CBSE Class 10 Science Practical Skills – Types of Reactions

CBSE Class 10 Science Practical Skills – Types of Reactions

Basic Building Concepts
A chemical reaction is a chemical transformation or change in which one or more substances called the reactants are converted to one or more different substances called the products.

Types of Chemical Reactions
There are four types of chemical reactions:

  1. Combination Reactions: Combination reactions are those reactions in which two or more elements or compounds combine to form a more complex compound.
    CBSE Class 10 Science Practical Skills – Types of Reactions 1
  2. Decomposition Reactions: Decomposition reactions are those reactions in which a single compound breaks down into its components or simpler compounds.
    CBSE Class 10 Science Practical Skills – Types of Reactions 2
  3. Displacement Reactions: Displacement reactions are those reactions in which more reactive element takes up the place of another element in a compound and sets the less reactive one free.
    CBSE Class 10 Science Practical Skills – Types of Reactions 3
    You can also download NCERT Solutions Class 10 Science to help you to revise complete syllabus and score more marks in your examinations.The reactivity of metals depends upon the tendency to lose electrons. The more the tendency of a metal to lose an electron, the more will be its reactivity. Non-metals react by gaining electrons. The more the tendency of a non-metal to gain an electron, the more reactive is the non-metal.
  4. Double Displacement Reactions: In a double displacement reaction, ions of two compounds switch places to form two new compounds. Two reactants yield two products.
    CBSE Class 10 Science Practical Skills – Types of Reactions 4

EXPERIMENT 3(a)

Aim  
To perform and observe the action of water on quicklime and classify the reaction.

Materials Required 
Calcium oxide, water, beaker, glass rod, dropper, red litmus paper, test tube, filter paper, funnel.

Theory 
Quicklime reacts with water to form calcium hydroxide. As in this reaction two substances – quicklime and water combine to form a new substance, therefore, this reaction is called combination reaction. This chemical change can be represented by the given chemical equation:
CBSE Class 10 Science Practical Skills – Types of Reactions 5
During this chemical change, heat is also released. Therefore, this is also an example of exothermic reaction.

Procedure And Observation Table
The experimental procedure is described in the table:
CBSE Class 10 Science Practical Skills – Types of Reactions 6

Result
Two compounds, viz. quicklime and water combine to form calcium hydroxide. Therefore, this reaction is an example of combination reaction.

Precautions 

  1. Quicklime can cause severe burns, therefore, it should be handled with spatula.
  2. As the reaction between quicklime and water is exothermic, water should be poured over quicklime slowly.
  3. The filtrate collected should be clear.

EXPERIMENT 3(b)

Aim 
To perform and observe the action of heat on crystals of ferrous sulphate and classify the reaction.

Material Required 
Ferrous sulphate crystals, test tubes, test tube holder, blue limus paper.

Theory
The crystals of ferrous sulphate are green in colour. When these crystals are heated, following reaction takes place.
CBSE Class 10 Science Practical Skills – Types of Reactions 8
In this reaction, a single reactant breaks down to give simple products. Therefore, this is a decomposition reaction.
Ferrous sulphate crystals (FeS04.7H20) lose water when heated and the colour of crystals changes. It then decomposes to ferric oxide(Fe203), sulphur dioxide (S02) and sulphur trioxide (S03). Ferric oxide is solid while S02 and S03 are gases. Both S02 and S03 are acidic and hence, these gases turn the blue litmus red. Sulphur dioxide can reduce an acidified solution of potassium dichromate. This reaction can be utilised to confirm the presence of sulphur dioxide.
CBSE Class 10 Science Practical Skills – Types of Reactions 9

Procedure And Observation Table 
The experimental procedure is given in the following table:CBSE Class 10 Science Practical Skills – Types of Reactions 10

Resulst
On heating, ferrous sulphate decomposes to give ferric oxide, sulphur dioxide and sulphur trioxide. This decomposition reaction.

Precautions  

  1. While heating ferrous sulphate, keep the mouth of test tube away from you and your classmates.

EXPERIMENT 3(c)

Aim
To perform and observe the reaction of iron nails kept in copper sulphate solution and classify the reaction.

Materials Required
Iron nails, copper sulphate solution, test tubes, test tube stand, sandpaper and thread.

Theory
When an iron nail is immersed in copper sulphate solution, following reaction takes place:
CBSE Class 10 Science Practical Skills – Types of Reactions 12
In the above reaction, iron ions (Fe2+) being more reactive displaces copper ions (Cu2+) and a new compound ferrous sulphate is formed. This type of reactions is called displacement reaction.

Procedure 

  1. Take two iron nails and clean them by rubbing with sandpaper.
  2. Take two test tubes and mark them as ‘A’ and ‘B’.
  3. In each test tube, pour about 10 ml of copper sulphate solution.
  4. Tie one iron nail with a thread and immerse this carefully in the copper sulphate solution in test tube A for about 20 minutes. Keep aside one nail for comparison.
  5. After 20 minutes, take out the iron nail from the copper sulphate solution.
  6. Compare the intensity of blue colour of copper sulphate solutions of both   the  test    tubes ‘A’ and ‘B\
  7. Also, compare the colour of iron nail dipped in copper sulphate solution with one kept aside.
    CBSE Class 10 Science Practical Skills – Types of Reactions 13

Observations
The initial colour of copper sulphate solution was blue which after immersing iron nails turns to light green.
The initial colour of iron nail was grey. After immersing the nail into copper sulphate solution, a brown coating developed over it. Because of this coating iron nail appears reddish brown.

Result
On keeping the iron nails in copper sulphate solution, a displacement reaction takes place. In this displacement reaction, iron displaces copper and two new products ferrous sulphate and copper are formed.

Precautions 

  1. The iron nails should be cleaned by rubbing them with a sandpaper.
  2. The test tube containing iron nails and copper sulphate solution should not be disturbed.

EXPERIMENT 3(d)

Aim
To perform and observe the reaction between sodium sulphate and barium chloride solutions and classify the reaction.

Materials Required
Sodium sulphate solution, barium chloride solution, test tubes, beaker.

Theory
When the solutions of sodium sulphate and barium chloride are mixed, a white precipitate of barium sulphate is formed. Chemical equation for this chemical change can be given as follows:
CBSE Class 10 Science Practical Skills – Types of Reactions 14
In this reaction, both sodium sulphate and barium chloride exchange ions. Hence, this type of reaction is called double displacement reaction.

Procedure 

  1. Take 5 ml of sodium sulphate solution in a test tube and mark it as ‘A’.
  2. Take 5 ml of barium chloride solution in another test tube and mark it as ‘B’.
  3. Mix the solutions of test tubes ‘A’ and ‘B’ in a beaker.
  4. With the help of a clean glass rod, stir the mixture kept in beaker.
  5. Record your observation.

CBSE Class 10 Science Practical Skills – Types of Reactions 15

Observation
On mixing the solutions of sodium sulphate and barium chloride, a white precipitate is formed.

Result
On mixing the solutions of sodium sulphate and barium chloride, a double displacement reaction takes place.
In this reaction sodium sulphate and barium chloride exchange ions and new products barium sulphate (white ppt) and sodium chloride are formed.

