature of solvent,
ii) Size of solute particles,
iii) Stirring of the solution.

Question 6.
When do you say that a solution is dilute solution?
Answer:
If the amount of solute present is little, the solution is said to be dilute.

Question 7.
What do you say that a solution is a concentrated solution?
Answer:
If the amount of solute present is more in a solution, then the solution is said to be a concentrated solution.

Question 8.
Define suspension.
Suspensions are the heterogeneous mixtures of a solid and a liquid in which the solids do not dissolve, like mixtures of soil and water.
Ex : Mixture of sand and water.

Question 9.
Define emulsion and give an example.
Answer:
Emulsion is a mixture consisting of two liquids that do not mix and settle into layers when they left undisturbed.
Ex : Mixture of oil and water.

Question 10.
What is a colloid?
Answer:
Colloids are heterogeneous mixtures in which the particle size is too small to be seen with the naked eye, but big enough to scatter light.
Ex : Milk, Cheese, Ghee, etc.

Question 11.
What is Tyndall effect?
Answer:
Scattering of a beam of light is called Tyndall effect.

Question 12.
What technique do you use to separate the colours?
Answer:
The laboratory technique called chromatography is used for the separation of mixtures into its individual components like inks and dyes.

Question 13.
When do we use fractional distillation method for the separation of miscible liquids?
Answer:
To separate two or more miscible liquids when the difference in their boiling points is less than 25°C, fractional distillation process is used.

Question 14.
What is the definition given by Lavoisier for the ‘element’?
Answer:
According to Lavoisier, an element is a form of matter that cannot be broken down by chemical reactions into simpler substances.

Question 15.
What is the principle involved in separation of immiscible liquids using separation funnel?
Answer:
The underlying principle involved in separation of immiscible liquids using separating funnel is that the immiscible liquids separate out into layers depending on their densities.

Question 16.
What is the use of glass beads in the fractional distillation column?
Answer:
The glass beads in fractional distillation column provide maximum possible surface area for the vapours to cool and condense repeatedly.

Question 17.
How will you separate a mixture containing kerosene and petrol (difference in their boiling points is more then 25°C). Which are miscible with each other?
Answer:
Kerosene and petrol are separated by using distillation process because the difference in boiling point is more than 25°C.

Question 18.
What type of mixtures are separated by the techniques of crystallisation?
Answer:
Salt from water, sugar from water and sodium chloride from its solution in water, etc. are the mixtures to be separated by the techniques of crystallisation.

9th Class Physical Science 3rd Lesson Is Matter Pure? 2 Marks Important Questions and Answers

Question 1.
What is a centrifuge? What are its uses?
Answer:
Centrifuge is a machine used to separate the particles of higher mass and lower mass from a mixture.
Uses :

1. To separate cream from milk.
2. In diagnostic laboratories, to test blood and urine samples.
3. Dryer in a washing machine.

Question 2.
Define a mixture and mention its properties.
Answer:
Mixture :
A mixture is generally made of two or more components that are not chemically combined.

Properties :

1. The substances in a mixture retain their own properties.
2. The substances in a mixture can be physically separated.

Question 3.
What are homogeneous and heterogeneous mixtures? Give examples.
Answer:
Homogeneous mixture:
A homogeneous mixture is a mixture in which the components of the mixture are uniformly distributed throughout it.
Ex :
Lemonade, sugar solution, etc.

Heterogeneous mixture :
A heterogeneous mixture is a mixture made up of different substances or the same substance in different states which are not uniformly distributed in it.
Ex :
Oil and water; Naphthalene and water, etc.

Question 4.
Define solution, solvent and solute.
Answer:
Solution :
The homogeneous mixture of two or more substances is that we cannot separate them by the process of filtration called a solution.

Solvent:
The component of the solution that dissolve the other component in it (usually the component present in larger quantity) is called solvent.

Solute :
The component of the solution that is dissolved in the solvent (usually the component present in lesser quantity) is called solute.

Question 5.
Mention the properties of a solution.
Answer:

1.  The particles of a solution cannot be seen with our naked eye.
2. They do not show Tyndall effect.
3. The solute particles do not settle down when left undisturbed.
4. Solution is a homogeneous mixture.

Question 6.
What are the disperse phase and dispersion medium of a colloidal solution?
Answer:
Disperse phase :
Disperse phase is the substance that present in small proportions and consists of particles of colloidal size (lnm to 100 nm).

Dispersion medium :
Dispersion medium is the medium in which the colloidal particles are dispersed.

Question 7.
Define miscible and immiscible liquids.
Answer:
Miscible liquid :
A liquid is said to be miscible if it dissolve completely in another liquid.
Ex : Alcohol is miscible in water.

Immiscible liquid :
An immiscible liquid is one which doesn’t dissolve but forms a layer over another liquid and can be separated easily.
Ex : Oil is immiscible in water.

Question 8.
Define element and compound. Give examples.
Answer:
Element:
Element can be defined as a basic form of matter that cannot be broken down into simpler substances by chemical reactions.
Ex : lron, gold, silver, sodium, magnesium, etc.

Compound :
Compound can be defined as pure substance that can be separated into two or more components by means of chemical reactions.
Ex : Copper sulphate, ammonium chloride, etc.

Question 9.
How do you appreciate the efforts of scientists in discovering elements?
Answer:

• Generally elements are available in nature in the form of their ores.
• Study of properties of elements lead to the development of civilization.
• The efforts of early alchemists-up to and including Newton, Hennig Brand, Sir Humphry Davy are appreciable for their works in unearthing new elements.
• The definition of element and compound given by Robert Boyle and Lavoisier lead to study the properties of elements and compounds.

Question 10.
Name the technique to separate,
i) butter from curd
ii) salt from sea-water
iii) camphor from salt
Answer:
i) Centrifugation method is used to separate butter from curd .
ii) Crystallisation is used to separate salt from water.
iii) Sublimation technique is used to separate camphor from salt.

Question 11.
What are the factors on which solubility depends on?
Answer:
The factor influence solubility are

1. nature of solute
2. nature of solvent
3. temperature.

Question 12.
What is a concentrated and dilute solution?
Answer:
If the amount of solute is less in a solution, then it is called dilute solution.

If the amount of solute is more in a solution, then the solution is called concentrated solution.

Question 13.
How do you separate following mixture?
a) Iodine from sodium chloride
b) Petrol from water
c) Butter from milk
d) Sugar from water
Answer:
a) Sublimation
b) Separating funnel
c) Centrifugation
d) Evaporation

Question 14.
Identify pure substance and mixture from this figure. Why?

Answer:
a) Fig ‘a’ is a pure substance. Because particles are evenly distributed.
b) Fig ‘b’ is a mixture. Because particles are unevenly distributed.

9th Class Physical Science 3rd Lesson Is Matter Pure? 4 Marks Important Questions and Answers

Question 1.
Define the terms :
a) Solubility
b) Saturated solution
c) Unsaturated solution
d) Concentration
Answer:
a) Solubility :
The amount of solute present in a saturated solution at a certain tem-perature is called its solubility.

b) Saturated solution :
When no more solute can be dissolved in the solution at a certain temperature, it is said to be a saturated solution.

c) Unsaturated solution :
If the amount of solute present in the solution is less than that in the saturated solution is called an unsaturated solution.

d) Concentration of a solution:
The concentration of a solution can be defined as the amount (mass) of solute present in a given amount (mass) of solution or the amount (mass) of solute dissolved in a given volume of the solution.

Question 2.
Compare the properties of suspensions and colloids.
Answer:

Question 3.
Explain the process of preparation of ice cream.
Answer:

1. Ice cream is made by churning a mixture of milk, sugar and flavours.
2. This mixture is slowly chilled to form ice cream.
3. The churning process disperses air bubbles into the mixture by foaming and break up the large ice crystals into tiny particles.
4. The result is a complex substance which contains solids, liquids and gases.
5. This is the ice cream.
6. Ice cream is a colloid.

Question 4.
What is chromatography? What are its uses?
Answer:
Chromatography :
Chromatography is a laboratory technique for the separation of mixtures into its individual components.
Uses:

1. Used to separate components of ink and dyes.
2. Used to separate the coloured pigments in plants.
3. Used to determine the chemical composition of many substances.
4. Used in crime scene investigations.
5. Used in hospitals to detect alcohol levels in a patient’s blood stream.
6. Used by environmental agencies to detect the level of pollutants in water supplies.
7. Used by pharmacists to determine the amount of each chemical found in each product.

Question 5.
Explain the process of separation of components of air briefly.
Answer:

1. If we want oxygen gas from air, we have to separate out all the other gases present in air.
2. The air is compressed by increasing the pressure and then cooled by decreasing the temperature to get liquid air.
3. This liquid air is allowed to warm up slowly in a fractional distillation column where gases get separated at different heights depending upon their boiling points.

Question 6.
Distinguish between mixtures and compounds.
Answer:

Question 7.
Draw a flow chart shows the process of obtaining gases from air.
Answer:

1. We have learnt that air is a homogeneous mixture.
2. It can be separated into its components.
3. The following are the steps involved in separating the components of air.

Question 8.
Draw a flow chart to understand the chemical and physical nature of the matter.
Answer:

Question 9.
Give some daily life experiences where you can observe “Tyndall effect”.
(OR)
What is Tyndall effect? Write any two applications of Tyndall effect.
Answer:
Tyndall effect:
Scattering a beam of light is called the ‘Tyndall effect’.

Daily life experiences:

1. Select a room where the sun light falls directly through a window.
   Close the window in such a way that a slit is left open between the windows.
   We observe a beam of light passing through the slit.
2. While walking on a road having a lot of trees on both sides, when the sun light passes through branches and leaves, we can see the path of dust particles.
3. In cinema halls we can observe the beam of light scatters from projector to the screen.
4. When smoke in the kitchen is exposed to sun light, we can observe the path of smoke particles.

Question 10.
How do you separate the mixture of napthaleine powder and salt powder?
Answer:
Aim :
To separate components in the mixture of napthaleine and salt.

Apparatus:
China dish, cotton plug, funnel, burner.

Method :
Separation mixtures by sublimation.

Procedure :

1. Take 4 table spoons of mixture in a China dish.
2. Take the glass funnel and plug the mouth of the funnel with cotton plug.
3. Invert the funnel over the China dish.
4. Keep the dish on the stand of stove and heat for some time.

Observation :

1. Vapours of napthaleine solidified on the walls of the funnel.
2. Salt remains in the China dish.

SCERT AP Board 9th Class Social Solutions 19th Lesson Expansion of Democracy Textbook Questions and Answers.

AP State Syllabus 9th Class Social Studies Solutions 19th Expansion of Democracy

9th Class Social Studies 19th Lesson Expansion of Democracy Textbook Questions and Answers

Improve Your Learning

Question 1.
Map 1: Democratic Governments in 1900 – 1950

Map 2 : Democratic Governments in 2011

a) On the basis of these maps, identify up to three countries (in some cases you won’t find three countries) that were democratic in these continents for the given years and make a table as given.

Answer:

b) identify some African countries with democracy in 2011.
Answer:
Egypt, Libya, Tunisia are countries which got independence in and around 2011.

c) Make a list of big countries that were not democratic in 2011.
Answer:
1) Asian countries :
China, Kazakhstan, Turkmenistan, Saudi Arabia, etc.

2) African countries :
Algeria, Ethiopia, Chad, Zaire, Morocco, Mauritania, Angola, etc.

The above countries were not democratic in 2011.

Question 2.
Read the maps again and think about the following points.
a) Based on the maps, can we say that the Twentieth century was a significant era for the spread of democracy?
Answer:

1. At the beginning of the 20th century only few countries of Europe and America were independent, e.g.: Spain, France, England, Norway, Argentina, Chile, Bolivia and Peru, the USA, Canada, Alasca.
2. After World War II almost all countries fought against colonial powers and got independence.
3. Though there are still some non-democratic countries, we can call 20th century as an era of democracy.

b) During the early 20 century, democracy was mostly in the continents like Europe and Americas. While in certain continents like Africa and Asia there were almost no democratic countries.

c) Even today there are certain areas that have not established democratic governments such as Saudi Arabia and Ethiopia.

Question 3.
Most countries often claim themselves to be democratic by conducting elections. How did this occur in the context of Myanmar and Libya?
Answer:

1. Both the countries Myanmar and Libya claim themselves as independent and democratic.
2. But in practical view, they are not democratic countries.
3. Unlike democratic countries –
   a) They did not allow multi-party elections and one party usually ruled for several years.
   b) Even they did not allow free elections.
   c) Sometimes they did not allow the elected representatives to form governments.
   Ex : NLD, led by Suu Kyi got 80% seats, was not allowed to form government.
   d) They did not allow freedom of expression or freedom to form organizations, or freedom to protest against government.

