Class 10

Samacheer Kalvi 10th English Vocabulary Phrasal Verb

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Attempt all english grammar practice sections covered in the Samacheer Kalvi 10th English Grammar Book and excel in reading, writing, and speaking english with great fluency.

Tamilnadu Samacheer Kalvi 10th English Vocabulary Phrasal Verb

Replace the underlined phrasal verb with a single word or vice versa in the following sentences.
Question 1.
The jailor could not make out who was trying to scale the compound wall as there was pitch darkness.
(a) to make (b) understand (c) to patch up (d) organise
Answer:
(b) understand

Question 2.
She put on her rain coat and went out in her scooter.
(a) weighed (b) took (c) wore (d) designed
Answer:
(c) wore

Samacheer Kalvi 10th English Vocabulary Phrasal Verb

Question 3.
It is the duty of sons/daughters to take care of parents in old age.
(a) right (b) box (c) hatch (d) safeguard
Answer:
(d) safeguard

Question 4.
Raja and Chandran finally saw eye to eye on the new business venture.
(a) agreement (b) faced each other (c) scorned (d) met
Answer:
(a) agreement

Question 5.
The party candidates got through with a thumping majority in the recent by-elections.
(a) had a tough time (b) escaped (c) succeed (d) illegal entry
Answer:
(c) succeed

Question 6.
The NGOs and Disaster management force pulled together to reach the relief supplies to the stranded people.
(a) pulled each other (b) managed (c) negotiated (d) worked harmoniously
Answer:
(b) managed

Question 7.
Drinking tells upon one’s health.
(a) is good for (b) ruins (c) advises (d) boosts
Answer:
(b) ruins

Question 8.
The Government pleader wanted the will in black and white and refused to accept the spoken words of the deceased.
(a) carbon paper (b) black pen (c) proof (d) photocopy
Answer:
(c) proof

Question 9.
The Prime Minister announced that the financial position will turn around within 50 days.
(a) become worse (b) diminish (c) change (d) improve/recover
Answer:
(d) improve/recover

Question 10.
The sons and son-in-law fell out over sharing the company’s profit.
(a) quarreled (b) fell down (c) fainted (d) were anxious
Answer:
(a) quarreled

Question 11.
Nirmala was at sea as Government buses did not operate in the whole city.
(a) making sand castle (b) ashore (c) confused (d) playful
Answer:
(c) confused

Samacheer Kalvi 10th English Vocabulary Phrasal Verb

Question 12.
Kumar spoke pointlessly irritating his fans.
(a) beat about the bush (b) blew his own trumpet (c) told a cock and bull story (d) moved heaven and earth
Answer:
(a) beat about the bush

Question 13.
Chasing wealth has become a common trait among many politicians now.
(a) run on (b) run down (c) running after (d) run around
Answer:
(c) running after

Question 14.
Socrates persuaded people to believe that those who knew what they did not know were wise.
(a) brought the people round (b) brought them home (c) drove home (d) ate their humble pie
Answer:
(a) brought the people round

Question 15.
It was difficult to restrain my tears on seeing the natural calamity in Japan devastating the lives of people.
(a) hold on (b) hold back (c) hold off (d) hold away
Answer:
(a) hold on

Question 16.
The boss turned down the union leaders’ demand for 11% bonus.
(a) dismissed (b) rejected (c) considered (d) fired
Answer:
(b) rejected

Question 17.
Priya complied with the instructions of the company.
(a) modified (b) neglected (c) was angered (d) agreed to
Answer:
(d) agreed to

Question 18.
Under the influence of magic mushroom, the college student talked through his hat.
(a) discussed (b) Spoke carelessly (c) talk nonsense (d) spoke looking above
Answer:
(c) talk nonsense

Question 19.
Rajalingam is a man of letters.
(a) thoughtful person (b) writes letters (c) scholar (d) reads letters
Answer:
(c) scholar

Question 20.
There is no hard and fast instructions to leave the slippers outside a library.
(a) proper (b) strict (c) necessary (d) advice
Answer:
(b) strict

Samacheer Kalvi 10th English Vocabulary Phrasal Verb

Question 21.
Laymen should never meddle with law.
(a) interfere with (b) play with (c) use (d) make
Answer:
(a) interfere with

Question 22.
Mistry burnt his fingers in the meger of two sinking steel plants in Africa.
(a) pointed his fingers (b) hurt his fingers (c) caught fire (d) incurred loss
Answer:
(d) incurred loss

Question 23.
Students are expected to discharge their duties towards themselves and to their parents.
(a) carry on (h) carry off (c) carry out (d) carry away
Answer:
(c) carry out

Question 24.
You must resist continuously to defend your right views.
(a) stand off (b) stand out (c) stand in (d) stand by
Answer:
(b) stand out

Question 25.
Students should know how to have a friendly relationship with their class.
(a) get up (b) get back (c) get on (d) get into
Answer:
(c) get on

Question 26.
I will discard these letters.
(a) throw out (b) throw off (c) take off (d) take up
Answer:
(a) throw out

Question 27.
The champion yielded to the strength of his opponent.
(a) gave on (b) gave back (c) gave in (d) gave up
Answer:
(c) gave in

Question 28.
He renounced his wealth and became a social worker.
(a) gave in (b) gave on (c) gave up (d) gave out
Answer:
(c) gave up

Samacheer Kalvi 10th English Vocabulary Phrasal Verb

Question 29.
Naresh wishes to die working.
(a) die in harness (b) die eating his words (c) laugh in his sleeves (d) take the cues
Answer:
(a) die in harness

Question 30.
Kabeer was rescued at the eleventh hour.
(a) initially (b) last-minute (c) on the cards (d) bolt from the blue
Answer:
(b) last minute

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Samacheer Kalvi 10th English Grammar Nominalisation

You can Download 10th samacheer kalvi english grammar with answers Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations. Attempt all english grammar practice sections covered in the Samacheer Kalvi 10th English Grammar Book and excel in reading, writing, and speaking english with great fluency.

Tamilnadu Samacheer Kalvi 10th English Grammar Nominalisation

Nominalisation is a function that not only helps you to create variety in your writing but also thwarts you from repeating the same verb/word over and over again. It can also make the text brief by packing a great deal of information into a few words. As a result of using nominalisation, your writing will be more formal. It is a noun phrase generated from another word class, usually a verb. (Other word classes include adjectives and nouns) In other words, the process of nominalisation turns verbs into nouns which may be things, concepts or people.

Samacheer Kalvi 10th English Grammar Nominalisation

Read the sentences below and identify which one contains a nominalised expression.
Question 1.
(a) The production of a mathematical formula by mathematics experts has explained the modem phenomena.
(b) Mathematics experts have produced a mathematical formula which explains the modem phenomena.
Answer:
(a) The production of a mathematical formula by mathematics experts has explained the modem phenomena.