Precautions                                                                                                                                   –

  1. Test tubes, beaker and glass rod should be cleaned.
  2. Equal volumes of sodium sulphate and barium chloride solutions should be used.

INTERACTIVE SESSION

 

Question 1:
What is the aim of your experiment?
Answer:
The aim of my experiment is to study the various types of chemical reactions.

Question 2:
How many types of chemical reactions are there?
Answer:
There are basically four types of chemical reactions, Combination reaction, Decomposition reaction, Displacement reaction and Double displacement reaction.

Question 3:
What type of reaction is combustion of hydrogen?
Answer:
It is a combination reaction.

Question 4:
Give the equation involved in the above process.
Answer:
2H2(g) + O2(g)→ 2H2O(l)

Question 5:
Can the above reaction be classified as a redox reaction?
Answer:
Yes, it can be classified as a redox reaction.

Question 6:
If we add Ag to an aqueous solution of CuS04, what happens and why?
Answer:
No change is observed because Ag being less reactive than Cu is unable to displace it from its salt solution.

Question 7:
What would happen if dil. HCl is added to (CH3COO)2Pb (lead acetate)?
Answer:
A white precipitate of PbCl2 will be obtained.

Question 8:
Give the equation involved and identify the type of chemical reaction.
Answer:
The equation involved is
(CH3COO)2Pb(aq) + 2HCl(aq) → 2CH3COOH(aq) + PbCl2(s)
This is a double displacement reaction.

Question 9:
Identify the type of chemical reaction occurring in the forward and backward processes of
CaC03 \(\overset { \Delta  }{ \rightleftharpoons  }\)CaO + C02.
Answer:
The forward reaction is a decomposition reaction while the backward reaction is a combination reaction.

Question 10:
What type of reaction is
Na2C03(aq) + 2HCl(aq)→ 2NaCl(aq) + H20(l) + C02(g)?
Answer:
It is a double displacement reaction.

Question 11:
How is it a double displacement reaction?
Answer:
In this reaction, the \({ CO }_{ 3 }^{ 2- }\) ions and Cl– ions are interchanging their positions, and H2C03 which is formed undergoes decomposition to give H20 and C02 as
H2C03(aq) \(\rightleftharpoons\)H20(aq) + CO2(g)

Question 12:
Why do displacement reactions occur?
Answer:
Displacement reactions occur due to the difference in reactivities of the elements. A more reactive element (metal or non-metal) displaces a less reactive element (metal or non-metal) from its salt solution.

NCERT LAB MANUAL QUESTIONS

Question 1:
Fill in the blanks:
(а) Sodium sulphate and barium chloride are ___________ (ionic/covalent) compounds.
(b) As the white precipitate of barium sulphate is formed___________________ (immediately/some­time after mixing the two solutions), the reaction between____________________ (ionic/covalent)
compounds is   (instantaneous/slow).
Answer:
(a) ionic
(b) immediately, ionic, instantaneous.

Question 2:
Why does the colour of copper sulphate solution change when an iron nail is dipped in it?
Answer:
The colour of copper sulphate solution changes when an iron nail is dipped in it because Fe is more reactive than Cu and can displace it from its salt solution.
CBSE Class 10 Science Practical Skills – Types of Reactions 16

Practical Based Questions 

Multiple Choice Questions/VSA

1. A student took solid quicklime in a china dish and added a small amount of water. He heard [AI 2010]
(a) a popping sound
(b) a crackling sound
(c) a hissing sound
(d) no sound at all

2. On heating ferrous sulphate crystals, one would get  [CBSE 2012, CBSE Sample Paper 2009]
(a) sweet smell
(b) rotten egg smell
(c) irritating choking smell
(d) none of the above

3. Hydrated ferrous sulphate is commonly known as
(a) blue vitriol
(b) green vitriol
(c)  yellow vitriol
(d) brown  vitriol

4. On passing C02 gas through the product formed by the reaction between CaO and H20, solution becomes
(a)  red
(b) pink
(c)  black
(d) white

5. On heating ferrous sulphate in a test tube it undergoes
(а) combination reaction
(b) decomposition reaction
(c) displacement reaction
(d) double displacement reaction

6. An iron nail is placed in a solution of copper sulphate. The nail is taken out after 10 minutes. The nail will be found to be covered with [CBSE 2012]
(a) brown deposit
(b) black deposit
(c) white deposit
(d) yellow deposit

7. CaO is commonly known as
(a) lime water
(b) slaked lime
(c) quicklime
(d) lemon water

8. The solid residue obtained on heating ferrous sulphate in a glass tube is
(a) ferrous sulphide
(b) ferrous oxide
(c) ferric oxide
(d) ferrous sulphite

9. Which of the following information about the reaction of CaO with water is not true?
(a) CaO reacts with water vigorously.
(b) During the reaction the test tube becomes hot.
(c) CaO reacts with water to form slaked lime.
(d) During the reaction dazzling white is produced.

10. When iron nails are kept in the solution of copper sulphate, the colour of the solution changes from
(a) green to yellow
(b) blue to green
(c) green to blue
(d) yellow to green

11. Precipitate formed on mixing the solutions of barium chloride-and sodium sulphate is of
(a) barium sulphate
(b) sodium chloride
(c) barium sulphite
(d) sodium sulphite

12. In ferrous sulphate, the valency of iron is
(a) 1
(b) 2
(c) 3
(d) 4

13. Which of the following represents a combination reaction?
(a) Reaction of zinc metal with copper sulphate solution
(b) Heating of lead nitrate
(c) Reaction between silver nitrate and sodium chloride
(d) Burning of magnesium in air.

Short Answer Questions

1. What is the difference between burning of magnesium ribbon in air and heating of ferrous sulphate crystals? Write equations for these reactions.

2. Why does a moist blue litmus paper turn red when it is brought near the mouth of the test tube in which ferrous sulphate crystals are being heated?

3. What happens when:
(a) solutions of sodium sulphate and barium chloride are mixed?
(b) an iron nail is dipped in copper sulphate solution for 20 minutes?

4. What precautions would you take while handling quicklime?

5. What will be the nature of solution formed when calcium oxide is dissolved in water? Name the substance formed when carbon dioxide gas is passed through this solution.

ANSWER KEY

Multiple Choice Questions/VSA

  1. (c)
  2. (c)
  3. (b)
  4. (d)
  5. (b)
  6. (a)
  7. (c)
  8. (c)
  9. (d)
  10. (b)
  11. (a)
  12. (b)
  13. (d)

Short Answer Questions
1.
CBSE Class 10 Science Practical Skills – Types of Reactions 17

2. On heating ferrous sulphate crystals (FeS04.7H20) it decomposes to ferric oxide, sulphur dioxide and sulphur trioxide. Ferric oxide is solid while sulphur dioxide and sulphur trioxide are gases. Both sulphur dioxide and sulphur trioxide are acidic and hence these gases turn the moist blue litmus red.

3. (a) When solutions of sodium sulphate and barium chloride are mixed, a white precipitate of barium sulphate is formed.

CBSE Class 10 Science Practical Skills – Types of Reactions 18

(b) When an iron nail is dipped in copper sulphate solution, following reaction takes place
CBSE Class 10 Science Practical Skills – Types of Reactions 19
In the above reaction, iron ions (Fe2+) being more reactive displaces copper ions (Cu2+) and a new compound ferrous sulphate is formed.