Both the countries did not have any conditions for a democracy to flourish. Hence they cannot claim themselves to be democratic by conducting elections.

Question 4.
Why do you think the rulers try to control the media? Do you know how is media controlled in your area?
Answer:

• Mass Media is powerful weapon which can make or break any governments.
• Restrictions on media helps them to remain in power.
• Hence the rulers always try to control the media.
• So many times in India too government censors certain news. This generally happens without the notice of common man.

Question 5.
Write an imaginary dialogue between a person from Libya and Myanmar comparing the events and struggle for democracy in their respective countries.
Answer:
Person from Libya : Hai, I am xxxx, as I have already told you the monarchy is over thrown in our country.
Person from Myanmar : Yes, I came to know about that who is ruling your country now.
Libya : Gaddafi has taken control of our country. What about your country.
Myanmar : In 1962, the government was overthrown and ‘Ne Win’ military rule is going on.
Libya : First of all we thought he could rule us. He laid foundation for development. What is your country’s position?
Myanmar : Under military rule, our country did not make any progress.
Libya : UNO is supporting our people’s to demands.
Myanmar : Other countries are also showing sympathy us.
Libya : We protested against.
Myanmar : Suu Kyi is in house arrest she played good role.
Libya : Gaddafi is overthrown in 2012. O.K. Bye.
Myanmar : We got new government in 2012. Bye.

Question 6.
How do literacy and mass education help for the functioning of democracy?
(OR)
How do the literacy help for the effective functioning of democracy?
Answer:

• Literacy and education play an important role in the development of individual and society.
• Knowledge liberates citizens from ignorance.
• Any society needs a vigilant, conscious, and informed public for the successful functioning of the democracy.
• Education enables people to think critically, rationally, and scientifically.
• The right to vote can be properly exercised when voter can read newspapers, follow national and international developments, and participate in democratic process effectively.
  Hence the proper functioning of democracy always depends on the literacy and mass education.

Question 7.
What is the difference between democracy and dictatorship?
Answer:
Differences between democracy and dictatorship :

Question 8.
What is the role played by Aung San Suu Kyi in fighting for democracy in Myanmar?
Answer:

• Aung San Suu Kyi, daughter of Aung San who took the lead in staging protest against the military rule.
• Suu kyi fought for reforms in Burma.
• She established a new political party “National League for Democracy (NLD) and won majority (80%) of the seats even though she was in prison.
• Suu Kyi was released from house arrest after the elections of 2010.
• She questioned on the malpractices of elections.
• In 2011 Suu Kyi’s ‘NLD’ contested in the elections and have won 43 out of 45 parliamentary seats that were vacant.
• The freeing of Suu Kyi and the successful participation of NLD in elections are considered the beginning of democracy in Burma.

Question 9.
Read the last paragraph of this chapter and answer the question.

Today, it is increasingly becoming clear to the people that democracy which respects the freedom and rights of all people may be the best way to solve some of the complex problems the countries face. Today, a new kind of democracy is being forged across the world in which even the poorest and the most vulnerable people will have a voice and will be able to influence policies and ensure justice and peace for all.

What is a new kind of democracy?
Answer:

1. The poorest and the most vulnerable people will have a voice.
2. The poorest will be able to influence the policies.
3. The new kind of democracy will ensure justice and peace for all.

Question 10.
Read the newspapers and note down any news regarding the struggle for democracy in Libya or Egypt or any other country. Prepare a file of such news clippings and display them in the classroom.
Answer:
Struggle for democracy in Libya :
A few months ago the National Transitional Council (NTC), which has governed Libya since the first few weeks of the revolt in 2011, announced that the assembly would not draft the constitution itself but instead appoint a 60-member committee to draft it. The members of this committee were supposed to be chosen from outside the assembly and represent the country’s three geographic regions of Libya – Tripolitania, Cyrenaica, and Fezzan — in equal numbers. Yet, a few weeks ago, the NTC changed policy again at the last moment, declaring that the members of the constitutional committee would not be appointed by the assembly but directly elected by the people, though it’s not clear when. Confused? So are Libyans.

There are rumors in Libya that most members of the NTC are not happy about the idea of dissolving the institution and going back home. It’s just a rumor, but the group’s decision to revoke constitution-writing powers from the new assembly is making people suspicious, and that’s the point. The NTC likely fears too much power going to Islamists, who are notoriously less friendly toward the NTC than are other groups. We can’t know the NTC’s motivations for sure, but their recent moves diminished the power of the new assembly, which they may have feared would be dominated by Islamists, who swept national elections in neighboring Tunisia and Egypt. A more democratic Libya would re¬ject the NTC’s odd rule-changing and reinstate the elected assembly’s power to write the constitution. After all, this is what Libyans voted for. So should the same Western powers that supported the Libyan revolt.

Libya has come a long way since Gaddafi’s fall, but it still hasn’t been able to solve two major security problems: the armed militias that still roam the country and the state’s deteriorating control of its national borders. Fortunately, this is where new assembly can step in, finding agreement among the various parties and militias and forming a govern-ment, one that is as inclusive as possible, to administer and rebuild Libya. The interna-tional community can help, including by training and equipping the police and security forces, both of which were devastated by the recent conflict.

A successful election is just the start of dealing with one of Libya’s most important challenges right now: national unity. Regional and local claims and jockeying for power threaten to undermine the legitimacy of and support for the national government. A few thousand inhabitants of the eastern provinces care calling for a federalist state, if not of outward secession. While this is definitely a minority position, it is a very dangerous one because it could easily, at the administration’s first real difficulty, split the government and the people, thus slowing or even reversing Libya’s progress toward stability. Most Libyans, as well as the interested Western nations, are rightly happy with Libya’s progress toward becoming a stable, unified, democratic state. But if they want that progress to continue, they’ll all have to work together.

9th Class Social Studies 19th Lesson Expansion of Democracy InText Questions and Answers

Question 1.
What kind of problems do you think these pose for establishing democratic government? (Text Book Page No. 235)
Answer:

• Bringing democratic participation of all the people under conditions of tribalism, normalism, illiteracy, and restrictions on women was difficult.
• Encouraging participation of common people in public affairs through peoples councils and elected Peoples Assembly in the centre in also difficult.

Question 2.
Even though the people had benefited much from the Gaddafi government, why do you think they rose in rebellion against it? (Text Book Page No. 237)
Answer:

• The government of Gaddafi was not ready to trust these democratic bodies.
• “Revolutionary Councils” were appointed.
• The democratic bodies had to implement the decisions of these non-elected leaders.
• The RCC used brute armed force to arrest, torture, and kill political opponents.
• There was no freedom of press and no one could start any trade union or other associations.
• The civic amenities were deplorable.
  Hence rebellions rose against the government of Gaddafi.

Question 3.
Even though the Gaddafi government claimed to be a democratic government, what aspects of democracy were absent? What aspects of democratic government were present in it? (Text Book Page No. 237)
Answer:
Aspects of democracy absent in the government of Gaddafi:

1. Democratic bodies had to implement the decisions of non-elected leaders.
2. Freedom of press, freedom to form trade unions and associations were prohibited.
3. No political parties were allowed to function in Libya.
4. This led to concentration of power and wealth in the hands of few.

Aspects of democracy present in the government of Gaddafi :

1. Free universal education was provided.
2. Free medical care for all was also provided.
3. Oil profits were distributed to all the citizens.
4. Subsidised housing schemes were introduced.
5. Women were given with equal opportunities and status in the society.

Question 4.
Why are civil liberties important for democracy? Explain in the context of Libyan experience. (Text Book Page No. 237)
Answer:

• “Liberty” is one of the aspects of democracy.
• Civil liberties include liberty of thought, speech, expression, faith, belief and worship.
• These “liberties” were missing in Libya.
• Liberty of expression was brutally crushed.
• The RCC was also very intolerant of criticism and opposition.
• People were not at liberty to express their discontent.
  Thus lack of civil liberties led to the downfall of the government of Gaddafi in Libya.

Question 5.
Why do you think democracy was not able to establish itself in Burma after its independence? (Text Book Page No. 240)
Answer:

• Burma became independent just 5 months after Indian independence.
• It appeared that Burma too would emerge as a democratic republic.
• However, the Burmese did not have a united political party to lead them at the time.
• Burma consisted of a large number of small states and ethnic linguistic regions.
• Aung San, the leader of the nationalist movement and the leader of the ethnic group was assassinated.
• Burmese military began its slow advance into the ethnic states to rule by force.
• They were illiterate, no able leader, no power to fight with military, etc., were the reasons for the failure to establish democracy in Burma.
• Finally, in 1962, the elected government was overthrown by a coup, and army “General Ne Win” took over the charge of the country.

Question 6.
Why do you think democracy was not able to establish itself in Libya after its independence? (Text Book Page No. 240)
Answer:

• Libya got its independence in 1951 and the power was transferred to king Idris.
• In the year 1969 under the leadership of Gaddafi monarchy was abolished and the country was declared as the “Socialist Libyan Arab Republic”.
• But the people were concerned about their own tribe and its honour than about the welfare of the people.
• Most of the people were poor nomadic animal herders who were also illiterates.
• Women were confined to purdah and were not allowed to participate in public activities.
• On top of this the government of Gaddafi was not ready to trust the bodies of democracy. Hence the democratic participation of all people under these conditions was difficult.

Question 7.
How did students and youth play an important role in bringing democracy to both Libya and Burma? (Text Book Page No. 240)
Answer:

• People from across the country began to interact through internet and mobile phones to share their misery.
• Use of internet and Facebook helped them to get the support of the people all over the world.
• The youth and people started protesting against delay in the building of houses and political corruption.
• In Burma, the students took the lead in staging protest against the military rule. Finally military power was overthrown in both the countries and democracies are established.

Question 8.
What similarities of events do you find in the description of events in Libya and Burma? (Text Book Page No. 240)
Answer:

• In both the countries, students, youth and people participated in the protest movements.
• Use of mobiles and internet and social networking sites like Facebooks were common.
• “UNO” supported both the countries and declared Libya as “No fly zone” and ordered for a referendum in Burma.
• Economic sanctions were imposed on both the countries.
• In both the countries the protest was to overthrow the military regime and establish a democratic form of government.
• Lastly both the countries successfully conducted elections in a fair way and elected their new leader.

Question 9.
Underline the statements that are related to political party and voting in both Libya and Burma. (Text Book Page No. 240)
Answer:
a) Libya

1. RCC – Revolutionary Command Council.
2. Election – 2012 new government sworn in on Nov. 2012. Over 100 political parties participated and 200 representatives were elected.

b) Burma

1. 1951, 56 and 60 elections were held.
2. 1990 elections – NLD party established by Suu Kyi.
3. 2010 elections were held.
4. In 2011 ‘NLD’ won 43 out of 45 seats.

Question 10.
Track the changes that you may have heard about Libya and Burma during the year 2012 and write it. (Text Book Page No. 240)
Changes in Libya :

1. In 2012 the National Transitional Council (NTC) handed overthe powerto Libya’s newly elected Parliament the General National Congress (GNC).
   The Congress appointed a Prime Minister Ali Zidan, who formed an interim government.

Changes in Burma :
Burma’s Pro-democracy leader Aung San Suu Kyi greeted supporters from her vehicle during her election campaign in Aung Pan in the southern Shan State of Burma (Myanmar) on March 1, 2012.

Question 11.
Dictators try to control press and TV media. Do you know other ways of sharing information and ideas between people? (Text Book Page No. 237)
Answer:

• Mobile phone occupies the first place in sharing information and ideas.
• ‘Fax’ is one of the ways of sending message from one place to another.
• Today internets are available everywhere.
• We can send e-mails to exchange information and ideas.
• Social networking sites play important role in sharing informations.
  Ex : Facebook, Twitter, etc.

Question 12.
The Tunisian struggle began with the death of one trader. The struggle gained strength largely through the use of social networking websites like Facebook. Why do you think it is not easy for governments to control them? (Text Book Page No. 237)
Answer:

• Technology has changed much.
• For development, every country has to work on internet.
• Computer have become a part of our life.
• Hence it is difficult to control social networking websites.

Question 13.
Locate “Libya” and “Myanmar” in the world map. Which continents are they located on? (Text Book Page No. 234)
Answer:
Libya is in Africa continent.
Myanmar is in Asia continent.

SCERT AP Board 9th Class Social Solutions 18th Lesson Impact of Colonialism in India Textbook Questions and Answers.