Question 2.
(a) Student numbers are increasing drastically from year to year and the college is concerned.
(b) The drastic increase in student numbers causes concern at the college.
Answer:
(b) The drastic increase in student numbers causes concern at the college.

Question 3.
(a) The rise of Planet Earth’s temperature is a result of Global Warming.
(b) The temperature of the planet Earth is rising as a result of Global Warming.
Answer:
(b) The drastic increase in student numbers causes concern at the college.

Question 4.
(a) The indication of the statistical report that Sales figures are down by 15% on last month’s achievement is quite perturbing.
(b) The Statistical report indicates that the sales figures are down by 15% on last month is quite perturbing.
Answer:
(a) The indication of the statistical report that Sales figures are down by 15% on last month’s achievement is quite perturbing.

Samacheer Kalvi 10th English Grammar Nominalisation

Question 5.
(a) A thorough scrutiny of the medical reports by a team of doctors in the lab was done before writing their findings for treatment.
(b) A team of doctors thoroughly scrutinised the medical report in the lab before they wrote their findings for treatment.
Answer:
(a) A thorough scrutiny of the medical reports by a team of doctors in the lab was done before writing their findings for treatment.

Match the following items on the right to the items on the left and fill in the blanks in the given sentences with suitable nominalizations:

1 Analyse (a) indication
2 Participate (b) illustration
3 Deduce (c) implication
4 Invest (d) restriction
5 Reject (e) sustainable
6 Restrict (f) rejection
7 Illustrate (g) analysis
8 Indicate (h) investment
9 Implicate (i) deduction
10 Sustain (j) participation

Answer:
1. (g)
2. (f)
3. (i)
4. (b)
5. (f)
6. (d)
7. (b)
8. (a)
9. (c)
10. (c)

Samacheer Kalvi 10th English Grammar Nominalisation

Complete the following sentences using the noun form of the words given in brackets
1. A business trial needs ……………………….. (invest)
2. Cycling is a ……………………….. form of transport, (sustain)
3. His ……………………….. is highly persuasive, (analyse)
4. His ……………………….. helped him to solve the issue, (deduce)
5. His expression gave no ……………………….. of what was going on in his mind, (indication)
6. She suffered ……………………….. and cried in agony, (reject)
7. The ……………………….. is very interesting, (illustrate)
8. The ……………………….. took a while to sink in. (implicate)
9. The Management expected more ……………………….. from the PTA. (participate)
10. The park is open to the public without any ……………………….. (restrict)
Answer:
1. investment
2. sustainable
3. analysis
4. deduction
5. indication
6. rejection
7. illustration
8. implication
9. participation
10. restriction

Samacheer Kalvi 10th English Grammar Nominalisation

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Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements

You can Download Samacheer Kalvi 10th Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements

Samacheer Kalvi 10th Science Periodic Classification of Elements Textual Evaluation Solved

I. Choose the best answer.

Question 1.
The number of periods and groups in the periodic table are ____.
(a) 6, 16
(b) 7, 17
(c) 8, 18
(d) 7, 18.
Answer:
(d) 7, 48.

Question 2.
The basis of modern periodic law is:
(a) atomic number
(b) atomic mass
(c) isotopic mass
(d) number of neutrons
Answer:
(a) atomic number

Question 3.
_____ group contains the member of the halogen family.
(a) 17th
(b) 15th
(c) 18th
(d) 16th.
Answer:
(a) 17th

Question 4.
……….is a relative periodic property.
(a) atomic radii
(b) ionic radii
(c) electron affinity
(d) electronegativity
Answer:
(d) electronegativity

Question 5.
Chemical formula of rust is ____.
(a) FeO.xH2O
(b) FeO4.xH2O
(c) Fe2O3.xH2O
(d) FeO.
Answer:
(c) Fe2O3.xH2O

Question 6.
In the aluminothermic process the role of Al is ____.
(a) oxidizing agent
(b) reducing agent
(c) hydrogenating agent
(d) sulphurising agent.
Answer:
(b) reducing agent

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Question 7.
The process of coating the surface of metal with a thin layer of zinc is called:
(a) painting
(b) thinning
(c) galvanization
(d) electroplating
Answer:
(c) galvanization

Question 8.
Which of the following have inert gases 2 electrons in the outermost shell?
(a) He
(b) Ne
(c) Ar
(d) Kr.
Answer:
(a) He

Question 9.
Neon shows zero electron affinity due to:
(a) stable arrangement of neutrons
(b) stable configuration of electrons
(c) reduced size
(d) increased density
Answer:
(b) stable configuration of electrons

Question 10.
____ is an important metal to form an amalgam.
(a) Ag
(b) Hg
(c) Mg
(d) Al.
Answer:
(b) Hg

II. Fill in the blanks.

Question 1.
If the electronegativity difference between two bonded atoms in a molecule is greater than 1.7, the nature of bonding is ____.
Answer:
Ionic bond.

Question 2.
____ is the longest period in the periodical table.
Answer:
Sixth period.

Question 3.
______ forms the basis of modem periodic table.
Answer:
Atomic number.

Question 4.
If the distance between two Cl atoms in Cl2 molecule is 1.98 Å, then the radius of the Cl atom is ____.
Answer:
0.99 Å.

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Question 5.
Among the given species A, A+, and A, the smallest one in size is ______.
Answer:
A+.

Question 6.
The scientist who propounded the modem periodic law is ______.
Answer:
Henry Moseley.

Question 7.
Across the period, ionic radii ______ (increases,decreases)
Answer:
Decreases.

Question 8.
_______ and ______ are called inner transition elements.
Answer:
Lanthanides and Actinides.

Question 9.
The chief ore of Aluminium is ______.
Answer:
Bauxite (Al2O3.2H2O).

Question 10.
The chemical name of rust is ______.
Answer:
Hydrated ferric oxide.

III. Match the following.

Question 1.

1. Galvanisation (a) Noble gas elements
2. Calcination (b) Coating with Zn
3. Redox reaction (c) Silver-tin amalgam
4. Dental filling (d) Alumino thermic process
5. Group 18 elements (e) Heating in the absence of air

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

IV. True or False: (If false give the correct statement)

Question 1.
Moseley’s periodic table is based on atomic mass.
Answer:
False.
Correct Statement: Moseley’s periodic table is based on atomic number.

Question 2.
Ionic radius increases across the period from left to right.
Answer:
False.
Correct Statement: Ionic radius decreases across the period from left to right.

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Question 3.
All ores are minerals, but all minerals cannot be called as ores.
Answer:
True.

Question 4.
Al wires are used as electric cables due to their silvery – white colour.
Answer:
False.
Correct Statement: Al wires are used as electric cables due to their good conductor of electricity.