4. (i) Quicklime can cause severe bums, therefore it should be handled with a spatula.
(ii) As reaction between quicklime and water is exothermic, water should be poured over quicklime slowly.

5. On dissolving calcium oxide in water, calcium hydroxide is formed. When a drop of this liquid is put on a red litmus paper, it turns blue. This shows calcium hydroxide is basic in nature. When carbon dioxide gas is passed through calcium hydroxide (lime water), it turns milky due to formation of calcium carbonate.
CBSE Class 10 Science Practical Skills – Types of Reactions 20

Science Practical SkillsScience LabsMath LabsMath Labs with Activity

Omission Exercises for Class 8 CBSE With Answers

In the passages given below, one word has been omitted in each line. Write the word in your answer sheet along with the word that comes before and the word that comes after it, against each line number.

In the following passage, one word has been omitted in each line. Write the missing word along with the word that comes before and the word that comes after it in your answer sheet against the blanks given. The word that forms your answer should be underlined. The first one has been done for you.

Looking for an easy way to Learning of new elementary english grammar and composition for class 8 answers, Solutions. You have to learn basic English Grammar topics like Tenses Verbs, Nouns, etc… In this article, we will review the best English Grammer Topics and compare them against each other.

Omission Exercises for Class 8 CBSE With Answers PDF

Omitting is a stage of the writing process in which a writer fails to include or mention preposition, article, conjunctions, tenses, pronouns, modal verbs, etc. (PPACTS) In other words, Omitting is defined as left out or left undone.

Omission Exercises Solved Example With Answers for Class 8 CBSE

Read the following passage. There is one word missing in each line where a slash (/) has been marked. Write the correct word in the space provided. Omitting (sample)

Man is basically / animal. The instinct of fighting is a. _________
inborn in him. Thirst for power/glory is a part of b. _________
his personality. / times, he behaves like a savage, c. _________
irrational beast. In spite of all claims / the modern d. _________
civilisations, man / even today busy in pilling up and e. _________
preparing terrible weapons/war. f. _________
Answer:
a. an
b. and
c. At
d. of
e. is
f. of

Omission Exercises Practice Example for Class 8 CBSE

Read the following passages. There is one word missing in each line where a slash (/) has been marked. Write the correct word in the space provided.

Question 1.
Directions: Complete the sentence using the word or set of words for each blank that best fits the meaning sentence as a whole.
(i) Andrew ___________ right now. He wants to pass his test tomorrow.
(a) is sleeping
(b) is teaching
(c) is studying
(d) is eating

(ii) Kline ___________ a letter to his parents right now.
(a) is studying
(b) is writing
(c) is speaking
(d) is singing

(iii) Right now, William ___________ dinner for his family.
(a) is reading
(b) is talking
(c) is doing
(d) is cooking

(iv) Teresa and Jon ___________ soccer right now.
(a) are talking
(b) are writing
(c) are playing
(d) are making

(v) Right now, Marion ___________ a new car.
(a) is running
(b) is sleeping
(c) is buying
(d) is watching

(vi) Right now, Natasha and I ___________ The water feels good.
(a) are running
(b) are studying
(c) are helping
(d) are swimming

(vii) Right now, Marcel ___________ with his dog.
(a) is trying
(b) is playing
(c) is making
(d) is having

(viii) Tommy and I ___________ to a party on Saturday.
(a) are dancing
(b) are having
(c) are going
(d) are making

(ix) The baby ___________ right now. Don’t wake her up!
(a) is sleeping
(b) is walking
(c) is speaking
(d) is crying

(x) You ___________ English now.
(a) are drawing
(b) are studying
(c) are eating
(d) are having

Question 2.
Choose the correct option.
(i) Medieval knights were often ___________ for their outstanding chivalry and success in combat, but the truth is most knights only saw action in sparring matches or other competitions.
(a) commended
(b) envied
(c) acknowledged
(d) recognized

(ii) The athlete had been badly injured during play; although a nurse applied a cold press to the affected area, his ankle immediately began to ___________.
(a) swell
(b) cool
(c) diminish
(d) relapse

(iii) In order to ___________ his reign, the king had all of his competitors ___________.
(a) cancel, killed
(b) extend, eliminated
(c) solidify, promoted
(d) maintain, knighted

(iv) The elderly professor was often seen sitting in contemplation ___________. I imagine he was ___________ his long academic career.
(a) reliving
(b) reflecting on
(c) engaging in
(d) defending

(v) Compared to the skyscrapers that are virtually ubiquitous in modern cities, most city dwellings are quite ___________.
(a) diminutive
(b) massive
(c) spacious
(d) variable

CBSE XI Accountancy – Balance Sheet

BALANCE SHEET 

Balance Sheet has two sides. On the left hand side, the “liabilities” of the business are shown while on the right hand side the assets of the business appear.

It will be useful here to quote definitions of the Balance Sheet given by some prominent writers. According to Palmer, “The Balance Sheet is a statement at a given date showing on one side the trader’s property and possessions and on the other side his liabilities.” According to Freeman, “A Balance Sheet is an itemised list of the assets, liabilities and proprietorship of the business of an individual at a certain date.” The definition given by the American Institute of Certified Public Accountants makes the meaning of Balance Sheet more clear. According to it, Balance Sheet is ‘a list of balances of the asset and liability accounts. This list depicts the position of assets and liabilities of a specific business at a specific point of time.”

Proforma of Balance Sheet

There is no prescribed form of Balance Sheet for a sole proprietary and partnerhip concern. However, the assets and liabilities may be shown in any of the following order.

1. Liquidity Order.

2. Permanency Order.

1. Liquidity order. In case a concern adopts liquidity order, the assets which are more readily convertible into cash come first and those which cannot be so readily converted come next and so on. Similarly those liabilities which are payable first come first, and those payable later, come next and so on.

Depreciation Accounting – Uniform Charge Methods

Uniform Charge Methods 

In case of these methods depreciation is charged on uniform basis year after year. Such methods are considered appropriate only for such assets which are uniformly productive. Following three methods fall in this category.

Fixed instalment method. This is also termed as Straight Line Method (SLM).

According to this method, depreciation is charged evenly every year throughout the effective life of the asset The amount of depreciation is calculated as follows.

 Depreciation = Original Cost of the Fixed Asset — Estimated Scrap Value/ Life of tie Asset in Number of Accounting Periods

Depreciation to be charged each year can also be expresscd as a percentage of cost.

Merits. (I) The method is simple to understand and easy to apply.

(ii) The value of the asset can be reduced to zero (or its scrap value) under this method. 

Fundamentals of Accounting – Ledger

Ledger is the principal book of accounts where similar transactions relating to a particular person or property or revenue or expense are recorded. In other words, it is a set of accounts. It contains all accounts of the business enterprise whether real, nominal or personal. The main function of a ledger is to classify or sort out all the items appearing in the journal or other subsidiary books under their appropriate accounts so that at the end of the accounting period each account will contain the entire information of all the transactions relating to it in a summarised or condensed form.

For instance, all the transactions that have taken place with Mr. Mathur will be entered in Mathur’s Account.

Similarly, all items relating to cash, sales, purchases, salaries, discount, etc. appear in their respective accounts.