AP State Syllabus 9th Class Social Studies Solutions 18th Impact of Colonialism in India

9th Class Social Studies 18th Lesson Impact of Colonialism in India Textbook Questions and Answers

Improve Your Learning

Question 1.
How did people use the forests before the rule of the British? Why was there less danger of the forests being fully destroyed in those days?
Answer:

• The adivasis used forests for hunting, gathering tubers, fruits, flowers and herbs and for gazing their cattle.
• They cut wood, cleared the land to cultivate crops.
• They cut trees to build their homes etc.
• They did not blindly cut large tracts of forests but only small patches.
• They cut only old trees and allowed new trees to grow.
  Therefore there was less danger of the forests being fully destroyed in those days.

Question 2.
Against whom did the adivasis revolt? In what ways did they demonstrate their anger and protest? Give some examples.
Answer:

• The Adivasis revolted against the police department, the forest department and the moneylenders.
• During the protests they would burn down many police stations, posts of the forest department and houses of the moneylenders.
• In many places they would set fire to the entire jungle.
• The revolt of Santhals of Jharkhand in 1856, the Koya revolt of A.P. in 1880 and 1922, the revolt of the Maria and Muria of Bastar in 1910, etc. were some of the revolts of adivasis.

Question 3.
How were the revolts of the adivasis suppressed by the British?
Answer:

• In most of the revolts the leaders were arrested and were kept behind bars,
  e.g.: Birsa Munda died in prison in 1900.
• The leaders were traped and shot dead by the Britishers,
  e.g.: Sita Rama Raju of A.P.
• The Adivasis were armed only with bows and arrows.
• They could not stand before the gun-bearing British army.
  e.g. : In a fierce battle 15000 Santhals were killed and their revolt was finally suppressed.

Question 4.
Make a timeline to show when adivasi protests occurred in different parts of India.
Answer:

Question 5.
What problems did the Indian industrialists have with the British government?
Answer:
The problems of the Indian industrialists during the British government were –

1. The British government had levied a special tax on cloth made by Indian weavers in order to help the cloth industry of Britain.
2. The British government refused to levy the similar tax on the British cloth.
3. Later the government levied a 3 /2% tax on the British goods and the same tax was levied on the cloth made in India too.
4. With this the British government made it clear that it would protect mainly the interests of the British factories.

Question 6.
During British rule, why was it easier for the European companies rather than Indian companies to set up industries? Give a few reasons.
Answer:

• Indian industry had got a little help from the British government.
• A very large number of factories, banks, ships etc., were in the hands of Europeans, not in the hands of Indians.
• British industries had easy access to all types of officers and authorities of the British government, whereas Indians never had such reach.
• All the foreign trade was in the hands of European companies, hence, they had no shortage of funds.

Question 7.
Labour laws were first made for child labourers, then for women and lastly for men. Why were these laws made in this order?
Answer:

• The first Factory Act in 1881 made rules especially for the welfare of the children.
• As the children are tender hence the first priority was given for the welfare and regularized their working hours and children below 7 years were restricted to work in factories.
• In 1891, laws were made in the interest of women labour as they are sensitive when compared with men.
• Lastly in 1911, the working hours of men were regularised.

Question 8.
How could education affect industrial development ? Discuss in the class.
Answer:

• Industrial development needs a lot of educational workers and officers at all levels.
  We need lot of technicians, scientists, engineers, management personnels, lot of support system etc.
  Previously lack of “technical know how” led to the establishment of factories with foreign collaboration
  Now due to education affect, we are technically skillful and can establish industries without any foreign collaboration.

Question 9.
Identify the large industrial cities on outline map of India during 20th century.

Answer:

1. Mumbai
2. Ahmedabad
3. Chennai
4. Jamshedpur
5. Kanpur
6. Kolkata
7. Hyderabad
8. Surat
9. Visakhapatnam
10. Pune
11. Nagpur
12. Indore
13. Salem

Question 10.
Find out where each of these adivasi struggles took place, and mark their locations on a map of India.
Answer:

1. Jharkhand
2. Chotanagpur Plateau
3. Uttarkhand
4. Chintapalli
5. Adilabad

Question 11.
Read the para under the title ‘Adivasi Revolts’ on page 222 and comment on it.
Adivasi Revolts :
We have seen how the conditions of the adivasi farmers who lived in the jungle worsened in British times. The Baiga, Muria, Gond and Bhil tribes of Madhya Pradeshand Chattisgarh, the Koya, Reddy, and Kolam tribes of Andhra Pradesh and the Saora adivasis of Orissa, were all no longer able to practice their old form of cultivation. They were having to become labourers for either the Forest Department or for contractors. Or they were becoming bonded labourers for moneylenders or farmers who had come from outside.
Answer:

1. As soon as the British took over Eastern India, tribal revolts broke out to challenge the alien rule.
2. In the early years of colonization, no other community in India offered such heroic resistance to British rule or faced such tragic consequences as did the numerous Adivasi communities.
3. As punishment for Adivasi resistance to British rule, ‘The Criminal Tribes Act’ was passed by the British Government in 1871.
4. As the freedom movement widened, it drew adivasis into all aspects of the struggle.

Question 12.
Visit an office of the Forest Department and interview the official on how forest could be preserved and wisely used by both industries and local people.
Answer:
Interview with Forest Ofiicer :
Student (S) : “Good Morning Sir, tell us about your eduction.”
Forest Officer (F.O) : “I was a village man. After completing my graduation, I appeared for the APPSC. Later I got selected and trained at Dehardun. I was appointed in forests in East Godavari Dist.
Student : Sir, elaborate upon your works as a Forest Officer.”
Forest Officer : “My work involved preservation of forest. As a Forest Officer it is my duty to safeguard the forests. Today, the world’s demand for timber and paper continues to grow. As we lose the forest, we also lose the habitat for many species, including human tribes.”
Student : “What precautions should we take to preserve the forests ?”
Forest Officer : 1. The government should ban the import of illegally logged timber.
2. The people should use less paper and wood.
3. People should invest in forest communities.
Student : “How can the forests be used wisely by both industries and local people ?”
Forest Officer : “Fine, there are certain things that everyone of us can do.
1. We should plant new trees.
2. We should practise the 3Rs. ‘Reduce, Reuse and Recycle’.
Reduce the amount of products of trees.
Reuse the items of forests, use the recycling process for some items.
3. Harvesting trees to create young regrowing forest in the place of cut forests.
4. We should keep all wildlife in our minds.
Student : “Thank you Sir, you gave us good information. Bye, sir”
Forest Officer : “Very good my boy. God bless you.”

Question 13.
Visit a nearby factory in your area find out its history how has the technology changed, where do the workers come from, try and talk to the employers and some workers to get their views.
Answer:
We have visited Sri Padmavathi Polymers.
Sri K. Chalapathi Rao and Sri C.V. Narasimha Rao are the partners of this factory. The factory was established in the year 2007. There are 50 employees in this factory. They are manufacturers and suppliers of Thermocol Boxes like EPS box, Apple box, Fish box, etc.

They import the thermocol balls from some other country. They heat these balls and mould them in different shapes.

The employers are present in the factory when we visit it. We met Smt. Subhadra, Accountant there. They are very happy to work there. They said that the facilities arranged by the authorities were well. There are shift duties in the factory. Women workers work during the day time only. The salary structures are also fine. They have eight working hours a day. We observe the surroundings in the factory. They are neat and clean. They grow plants for fresh air.

9th Class Social Studies 18th Lesson Impact of Colonialism in India InText Questions and Answers

Question 1.
Discuss what “Protected market” means. (Text Book Page No. 225)
ANswer:

• “Protected Market” is the policy according to which goods made in a specific area be protected from foreign goods.
• Protection is given to the indigeneous goods by levying tax on imports. Thereby free incoming of imports is restricted to protect local markets.
• Indian markets were not protected during the British rule.

Question 2.
The Indians demanded that a tax be imposed on British goods coming to India.
1) Do you think this was a fair demand? (Text Book Page No. 225)
2) Should the government have treated British and Indian industries equally?
Answer:

1. Yes, Indians’ demand of taxing the British goods coming to India was a fair demand.
2. Yes, the government should have treated British and Indian industries equally.

Question 3.
Why did a rapid development take place in Indian industry during the First World War? (Text Book Page No. 226)
Answer:

• During the First World War, the import of foreign goods into India fell sharply.
• Cargo ships were diverted to war related duties, and hence there was a shortage of ships.
• The factories of Europe produced things needed for the war.
• So under these circumstances, the factories in India started selling their goods in greater quantities.
• Enthused by these heavy sales there was a rapid development of industries.

Question 4.
What industries were established in India during British rule? (Text Book Page No. 227)
Answer:

• From 1850 onwards, machine based industries had begun to set up in India.
• The biggest industry was the spinning and weaving of textiles.
• The jute industry also developed during this peirod.
• The greatest example of the achievements of Indian industrialists was the setting up of a steel factory at Jamshedpur in 1907.

Question 5.
What were the difficulties in the development of Indian industries at the time of Independence? (Text Book Page No. 227)
Answer:

• Tax levied on foreign goods was not adequate to protect our industries or goods.
• The British government did not pay adequate attention to develop the resources and facilities such as coal and iron and railway, roadways and electricity.
• Indian industrialists had to buy machines from abroad and they did not start in India.
• Educated workers like scientists, engineers and technicians were not available in India.
• Hence we depended on foreigners for “technical know how”.
• The above were the difficulties in the development of Indian industries at the time of independence.

Question 6.
In the early days of factories in India : (Text Book Page No. 229)
a) What were the rules regarding work and rest for labourers?
b) What were the rules regarding payment of wages ?
c) For what reasons would there be cuts and reductions in the labourers’ wages?
Answer:
a) Rules regarding work and rest for labourers :

1. Once the work began, there was no question of stopping.
2. There was no fixed time break even for meals.
3. Taking out 15-20 minutes from their work and would eat their meal.
4. The working atmosphere was unhygienic and would pass in the heat, humidity, noise, dust and suffocation of the mill.
5. The work would stop at sunset, when it would impossible to see.

b) Rules regarding payment of wages :

1. Wages were given in proportion to the amount of goods produced.
2. The owners laid the condition that “as much as you make, so much will you be paid”.
3. The labourers were not able to get any fixed income each month.
4. At the end of the month, the owners would not even pay the full payment. They would keep some amount till the end of the next week so that the worker would not leave the work.

c) Reasons for cuts and reductions in the wages :

1. There were plenty of fines.
2. The owners would fine the labourers
   a) if they came late,
   b) if the cloth spoilt,
   c) if the owner thought the labourer did not work sincerely.
3. These fines were deducted from the month’s wages.

Question 7.
Why did labourers go on strikes? (Text Book Page No. 230)
Answer:

1. Labourers struggled against their oppressive working conditions.
2. They went on strike for fixed incomes and other facilities such as –
   a) regulation of working hours
   b) improvement of their working conditions
   c) weekly break and leave
   d) regarding employment of children

Question 8.
Why were strikes used instead of any other action? (Text Book Page No. 230)
Answer:

• During strikes all workers would participate.
• Due to that the work would stop and the production would come down.
• One day strike would lead to lakhs of rupees loss to all industrialists.
• Hence strikes were used instead of any other work.

Question 9.
Why did the educated people of India not pay much attention to the interests of factory labourers in the beginning? (Text Book Page No. 231)
Answer:

• In the beginning most of the educated people of India paid no need to the problems of the labourers.
  They believed that if laws were made in the interests of the labourers, industries would not be able to develop in India.

Question 10.
How would the labour laws have affected the industrialists? (Text Book Page No. 231)
Answer:

• The industrialists were forced to give a break of half an hour after every six hours of work.
• The working hours of men, women and children were regularised.
• The mill production came down.
• The expenses of the owners increased.
• They were forced to improve the working conditions of the workers.

Question 11.
The British industrialists were against the development of factories in India, yet they took the side of Indian labourers. Why? (Text Book Page No. 231)
Answer:

• If fixed incomes and facilities were provided, the mill production would come down and the expenses of the owners would go up.
• Then the goods produced in the factories would be more expensive.
• Then the goods from Britain would be sold easily.
• The development of Indian industries would come to a standstill.
  Thus the British industrialists were just pretending to show concern for the welfare of the Indian labourers.

Question 12.
Below what age could children not be employed as labourers in British times? (Text Book Page No. 231)
Answer:

• According to the Factory Act of 1881, children below the age of 7 were not allowed to work in the factories.
• According to the Factory Act of 1891, children below the age of 9 were not allowed to work in the factories.

Question 13.
According to the labour laws what was the maximum number of hours that children, women and men could be expected to work? (Text Book Page No. 231)
Answer:

• According to the Factory Act of 1881, the children’s working hours were reduced to 9 hours a day.
• According to the Factory Act of 1891, the women labourers cannot be made to work more than 11 hours a day.
• The men labourers cannot be made to work for more than 12 hours every day as per the Factory Act of 1911.