Question 5.
An alloy is a heterogeneous mixture of metals.
Answer:
False.
Correct Statement: An alloy is a homogenous mixture of metals.

V. Assertion and Reason:

Answer the following questions using the data given below.
(i) A and R are correct, R explains the A.
(ii) A is correct, R is wrong.
(iii) A is wrong, R is correct.
(iv) A and R are correct, R doesn’t explain A.

Question 1.
Assertion: The nature of bond in HF molecule is ionic
Reason: The electronegativity difference between H and F is 1.9.
Answer:
(i) A and R are correct, R explains the A.

Question 2.
Assertion: Magnesium is used to protect steel from rusting.
Reason: Magnesium is more reactive than iron.
Answer:
(i) A and R are correct, R explains the A.

Question 3.
Assertion: An uncleaned copper vessel is covered with a greenish layer.
Reason: copper is not attacked by alkali
Answer:
(iv) A and R are correct, R doesn’t explain A.

VI. Short Answer Questions.

Question 1.
A is a reddish-brown metal, which combines with O2 at < 1370 K gives B, a black coloured compound. At a temperature > 1370 K, A gives C which is red in colour. Find A, B and C with reaction.
Answer:
(i) Reddish brown metal (A) is copper.

(ii) (A) reacts with O2 at bleow 1370 K gives Copper (II) oxide (B), which is black in colour.
2Cu + O2 \(\xrightarrow [ 1370k ]{ below }\) 2CuO (Copper (II) oxide) (B).

(iii) (A) reacts with O2 at above 1370 K gives Copper (I) oxide (C), which is red in colour.
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 1

Question 2.
A is a silvery – white metal. A combines with O2 to form B at 800°C, the alloy of A is used in making the aircraft. Find A and B.
Answer:
(i) Silver – white metal (A) is Aluminium.

(ii) (A) combines with O2 to form aluminium oxide at 800°C.
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 2

(iii) Duralumin is the alloy of Al, which is used to make aircraft
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 3

Question 3.
What is rust? Give the equation for formation of rust.
Answer:
Rust is hydrated ferric oxide, Fe2O3.xH2O. It is formed when iron is exposed to moist air.
4 Fe + 3O2 + xH2O > 2Fe2O3.xH2O

Question 4.
State two conditions necessary for rusting of iron.
Answer:
Conditions for rusting of iron:

  • The presence of water and oxygen is essential for the rusting of iron.
  • Impurities in the iron, the presence of water vapour, acids, salts and carbon dioxide hasten to rust.
  • Pure iron does not rust in dry and CO2 free air. It also does not rust in pure water, free from dissolved salts.

VII. Long Answer Questions

Question 1.
(a) State the reason for the addition of caustic alkali to bauxite ore during purification of bauxite.
(b) Along with cryolite and alumina, another substance is added to the electrolyte mixture. Name the substance and give one reason for the addition.
Answer:
(a) Naturally, Bauxite is not soluble in normal solvents. Therefore the addition of caustic alkali to bauxite plays an important role while extraction of aluminium. Caustic alkali dissolves bauxite forming soluble sodium meta aluminate while impurities remain insoluble and precipitate as red mud.
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 4

(b) Along with cryolite and alumina, another substance is added to the electrolyte mixture is Fluorspar. Adding of fluorspar lowers the fusion temperature of the electrolyte.

Question 2.
The electronic configuration of metal A is 2, 8, 18, 1. The metal A when exposed to air and moisture forms B a green layered compound. A with conc. H2SO4 forms C and D along with water. D is a gaseous compound. Find A, B, C and D.
Answer:
(i) The electronic configuration of metal (A) is 2, 8, 18, 1. A is copper (Z = 29)

(ii) (A) Copper exposed to air and moisture forms green layered compound (B) that is a copper carbonate.
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 5

(iii) Copper (A) reacts with conc.H2SO4 to give copper sulphate (C) and Sulphur dioxide (D).
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 6

Question 3.
Explain the smelting process.
Answer:
Smelting (in a Blast Furnace): The charge consisting of roasted ore, coke and limestone in the ratio 8 : 4 : 1 is smelted in a blast furnace by introducing it through the cup and cone arrangement at the top. There are three important regions in the furnace.
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 7
(a) The Lower Region (Combustion Zone): The temperature is at 1500°C. In this region, coke bums with oxygen to form CO2 when the charge comes in contact with a hot blast of air.
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 8
It is an exothermic reaction since heat is liberated.

(b) The Middle Region (Fusion Zone): The temperature prevails at 1000°C. In this region, CO2 is reduced to CO.
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 9
Limestone decomposes to calcium oxide and CO2
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 10
These two reactions are endothermic due to absorption of heat. Calcium oxide combines with silica to form calcium silicate slag.
CaO + SiO2 → CaSiO3

(c) The Upper Region (Reduction Zone): The temperature prevails at 400°C . In this region carbon monoxide reduces ferric oxide to form a fairly pure spongy iron.
\(\mathrm{Fe}_{2} \mathrm{O}_{3}+3 \mathrm{CO} \stackrel{400^{\circ} \mathrm{C}}{\longrightarrow} 2 \mathrm{Fe}+3 \mathrm{CO}_{2}\)
The molten iron is collected at the bottom of the furnace after removing the slag.
The iron thus formed is called pig iron. It is remelted and cast into different moulds. This iron is called cast iron.

VIII. HOT Questions.

Question 1.
Metal A belongs to period 3 and group 13. A in red hot condition reacts with steam to form B. A with strong alkali forms C. Find A, B and C with reactions.
Answer:
(i) Metal (A) belongs to period 3 and group 13, is Aluminium (Al).

(ii) (A) Al in red hot condition reacts with steam to form Aluminium oxide (B).
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 11

(iii) Aluminium (A) reacts with strong alkali forms of sodium meta aluminate (C).
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 12

Question 2.
Name the acid that renders aluminium passive. Why?
Answer:
Dil. or cone. HNO3 does not attack aluminium, but renders Al passive due to the formation of oxide film on its surface.

Question 3.
(a) Identify the bond between H and F in the HF molecule.
(b) What property forms the basis of identification?
(c) How does the property7 vary in periods and in groups?
Answer:
(a) The nature of the bond in the HF molecule is ionic.
(b) Electronegativity.
(c) Along the period, from left to right in the periodic table the electronegativity increases because of the increase in the nuclear charge which in turn attracts the electrons more strongly. On moving down a group, the electronegativity of the elements decreases because of the increased number of energy levels.