Ledger is defined as a “Book which contains in a summarised and classified form of permanent record of all transactions. Ledger is called the principal book of account as final information pertaining to financial position of a business emerges from this book.

Determiners Exercises With Answers for Class 8 CBSE

Determiners Exercises With Answers for Class 8 CBSEDeterminers are words which come before nouns. They contain several classes of words, including pronouns and adjectives. They determine or limit the noun by giving some additional information about it. Determiners show whether a noun refers to is a general or a specific object, person, or place. They indicate which or how many things the noun refers to. Determiners define or limit a noun to the singular or plural. They indicate the amount or quantity. Determiners and nouns together make noun phrases. They make noun phrases with adjectives too. Determiners may precede numerals too.

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Determiners Exercises With Answers for Class 8 CBSE PDF

A determiner is used to modify a noun. It indicates reference to something specific or something of a particular type. There are nearly five types of determiners.

These include:

  1. Articles
  2. Demonstratives
  3. Possessives
  4. Quantifiers
  5. Numbers
  6. Ordinals

Article Determiners:

As we know, a and an are indefinite articles and the is the definite article. Of the three, a and an are the most common general determiners, whereas the is the most common specific determiner. A and an are used with singular countable nouns while referring to a general class of nouns like a frog, a ship and a biscuit. We do not use alan before uncountable nouns like rice, water or smoke. A is used before words that begin with a consonant sound and an is used before words that begin with a vowel sound.

Remember, a word might begin with a consonant letter but it might begin with a vowel sound or it might begin with a vowel and have a consonant sound.

Examples:

  • an umbrella a uniform an heir a unicorn
  • an honourable man a useful item an M.A. student (M—em sound)

The is used:
1. to refer to a specific noun.
Examples:

  • the letter I received, the thief who stole“;

2. before a noun which we have already mentioned before. The first time we use alan and the second time we use the.
Example:

  • I saw a cat … The cat jumped on me.

3. when there is only one of the thing.
Examples:

  • the sun, the Earth, the Tropic of Cancer, the environment, the internet

4. with the superlative degree.
Examples:

  • one of the greatest footballers, the cutest dog

5. before some adjectives in positive and comparative degree.
Examples:

  • the great king, the smaller shoe

6. before adjectives that act as nouns.
Examples:

  • the poor of this country …, the more the merrier … (poor and more refer to people)

7. before singular nouns to indicate an entire group, class or species.
Example:

  • The cheetah is the fastest land animal. (all cheetahs)

But not before man or woman.
Example:

  • Man is a social being.

8. with some proper nouns like names of lakes, rivers, forests, mountain ranges, famous buildings, names of some countries, etc.
Examples:

  • the Western Ghats, the Indian Ocean, the Sutlej, the Taj Mahal, the USA, the UK, the UAE

9. with the names of holy books.
Examples:

  • the Bible, the Holy Koran, the Bhagwad Gita

10. when both the speaker (writer) and listener (reader) know the person or thing.
Examples:

  • the teachers, the President

11. before only, first, second, last, etc.
Examples:

  • the first floor, the last day of school, the only child.

Demonstrative Determiners:

These are used as pronouns or as adjectives and are specifically used to state the distance from the subject. They are this, these, that and those.
Example:

  • That garden is very big.
  • Those are the stories of bygone days.

Possessive Determiners:

Possessives are words that show ownership or a relationship between people or things. Look at the words in italics in this sentence.

Kumud and her companions were on their way to the Bandipur National Park.

The words her and their determine whose companions and way. The other possessive adjectives like my, our, your, his, her, its, theirs are also determiners.
Example:

  • Suraj’s father sold his car two months ago.

Quantifiers:

Words that show how much or how many (quantity) are called quantifiers. These include many, a little, few, some, a lot of, etc. Some of them are only used with countable and some of them are used only with uncountable nouns. Some others are used with both countable and uncountable nouns.

  • Quantifiers used with countable nouns show how many.
  • Quantifiers used with uncountable nouns show how much.

Number Determiners:-

These determiners are just used to specify the exact count or number in a sentence. They are one, two, fifty, thirty, etc.
Example:

  • There are five mangoes in the basket.
  • Each child got two chocolates.

Ordinal Determiners:-

These are to determine the class or present the position of the subject in the sentence. They are first, second, last, next, etc.
Example:

  • Raman stood first in the long jump.
  • Sushil was the last to receive the prize.

Fill in the following blanks with the suitable determiners.

A. Misers are generally characterised as men without honour or without humanity, who live _______________ to accumulate, and to this passion sacrifice every other happiness. They have been described as mad men _______________ in the midst of abundance, banish _______________ pleasure, and make from imaginary wants realnecessities. But _______________ very few, correspond to the exaggerated pictures; perhaps there is not one in _______________ all these circumstances are found united. Instead of this we find the sober and the industrious branded by the vain and the idle with the odious appellation; men _______________ buy frugality and labour, raise themselves above _______________ equals, and contribute their share of industry to _______________ common stock.

B. Discontentment is _______________ root cause of all unhappiness. Contentment is blissful whereas discontentment is a curse. _______________ more discontented we are, _______________ more unhappy we are. We may have _______________ amounts of money in the bank, we may own vast farms or palaces or factories, we may be monopolists with beautiful sources of income, we will never be happy if we are discontented. A discontented man is always a slave to his desires. He acts as _______________ enemy. He does not care for _______________ position or prestige. He does not care for _______________ mental or physical health. He only wants the satisfaction of _______________ desires. He can act as his _______________ friend if he acquires contentment, but he does not do so. It is in his own hands to be free or to be a slave. If he controls _______________ desires he becomes free, if he is controlled by _______________ desires, he becomes _______________ slave.

C. Books are _______________, delightful company. If you go into _______________ room filled with books even without taking them down from _______________ shelves, they seem to speak to you seem to welcome you seem to tell you that they have something inside _______________ covers that will be good for you and that they are willing to impart it to you. Value them and endeavour to use them well. As to _______________ books which you should read there is _______________ anything definite that can be said.

D. The spirit of sportsmanship is what we lack today. The sports tell us _______________ we should react to defeat or disappointment with _______________ smile. We should not go about insisting on _______________ success in whatever we attempt. It is not possible for _______________ man to succeed in _______________ desire he has. There may be ambition of groups, there may be ambition of individuals which they set before themselves and they must try, if they are disappointed in the carrying out of their ambitions to take _______________ disappointment and _______________ defeat with a smile and to learn from it. What will happen if every individual in the street wishes to go his _______________ particular way without observing the rules of traffic, there will be clashes, there will be accidents. What happens on the streets will also happen in the political and public sphere of the country.

E. Many men and women are so money-minded _______________ they don’t undertake any serious work that does not pay. They believe that it is foolish to exert themselves for such study and brain work as cannot be converted into cash. Hard work only for money and then plenty of play and pleasure: this seems to be _______________ rule of life. They value intellect only as _______________ key to material prosperity and regard personal mental development as _______________ foolish fad. _______________ miserable materialistic psychology is very deeply rooted in _______________ classes of society. Rich and poor _______________ suffer from it. _______________ old working woman complained to me of _______________ son’s habit of occasionally buying some cheap books, and said, “He wastes _______________ money on books. What good are they to _______________? He is _______________ carpenter, not _______________ school master.”