Question 14.
Which were the two main labourers’ unions to be formed in India during British times? (Text Book Page No. 231)
Answer:

• Girni Kamgar Union was formed with the help of labourers of Mumbai.
• The Mazdoor Mahazan was formed in Ahmedabad under the influence of Gandhiji.

Question 15.
In which year were you born? Mark it on this time line. Also mark the births of your parents and some grandparents or other old relatives you can find out about. (Text Book Page No. 231)
Answer:
I was born on ……………. . My father was born on ……………. . My mother was born on ……………. . My grand father was born on My grand mother was born on ……………. .

Question 16.
Find out whether any of the people whose births you marked were affected by the labour laws. (Text Book Page No. 231)
Answer:
My grandfather was affected by labour law. He worked in a sugar factory. So he obtained many benefits by labour law. Working hours duration, medical, housing etc., facilities were obtained.

Question 17.
Underline four sentences that represent the situation of adivasis and their use of forests before British rule. (Text Book Page No. 220)
Answer:

• Before British rule adivasis and villagers living in and near forests got many things they needed for their daily lives from the forests.
• They were the owners of the forests.
• They used the forests for hunting, gathering tubers, fruits,flowers and herbs and for grazing their cattle.
• They cut wood to build their homes and to make implements. They took things for their personal use.

Question 18.
Have you seen old wooden sleepers used in railway tracks ? What are they being replaced with today? Discuss why this replacement is taking place. (Text Book Page No. 221)
Answer:
Yes, I have seen wooden sleepers in railway tracks when I was very young. They are replaced by concrete sleepers today. Interest in concrete rail road ties increased after World War – II following advances in the design, quality and production of pre-stressed concrete. Concrete ties were cheaper and easier to obtain than timber and better able to carry higher axle weights and sustain higher speeds. Concrete sleepers have a longer service life and require less maintenance than timber due to their greater weight which helps them remain in the correct position longer.

Problems with wood ties include rot, splitting, insect infestation, plate-cutting, etc. In addition to these, the government wanted to reduce the burden on the forests.

So the concrete sleepers are introduced and replaced the wooden sleepers.

Question 19.
What do the present laws set as minimum age, below which children cannot be employed as labourers? (Text Book Page No. 231)
Answer:
According to the recent factory acts no child below 14 years of age can be employed as labour in factories or coalmines or any other jobs.

Question 20.
Why is a union or labourers’ organization important for labourers? Discuss. (Text Book Page No. 233)
Answer:

• Any union or organizations fight for the common cause of all workers.
• They fight for the right of the workers.
• They protect the workers from the harassment of owners.
• They also fight for the hike in salaries and compensation for accident deaths, etc.

AP State Syllabus AP Board 9th Class Physical Science Solutions Chapter 12 Units and Graphs Textbook Questions and Answers.

AP State Syllabus 9th Class Physical Science Solutions 12th Lesson Units and Graphs at Curved Surfaces

9th Class Physical Science 12th Lesson Units and Graphs Textbook Questions and Answers

Improve Your Learning

9th Class Physical Science 12th Lesson Units and Graphs 1 Mark Questions and Answers

Question 1.
What is Unit?
Answer:
A unit is a standard measure used for comparing measurements.

Question 2.
Why do we use different units for different items?
Answer:
Depending on the quantities of material the units may be expressed.

Question 3.
Write fundamental quantities in MKS system.
Answer:
Mass (m), Length (l) and Time (t).

Question 4.
What are fundamental quantities?
Answer:
Fundamental quantities are those physical quantities that cannot be expressed in terms of other quantities.

Question 5.
What is fundamental unit?
Answer:
Units used to express fundamental quantities are called fundamental units.

Question 6.
Write fundamental units in MKS system.
Answer:
Meter, Kilogram and Second.

Question 7.
What is CGS system?
Centimeter, Grams and Seconds.

Question 8.
What is SI system? When was it introduced?
Answer:
SI system means International System of units. It was introduced in 1971.

Question 9.
List the fundamental quantities that are added to SI system.
Answer:
Electricity, light intensity, quantity of substance, temperature and plane angle.

Question 10.
What is difference between MKS and SI systems?
Answer:

• MKS system has only three fundamental quantities. Those are length, mass and time.
• SI system has eight fundamental quantities. Those are length, mass, time, electricity, light intensity, quantity of substance, temperature, plane angle.

Question 11.
What is derived quantity?
Answer:
The quantities that are obtained by combining fundamental quantities either by multiplication or division or both operations are called derived quantities.

Question 12.
What are derived units?
Answer:
The derived units of measurement derived from the fundamental units.

Question 13.
Write derived units of area and volume.
Derived units of area = m²
Derived units of volume = m³

Question 14.
What are the fundamental units are used to express the units of Force?
Answer:

Hence fundamental units used to express force are kg, m, s.

Question 15.
Which conversion factor is used to convert kilometers into meter?
Answer:
1000.

Question 16.
Which conversion factor is used to convert meters into kilometers?
Answer:
10^-3.

Question 17.
Write conversion factor to convert km/hr into m/s.
Answer:
\(\frac{5}{18}\)

Question 18.
Write some units of measurements expressed in the name of scientists.
Answer:
Newton (N), Pascal (Pa), Joule (J), Watt (W), etc.

Question 19.
What is graph?
Answer:
A pictorial form of representation that shows the relation between two quantities can be called a graph.

Question 20.
What are independent and dependent variables?
Answer:
Independent variables are controlled by us. Whereas dependent variables are changed due to the change in dependent variable.

Question 21.
Which variable is taken on x – axis?
Answer:
Independent variable.

Question 22.
What are grids on graph paper?
Answer:
On a graph paper, there are thick as well as fine vertical and horizontal lines. These intersecting lines form squares or grids.

Question 23.
What is Range?
Answer:
Range = highest value – lowest value.

Question 24.
What is scaling?
Answer:
Pointing of the values in the table on x – axis and y – axis is called scaling.

Question 25.
What is scale?
Answer:
The interval taken pointing values on axis is called scale.

Question 26.
How do you find x – axis scale?
Answer:

Question 27.
What is curved line graph?
Answer:
If a graph is in curved shape, then it is curved line graph.

Question 28.
What is Hooke’s law?
Answer:
The elongation of the spring is proportional to the applied mass within the elastic limit of the spring.

Question 29.
What is slope of the straight line graph?
Answer:

Question 30.
What is slope of a graph?
Answer:
The tan value of the angle at x – axis is the slope of a graph.
tan θ = \(\frac{\Delta \mathrm{y} }{\Delta \mathrm{x}}\)

Question 31.
What is area of a graph?
Answer:
The product of the physical quantity of y – axis and x – axis may explain another physical quantity. Hence, it is said to be area of the graph.

Question 32.
What does slope indicate to the graph of displacement and time?
Answer:
Velocity.

Question 33.
What does area of the graph of acceleration Vs time indicate?
Answer:

Question 34.
Predict shape of the graph if you plot a graph by taking time on x – axis and velocity of a free fall body on y – axis.
Answer:
Straight line.

Question 35.
Guess the shape of the graph if you plot a graph of time and distance covered by a bus.
Answer:
Curved graph.

Question 36.
Rithvik wrote ‘3 kgs of sugar’ on the black board. Correct him by asking a question.
Answer:
Is it correct to mention kg in plural form while writing units?

Question 37.
Karthik got a doubt by seeing ‘3 newtons’ on the black board. What would be it?
Answer:
Which quantity is measured in newtons ?

Question 38.
What are the materials / apparatus required to prove Hooke’s law?
Answer:

1. Spring,
2. Weights,
3. Scale,
4. Stand.

Question 39.
Area, volume, density, mass
a) Write any one fundamental quantity from the above data.
b) Write any one derived quantity from the above data.
Answer:
a) mass.
b) volume.

Question 40.
‘Dheeraj counted distance travelled by him for every 10 min.’
From the above data write independent and dependent variables.
Answer:
Time (min) is independent variable distance is dependent variable.

Question 41.

Plot the data points (6, 4) and (0, 0) in the above graph.
Answer:

Question 42.
How do you remember scientists through units of measurements?
Answer:
Some units are expressed in the names of the scientists like newton, joule, etc. When we use these units, scientists are remember once again.

Question 43.
What is the use of graph?
Answer:

• We can solve so many problems by using graphs.
• We can know the relation between two physical quantities through graphs.

Question 44.
Calculate the Range of 5, 7, 3, 8, 18, 4, 2, 6.
Answer:
Range = highest value – lowest value
= 18-2 = 16.

Question 45.
If the range is 10 and no. of grids horizontally is 20. How can you take scale X-axis?
Answer:

2) I will take 0.5,1,1.5, 2, 2.5,3,3.5, 4, 4.5, 10 on the X-axis. As a scale on x-axis.

Question 46.
How slope of displacement Vs time graph is useful?
Answer:
We can calculate velocity by calculating slope of line in displacement Vs time graph.

Question 47.
How area of velocity Vs time graph is useful?
Answer:
Area of velocity Vs time graph is useful to find the position of the object.

Question 48.

What is the acceleration at ‘B’?
Answer:

Acceleration is 1 m/s².

Question 49.

Find the acceleration at ‘A’.
Answer:

Question 50.

How much distance is travelled by the object from A to B in the graph?
Answer:
Zero.

9th Class Physical Science 12th Lesson Units and Graphs 2 Marks Questions and Answers

Question 1.
What is a unit? Where it be placed?
Answer:

• A unit is a standard measure used for comparing measurements.
• Unit should be placed right side of the magnitude of every physical quantity. For eg : 2 kg, 7 m.

Question 2.
Differentiate fundamental quantities and derived quantities.
Answer:

Question 3.
Derive units of density.
Answer:

Question 4.
Write different system of measurements.
Answer:

1. FPS : Foot, Pound, Second.
2. CGS : Centimeter, Gram, Second.
3. MKS : Meter, Kilogram, Second.
4. SI : Meter, Kilogram, Second, Ampere, Candela, Mole, Kelvin, Radian.

Question 5.
Derive units to the given physical quantities.
Answer:

Question 6.
Which of the following are correct? Why?
Answer:
A) m/s
B) m/s/s
C) m-s²
D) 10.kgs
E) Pascal
F) joule
Answer:
A) and F) only are correct
B) two solidus are used – wrong.
C) line break is used – wrong.
D) ‘•’ and plural of kg are used – wrong.
E) capital letter used (P) – wrong.

Question 7.
Write correct form of units in the following.
(j) DB
(ii) mhz
(iii) 20 – m
(iv) kg.m-s^-2
Answer:
(i) dB
(ii) MHz
(iii) 20 m
(iv) Kg.m.s^-2

Question 8.
How do you expect the shape of the given graphs?
(a) a ∝ b
(b) a ∝ \(\frac{1}{\mathbf{b}}\)
Answer:
a) It may be straight line graph.
b) It may be curved line graph.

Question 9.
From the graph,
a) What is indicated by slopes of the lines OA, OB, OC?
b) Which line shows high speed than other lines? Why?

Answer:
a) Slopes of the lines indicate speeds of the objects.
b) OA shows high speed than other lines.
Because it has high slope than others.

Question 10.

a) Which is independent variable?
b) Which is dependent variable?
c) Predict how the graph is.
d) Find the range on Y – axis.
Answer:
a) Mass
b) Weight
c) It may be in straight line.
d) On Y – axis, values are 98, 196, 294, 392, 490.
Range = 490 – 98 = 392

Question 11.
Plot the given data points on the given graph paper and join the dots.
Data points : (8, 10) (20, 15) (40, 22.5) (48, 0)

Answer:

Question 12.
Draw a graph roughly to show uniform velocity of a body.
Answer:

Question 13.
Draw a graph that shows a body without movement after travelling sometime.
Answer:

Question 14.
How do you appreciate the role of graphs in solving problems?
Answer:

• Graphs can be used to compare different physical quantities like time- displacement, time-velocity, pressure-volume, etc. and helps in solve the problems.
• Graphs are very useful to find the path of an object which is in motion and it is easy to calculate velocity, acceleration, position, etc. at particular time and particular point of the object.
• Graphs are very useful minimum, maximum values of some physical quantities. For example to find minimum deviation of a prism graphs are very useful.
• In this way graphs are appreciable for their role in solving problems.

Question 15.
From the given graph find the slope and area at point B.
Answer:

Question 16.
Convert 3 m/s into km/hr.
Answer:

Question 17.
A ball of 100 g mass is thrown with initial velocity of 0.01 km/s. What is its momentum at that time?
Answer:
Momentum = mass × velocity
Here, mass of the ball = 100 gr = 100 × \(\frac{1}{100}\) kg ⇒ m = 0.1 kg
Velocity of the ball = 0.01 km/s = 0.01 × 1000 m/s ⇒ v = 10 m/s
Momentum of the ball = mxv = 0.1 × 10 kg.m/s = 1 kg.m/s

Question 18.