Samacheer Kalvi 10th Science Periodic Classification of Elements Additional Questions Solved

I. Choose the best answer.

Question 1.
Which period contains only two elements?
(a) Second
(b) First
(c) Third
(d) Fifth.
Answer:
(b) First

Question 2.
The sixth period contains inner transition elements.
(a) 18
(b) 14
(c) 10
(d) 8
Answer:
(b) 14

Question 3.
Lanthanides and Actinides are called as _____.
(a) Alkali metals
(b) Inner transition elements
(c) Transition elements
(d) Representative elements.
Answer:
(b) Inner transition elements

Question 4.
The number of valence electrons present in Halogens is:
(a) One
(b) Seven
(c) Zero
(d) Two
Answer:
(b) Seven

Question 5.
The distance between the two hydrogen nuclei of the molecule is 0.74 Å. So its covalent radius is _____.
(a) 0.74 Å
(b) 0.99 Å
(c) 0.37 Å
(d) 7.4 Å.
Answer:
(c) 0.37 Å

Question 6.
Along the groups, atomic radius _____.
(a) decreases
(b) increases
(c) decreases then increase
(d) no change.
Answer:
(b) increases.

Question 7.
Which one of the following elements will have the highest electronegativity?
(a) chlorine
(b) nitrogen
(c) caesium
(d) fluorine
Answer:
(d) fluorine

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Question 8.
Electron affinity is measured in _____.
(a) kJ-1
(b) mol-1
(c) kJ/mol
(d) kJ/mol2.
Answer:
(c) kJ/mol

Question 9.
Noble gases have ______ electron affinity.
(a) positive
(b) negative
(c) zero
(d) high.
Answer:
(c) zero

Question 10.
The element with positive electron gain enthalpy is:
(a) Hydrogen
(b) Sodium
(c) Argon
(d) Fluorine
Answer:
(b) Sodium

Question 11.
The mineral from which a metal can be readily and economically extracted on a large scale is said to be a / an _____.
(a) Ore
(b) Flux
(c) Slag
(d) Gangue.
Answer:
(a) Ore

Question 12.
Flux + Gangue → _____?
(a) Mineral
(b) Matrix
(c) Slag
(d) Smog.
Answer:
(c) Slag

Question 13.
………… is used for anodizing process.
(a) Zinc
(b) iron
(c) Aluminium
(d) Tin
Answer:
(c) Aluminium

Question 14.
The ore which can be purified by gravity separation method is _____.
(a) Haematite
(b) oxide ores
(c) sulphide ores
(d) both (a) and (b).
Answer:
(d) both (a) and (b).

Question 15.
The calcium silicate slag is formed in ………. zone.
(a) combustion zone
(b) fusion zone
(c) reduction
(d) molten
Answer:
(b) fusion zone

Question 16.
Zinc blende is purified by _____.
(a) Hydraulic method
(b) Magnetic separation method
(c) Froth floatation method
(d) Chemical method.
Answer:
(c) Froth floatation method

Question 17.
Bauxite ore is purified by _____.
(a) Leaching process
(b) Hydraulic method
(c) Froth floatation method
(d) Magnetic separation method.
Answer:
(a) Leaching process

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Question 18.
When copper reacts with dil.HNO3 it liberates …………. gas.
(a) SO2
(b) NO2
(C) CO2
(d) NO
Answer:
(d) NO

Question 19.
Which metal process low melting point?
(a) Gallium
(b) Caesium
(c) Aluminium
(d) Copper.
Answer:
(a) Gallium

Question 20.
Which one of the following is not an ore of aluminium?
(a) Bauxite
(b) Haematite
(c) Cryolite
(d) Corundum.
Answer:
(b) Haematite

Question 21.
……….. is stored in Kerosene.
(a) Iron
(b) Silver
(c) Sodium
(d) Aluminium
Answer:
(c) Sodium

Question 22.
Electrolytic reduction of alumina into aluminium is ______.
(a) Hall’s process
(b) Alumino thermic process
(c) Baeyer’s process
(d) Bessemerisation process.
Answer:
(a) Hall’s process

Question 23.
In Hall’s process, cathode used is ______.
(a) Iron tank
(b) Graphite
(c) Pure alumina
(d) Iron tank linked with graphite.
Answer:
(d) Iron tank linked with graphite.

Question 24.
The metal oxides are usually……….. in nature.
(a) basic
(b) acidic
(c) amphoteric
(d) neither acidic nor basic
Answer:
(a) basic

Question 25.
A silvery-white metal is ______.
(a) Aluminium
(b) Copper
(c) Iron
(d) Zinc.
Answer:
(a) Aluminium

Question 26.
Aluminium reacts with NaOH to give ______.
(a) Al2O3
(b) AlCl3
(c) NaAlO2
(d) Al(OH)3
Answer:
(c) NaAlO2

Question 27.
Atoms of the elements belonging to the same group of periodic table will have:
(a) same number of protons
(b) same number of electrons in the valence shell
(c) same number of neutrons
(d) same number of electrons
Answer:
(b) same number of electrons in the valence shell

Question 28.
Chief ore of copper is ______.
(a) CuFeS2
(b) Cu2O
(c) Cu2S
(d) CuSO4
Answer:
(a) CuFeS2

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Question 29.
Molecular formula for copper pyrites ______.
(a) Cu2O
(b) Cu2S
(c) CuCO3
(d) CuFeS2
Answer:
(d) CuFeS2

Question 30.
The electronegativity of fluorine is:
(a) 4.0
(b) 3
(c) 2.8
(d) 2.1
Answer:
(a) 4.0

Question 31.
The second most abundant metal available next to aluminium is ______.
(a) Cu
(b) Ag
(c) Au
(d) Fe.
Answer:
(d) Fe.

Question 32.
Most important ore of iron is ______.
(a) Haematite
(b) Magnetite
(c) Iron pyrite
(d) Cryolite.
Answer:
(a) Haematite

Question 33.
The volatile impurities present in haematite are:
(a) Carbon and Nitrogen
(b) Oxygen and Nitrogen
(c) Helium and Oxygen
(d) Sulphur and Phosphorus
Answer:
(d) Sulphur and Phosphorus

Question 34.
The solute present in brass is:
(a) copper
(b) zinc
(c) tin
(d) magnesium
Answer:
(b) zinc

Question 35.
Which one of the following is used for making pressure cookers?
(a) Brass
(b) Magnalium
(c) Duralumin
(d) Nickel steel
Answer:
(c) Duralumin

Question 36.
Which is used as propeller?
(a) Stainless steel
(b) Nickel steel
(c) Brass
(d) Magnalium.
Answer:
(b) Nickel steel

Question 37.
Gold does not occur in the combined form. It does not react with air or water. It is in the ______ state.
(a) native
(b) combined
(c) complex
(d) molten.
Answer:
(a) native

Question 38.
Which of the following metal is not found in a free state?
(a) Ag
(b) Au
(c) Pt
(d) Al.
Answer:
(d) Al.