F. _______________ wants to take rest, but _______________ know how to enjoy it. _______________ rich and _______________ poor, _______________ young and the old, _______________ go to bed at night, but _______________ enjoy a restful sleep. Generally people do not know the right manner of taking a rest. This is why they do not feel rejuvenated even _______________ having seven to eight hours sleep at night. Before describing _______________ right manner of taking rest, it must be clearly understood _______________ man’s physical state of health effects _______________ thoughts considerably and vice-versa. It is _______________ well recognised fact that when a man’s stomach is heavy and the food is not properly digested his thoughts wander about _______________ mood becomes restless. But if the stomach is light and body healthy, the man’s thoughts, too, are calm. In a healthy state, _______________ man’s brain is active and the mind cheerful and he does not bother much about the worries of _______________ world.

More about Determiners

Fundamentals:

  1. It’s possible to have no determiner in a sentence. Example: John likes dogs. People breathe air. This is called ‘zero determiners’, and is usually possible with proper nouns (ie names), ‘plural’, ‘countable nouns’ and ‘uncountable nouns’.
  2. All determiners, when present in a sentence, come at the beginning of a noun phrase (before any adjectives): the big black dog /my favorite car
  3. Depending on its position before the noun, a determiner can be:

Pre-determiner – Central Determiner – Post-determiner – Noun
all – the – many – roads

a central determiner, a pre-determiner or a post-determiner.

3. If you have a ‘main determiner”, we can have only one noun. The main determiners are:

  • articles: a/an, the
  • demonstratives: this/that, these/those
  • possessives: my/your/his etc

So if we have an article in a sentence, we cannot also have a demonstrative. If we have a possessive, we cannot have an article. We can have one article or one demonstrative or one possessive. For example, we can say “this dog” or “my dog”, but we cannot say “this my dog”. The table below shows how the main determiners “mutually exclude” each other:

articles demonstratives possessives noun
a dog
the soup
this flower
those birds
my sister
their car

4. Some determiners function as “pre-determiners” — they can come before the main determiner. We can have one pre-determiner: all the right people/half my weight

5. Other determiners function as “post-determiners” — they can come after the main determiner. We can have one or more post-determiners: the next time/my first two jobs

6. If we have more than one determiner, the table below is a guide to the normal order. Remember, this is a guide only. Not every combination is possible.
Determiners Exercises With Answers for Class 8 CBSEPre-determiners / Central Determiners / Post-determiners

There are different types of pre-determiners determiners. The main ones are:

Main Pre-determiners Example Words Example Phrases
multipliers twice, double three times. twice the money
fractions half, one fourth. half an hour
Intensifiers what, such, rather, quite What a mess!
other words both, all both my legs

Main Central determiners include:

Main post-determiners Example Words Example Phrases
cardinal numbers one, two, eighty. the three eagles
ordinal numbers first, second, twenty-third. the first time
general ordinals last, next, previous, latter, subsequent. our next meeting
quantifiers few, several, many. his several successes

Language Tips about Determiners
Some words can be determiners or post-determiners, depending on the number of determiners in a sentence and their place.
Examples:
‘two’ is a determiner in: I need two rackets.
‘two’ is a post-determiner in: I need the two rackets from the garage, (‘two’ is placed after the centra! determiner ‘the’)
‘many’ is a determiner in: We know many uses for these products.
‘many’ is a post-determiner in: We know their many uses, (‘many’ is placed after the central determiner ‘their’)
Usually, we only use one pre-determiner. However, it is possible to use two post determiners, as shown in the examples below.
Examples:

  • his next two projects, the first three days, etc

A. Complete sentences using correct determiners.

1. I make _______________ his salary! (half/all)
2. We brush our teeth _______________ a day. (two/twice)
3. _______________ the customers were satisfied, (all/both)
4. Are you available for the _______________ meeting? (last/next)
5. _______________ my uncles live in Switzerland, (both/twice)
6. _______________ this amount is enough, (all/one third of)
7. _______________ a great invention! (What/How)
8. This is _______________ an amazing story! (so/such)
9. I never want to speak to those _______________ crooks again, (both/two)
10. He explained his _______________ projects, (much/many)

B. Rearrange the words to make sentences and underline the determiners.
1. ate / it / she / half / of
2. proud / many / of / is / achievements / he / his
3. such / is / difficult / a / this / exercise

C. Which is the correct phrase: A, B or both? Tick the correct one.

1. the first two hours 1. the two first hours
2. a such good investment 2. such a good investment
3. several his objectives 3. his several objectives
4. my both ears 4. both my ears
5. two-fifths of the candidates 5. two-fifth candidates
6. twice the money 6. double the money
7. my two eyes 7. both my eyes
8. the all day 8. all the day
9. their few friends 9. few their friends
10. the last four days 10. the four last days
11. double that salary 11. double of that salary
12. four times of the number of people 12. Four times the number of people
13. twice the number 13. twice of the number
14. all the people have problems 14. the people all have problems
15. half this milk is spoiled 15. half of this milk is spoiled

D. Read the sentences underline the words which are determiners.

1. Most days, Manish speaks to Neha at least once a day.
2. He earns twice her salary.
3. Last week, he took her to quite an expensive restaurant.
4. That evening, he spent three times the amount he had anticipated!
5. What a gentleman!

E. Determine whether the following statements are True or False.

1. Usually, we use several pre-determiners. True/False
2. ‘Next’ is a pre-determiner. True/False
3. Some words can be determiners or post-determiners. True/False
4. It is rare to have a pre-determiner, a central determiner, and a post-determiner in one sentence. True/False

F. Match the determiner on the left to its category on the right.

1. all a. pre-determiner
2. second b. central determiner
3. mine c. post-determiner
4. the d. not a determiner

G. Put the words in the correct order.

1. three / first / failed / attempts / he / the
____________________________________
2. difference / their / a / quite / contributions / made
____________________________________
3. our / engineering I both / study / sons / chemical
____________________________________
4. several / we / achievements / admire / his
____________________________________

Joint Venture and Partnership

JOINT VENTURE AND PARTNERSHIP

According to the Indian Partnership Act. “Partnership is the relations between persons who have agreed to share the profits of a business carried on by all or any of them acting for all.” Thus, both in joint venture and partnership there is some business activ,ity whose profit (or loss) is agreed to be shared by two or more than two persons. As a matter of fact in law, a joint venture is treated as a partnership. Of course, a partnership covers or is meant to cover a long period whereas ajoint venture is only for a limited purpose sought to be achieved in a short period. On account of this reason, joint venture is also sometimes termed as a temporary partnership’ or ‘partnership for a specific venture’ or ‘particular partnership’.

Joint Venture and Consignment

The following are the points of distinction between joint venture and consignment:

(1) .Relalionslnp: In case of a consignment transaction, the relationship between the consignor and the consignee is that of a principal and an agent. While in case of joint venture, the relationship amongst various venturers is that of partners, i.e., mutual agency. Each venturer is a principal as well as an agent for the other venturer.