Find the temperature on Day – 4 by using graph.
Answer:

From the graph the temperature on day – 4 is 43°C.

Question 19.
Observe table and answer the following.

i) 12 cm = …………. m
ii) 2 nm = …………. cm
Answer:
i) 12 cm = 12 × 10^-2 m
ii) 2 nm = 2 × 10^-7 cm
[From the table 1 nanometer = 10_-9 m; 1 centimeter = 10^-2 m.
1 nanometer to centimeter conversion factor = 10^-9-(-2) = 10^-7.]

Question 20.
Find the conversion factors
a) Picometers to Meters
b) Gigabytes to Kilobytes.
Answwr:
From the above table,
a) 1 picometer = 10^-12 m; 1 meter = 10° m
Conversion factor to convert picometers to meters = 10^-12-(-0) = 10^-12 m

b) 1 GB = 10⁹ bytes ; 1 KB = 10³ bytes
Conversion factor to convert GB to KB = 10^9-3 = 10⁶ bytes.

Question 21.
Find the conversion factors
a) Megawatts to Kilowatts
b) Kilowatts to Megawatts.
Answer:
From the above table,
a) 1 Megawatt = 10⁶ watts; 1 Kilowatt = 10³ watts
Conversion factor MW to KW = 10^6-3 = 10³ W

b) 1 KW = 10³ W and 1 MW = 10⁶ W
Conversion factor KW to MW = 10^3-6 = 10^-3 W

9th Class Physical Science 12th Lesson Units and Graphs 4 Marks Questions and Answers

Question 1.
Write any four rules of writing units of measurements.
Answer:
1) Values are written as a number followed by a space and a unit symbol.
eg : 24 kg, 2 cm, 5 s.

2) Symbols for derived units formed by multiplication are joined with a dot or a space.
eg : 30 N.m, 30 N.m

3) Symbols are mathematical entities, not abbreviations. So, do not have an appended period / full stop.
eg : 4 kg is correct, but 4 k.g. is incorrect.

4) All symbols for units are written in lowercase.
eg : m, s, kg, etc.

5) Symbols derived from the name of a person use uppercase letter for shortform.
eg : Pa, N, W, etc.

Question 2.
Write steps in the construction of a graph, to the given data in a tabular form.
Answer:

• Take a graph paper. Draw x – axis and y – axis on it.
• Identify independent variable and dependent variable from the data given in the table. Generally independent variables are decided by us, whereas dependent variables are changed due to the change in independent variable. Take independent variable on x – axis and dependent variable on y – axis.
• Calculate range for values taken on x – axis as well as y – axis, by using the formula. Range = highest value – lowest value.
• Determine the scale to be taken on x – axis and y-axis by calculating, range/no. of grids on axis. And mark the scale on the axes.
• Write names of the physical quantity which is taken on the axis. For eg : time (s), distance (m).
• Write the data points from the data given in the table such as (x₁ y₁) (x₂ y₂)
• Label the data points in the graph paper by put a dot where the corresponding horizontal and vertical line intersects of a data point.
• Joint the dots in the graph paper.

Question 3.
Fill the given table with suitable answers.

Answer:
a) N/m²
b) Pa [pascal]
c) s^-1
d) Force
e) m.kg.s^-2
f) m² . kg . s^-2
g) J/s (or) \(\frac{N.m}{s}\)
h) W [watt]

Question 4.
Fill the table with suitable answers.

Answer:

Question 5.

1) Who took rest while travelling?
2) After 100 min., what is the positions of Padma and Bhavani?
3) Whose speed is uniform?
4) What is the speed of Bhavani?
Answer:

1. Padma
2. Padma at 700 meters and Bhavani at 600 meters from the beginning point.
3. Speed of Bhavani is uniform.
4. \(\frac{600}{100}\)m/min. = 6 m/min.

Question 6.

a) Which physical quantity is taken as independent variable?
b) What is the scale on x – axis?
c) What is the scale on y – axis?
d) How the graph is?
Answer:
a) Distance
b) 1 cm = 100 m
c) 1 cm = 2 min.
d) It is a curved line graph.

Question 7.
Draw a graph to the given data.

Answer:
1) Draw x – axis and y – axis on a graph paper.
2) Here time is independent variable and displacement is dependent variable. So, take time on x – axis and displacement on y – axis.

3) Calculate the ranges of values on x – axis and y – axis.
Range on x – axis = 24 – 4 = 20
Range on y – axis = 15-2 = 13

4) Estimate scale on x – axis and y – axis.

So, scale on x – axis 1 cm = 2 min.
Scale on y – axis 1 cm = 1 km.
Mark the scales on x and y – axis.

5) Write time (min) at x – axis and displacement (km) at y – axis.

6) Write data points or data values as (4, 2) (8, 3) (12, 7) (16, 11) (20, 13) (24, 15).

7) Plot the above data points in the graph paper with dots.

8) Join the data points.

Question 8.
Draw velocity – time graph to the given table.

Answer:
1) Draw x – axis and y – axis on a graph paper.
2) Here time is independent variable and velocity is dependent variable. So, take time on x – axis and velocity on y – axis.

3) Calculate the ranges of values on x – axis and y – axis.
Range on x – axis = 180 – 20 = 160
Range on y – axis = 20 – 5 = 15

4) Estimate scale on x – axis and y – axis.

Take scale as 1 cm = 8 s on x – axis.
1 cm = 1 m/s on y – axis.

5) Write time (s) at x – axis, velocity (m/s) on y – axis.

6) Write data points as (20, 5), (40, 10), (60, 15) (80, 20) (100, 20), (120, 20) (140, 20) (160, 20) (180, 15).

7) Plot the data points in the graph paper with dots.

8) Join the dots.

Question 9.
Show that i) v = u + at, ii) s = ut + ½ at² in graphical method.
Answer:

1) Graph is plotted with time on x – axis and velocity on y – axis.

2) According to the above graph,
Velocity of the object at “t” value ”0″ = u
Velocity of the object at “t” value “t” = v

3) Difference between the time intervals = v – u

4) From the graph, x₁ = 0, x₂ = t, y₁ = u, y₂ = v

5) We know that slope refers acceleration to the velocity – time graph.
Hence acceleration (a) = \(\frac{\mathrm{v}-\mathrm{u}}{\mathrm{t}}\) ⇒ v – u = at ⇒ v = u + at ………… (1)

6) The area between the two straight lines drawn at u, v gives displacement of the object. The area of graph is in the shape of trapezium. It has a rectangle and a triangle.

7) Area of the graph = area of rectangle (ABCD) + area of triangle (DCE)

8) We know that area of the graph of velocity – time gives displacement(s).

Question 10.
Observe the following graph and calculate displacement of the object in 12 sec.

Answer:
1) Displacement (s) = Area of the graph = Area of ABDO rectangle + BDC triangle.
2) Area of the rectangle ABDO = 8 × 20 = 160.
3) Area of the triangle BDC = ½ × 20 × (12 – 8)
= ½ × 20 × 4 = 40.
4) Displacement (s) = 160 + 40 = 200 m.
5) Hence, displacement of the object in 12 sec. = 200 m.

Question 11.
Find the velocity from the graph at A.

Answer:

1. We know that area of the graph of acceleration – time gives velocity (v).
2. Join the line AB.
3. Velocity (v) = Area of ΔABO = ½ × 60 × 120 = 3600 m/s.

Question 12.
Find the force at point ‘B’.

Answer:

We know that
Force= Area of trapezium ABDO.
= Area of triangle AEB + Area of rectangle EODB

Question 13.
Using the following data. Draw displacement time graph.

Using above graph, what is the average velocity in First “4” Seconds
Answer:
Average velocity in first “4” seconds

9th Class Physical Science 12th Lesson Units and Graphs InText Questions and Answers

9th Class Physical Science Textbook Page No. 205

Question 1.
Which is bigger, 2 kg or 100 gr?
Answer:
2 kg.

Question 2.
What would be Rasheeda’s answer?
Answer:
2 kg.

Question 3.
If Rasheeda asked the shop keeper to give 2 sugar, 100 tea powder, can he be able to weigh the items? Why?
Answer:
No, the shop keeper cannot weigh. Because there is no measuring terms (units) to weigh.

Question 4.
Can you name the units of time? What are they?
Answer:
Second, minutes, hours, etc.

Question 5.
Why are they (different units to measure a physical quantity) required?
Answer:
Depending upon the quantity, different units to measure are required.

Question 6.
Can we express the mass of chalk in kilogram?
Answer:
It is difficult to measure directly in kilograms.

9th Class Physical Science Textbook Page No. 206

Question 7.
Why do we use different units for different items?
Answer:
Depending on the quantities of material the units may be expressed.

Question 8.
Why are these called fundamental quantities?
Answer:
These (length, mass, time, etc.) are independent quantities, cannot be expressed in terms of other quantities.

Question 9.
What fundamental quantities are there in the table?
Answer:
Length, mass, time electricity, light intensity, quantity of substance, temperature, plane angle.

Question 10.
What similarities have you noticed in MKS and SI systems?
Answer:
Length, mass, time are common in MKS and SI systems.

Question 11.
How do you find the area of the book?
Answer:
By multiplying length and breadth of the book.

Question 12.
What measurements are required to express area?
Answer:
Length and breadth.

9th Class Physical Science Textbook Page No. 208

Question 13.
How can you convert kilometers into meters?
Answer:
We can convert kilometers into meters by multiplying meters with conversion factor 1000.

9th Class Physical Science Textbook Page No. 211

Question 14.
What is the length of each side (of square grid)?
Answer:
1 cm.

Question 15.
What is the distance between the adjacent thin lines?
Answer:
1 mm.

Question 16.
Which axis is time plotted on and which axis represents distance?
Answer:
Time is plotted on x – axis, y – axis represents distance.

Question 17.
How are these (numbers on x – axis) interpreted?
Answer:
By calculating range of the values of data on x – axis.

Question 18.
What is the difference between the highest and the lowest values?
Answer:
40-5 = 35.

9th Class Physical Science Textbook Page No. 212

Question 19.
What is the advantage of knowing the range of values?
Answer:
If the graph is plotted with the help of calculated values of range, the graph is uniformly distributed through the graph paper and has a correct shape. Otherwise, it will be either too big or too small and will not be any help for analysis.

Question 20.
How to identify values on x-axis and y-axis?
Answer:
By determine the scale.

Question 21.
How to determine scale?
Answer:

Question 22.
Which values of distance in the table are equal to the values marked on y-axis?
Answer:
3, 12, 24, 24, 30, 33.

9th Class Physical Science Textbook Page No. 213

Question 23.
What is the shape of the line in the graph?
Answer:
It is curved line.

Question 24.
Did you notice any elongation of the spring?
Answer:
Yes, I noticed elongation of the spring.

Question 25.
How much was the elongation?
Answer:
Some extend. It can be calculated by difference in the lengths of the spring.

9th Class Physical Science Textbook Page No. 214

Question 26.
Can you identify the independent and the dependent variables?
Answer:
Mass is independent variable and elongation of the spring is dependent variable.

9th Class Physical Science Textbook Page No. 215

Question 27.
At what point plunger cannot move forward.
Answer:
It is depending upon conditions of the experiment.

Question 28.
Do you experience any pressure with air?
Answer:
Yes.

9th Class Physical Science Textbook Page No. 217

Question 29.
Let us say what is the slope of x – axis?
Answer:
Slope of the x – axis is zero.

9th Class Physical Science Textbook Page No. 218

Question 30.
What does the ratio explains the physical quantities on the y – axis and x – axis?
Answer:

The ratio explains the physical quantities on the y – axis and x – axis is velocity.

Question 31.
What is the velocity of the object at 1.5 seconds of time?
Answer:

9th Class Physical Science Textbook Page No. 207

Question 32.
Is litre a fundamental unit or a derived unit?
Answer:
One litre is the volume of a cube with 10 cm sides. (10 cm × 10 cm × 10 cm)
(or) 1 L = 10^-3 m³
Hence, litre is a derived unit.

9th Class Physical Science 12th Lesson Units and Graphs Activities

Activity – 1

Question 1.
You have noticed that different units are used to measure different materials. Based on your past experience fill in the table with suitable units of measurements used in general, put a tick mark.

Activity – 2 Derived Quantities – Derived Units

Question 2.
1) Let us measure the surface area of your book using a scale.
2) Measure the length and breadth of the book.
3) Area of the book can be obtained by multiplying length and breadth.
4) Length = ……………………..
5) Breadth = ……………………
Is area of fundamental quantity?
Answer:
No.