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Question 39.
Which one of the following does not react with copper?
(a) Oxygen
(b) Conc.H2SO4
(c) NaOH
(d) Conc.HNO3
Answer:
(c) NaOH

Question 40.
An element which is an essential constituent of all organic compounds belongs to ______ group.
(a) 14th
(b) 15th
(c) 16th
(d) 17th.
Answer:
(a) 14th

Question 41.
The highest ionization energy is exhibited by ______.
(a) Halogens
(b) Alkaline earth metals
(c) Transition metals
(d) Nobel gases.
Answer:
(d) Nobel gases.

Question 42.
Which two elements of the following belongs to the same period? (Al, Si, Ba, O).
(a) Si, Ba
(b) Al, Ba
(c) Al, Si
(d) Al, O.
Answer:
(c) Al, Si

Question 43.
98% pure copper and 2% impurities is called ______.
(a) Matte
(b) Copper pyrites
(c) blister copper
(d) cuprite.
Answer:
(c) blister copper

Question 44.
_____ is used in making anchors and electromagnets.
(a) Steel
(b) Pig iron
(c) Cast iron
(d) Wrought iron.
Answer:
(d) Wrought iron.

Question 45.
Which reagent does not react with iron?
(a) Conc. HNO3
(b) Conc.H2SO4
(c) Steam
(d) Dil. HNO3
Answer:
(a) Conc. HNO3

II. Fill in the blanks.

Question 1.
Matte is a mixture of ______.
Answer:
Cu2S + FeS.

Question 2.
Second group elements are called ______.
Answer:
Alkaline earth metals.

Question 3.
Ionisation energy is measured in _____ unit.
Answer:
kJ/mol

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Question 4.
The ionisation energy ______ along the period.
Answer:
Increases.

Question 5.
______ property, which predicts the nature of bonding between the atoms in a molecule.
Answer:
Electronegativity.

Question 6.
If the difference in electronegativity between two elements is 1.7, the bond has ____ and _____.
Answer:
50% ionic character, 50% covalent character.

Question 7.
If the difference in electronegativity between two elements is less than 1.7, the bond is considered to be ______.
Answer:
Covalent.

Question 8.
If the difference in electronegativity between two elements is greater than 1.7, the bond is considered to be ______.
Answer:
Ionic.

Question 9.
The process of extracting the ores from the earth’s crust is called ______.
Answer:
Mining.

Question 10.
______ is the main principle behind in Hydraulic method.
Answer:
Specific gravity.

Question 11.
Froth floatation process is preferable for ______ ores.
Answer:
Lighter
(or)
Sulphide.

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Question 12.
On heating in air, iron forms ______.
Answer:
Fe3O4

Question 13.
Iron reacts with Chlorine to form _____ compound.
Answer:
Ferric chloride.

Question 14.
The corrosive action in the absence of moisture is called ______.
Answer:
Dry corrosion.

Question 15.
______ technique used to renovate the Pamban bridge.
Answer:
Protective coating.

Question 16.
The atomic number is the number of ____ in the nucleus or number of ______ revolving around the nucleus in an atom.
Answer:
Protons, electrons.

Question 17.
The long form of periodic table is based upon the _____ of elements.
Answer:
Electronic configuration.

Question 18.
In the periodic table, the horizontal rows are called _____ and vertical columns are called ______.
Answer:
Periods, groups.

Question 19.
The modem periodic table has been divided into ______ blocks known as _______ blocks.
Answer:
Four, s, p, d, f

Question 20.
The ______ of the elements in a period decreases from left to right and the atomic radii of the elements present in a group downwards.
Answer:
Atomic size, increases.

Question 21.
_______ period is the longest period and it contains ______ elements.
Answer:
Seventh, 32.

Question 22.
In the periodic table, there are ______ groups and _____ periods.
Answer:
18, 7.

Question 23.
Metals like Ti, Cr, Mn, Zr find their application in the manufacturing of defence equipment called ______.
Answer:
Strategic metals.

Question 24.
The metal ______ plays a vital role in nuclear reactions releasing nuclear energy and used in nuclear weapons.
Answer:
Uranium.

Question 25.
Copper, silver and gold are called _______ as they are used in making ____ and ______.
Answer:
Coinage metals, coins and jewellery.

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Question 26.
Purity of gold is expressed in ______ and ______ is pure gold.
Answer:
Carats, 24 – carat gold.

Question 27.
_______ is an ore of aluminium and _____ is its mineral.
Answer:
Bauxite, clay.

Question 28.
All ______ cannot be called as ores but all ______ are minerals.
Answer:
Minerals, ores.

Question 29.
The process of extracting the ores from the earth’s crust is called ______.
Answer:
Mining.

Question 30.
The rocky impurity associated with the ore is called ____ or ______.
Answer:
Gangue, matrix.

Question 31.
_____ is a substance added to the ore to reduce the fusion temperature and to remove impurities.
Answer:
Flux.

Question 32.
____ is the process of reducing the roasted metallic oxide to metal.
Answer:
Smelting.

Question 33.
Slag is the fusible product formed when ____ reacts with ____ during the extraction of metals.
Answer:
Flux, gangue

Question 34.
The temperature applied in Hall’s process is _____ and the voltage used in ______.
Answer:
900 – 950°C, 5 – 6V

Question 35.
_____ is used in making manhole covers and drain pipes and _______ is used in making transmission cables and T.V. towers.
Answer:
Pig iron, steel.

Question 36.
______ is defined as the slow and steady destruction of a metal by the environment.
Answer:
Corrosion.

Question 37.
_______ is a process of coating zinc on iron sheets by using electric current.
Answer:
Galvanization.

III. Match the following.

Question 1.

i. Boron family (a) Group 17
ii. Carbon family (b) Group 16
iii. Nitrogen family (c) Group 13
iv. Chalcogen family (d) Group 15
v. Halogen family (e) Group 14

Answer:
i – c, ii – e, iii – d, iv – b , v – a.

Question 2.

i. Alkali metals (a) Lanthanides & Actinides
ii. Alkaline earth metals (b) Groups 3 – 12
iii. Transition elements (c) Group 2
iv. Inner transition elements (d) Group 1

Answer:
i – d, ii – c, iii – b, iv – a.

Question 3.

i. Group 18 (a) Main group elements
ii. Group 3 – 12 (b) Noble gases
iii. Group 13 – 18 (c) Halogens
iv. Group 17 (d) Transition elements

Answer:
i – b, ii – d, iii – a, iv – c.

Question 4.

i. Copper (a) Lustrous greyish white metal
ii. Iron (b) Cn 112
iii. Aluminium (c) Reddish-brown metal
iv. Copernicium (d) Silvery white metal

Answer:
i – c, ii – a, iii – d, iv – b.