(II) Sharing of profits: In case of consignment, the consignee gets only a commission on the goods sold by him on behalf of the consignor while in case of joint venture each venturer gets a share in the profits of the venture,

(iii) Transfer of risk: tn case of consignment, till the goods are sold the risk continues to be of consignor while ajoint venture is a temporary partnership hence the risk continues of all venturers.

A Question of Trust Extra Questions and Answers Class 10 English Footprints Without Feet

In this article, we are providing A Question of Trust Extra Questions and Answers PDF Class 10 English Footprints Without Feet CBSE, Extra Questions for Class 10 English Footprints Without Feet was designed by subject expert teachers.

A Question of Trust Extra Questions and Answers Class 10 English Footprints Without Feet

Extract Based Questions [3 Marks each]

Read the following extracts carefully and answer the questions that follow.
Question 1.
So he robbed a safe every year. Each year he planned carefully just what he would do, stole enough to last for twelve months, and secretly bought the books he loved through an agent.
(a) Who is ‘he’ in the above extract?
(b) Why did ‘he’ rob only one safe every year?
(c) Find the word from the extract that means the opposite of ‘openly’.
(d) What is the present tense of ‘stole’?
Answer:
(a) ‘He’ in the above extract is Horace Danby.
(b) He robbed only one safe every year because he robbed just enough to satisfy his hobby of buying and collecting rare and expensive books. Otherwise, he was just an honest lock-maker.
(c) The word is ‘secretly’.
(d) Its present tense is ‘steal’.

Question 2.
A small dog was lying in the kitchen. It stirred, made a noise, and moved its tail in a friendly way. [CBSE 2014]
(a) What is the name of the dog mentioned in the above extract?
(b) In which house is the kitchen referred to located?
(c) Find a word from the passage that means the same as ‘cordial’.
(d) What is the opposite of ‘friendly’?
Answer:
(a) The name of the dog mentioned in the above extract is Sherry.
(b) The kitchen referred to is located in Shotover Grange.
(c) The word is ‘friendly’.
(d) Its opposite is ‘hostile’.

Question 3.
The voice went on, “You can cure it with a special treatment, you know, if you find out just what plant gives you the disease. I think you’d better see a doctor, if you’re serious about your work.”
(a) Whose voice is referred to in the above extract?
(b) What disease was the voice referring to?
(c) Find a word from the passage that means the same as ‘ailment’.
(d) What part Of speech is the word ‘it’ in the extract?
Answer:
(a) The voice referred to in the above extract is of the young lady who pretended to be a member of the household.
(b) The disease the voice was referring to was hay fever, with which Horace Danby was afflicted.
(c) The word is ‘disease’.
(d) ‘It’ is a pronoun.

Question 4.
She laughed, and he begged, thinking that he had persuaded her, “Look, I have no right to ask you for anything, but I’m desperate.”
(a) Who are ‘she1 and ‘he’ in the above extract?
(b) Why did ‘he’ say that he was desperate?
(c) Find a word in the passage that means the same as ‘convinced1.
(d) What is the opposite of ‘persuaded’?
Answer:
(a) ‘She’ is young lady who Horace met in the house and ‘he’ is Horace Danby.
(b) Horace was desperate because he had been caught stealing and did not want to go to prison.
(c) The word is ‘persuaded’.
(d) Its opposite is ‘dissuaded’

Short Answer Type Questions [2 Marks each]

Question 1.
Whom did Horace Danby see in the kitchen? How did they greet each other? What tact did Horace apply there? [CBSE 2013]
Answer:
Horace Danby saw the family dog, Sherry, in the kitchen. The dog greeted Horace by stirring, making a noise and wagging its tail in a friendly way. Horace greeted the dog by tactfully calming it down, calling it by its name and showing love to it.

Question 2.
How did Danby prepare for the robbery at Shotover Grange? [CBSE 2011]
or
How did Horace Danby plan his robberies? [CBSE2012]
Answer:
Danby always planned his robberies meticulously. He prepared for the robbery at Shotover Grange by studying the house, the electric wiring, paths and garden. He knew that the family normally lived in the city and knew about the movement of the servants, who had gone out that afternoon. He had kept his tools ready, packed in a bag.

Question 3.
What was the passion of Horace Danby and how did he satisfy it? [CBSE 2011]
Answer:
The passion of Horace Danby was collecting rare and expensive books. To satisfy this passion, he needed money and arranged it by robbing one safe every year and then secretly buying the books through an agent.

Question 4.
Describe the safe at Shotover Grange.
or
Where was the safe at Shotover Grange? What was there inside it? What did Horace expect to get if he sold them one by one? [CBSE 2012]
Answer:
The safe at Shotover Grange was kept in the drawing room behind a poor painting and had jewels worth about 15000 pounds kept in it. It had a poorly built burglar alarm, but could be opened only through a specific code. Horace expected to get 5000 pounds if he sold the jewels one by one.

Question 5.
How can you say that Horace Danby was good and respectable but not completely honest?
Answer:
Horace Danby was good and respectable because he was an expert in his profession of making locks. However, as he loved collecting rare and expensive books, he robbed a safe every year to finance the purchase of these books through an agent. Thus he was not completely honest

Question 6.
How did flowers hinder Horace in his work? [CBSE 2013]
Answer:
Flowers hindered Horace in his work because he had hay fever, a disorder affecting the nose and throat, caused by allergy to pollen or dust. Due to this problem, whenever he came close to flowers, he began to sneeze’ and could be caught. He had to cover his face.

Question 7.
Why was Horace Danby sure that his robbery at Shotover Grange woukhbe a successful one? [CBSE 2014]
Answer:
Horace Danby was sure that his robbery at Shotover Grange would be a successful one because he had studied the house, the drawing room where the safe was kept, the wiring and its garden. He had also studied the movement of the servants, so he had planned well, thus ensuring that nothing could go wrong.

Question 8.
Why does Horace Danby get angry when anyone talks about ‘honour among thieves’?
Answer:
When anyone talks about ‘honour among thieves’, Horace Danby gets angry because the young lady who cheated him was also a thief, yet did not follow this saying.

Question 9.
What are the subtle ways in which the lady manages to deceive Horace Danby into thinking she is the mistress of the house?
Answer:
The subtle ways in which the lady manages to deceive Horace Danby into thinking she is the mistress of the house are her grace, charm, comfort level, knowledge, persistence, way of talking confidently and familiarity with the household. She even threatens to get him arrested, which convinces Horace Danby that she is genuine.

Question 10.
What did Horace Danby wonder about for a moment? What did he think and decide? [CBSE 2010]
Answer:
On seeing the poor painting in front of the safe, Horace Danby wondered for a moment whether to collect pictures instead of books. But then, he thought that books were better in a small house like his, as paintings took up too much room.

Question 11.
What did Horace do every year and why?
Answer:
As Horace was fond of rare, expensive books, he stole a safe every year, to have just enough money to last twelve months for buying such books to his heart’s content.

Question 12.
Whom did Horace meet at Shotover Grange? How did the meeting affect his plans?
Answer:
Horace met a young, pretty woman dressed in red at Shotover Grange. She pretended to be the owner’s wife and deceived him into breaking open the safe to remove the jewels for her. She threatened even to call the police. This meeting adversely affected his plans, as he was not able to get away with the jewels.