Which fundamental quantity is used to derive area?
Answer:
Length.

From the activity, we can say area is a derived quantity, which is obtained by multiplication of length and breadth which are fundamental quantities.

Activity 3

Question 3.
Let us observe the given table and try to find out fundamental and derived units for the given information.

1) Which derived units are obtained by the multiplication of fundamental units?
Answer:
Area, volume

2) Which units are derived from only the fundamental quantity length?
Answer:
Area, volume

3) Which derived quantity has no units?
Answer:
Relative density

4) What are the fundamental units of volume?
Answer:
Length

5) What quantities are derived from time?
Answer:

1. Velocity
2. Acceleration
3. Force
4. Pressure

Activity – 4

Question 4.
Draw a curved line graph to the given table.
Answer:
1) Anitha travels to her grandmother’s village by car.
2) She observed the Odometer (the instrument that measures the distance travelled) fitted in the car.
3) She recorded the reading shown by the odometer once every 5 minutes for 40 minutes.
4) Look at the table prepared by Anitha.

5) ‘We show the relation between two quantities using a graph.
6) Here time is independent variable and distance is dependent variable.
7) The steps in the construction of a graph

i) Draw x – axis and y – axis on a graph paper.
Plot time on x – axis as it is independent variable whereas distance on y – axis as it is dependent variable.

ii) Find the range on x – axis
Range on x – axis = highest value – lowest value = 40 – 5 = 35 Find the range on y – axis
Range on y – axis = highest value – lowest value = 33 – 3 = 30

iii) Determine the scale

iv) Names on the axis
Write time (min.) on x – axis.
Write distance (km) on y – axis.

v) Write the data points from the table.
(0, 0), (5, 3), (10, 8), (15, 12), (20, 19), (25, 24), (30, 24), (35, 30), (40, 33).

vi) Labelling of data points :
Label above data points with dots where vertical and horizontal lines are intersect to the respective data points.

vii) Join the dots.

What is the shape of the line graph?
Answer:
It is curved in shape.

Activity 5

Question 5.
Draw a straight line graph to the given table.

Answer:

• Take a spring / rubber band.
• Measure the length of the spring with a scale.
• Fix the spring to the stand.
• Suspend the weight to the second end of the spring.
• Now, again measure the length of the spring.
• Calculate the elongation.
•  This way, keep on changing the weights and measure the elongation of the spring with scale.

Record the readings in the table.

9) Here mass (gm) is independent variable and elongation is dependent variable.
10) Plot the graph.

1. Which quantity is taken on the x-axis ? In what units it was expressed? Why was it taken on the x-axis?
Answer:

1. Mass is taken on the x – axis.
2. It was expressed in grams.
3. Mass is independent variable, so it was taken on the x – axis.

2. Which quantity is taken on the y-axis? In what units it was expressed? Can this be called an independent variable?
Answer:

1. Elongation of the spring was taken on the y – axis.
2. It was expressed in millimeters.
3. It cannot be called as independent variable, because the values of elongation are obtained in the experiment.

3. The value of range on the x – axis
Answer:
Range = 50 – 0 = 50

4. The value of range on the y-axis
Answer:
Rang = 10 – 0 = 10

5. Scale on the x-axis
Answer:
10

6. Scale on the y-axis
Answer:
2

7. Data values on the x-axis
Answer:
0, 10, 20, 30, 40, 50.

8. Data values on the y-axis
Answer:
0, 2, 4, 6, 8, 10.

9. What is the shape of the line that joined the intersecting points?
Answer:
Straight line.

10. What does the slope of a curve tell us?
Answer:
Relation between mass and extension of the spring.

11. What is the reason for the elongation of the spring?
Answer:
Due to mass suspension to the spring.

12. What relation did you notice between the mass and elongation of spring?
Answer:
Elongation is directly proportional to mass.

13. Wliat could be the relation between the two quantities when the graph is a straight line?
Answer:
It could be directly proportional.

14. Based on the graph, which of the following sentences are correct?
a) If mass increases the elongation of spring increases.
b) If mass decreases the elongation of spring increases.
c) Even if mass increases, there will be no change in the elongation of the spring.
Answer:
a), b) are correct.

Activity – 6

Question 6.
Plot a graph showing inversely proportional measurements.
Answer:

1. Take a 50 ml syringe.
2. Fill the syringe with air by pulling a plunger.
3. To avoid escape of air from syringe close the nozzle of syringe with your finger.
4. Now push (apply the force) the plunger slowly.
5. While you are pushing the plunger you may experience more pressure with the decrease of volume of air in syringe, hence you need to apply more force on plunger.
6. Let us find out the relation between the pressure and volume of air.
7. Observe the following data table.

Physical Quantity on x – axis
Answer:
Pressure

Physical Quantity on y – axis
Answer:
Volume

What is the independent variable?
Answer:
Pressure

What is the dependent variable?
Answer:
Volume

What is the range of values on vertical axis?
Answer:
Range = 50 – 18.7 = 31.3

What is range of values on horizontal axis?
Answer:
Range = 3.2 – 1.2 = 2

What is the shape of the graph?
Answer:
Curved in shape (Parabolic).

What relation you noticed between two physical quantities based on data points in the graph?
Answer:
I have noticed that there is decrease in volume with increase of pressure. Hence these two quantities said to be inversely proportional.

Activity – 7

Question 7.
Observe the following graphs and write your analysis in the given table.

SCERT AP Board 9th Class Social Solutions 4th Lesson Atmosphere Textbook Questions and Answers.

AP State Syllabus 9th Class Social Studies Solutions 4th Lesson Atmosphere

9th Class Social Studies 4th Lesson Atmosphere Textbook Questions and Answers

Improve Your Learning

Question 1.
Explain the composition of the atmosphere.
Answer:

• The atmosphere is a sea of gases surrounding the Earth.
• There are many gases in the atmosphere.
• Of all the gases in the atmosphere oxygen (21%) and nitrogen (78%) dominate.
• Other gases are in very small percentages, these include argon, neon, carbon dioxide (0.03%), methane, ammonia, ozone, etc.
• Water vapour accounts for about 0.4% by volume over the whole atmosphere.
• Apart from these gases the atmosphere also has the fine dust particles called particulates.

Question 2.
Discuss the structure of the atmosphere along with a diagram.
Answer:
On the basis of the chemical composition the atmosphere is divided into two broad layers. They are -1) Homosphere II) Heterosphere
I) Homosphere : This layer is characterized by uniformity in composition of gases like
Nitrogen, Oxygen, Orgon and Carbondioxide. It consists of the three thermal layers such as Troposphere, Stratosphere and Mesosphere. It extends up to the height of 90 kms.

A) Troposphere :
i) It is the lower most of layers of the atmosphere.
ii) It extends to a height of 8 kms near the poles and about 18 kms at the equator.
iii) It contains 75% of the total gaseous mass of the atmosphere.
iv) The entire weather phenomenon happens in this layer.
v) The life is present in this layer.

B) Stratosphere :
i) This layer extends up to a height of 50 kms.
ii) This layer is free from clouds and associated weather phenomenon.
iii) These conditions are most ideal for flying jet aircrafts.
iv) This layer contains Ozone layer.

C) Mesosphere :
i) It extends up to a height of 80 kms.
ii) Meteorites burn up as they enter this layer from the space.
iii) The temperature starts decreasing with the increase in altitude.

II) Heterosphere : Because of its heterogenous composition this layer is called heterosphere. This layer is above 90 kms of the atmosphere. It has two thermal layers called Thermosphere and Exosphere.
A) Thermosphere:
i) It extends up to 400 kms.
ii) Here the temperature rises rapidly with increase in height.
iii) It contains electrically charged particles known as ions. Hence this layer is called Ionosphere.
iv) Radio waves are reflected back to the earth through this layer.
v) It is also known as ‘Ionosphere’.

B) Exosphere :
i) The upper most layer of the atmosphere.
ii) Very little is known about this layer.

Question 3.
Differentiate weather and climate.
(OR)
Write the differences between weather and climate?
Answer:

• The difference between weather and climate is a measure of time.
• Weather is what conditions of the atmosphere are over a short period of time and climate is how the atmosphere “behaves” over relatively long period of time.
• Weather is basically the way the atmosphere is behaving, mainly with respect to its effects upon life and human activities.
• Whereas climate is the description of the long-term pattern of weather in a particular area.
• In most places weather can change from minute to minute, hour to hour, day-to-day and season-to-season. Whereas the climate is the average of weather overtime and space.
• In short, climate is what we expect whether a hot summer or a cool winter and weather is what you get or experience at present.

Question 4.
Compare and contrast convectional and orographic rainfall.
Answer:
Comparison between convectional and orographic rainfall:
1) Both types of rainfall are caused by vertical ascent of heated air.
Contrast between convectional and orographic rainfall :

1. While orographic rainfall is caused when the mountain forces the air to rise over mountain or the elevation in its path; the convectional rainfall occurs when moisture over the heated ground becomes warmer than the surrounding air.
2. While convectional rainfall is common on summer days in interior part of the continents the orographic rainfall occurs in the windward sides of mountains.
3. While the orographic rain occurs in the mountainous regions, the convectional rain takes place in the equatorial regions.

Question 5.
Describe the distribution of world rainfall.
Answer:

• Between the latitudes 10° and 30° N and S of the equator, due to the trade winds, rainfall is heavier on the eastern coasts, and decreases towards the West.
• Between the latitudes 40° and 60° N and S of the equator due to the westerlies, the rainfall is heavy on the west coast, and goes decreases towards the East.
• Low pressure areas, especially around the equator receiver high rainfall than high pressure areas.
• The rainfall is more over the oceans than on the continent.

Question 6.
How do climatic changes influence the human life?
Answer:
Due to climatic changes the following changes are taking place.

1. The climatic changes led to the emergence of large scale environmental hazards such as global warming, increase of green house gases etc.
2. Development of planet’s flora and fauna is mainly due to climatic changes.
3. Globally the average sea level has risen by 17 cm in the 20th century.
4. Climatic changes are affecting food habits and culture of the people of any area.
5. Due to global warming both the Greenland and Antarctic ice sheets have lost significant amounts of ice.
6. Thus the climatic changes are influencing human life significantly.

Question 7.
Explain relative humidity.
Answer:

• The amount of water vapour present in the atmosphere is called humidity.
• Relative humidity is the ratio between the maximum water vapour that the air can hold at a given temperature and pressure and the actual amount of water vapour it holds at any given time.
• For example, at 20°C temperature air can contain 80 gms of water vapour per cubic meter. If the actual water vapour present is 40 gms, the relative humidity is 50%.
• If the atmosphere has 100% relative humidity, it is known as saturation level.
• Relative humidity decreases with increase of temperature and decrease of water vapour,
• In high humidity, our sweat doesn’t cool us because it cannot evaporate.
• In low humidity we feel more thirsty.

Question 8.
Why does the amount of water vapour decrease rapidly with altitude?
Answer:
The water vapour is attracted towards the surface or close to the surface due to the gravitational pull of the earth. Hence the amount of water vapour decreases with altitude.

Question 9.
What is Coriolis effect ? And explain its effects.
(OR)

What is Coriolis effect and how does it influence the wind system?
Answer:
1. Because of the impact of Earth’s rotation on its own axis, the winds move slightly to the right in the northern hemisphere, and to the left in the southern hemisphere. This effect is called Coriolis effect.
2.

3. At the equator the Coriolis effect is ‘O’ and at the poles it is maximum.

The most important effects of Coriolis force are :
a) The deflection of winds and currents in the ocean.
b) It has significant effect on planes and missiles also.
c) In the northern hemisphere these winds move to the right and in the southern hemisphere to the left. This usually creates the westerly winds moving from the subtropical areas to the poles.
d) The Coriolis effect also affects the movement of ocean currents.

Question 10.
Identify the given local winds in the world map.
a) Chinook
b) Loo
c) Simoon
d) Yoma
e) Norwester
f) Mistral
g) Puna
h) Pampero
Answer:

Question 11.
Read the para under the title “Effects of Planetary Winds” on page 43 and comment on it.
Effects of Planetary Winds: You would have noted that the pressure and wind systems are actually a result of the impact of Lithosphere and Hydrosphere on Atmosphere. These winds play a crucial role in transporting heat and moisture across the world. That is why no part of the world gets too cold or too hot for life to survive. Had there been no atmosphere (as on the Moon) it would have got intolerably hot in day time or in the tropics and intolerably cold at night or in the Polar regions. However, these winds do not distribute heat or moisture uniformly – which is why we have some parts of the earth quite hot, some parts cooler and some parts with high rainfall and some which are deserts.
Answer:
Planetary winds are winds that are created in the different Global circulation cells.