Question 5.

Alloys Composition
i. Brass (a) Al, Mg, Mn, Cu
ii. Duralumin (b) Cu, Zn
iii. Bronze (c) Al, Mg
iv. Magnalium (d) Cu, Sn

Answer:
i – b, ii – a, iii – d, iv – c.

Question 6.

Elements Electronegative value
i. F (a) 2.5
ii. Cl (b) 2.8
iii. Br (c) 3.0
iv. I (d) 4.0

Answer:
i – d, ii – c, iii – b, iv – a.

Question 7.

Process Ores
i. Hydraulic process (a) ZnS
ii. Magnetic separation (b) Fe2O3
iii. Froth floatation process (c) SnO2
iv. Leaching process (d) Al2O3. 2H2O

Answer:
i – b, ii – c, iii – a, iv – d.

Question 8.

i. Cuprite (a) Halide ore
ii. Marble (b) Oxide ore
iii. Fluorspar (c) Sulphide ore
iv. Galena (d) Carbonate ore

Answer:
i – b, ii – d, iii – a, iv – c.

Question 9.

Alloy Metals present Uses
1. Brass Fe, C, Ni Statues, Coins
2. Bronze Al, Mg, Mn, Cu Aircraft, Pressure cookers
3. Duralumin Fe, C, Ni, Cr Cables, Propeller
4. Magnalium Cu, Sn Automobile parts, Utensils
5. Stainless steel Cu, Zn Scientific instruments, Air craft
6. Nickel steel Al, Mg Medals, decorative items

Answer:

Alloy Metals present Uses
1. Brass Cu, Zn Medals, decorative items
2. Bronze Cu, Sn Statues, Coins
3. Duralumin Al, Mg, Mn, Cu Aircraft, Pressure cookers
4. Magnalium Al, Mg Scientific instruments, Air craft
5. Stainless steel Fe, C, Ni, Cr Automobile parts, Utensils
6. Nickel steel Fe, C, Ni Cables, Propeller

Question 10.

Metal Ore Chemical formula
1. Copper Bauxite ZnCO3
2. Aluminium Haematite CuFeS2
3. Iron Copper pyrite Fe2O3
4. Zinc Calamine Al2O3.2H2O

Answer:

Metal Ore Chemical formula
1. Copper Copper pyrite CuFeS2
2. Aluminium Bauxite Al2O3.2H2O
3. Iron Haematite Fe2O3
4. Zinc Calamine ZnCO3

IV. State whether true or false. If false, give the correct statement.

Question 1.
First period contains only one element.
Answer:
False.
Correct Statement: First period contains two elements.(Hydrogen & Ftelium)

Question 2.
The valency of all alkali metals is one.
Answer:
True.

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Question 3.
Noble gases are more reactive.
Answer:
False.
Correct Statement: Noble gases are less reactive.

Question 4.
The atomic radius decreases from Li to B?
Answer:
True.

Question 5.
As the positive charge increases, the size of the cation also increases.
Answer:
False.
Correct Statement: As the positive charge increases, the size of the cation also decreases.

Question 6.
Copper pyrite ore is concentrated by gravity separation method.
False
Correct Statement: Copper pyrite ore is concentrated by froth floatation process.

Question 7.
Aluminium alloyed with gold and silver for making coins and jewels.
Answer:
False.
Correct Statement: Copper alloyed with gold and silver for making coins and jewels.

Question 8.
The corrosive action in the presence of moisture is called wet corrosion.
Answer:
True

Question 9.
The physical and chemical properties of elements are the periodic function of their atomic numbers – modern periodic law.
Answer:
True.

Question 10.
The long form of periodic table consists of horizontal rows called groups and vertical columns called periods.
Answer:
False.
Correct statement: The long form of periodic table consists of horizontal rows called periods and vertical columns called groups.

Question 11.
The first period in the periodic table is the shortest period and contains 8 elements from Lithium to Neon.
Answer:
False.
Correct statement: The first period in the periodic table is the shortest period and contains 2 elements Hydrogen and Helium.
(OR)
The second period in the periodic table is the short period and contains 8 elements from Lithium to Neon.

Question 12.
The sixth period in the periodic table is the longest period and contains 32 elements.
Answer:
True.

Question 13.
Group 1, 2 and 13 – 18 are called normal elements.
(or)
Main group elements.
(or)
Representative elements.
Answer:
True.

Question 14.
The atomic size of the elements in a period increases from left to right.
Answer:
False.
Correct statement: The atomic size of the elements in a period decreases from left to right.

Question 15.
In a period, the metallic character of the element increases while their non-metallic character decreases.
Answer:
False.
Correct statement: In a period, the metallic character of the element decreases while their non-metallic character increases.

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Question 16.
The last element authenticated by IUPAC is Cn 112 [Copemicium].
Answer:
True.

Question 17.
Silver was the first metal to be used in making utensils and weapons.
Answer:
False.
Correct statement: Copper was the first metal to be used in making utensils and weapons.

Question 18.
The strategic metals such as copper, silver and gold are used in the manufacturing of defence equipment.
Answer:
False.
Correct statement: The strategic metals such as titanium, chromium manganese, zirconium are used in the manufacturing of defence equipment.

Question 19.
Copper, silver and gold are called coinage metals.
Answer:
True.

Question 20.
For making ornaments, 24 – carat gold is used which is pure gold.
Answer:
False.
Correct statement: For making ornaments, 22 – carat gold is used which contains 22 parts of gold by weight and 2 parts of copper by weight.

Question 21.
The mineral from which a metal can be readily and economically extracted on a large scale is said to be ore.
Answer:
True.

Question 22.
The rocky impurity associated with the ore is called flux.
Answer:
False.
Correct statement: The rocky impurity associated with the ore is called gangue or matrix.

Question 23.
Slag is the fusible product formed when flux reacts with gangue during the extraction of metals.
Answer:
True.

Question 24.
Metals which have high chemical reactivity are found in a free state or in the native state.
Answer:
False.
Correct statement: Metals which have low chemical reactivity are found in a free state or in the native state.

Question 25.
Aluminium is the metal found most abundantly in the earth’s crust.
Answer:
True

Question 26.
Aluminium is a reddish-brown metal and it is a bad conductor of heat and electricity.
Answer:
False.
Correct statement: Aluminium is a silvery – white metal and it is a good conductor of heat and electricity.

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Question 27.
Aluminium reacts with strong caustic alkalis forming aluminates.
Answer:
True

Question 28.
Conc. Nitric acid renders aluminium active due to the formation of nitride film on its surface.
Answer:
False.
Correct statement: Cone. Nitric acid renders aluminium passive due to the formation of oxide film on its surface.