Long Answer (Value Based) Type Questions [8 Marks each]

Question 1.
What precautions did Danby take to avoid arrest? What blunder did he commit in his last venture?
Answer:
To avoid arrest, Danby always studied all aspects of the safe he had targeted that year thoroughly, including the habits of the owners and servants, the layout of the house, any burglar alarms etc. He carried a set of select tools to break open safes and always wore gloves, so that he left behind no fingerprints.
In his last venture at Shotover Grange, he committed the blunder of not wearing gloves while cracking open the safe, probably because he was distracted by the young lady threatening to call the police, thus leading to his arrest soon afterwards.

Question 2.
Why was Horace Danby arrested although he failed to profit from the robbery at Shotover Grange?
Answer:
Horace Danby was arrested although he failed to profit from the robbery at Shotover Grange, because he broke open the safe to give the lady in red the jewels, thinking her to be the wife of the owner who had forgotten the number combination to open the safe. Actually he wanted to escape scot-free, as he had been caught red-handed by the lady and wanted to keep her happy. However, his fingerprints were all over the room, as he had forgotten to wear his gloves while opening the safe. Thus he was arrested soon afterwards.

Question 3.
Horace was clever but the lady in red was cleverer. Do you agree with this statement? Justify your answer.
Answer:
Yes, I agree with this statement. Horace was clever, as he planned the robbery carefully, studied the target, took the proper tools and also took his gloves, to ensure leaving no fingerprints. But the young lady in red had all the necessary information, and, posing as the mistress of the house, exploited Horace’s fear on being discovered, tricked him into cracking open the safe and handing her the jewels. She even ensured that Horace left his fingerprints at the site, as she distracted him by picking up a cigarette which Horace offered to light after removing his gloves. Thus the lady outwitted him.

Question 4.
Would you do something wrong (i.e. commit a crime) if you thought that the ends justify the means? Do you think that there are certain situations you can be excused for acting dishonestly? [CBSE 2011]
Answer:
Yes, intentions do justify actions. If something wrong is done unintentionally, it may be pardoned. However, it cannot be excused if it is carried out even when knowing it is wrong. As Horace had the intention to rob the safe by breaking it open, his crime is intentional. Although he had good intentions in helping the lady (who he thought was the mistress of the house), his crime cannot be excused. Breaking open the safe cannot be justified at all. There may be certain situations when you can be excused for acting dishonestly, but this is not so in Horace’s case.

Question 5.
Horace was a successful thief because he carefully planned his robberies. Should we call him a successful thief and still appreciate his work? Why or why not? [CBSE 2013]
Answer:
Yes, as a thief, Horace is successful because he carefully planned his robberies and completes them well. He was living his life as a good and honest citizen. However, the wealth he gathered due from his successful robberies did not belong to him. By stealing other people’s valuables, he may have become successful but he is actually a criminal. He may be efficient in – conducting his’-crimes so that he is successful, but we still cannot appreciate his work.

For More Resources

Role of Agriculture in the Indian Economy

ROLE OF AGRICULTURE IN THE INDIAN ECONOMY

Over the years 1921 -91, the size of labour force dependent on agriculture had more than doubled and over the next decade is projected to going by more than 25 per cent. This is contrary to the development economists’ observation that as country develops the share of labour force dependent upon agriculture as a source of livelihood declines. The occupational structure of the country has shown a lack of flexibility, the large proportion of the increasing labour force, in the absence of any alternative employment opportunities, has been absorbed in agriculture. It is observed that while the share of agriculture in GDP has been declined significantly, its share in the manufacturing sector has gone up. However, corresponding to this structural shift in production, the structure of employment has shown little change.

Since agriculture contributes significantly in the National Income, this sector is treated as major source of savings and hence capital formation for the economy. The pace of development is largely conditioned by the rate of capital formation in the economy. Since independence, large investment, both public and private, has been made in agriculture. In areas where agricultural practices are traditional, investment has also been on traditional lines like land and its improvement, tools and implements, farm structures, etc. But the pailern of investment in progressive areas, where modern technology has been adopted, has been predominantly in irrigation, land improvements, farm machinery and other infrastructures. Of course in recent years public investment in agriculture sector has declined. To stimulate growth, substantial capital investments are required for various infrastructure and inputs.

The Making of a Scientist Extra Questions and Answers Class 10 English Footprints Without Feet

In this article, we are providing The Making of a Scientist Extra Questions and Answers PDF Class 10 English Footprints Without Feet CBSE, Extra Questions for Class 10 English Footprints Without Feet was designed by subject expert teachers.

The Making of a Scientist Extra Questions and Answers Class 10 English Footprints Without Feet

Extract Based Questions [3 Marks each]

Read the following extracts carefully and answer the questions that follow.
Question 1.
So he did, and did he ever! Beginning in kindergarten, Ebright collected butterflies with same determination that has marked all his activities.
(a) What does ‘he did’ in the extract refer to?
(b) What else did he collect other than butterflies?
(c) Find a word from the extract which means ‘resolutenesss’.
(d) What is the opposite of ‘Beginning’?
Answer:
(a) ‘he did’ refers to Richard’s habit of collecting various things.
(b) He collected fossils, coins and rocks other than butterflies.
(c) ‘Determination’ is a word from the extract which means ‘resoluteness’.
(d) Its opposite is ‘Ending’

Question 2.
He would catch a female monarch, take her eggs, and raise them in his basement through their life cycle
(a) Who is ‘he’ in this extract?
(b) Why does he raise butterflies?
(c) Find a synonym for the word ‘rear’ from the extract given above.
(d) What part of speech is ‘them’?
Answer:
(a) Richard Ebright is ‘he’ in this extract.
(b) He raised butterflies to study their migration pattern.
(c) ‘Raise’ is the synonym of‘rear’ from the extract.
(d) It is a pronoun

Question 3.
“It was really a sad feeling to sit there and not get anything while everybody else had won something.”
(a) Who is the speaker of the above lines?
(b) Where was he competing at?
(c) Find a word from the extract which is the opposite of ‘nobody’.
(d) Write a synonym of ‘sad’.
Answer:
(a) Richard Ebright is the speaker of the above lines.
(b) He was competing at a county science fair.
(c) ‘Everybody’ is the opposite of ‘nobody’ from the extract.
(d) Its synonym is ‘Gloomy’.

Question 4.
If the theory proves correct, it will be a big step towards understanding the processes of life. [CBSE 2012]
(a) What is the theory about?
(b) Who proposed the theory?
(c) Which part of speech is ‘life’ as used in the given extract?
(d) Give a synonym of ‘correct’.
Answer:
(a) The theory is about how cells read their DNA.
(b) The theory was proposed by Richard Ebright and his friend James R. Wong.
(c) It is used as a noun.
(d) Its synonym is ‘right’.

Short Answer Type Questions [2 Marks each]

Question 1.
What rare achievement did Richard manage at the age of twenty-two?
Answer:
Richard had a rare honour at the age of twenty-two. He wrote an article with his friend about a theory of how cells work. The article was published in the scientific journal ‘Proceedings of the National Academy of Science.’ No one had this achievement at such a young age before him.

Question 2.
Richard became a collector at an early age. How?
Answer:
Richard was the only child of his parents. He had no company at home to play with. So, he started collecting things in his spare time. He would collect coins, fossils, rocks and butterflies as a hobby.