1. Polar Easterlies – blow from pole to 60°
2. Prevailing Westerlies – blow from 60° to 30°
3. Trade Winds – blow from 30° to 0°

These winds transport heat and moisture across the world. But the winds do not distribute heat or moisture uniformly.

Question 12.
Collect weather information covered by media such as newspapers, TV, Radio, etc. to understand weather phenomena.
Answer:
Weather information of major cities of India on 8, April 2020.

Question 13.
Collect the newspapers from July to December and note down the news related to extreme rainfall in different parts of country.
Answer:
Average annual rainfall of the states of India

9th Class Social Studies 4th Lesson Atmosphere InText Questions and Answers

Question 1.
List out some of the ways in which particulates in the atmosphere are beneficial and harmful to us. (Text Book Page No. 37)
Answer:
1. The fine dust particles present in the atmosphere are called particulates.

2. Particulates may come from natural processes such as sand storms over deserts and natural forest fires and from human activity such as burning forests, burning petroleum and industrial emissions.

3) Benefits of particulates :
a) The particulates can change atmospheric conditions that may be beneficial to life on Earth.
b) The particulates in the atmosphere cause the bright colour of the sunrise or sunset.
c) The particulates help rainfall and hailstones to fall.

4) Harmful effects of particulates :
a) They cause problems by altering temperature and rainfall patterns.
b) They can make it difficult for people to breathe.
c) They can make it difficult for the plants to breathe and photosynthesise.

Question 2.
In which layer is the life present? (Text Book Page No. 39)
Answer:
In troposphere the life is present. The suitable conditions that make life possible in the troposphere are :

1. The troposphere is the lower most layer of the atmosphere.
2. It contains about 75% of the total gaseous mass of the atmosphere and practically all the moisture and dust particles.
3. The entire weather phenomenon happens in this sphere.
4. Condensation, evaporation, precipitation, rainfall, cyclones etc., occur in this layer.

Question 3.
About which layer do we have very less knowledge? (Text Book Page No. 39)
Answer:

• Exosphere is the upper most layer of the atmosphere.
• This is the highest layer.
• Very less is known about it.

Question 4.
Which layer of the atmosphere is ideal for flying jet aircrafts? Why? (Text Book Page No. 39)
Answer:

• Stratosphere is ideal for flying jet aircrafts.
• Because this layer is almost free from clouds and associated weather phenomenon.
• These conditions are most ideal for flying jet aircrafts in this layer.

Question 5.
Our skin dries up more during winters. Why?
Answer:

• Water vapour (i.e., the humidity) is a very important component in the atmosphere.
• The relative humidity plays a large role in determining our comfort level.
• If the relative humidity is 100 percent, we feel much hotter than the actual temperature indicates because our skin, sweat does not evaporate at all.
• If the humidity is low, our skin and mucous membranes are dry.
• As a result of low humidity, we’ll have chapped lips, dry and itchy skin, and a dry sore throat when we wake up in the morning.
• Low humidity also dries the plants and furniture.

Question 6.
Observe the following figure and describe from which pressure belt to which pressure belt are the Westerlies, trade winds and polar Easterlies are blowing.

Answer:

• The Westerlies blow from subtropical high pressure belts to sub polar low pressure belts in both the hemispheres.
• The trade winds blow from sub tropical high pressure belt to equatorial IQW pressure belt.
• Polar Easterlies blow from polar high pressure belt to polar low pressure belt.

Question 7.
What will happen if water vapour is not present in air?
Answer:
1. The condensation of water vapour to the liquid or ice phase is responsible for clouds, rain, snow and other precipitations.

If water vapour is not present in the atmosphere, clouds, rains, snow will not occur. If there is no rain, life will not be possible on earth.

2. Water vapour is one of the green house gases. Green house gases play a major role in determining the balance of between the amount of radiation entering the Earth’s surface and the amount of radiation leaving the Earth’s surface.

The green house effect keeps the Earth’s surface about 33°C warmer thair-it would otherwise be.

Question 8.
Why is atmosphere important for us?
Answer:

• We breathe in oxygen which is one of the components of atmosphere.
• We breathe out carbon dioxide, which in turn is taken in by plants in their respiration.
• The atmosphere prevents harmful rays of the sun from reaching us.
• The green plants take in carbon dioxide, use sunlight and water to photosynthesise and we get delicious fruits, vegetables, and grains from them.
• These give us proteins, carbohydrates, sugars, fats, minerals and other nutrients that we need.
• The atmospheric winds transport water from the oceans deep into the continents in the form of rain.
• Atmospheric winds erode rocks and are responsible for the formation of many kinds of soils with whose fertility we grow many kinds of crops.
• Atmosphere helps in cooling monsoon rains.
• Atmosphere helps in diffusion of perfumes and helps in the travelling of sound waves.
• Thus we can say atmosphere is important for us.

Question 9.
Can you imagine why life is not possible on the Moon? (Text Book Page No. 37)
Answer:

• Life is not possible on the Moon because the Moon has no atmosphere.
• On Moon we don’t have atmospheric pressure without which we cannot live.
• Because of lack of atmosphere we don’t have any protection from ultra violet raditation.
• Because of the lack of magnetosphere, we will be frequently bombarded by the charged particles.
• There is no water on the Moon which is the first and foremost requirement for the life.
• For all the above reasons life is not possible on the Moon.

SCERT AP Board 9th Class Social Solutions 13th Lesson Democratic and Nationalist Revolutions 17th and 18th Centuries Textbook Questions and Answers.

AP State Syllabus 9th Class Social Studies Solutions 13th Democratic and Nationalist Revolutions 17th and 18th Centuries

9th Class Social Studies 13th Lesson Democratic and Nationalist Revolutions 17th and 18th Centuries Textbook Questions and Answers

Improve Your Learning

Question 1.
Identify the name of the country in the context of following statement: (UK, USA and France)
1) revolution where parliament system was established
2) country where king continues to play some role even after revolution
3) country that had to war against another in order to establish its democracy
4) The bill of rights was adopted
5) Overthrow of the monarchy was led by the peasants
6) Declaration of Rights of Man and Citizen was adopted
Answer:

1. UK
2. UK
3. USA
4. USA
5. France
6. France

Question 2.
What were the main ideas of social thinkers, which were significant to the establishment of new forms of governments? How did they gain popularity?
Answer:

• Philosophers such as John Locke and Rousseau envisaged a society based on freedom and equal laws and opportunities for all.
• Locke in his “Two Treatises of Government” advocated theory of Natural rights and opposed the doctrine of the divine and absolute right of the monarch.
• Rousseau carried the idea forward and laid foundation for democracy in his book “The Social Contract”.
• Montesquieu, in his book “The Spirit of Laws” proposed a division of power between the legislature, the executive and the judiciary.
• Voltair advocated restricted powers.
• Thomas Jefferson advocated to fight for the political rights of the people.
• These ideas were discussed in salons and coffee-houses.
• Spread among the people through books.
• These ideas were read aloud in groups to benefit those who could not read and write.

Question 3.
Describe the circumstances leading to the outbreak of revolutionary protest in France.
Answer:
The French Revolution is an important political revolution in the world. It has laid foundation for democracy and human rights. The following are the circumstances that led to the outbreak of the French Revolution.
1. Social causes:

1. The French society was divided into three estates.
2. The members of the first two estates, that is, the clergy and the aristocracy, enjoyed certain privileges and were exempted from paying taxes.
3. The burden of taxes was borne by the third estate alone. This problem was compounded by failure of crops.

2. Political causes :

1. In 1774, Louis XVI ascended the throne of France.
2. He was quite inefficient and was influenced by his wife.
3. The influence of nobles and priests also had bad effect on the administration.

3. Growth of Middle class :

1. The eighteenth century witnessed the emergence of new social groups, collectively termed the middle class.
2. This group of the third estate became powerful due to their access to education and new ideas.
3. They believed that no group in the society should be privileged by birth.

4. Intellectual causes :
The third estate was influenced by the philosophical thoughts of Locke, Rousseau, etc.

5. Summoning of Estate General :

1. Long years of war had drained the financial resources of France.
2. To increase the taxes to meet the expenses, in 1789, summoned the Estates General.
3. Summoning of Estate General was the immediate causes of the French Revolution.

Question 4.
Which groups of French society benefited from the revolution? Which groups were forced to relinquish power? Which sections of society would have been disappointed with the outcome of the revolution?
Answer:

• The third estate, i.e. landless labour, small peasants, middle class were benefited as their rights were recognized.
• The privileges enjoyed by the members of the first two estates were abolished.
• Hence the first two estates, i.e. the clergy and the aristocracy were disappointed with the outcome of the revolution.

Question 5.
After completing the chapter on Fundamental Rights, draw up a list of the democratic rights that we enjoy today whose origins could be traced back to the French Revolution.
Answer:
The origins of the following democratic rights we enjoy today were traced to the French Revolution.

1. Liberty
2. Equality
3. Right to participate in the formation of Legislature and Executive
4. Rule of law
5. Freedom of expression
6. Right to property.

Question 6.
Would you agree with the view that the message of Universal Rights was beset with contradictions? Explain.
Answer:

• Yes. The message of Universal Rights was beset with contradictions.
• Contradiction was evident as regards women. Women did not enjoy the same political rights nor were their wages equal to men.
• The French revolution has been the symbol of liberty, equality and fraternity but later the French became the conquerers instead of liberators.
• And it was the direct contradiction of the terms.
• Slave trade, the most inhuman practice was yet another blatant contradiction.

Question 7.
What made the American colonists to raise the slogan ‘No Taxation without Representation’?
(OR)
How did you understand the slogan ‘No Taxation without Representation?
Answer:

• The English Parliament assumed powers to make laws for the American states but the people of those states did not vote for the Parliament.
• American colonies were taxed heavily by the British Government.
• The Parliament often passed laws that favoured English traders at the cost of the people of the colonies.
• The American colonies therefore raised the slogan “No Taxation without Representation”.

Question 8.
What do understand by middle class ? How did it emerge in Europe?
(OR)
‘The eighteenth century witnessed the emergence of new social groups collectively termed the middle class’ – Explain about the emergence of middle class in Europe.
Answer:

• Within the Third Estate, a group of people had access to education and new ideas and became prosperous.
• They earned their wealth through expanding means of overseas trade and from the manufacture of goods such as woollen and silk textiles.
• This new social group was collectively termed as middle class.

Question 9.
Locate England, France, Prussia, Spain and Austria on the map of Europe.
Answer:

Question 10.
How do you understand women’s role in French Revolution
Answer:
Women’s role in French Revolution : From the very beginning women were active participants in the events which brought about so many important changes in French society. They hoped that their involvement would pressurise the revolutionary govern¬ment to introduce measures to improve their lives. Most women of the Third Estate had to work for a living. They worked as seamstresses or laundresses, sold flowers, fruits and vegetables at the market, or were employed as domestic servants in the houses of prosperous people. Most women did not have access to education or job training.

In order to discuss and voice their interests women started their own political clubs and newspapers. About sixty women’s clubs came up in different French cities. The Society of Revolutionary and Republican Women was the most famous of them. One of their main demands was that women enjoy the same political rights as men. They demanded the right to vote, to be elected to the Assembly and to hold political office.

During the Reign of Terror, the new government issued laws ordering closure of women’s clubs and banning their political activities. Many prominent women were arrested and a number of them executed. It was finally in 1946 that women in France won the right to vote.

Question 11.
Read the paragraph under the title “The Reign of Terror” of page 169 and comment on it.

Answer:
The Reign of Terror:
In the autumn of 1793, Robespierre and the Jacobins focused on addressing economic and political threats within France. What began as a proactive approach to reclaiming the nation quickly turned bloody as the government instituted its infamous campaign against internal opposition known as the reign of terror.

Beginning in September, Robespierre, under the auspicious of the committee of public safety, began pointing an accusing finger at any one whose beliefs seemed to be counter revolutionary – citizens who had committed no crime but merely had social or political agendas that varied too much from Robespierre. The committee targeted even those who shared many Jacobin views but were perceived as just slightly too radical or conservative. A rash of executions ensured in Paris and soon spread to smaller towns and rural areas.

During the nine-month period that followed, anywhere from 15,000 to 50,000 French citizens were beheaded at the guillotine. Even longtime associates of Robespierre such as Georges Danton, who had helped orchestrate the Jacobin rise to power, fell victim to the paranoia. When Danton wavered in his conviction, questioned Robespierre increasingly. The lives were on the edge of a blade.