Question 29.
Aluminium is a powerful reducing agent.
Answer:
True.

Question 30.
Duralumin alloy is light, having high tensile strength and corrosion-resistant.
Answer:
True.

Question 31.
Fe and Al2O3 are used in thermite welding.
Answer:
False.
Correct statement: Al powder and Fe2O3 is used in thermite welding.

Question 32.
The chief ore of copper is Ruby copper.
Answer:
False.
Correct statement: The chief ore of copper is copper pyrite.

Question 33.
Iron is a lustrous greyish white metal and can be magnetised.
Answer:
True.

Question 34.
The rust has the chemical formula as Fe3O4.
Answer:
False.
Correct statement: The rust has the chemical formula as Fe2O3. xH2O.

V. Assertion and Reason.

Question 1.
Assertion (A): Nobel gas is unreactive.
Reason (R): They have unstable electronic configuration in their valence shells.
(a) Both (A) and (R) are correct
(b) Both (A) and (R) are not correct
(c) (A) is correct but (R) is wrong
(d) (A) is wrong but (R) is correct.
Answer:
(c) (A) is correct but (R) is wrong

Question 2.
Assertion (A): The nature of bond in NaI molecule is covalent.
Reason (R): The electronegativity difference between Na and I is 1.5
(a) Both (A) and (R) are correct
(b) Both (A) and (R) are not correct
(c) (A) is correct but (R) is wrong
(d) (A) is wrong but (R) is correct.
Answer:
(a) Both (A) and (R) are correct

Question 3.
Assertion (A): Haematite ore was purified by Hydraulic method.
Reason (R): Haematite is oxide ore.
(a) Both (A) and (R) are correct
(b) Both (A) and (R) are wrong
(c) (A) is correct but (R) is wrong
(d) (A) is wrong but (R) is correct.
Answer:
(a) Both (A) and (R) are correct

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Question 4.
Assertion (A): Corundum is a chief ore of aluminium.
Reason (R): Molecular formula of Corundum is Al2O3
(a) (A) and (R) are correct, (R) explains the (A)
(b) (A) is correct, (R) is wrong
(c) (A) is wrong, (R) is correct
(d) (A) and (R) are correct, (R) doesn’t explain (A).
Answer:
(c) (A) is wrong, (R) is correct

Question 5.
Assertion (A): The chemical properties of the elements in the same period are not similar.
Reason (R): As the electronic configuration changes across the period, the chemical properties of the elements are not similar.
(a) Both (A) and (R) are correct
(b) Both (A) and (R) are not correct
(c) (A) is correct but (R) is wrong
(d) (A) is wrong but (R) is correct.
Answer:
(a) Both (A) and (R) are correct

Question 6.
Assertion (A): Copper, Silver and Gold are used in making coins and jewellery. So they are called coinage metals.
Reason (R): These metals release an enormous amount of nuclear energy.
(a) Both (A) and (R) are correct
(b) Both (A) and (R) are wrong
(c) (A) is correct but (R) is wrong
(d) (A) is wrong but (R) is correct.
Answer:
(c) (A) is correct but (R) is wrong

Question 7.
Assertion (A): Metals like Titanium, Chromium, Manganese and Zirconium are called strategic metals!
Reason (R): They find their applications in the manufacturing of defence equipment.
(a) Both (A) and (R) are correct
(b) Both (A) and (R) are wrong
(c) (A) is correct but (R) is wrong
(d) (A) is wrong but (R) is correct.
Answer:
(a) Both (A) and (R) are correct

Question 8.
Assertion (A): Gold, Silver and Platinum are the metals that are found in a free state.
Reason (R): Those metals have low chemical reactivity and are found in a free state or in the native state.
(a) Both (A) and (R) are wrong
(b) Both (A) and (R) are correct
(c) (A) is correct but (R) is wrong
(d) (A) is wrong but (R) is correct.
Answer:
(b) Both (A) and (R) are correct

Question 9.
Assertion (A): Aluminium occurs in the combined state.
Reason (R): It is a reactive metal and so it occurs in combined state.
(a) Both (A) and (R) are correct
(b) Both (A) and (R) are wrong
(c) (A) is correct but (R) is wrong
(d) (A) is wrong but (R) is correct.
Answer:
(a) Both (A) and (R) are correct

Question 10.
Assertion (A): In the aluminothermic process, Iron oxide is reduced to iron by igniting with Aluminium powder.
Reason (R): Aluminium is a powerful reducing agent.
(a) Both (A) and (R) are wrong
(b) (A) is correct but (R) is wrong
(c) (A) is wrong but (R) is correct
(d) Both (A) and (R) are correct.
Answer:
(d) Both (A) and (R) are correct

Question 11.
Assertion (A): When iron is dipped in conc.HNO3 it becomes chemically inert (or) passive.
Reason (R): Iron becomes passive when treated with nitric acid is due to the formation of a layer of iron oxide Fe3O4 on its surface.
(a) Both (A) and (R) are correct
(b) (A) is correct but (R) is wrong
(c) (A) is wrong but (R) is correct
(d) Both (A) and (R) are wrong.
Answer:
(d) Both (A) and (R) are wrong

Question 12.
Assertion (A): Duralumin is used in making aircraft, tools and pressure cookers.
Reason (R): Duralumin is an alloy that is light, strong, resistant to corrosion.
(a) Both (A) and (R) are wrong
(b) Both (A) and (R) are correct
(c) (A) is correct but (R) is wrong
(d) (A) is wrong but (R) is correct.
Answer:
(b) Both (A) and (R) are correct

Question 13.
Assertion (A): Nickel steel is used in making cables, aircraft parts and propeller.
Reason (R): Nickel steel alloy is hard, brittle and polishable.
(a) Both (A) and (R) are correct
(b) Both (A) and (R) are wrong
(c) (A) is correct but (R) is wrong
(d) (A) is wrong but (R) is correct.
Answer:
(c) (A) is correct but (R) is wrong

Question 14.
Assertion (A): Magnesium is used in a sacrificial protection method to prevent corrosion.
Reason (R): Magnesium is more reactive than iron. When it is coated on the articles made of steel, it sacrifices itself to protect steel.
(a) Both (A) and (R) are correct
(b) Both (A) and (R) are wrong
(c) (A) is correct but (R) is wrong
(d) (A) is wrong but (R) is correct.
Answer:
(a) Both (A) and (R) are correct

Question 15.
Assertion (A): Electroplating method not only protects but also enhances the metallic appearance.
Reason (R): Electroplating is a method of coating one metal with another by passing current.
(a) (A) is right, (R) is wrong
(b) (A) is right, (R) is not relevant
(c) (A) is right, (R) is relevant
(d) Both (A) and (R) are wrong.
Answer:
(c) (A) is right, (R) is relevant

VI. Short Answer Questions.

Question 1.
State modern periodic law.
Answer:
Modem periodic law states that the physical and chemical properties of elements are the periodic function of their atomic numbers.