Question 3.
Comment on the role played by Richard’s mother in his success.
Or
How did Ebright’s mother help him in becoming a scientist? [CBSE 2015]
Answer:
Richard’s mother made Richard the centre of her life. She would buy microscopes, telescopes and books for him. She arranged trips for him and would also prepare difficult tasks for him. This helped him to learn a lot.

Question 4.
How did ‘The Travels of Monarch X’ prove a turning point in his life?
Answer:
Richard was bored with collecting butterflies. At this time, his mother got the book ‘The Travels of Monarch X’ for him. After reading the book, he studied the migration of butterflies and it opened the world of science to him.

Question 5.
Why did Richard lose interest in tagging butterflies?
Answer:
Richard raised thousands of butterflies, tagged them and released them to study their migration. But soon, he lost interest because only two of his tagged butterflies were returned to him and they had travelled only seventy-five miles.

Question 6.
Which project did Richard undertake in the eighth grade?
Answer:
Richard undertook the project to find the cause of a viral fever that had killed thousands of butterflies. He thought that a beetle might carry the virus although he was not able to prove it.

Question 7.
Richard’s project on the purpose of the twelve tiny gold spots on a monarch pupa was highly valuable in two ways. List the two ways.
Answer:
This project had a huge impact. First, he discovered a hormone that was necessary for the growth of the pupa. Secondly, he got a chance to work at a famous laboratory.

Question 8.
Mentionany two of Ebright’s contributions to the world of science. [CBSE 2011]
Answer:
Ebright discovered a hormone that was necessary for the growth of a butterfly. His other important contribution proved to be his study of how cells read their DNA.

Question 9.
In addition to science, what were the other interests of Richard?
Answer:
A part from science, Richard was a good debater and a public speaker as well as a canoeist and an all-round a outdoors person. He loved photography as well.

Question 10.
Mr. Weiherer pays a glowing tribute to Richard. What did he say?
Answer:
Mr. Weiherer was Ebright’s social studies teacher. He praised him for his brilliant mind, his curiosity and a will to win for the right reason. He also admired Richard for his spirit to do his very best all the time.

Question 11.
Why do viceroy butterflies copy the monarch butterflies?
Answer:
Birds eat viceroy butterflies because they taste good to them, whereas monarch butterflies do not taste good to the birds. So the viceroys try to copy the monarchs to protect themselves from the birds.

Question 12.
Hobbies play a very important role in one’s life; elaborate this with reference to “The Making of a Scientist”. [CBSE 2016]
Answer:
Richard Ebright started collecting butterflies as a hobby. This led him to research and discover many things. Hence, hobbies play an important role in one’s life.

Question 13.
What were the factors which contributed in making Ebright a scientist? [CBSE 2014]
Answer:
Three qualities of Ebright which contributed were a first rate mind, a sense of curiosity and a will to win for the right reason.

Long Answer (Value Based) Type Questions [8 Marks each]

Question 1.
Richard’s mother had a great influence on him. Discuss.
Or
Discuss the role of Ebright’s mother in making him a scientist. [CBSE 2011]
Answer:
Richard’s mother played a huge role in making him a great scientist. She would take him on trips to encourage learning. He was a single child. After his father died, his mother made him the focus of her life. She would buy him all kinds of microscopes, telescopes and other equipment. After dinner, she gave him problems to solve. This helped Richard to learn a lot. She was his only companion for a long time. It was his mother who got him the book ‘The Travels of Monarch X’. This book opened the world of science for Richard. She also wrote to Dr Urquhart to guide her son. The scientist helped Richard and guided him. Thus, his mother actually shaped him into an extraordinary scientist.

Question 2.
Ebright’s study of monarch pupas had a far reaching impact. Elaborate.
Answer:
For a long time the scientific community had regarded the bright spots on a monarch pupa as purely ornamental. But Dr Urquhart did not believe it. Nor did Richard. He started his experiments on the monarch pupa. He built a device with the help of a friend. This led to the discovery of a hormone. Richard proved that the hormone was necessary for the growth of the butterfly. This discovery got him many honours. Also, it led to another important study. He began working on how cells read their DNA. DNA is the carrier of heredity and is called the blueprint of life. His theory could find answers to many cancers and diseases.

Question 3.
Richard Ebright displayed a well-rounded personality. Do you agree? Elucidate in the context of the given text. [CBSE 2016]
Answer:
Richard’s genius was obvious by the time he was in his second grade. He managed to collect all twenty-five . species of butterflies around his hometown and classify them. He also loved to collect coins, fossils and rocks. Science was not his only passion. He was an active member of his school’s oratory club and model United Nations club and was an effective debater and a public speaker. He loved photography as well.
He was an enthusiastic canoeist and an all-around outdoors person. Learning was easy for him. So he found it simple to devote time and energy to many other interests. He became a champion in whatever he did. He believed in the spirit of competition to win. But, he did not wish to defeat others just to win. He wanted to win to do his best. Thus, he displayed a well-tounded personality.

Question 4.
Dr Urquhart contributed significantly to Ebright’s growth as a scientist. Explain
Answer:
Richard had become bored with collecting butterflies. His mother got him a book on the migration of butterflies. Richard came in contact with Dr Urquhart through the book. Dr Urquhart directed him to study the migration pattern of butterflies.
When he did not win any prize in the science fair in seventh grade, he again wrote to Dr Urquhart to guide him. The scientist gave him many suggestions for new experiments. Richard performed these experiments throughout his high school and won many prizes. Later, he worked on why bright spots are found on a monarch pupa, motivated by Dr Urquhart. It led to the discovery of a new hormone. The discovery of this new hormone further led to an important theory. The theory was about how cells read their DNA. In this way Dr Urquhart proved to be his true mentor.

Question 5.
What are the values required to become a successful scientist like Richard Ebright? Elaborate with reference to the lesson ‘The Making of a Scientist’.
Answer:
Curiosity to know more and a motivation to find reasons for existence of anything or any phenomena are necessary for becoming a successful scientist. The urge to know more develops the scientific aptitude in a person. At a very young age, Ebright became competitive by participating in various county fairs. He never lost hope and kept on trying to do better. In addition to curiosity and motivation, Ebright displayed the qualities of hard work, sincerity, determination and patience. He also accepted failure and success in the right spirit. Thus, he became a successful scientist.

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Depreciation Accounting – How to fix Depreciation Amount

FIXATION OF DEPRECIATION AMOUNT

Following are the three important factors which should be considered for determining the amount of depreciation to be charged to the Profit and Loss Account in respect of a particular asset.

1. Cost of the asset The cost of the asset includes the invoice price of the asset, less any trade discount pius all costs essential to bring the asset to a useahie condition. It should be noted that financial charges, such as interest on money borrowed for the purchase of the asset, should not be included in the cost of the asset.

2. Estimated scrap value. The term scrap value means the residual or the salvage value which is estimated to be realised on account of the sale of the asset at the end of its useful life. In determining the scrap value, the cost to be incurred in the disposal or removing of the asset should be deducted out of the total realisable value.

3. Estimated useful life. This is also termed as economic lift of the asset. This may be calculated in terms of years, months, hours, units of output of other operating measures such as kilometers in case of a taxi or a truck.