Question 12.
Learn something more about the different personalities who played an important role in American and French revolution. Which of them impresses you the most and why? Write a paragraph on him/ her.
Answer:

1. Jacques – Pierre Brissot
2. Charles de Calonne
3. Lazare carnot
4. Marquis de Lafayatte
5. Jacques Necker
6. Maximillian Robespierre
7. Emmanuel – Joseph Sieyes
8. Thomas Jafferson

These are all participated and played an important role in French and America revolu-tions. But I like more Marquis de Lafayatte. Why because he participated in American and French Revolutions both.

Marquis de Lafayette :
Lafayate was one of the generals of Louis XVI. Born in a noble family of France, he displayed great qualities of courage and adventure on various occassions. He was also known for his political acumen. He was sent to America during American war of Independence. He helped George Washington in defeating England. While he was in America, he was deeply influenced by the drafting of a constitution and the grant of declaration of rights. On his return from America, he was elected to the estate general and participated in the French Revolution.

Jacques – Pierre Brissot:
A member of the Legislative Assembly and National Conven¬tion who held a moderate stance and believed in the idea of a constitutional monarchy.

Charles de calonne :
The controller general of finance appointed by king Louis XVI after Jacques Necker was forced out of office in 1781.

Lazare carnot :
A French soldier appointed by the committee of public society to help reorganise the failing war effort against Austria and Prussia.

Jacques Necker:
He was appointed as a genera! of finance in the late 1770s.

Maximilien Robespierre :
A brilliant political factician and leader of the radical Jacobins in the National Assembly.

Emmanuel-Joseph Sieyes :
A liberal member of the clergy, supporter of the third estate and author of the fiery 1789 pamphlet “What is the Third Estate”?

9th Class Social Studies 13th Lesson Democratic and Nationalist Revolutions 17th and 18th Centuries InText Questions and Answers

Question 1.
What was the effect of the Civil war on the king and the people of the England? (Text Book Page No. 161)
Answer:

• A civil war lasted in England for five years.
• Ultimately, Charles, I was defeated and executed in 1649.
• After Glorious Revolution in 1688, the powers of the king were restricted. Thus the Parliament’s supremacy was established.
• After a consistent struggle, the right to vote was gradually extended to all adults by 1928.

Question 2.
(Look at the chart on P.No. 166) Which groups of French society would have gained from the Constitution of 1791? Which groups would have had reason to be dissatisfied? (Text Book Page No. 168)
Answer:

• The Third Estate and the newly developed middle class were benefited from the revolution.
• They got equal rights with other social groups. They were given right to vote.
• They were given the rights such as right to live, freedom of speech, freedom of opinion and equality before law.
• Common tax is levied. It must be assessed equally on all citizens in proportion to their means. Thus the burden of taxes on common people was removed.
• The clergy the nobles and the king were forced to relinquish their powers and privileges.
• The Declaration of Rights of Man and Citizen declared that no group or individual may exercise authority that does not come from the people. With this the clergy and the nobles were deprived of their special rights and privileges.
• The new Constitution limited the powers of the monarch. Thus the king had to relinquish the powers of his autocracy. The powers concentrated in the hands of one person, were now separated and assigned to different institutions – the legislature, executive and Judiciary.
• According to the Declaration of Rights the common tax is levied. It must be assessed equally on all citizens in proportion to their means. Thus the clergy and the nobles lost their privilege and were forced to pay the taxes.

Question 3.
Fill in the blank boxes in the figure below with appropriate terms from among the following: (Text Book Page No. 163)
1) Food riots
2) Social unrest
3) Increase number of death
4) Rising food prices
5) Weaker bodies.
Answer:

Question 4.
Write an imaginary dialogue between persons from a king’s party and parliamentary party in our context. (Text Book Page No. 161)
Answer:
Parliamentary Party :
The parliament had now a better army in so much that if the Earl of Essex had immediately followed the king of Oxford, not yet well fortified, he might in all likelihood have taken it. For he could not want either men or ammunition. Whereof the city of London, which was wholly at the parliments devotion, had store enough.

Kings’ Party :
I cannot judge that. But this is manifest, considering the estate the king was in at his first marching from York, when he had neither money nor men nor arms enough to put them in hope of victory, that this year, take it altogether, was very prosperous.

Question 5.
Imagine the impact of the events of France on neighbouring countries such as Prussia, Austria-Hungary or Spain, all of which were absolute monarchies. How would the kings, traders, peasants, nobles or members of the clergy have reacted to the news of what was happening in France? (Text Book Page No. 168)
Answer:

• It is said that whenever France sneezes Europe catches cold.
• After the great French Revolution of 1789, France was acknowledged the leader of the progressive opinion in Europe.
• The 1830 revolution raised national spirit in the countries like Belgium, Germany, Italy, Spain, Portugal, and Poland. They led the movements for achieving National Independence.
• The rising tide of revolution in different countries became the cause of fear among the autocrat rulers. They joined to check the spread of the revolution.
• The main gift of French Revolution was the ideas of Liberty, Equality, and Fraternity.
• It ended the dominance of the theory of the divine right of kingship.
• It give death blow to social status by birth. The clergy and nobles lost their supremacy, dominance over polity and other sections of society.
• The clergy and the noble were devoid of their privileges in society.
• The Third Estate and the middle class were relieved from serfdom and the burden of over taxation.

SCERT AP Board 9th Class Social Solutions 10th Lesson Prices and Cost of Living Textbook Questions and Answers.

AP State Syllabus 9th Class Social Studies Solutions 10th Lesson Prices and Cost of Living

9th Class Social Studies 10th Lesson Prices and Cost of Living Textbook Questions and Answers

Improve Your Learning

Question 1.
Why is there a need to regulate prices?
Answer:

• Trades main aim is to earn profit, raise prices of many goods and particularly essential items by illegal ways.
• If there is no increase in wage for workers who are also consumers in the market, they cannot buy the goods.
• When these goods happen to be essentials such as wheat, rice, milk etc., this creates problem for the people.
• This necessitates the need for regulation of traders to regulate prices.

Question 2.
How are prices fixed by a seller/producer?
Answer:

• The traditional economic theories of pricing were based on the demand and the supply.
• In general the prices are fixed on the basis of full average cost of production per unit plus a margin of normal profit or some satisfactory margin of profit.
• Producer sells the goods to the seller.
• Seller in turn adds his profits and fixes the prices.

Question 3.
Differentiate the cost of living from the standard of living.
Answer:

Question 4.
Who is affected the most by increase in cost of living? Why?
Answer:

• People with fixed incomes, such as pensioners, daily wage earners, manual workers, small vendors, workers in small enterprises and in private low income jobs etc., are badly affected by increase in cost of living.
• These people’s income does not increase when there is inflation.

Question 5.
Which groups can get higher incomes whenever there is inflation?
Answer:
Not everyone is affected by rising prices. For some groups this rise in price levels is compensated. They are –

1. People working in central and state government offices and in some organizations get an additional payment called “Dearness Allowance” whenever prices rise. Therefore their income increases, along with inflation.
2. People doing business activities recover the higher cost of living by increasing the prices of goods they sell.
3. People providing services such as lawyers, doctors etc., increase their fees when prices increase.
4. Extremely rich people and those working in corporate sector are less affected by rising prices.

Question 6.
How is Wholesale Price Index different from Consumer Price Indices?
Answer:
Change in price is measured with the help of a statistical device referred to as “Price Index”. Price Index is of two types. They are –

1. Consumer Price Index
2. Wholesale Price Index

Question 7.
How is food inflation different from Consumer Price Indices?
Answer:

• CPI measures only changes in prices of a few selected consumer goods at a retail price.
• Different CPIs are published by the government.
• Whereas FPI (Food Price Index) is used to estimate rise in prices of food items called food inflation.
• The FPI consists wholesale price of food materials such as rice, wheat, pulses, vegetables, sugar, milk, eggs, meat, fish, and manufactured food materials such as edible oils.

Question 8.
What are the uses of the CPI?
Answer:
The CPIs are used to calculate the DA to be paid for government employees, to revise legal wage rates as part of Indian government laws and also to estimate the number of poor in India.

Question 9.
List of five problems with measuring CPI.
(OR)
Write any five issues that are considered while measuring CPI.
Answer:

• There are thousands of goods and services in the economy.
• Only selected consumer goods and changes in these goods are taken by the government to calculate CPI.
• Both quality and quantity of goods consumed keeps varying from time to time.
• Difficult to calculate CPI as the price levels vary from state to state.
• Even food habits keep varying among people.

Question 10.
How is Administrative Price Mechanism (APM) different from Minimum Support Price (MSP)?
Answer:

Question 11.
Read sixth paragraph under the heading ‘Role of Government in Regulating Prices’ and answer the question.

How does the APM affect the government revenue? Discuss.
Answer:

• Goods like Kerosene, Diesel, LPG, CNG and piped Natural Gas are subsidised by the government. .
• Under subsidised scheme the government purchases the goods at high prices and sells them at low prices.
• The loss is the subsidy and the. government bears the loss.
• Government is now 3% of its expenditure on subsidies.

Question 12.
Take any five goods or services used by your family and construct a Consumer Price Index for your family based on these five goods/services.

Answer:

Question 13.
Write True or False against the statement given below.
1) Inflation increases the standard of living of the people. [ ]
2) Value of money is shown by changes in its purchasing power. [ ]
3) Change in cost of living does not affect the standard of living of pensioners [ ]
4) Central Government workers are compensated for inflation by rise in DA. [ ]
5) WPI measures changes in the price level of only consumer goods. [ ]
Answer:

1. False
2. True
3. False
4. True
5. False

Question 14.
The following table shows the wholesale Price Indices of Industrial Goods. Prepare a line diagram answer the questions that follow.

Answer:

1.Which commodity’s price rose steeply over the years?
Answer:
Cement prices rose steeply.

2. What could be the reasons for a slow rise in the price of cotton cloth and fertilizers?
Answer:

• Demand of cotton is stable and price level are also stable.
• Government gives subsidies to the fertilizers. Hence prices are slowly increasing.

Question 15.
Write a letter to your Tehsildar on proper maintenance of Public Distribution System by indicating your suggestions.
Answer:

9th Class Social Studies 10th Lesson Prices and Cost of Living InText Questions and Answers

Question 1.
Price of Cotton and Rice (per quintal) during 2005-2011

(i) Calculate the index numbers of rice and cotton by assuming 2005-06 as the base year.
(ii) Draw a line diagram showing index number of rice and cotton. Keep the years in x-axis and index numbers on the y-axis. Discuss how the line goes up over the years. (Text Book Page No. 123)
Answer:
(i) Index numbers of rice
The value: of the index = 100; Original index value is = 600; In 2005-06 = \(\frac{600}{600}\) × 100 = 100%

ii)

There is a slight increase in rice from 2005-06 to 2006-07 and from here there is huge increase up to 2010-2011. Incase of cotton, from 2005-06 to 2006-08 there is a slight increase and from 2007-08 to 2008-09 there is a huge increase and from 2008-09 to 2010-11 the price is constant.

Question 2.
Tomorrow is Teacher’s Day. Your class students give you Rs.200 and send you to the market to buy some sweets and biscuits to celebrate this day with your teachers. When you go to the shop, you find that the price of a sweet packet is Rs. 60, and a biscuit packet is Rs. 20. If you buy 2 sweets packets, how many biscuit packets can you buy ? How much should you pay ? (Text Book Page No. 121)
Answer:
If we buy 2 sweet packets:
The cost of two sweet packets = 2 × 60 = 120
Remaining Amount = 200 – 120 = 80
No. of Biscuit packets we can buy = \(\frac{80}{20}\) = 4
Total Amount we paid = 200

Question 3.
Why did you buy such few packets? (Text Book Page No. 121)
Answer:
Prices of the goods have gone up and for the same amount of money i.e., Rs. 200/- we can buy lesser amounts of these commodities.

Question 4.
Suppose your classmates asked you to buy 5 packets of both sweets and biscuits this year also. How much would you have to pay then? (Text Book Page No. 121)
Answer:
For 5 packets sweets (5 × 60) = Rs. 300
For 5 packets biscuits (5 × 20) = Rs. 100
Total amount you pay = Rs. 400

Question 5.
How much more do you have to pay compared to last year? (Text Book Page No. 121)
Answer:
Total amount this year spent = Rs. 400
Total amount last year spent = Rs. 200
Excess amount paid = Rs. 200

Question 6.
Recent price increases : (Text Book Page No. 126)
During 2009-12, prices of many essential goods went up. You can see this from the following figures. Look at the figure carefully and answer the questions that follow.

1) If a family was buying rice for Rs. 20 a kg in 2005-06, how much would if have to pay in 2011?
2) In which years did the price of pulses increased considerably?
3) What is the percentage increase in the price of cotton?
4) Which commodity price has been more or less stable?
Answer:

1. Rs. 32 a kg
2. 2010 -11
3. Insufficient information
4. Edible oils