Question 2.
Write the flow chart of the long form of the periodic table.
Answer:
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 13

Question 3.
The distance between the adjacent copper atoms in solid copper is 2.56 Å. Calculate what is the metallic radius of Cu?
Answer:
Metallic radius of copper = \(\frac{2.56}{2}\) = 1.28 Å

Question 4.
Briefly write any four characteristics of a group in the periodic table.
Answer:

  • The elements present in a group have the same valency.
  • The elements present in a group have identical chemical properties.
  • The physical properties of the elements in the group very gradually.
  • The atomic radii of die elements present in a group increase downwards.

Question 5.
What is the principle behind Froth floatation?
Answer:
This process depends on the preferential wettability of the ore with oil (pine oil) and the gangue particles by water. Lighter ores, such as sulphide ores, are concentrated by this method. Eg: Zinc blende (ZnS).

Question 6.
What are minerals?
Answer:
A mineral may be a single compound or a complex mixture of various compounds of metals found in the earth, e.g. Clay Al2O3. 2SiO2. 2H2O is the mineral of Aluminium.

Question 7.
Write the increasing order of radii of the following species.
(a) Na, Na+, Cl, Cl
(b) Li, Na, K, Rb
Answer:
(a) Na+, Cl, Na, Cl
(b) Li, Na, K, Rb

Question 8.
Differentiate ore and mineral.
Answer:

Ore Mineral
1. Ores contain a large percentage of metal. 1. Minerals contain a low percentage of metal.
2. Ores can be used for die extraction of metals on a large scale readily and economically. 2. Metals cannot be extracted easily from minerals.
3. Bauxite Al2O3. 2H2O is the ore of aluminium. 3. Clay Al2O3.2SiO.2H2O is the mineral of aluminium.

Question 9.
Define metallurgy.
Answer:
The various steps involved in the extraction of metals from their ores as well as refining of crude metals are collectively known as metallurgy.

Question 10.
Elements a, b, c and d have the following electronic configurations
(a) ls2 2s² 2p6
(b) Is², 2s², 2p6, 3s², 3p1
(c) Is², 2s², 2p6, 3s², 3p6
(d) Is², 2s², Ip1
Answer:
(a) and (c), (b) and (d). Because the number of valence electrons are the same.

Question 11.
What is slag? Give an example.
Answer:
Slag is a fusible product formed when flux reacts with gangue during the extraction of metals.
Flux + gangue → slag
CaO + SiO2 → CaSiO3

Question 12.
Why the electron affinities of noble gases are zero?
Answer:
Noble gases show no tendency to accept electrons because the outer 5 and p orbitals of noble gases are completely filled. No more electrons can be added to them and hence their electron affinities are zero.

Question 13.
Why does gold, silver and platinum occur in free state?
Answer:
Gold, silver and platinum have low chemical reactivity and so they are found in the free state or in a native state.

Question 14.
How does Aluminium reacts with air?
Answer:
Reaction with air: It is not affected by dry air. On heating at 800°C, aluminium bums very brightly forming it’s oxide and nitride.
4Al + 3O2 → Al2O3(Aluminium oxide)
2Al + N2 → 2 AlN (Aluminium nitride)

Question 15.
How does Aluminium react with caustic soda? Give an equation.
Answer:
Aluminium reacts with caustic soda to give sodium meta aluminate with the liberation of H2 gas.
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 14

Question 16.
Prove that aluminium is a powerful reducing agent.
Answer:
Aluminium is a powerful reducing agent When a mixture of aluminium powder and iron oxide is ignited, iron oxide is reduced to iron. This process is known as the aluminothermic process.
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 15

Question 17.
Write a note on Aluminothermic process.
Answer:
As reducing agent: Aluminium is a powerful reducing agent. When a mixture of aluminium powder and iron oxide is ignited, the latter is reduced to metal. This process is known as aluminothermic process.
Fe2O3 + 2Al → 2Fe + Al2O3 + heat

Question 18.
What is the action of heat on copper?
Answer:
On heating at different temperatures in the presence of oxygen, copper forms two types of oxides CuO, Cu2O.
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 16

Question 19.
Explain the action of dilute nitric acid with copper.
Answer:
Copper reacts with dil.HNO3 with the liberation of Nitric oxide gas.
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 17

Question 20.
What happens when copper is treated with conc.HNO3 and with conc.H2SO4?
Answer:
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 18

Question 21.
What do you mean by Ferrous and Non-Ferrous alloys? Given an example for each.
Answer:
Ferrous alloys : Contain iron as a major component.
Eg: Stainless steel, Nickel steel

Non-Ferrous alloys : These alloys do not contain iron as a major part.
Eg: Aluminium alloy, Copper alloy.

Question 22.
Explain the action of air with iron.
Answer:
3Fe + 2O2 → Fe3O4 [Magnetic oxide (Black)].

Question 23.
What are amalgams? How are they prepared?
Answer:
An amalgam is an alloy of mercury with another metal.
Amalgams are formed by the metallic bonding with the electrostatic force of attraction between the electrons and the positively charged metal ions.

Question 24.
Explain the action of steam with iron.
Answer:
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 19

Question 25.
Mention the types of iron on the basis of carbon content.
Answer:

Pig iron Iron with 2 – 4.5% carbon
Wrought iron Iron with < 0.25% carbon
Steel Iron with 0.25 – 2% carbon

Question 26.
What is dry corrosion or chemical corrosion?
Answer:
The corrosive action in the absence of moisture is called dry corrosion. It is the process of a chemical attack on a metal by corrosive liquids or gases such as O2, N2, SO2, H2S etc… It occurs at high temperature, of all the gases mentioned above O2 is the most reactive gas to impart the chemical attack.

Question 27.
What is an amalgam? Give one example with its use.
Answer:

  • An amalgam is an alloy of mercury with metals such as sodium, gold and silver.
  • Dental amalgam is an alloy of mercury with silver and tin and it is used in the dental filling.

Question 28.
Explain sacrificial protection.
Answer:
Magnesium is more reactive than iron. When it is coated on the articles made of steel, it sacrifices itself to protect steel.

Question 29.
Define corrosion.
Answer:
Corrosion is defined as the slow and steady destruction of a metal by the environment. It results in the deterioration of the metal to form metal compounds by means of chemical reactions with the environment.
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 20

Question 30.
What is the action of Air and moisture on copper?
Answer:
Copper gets covered with a green layer of basic carbonate in the presence of CO2 and moisture.
2 Cu + O2 + CO2 + H2O → CUCO3.CU(OH)2

Question 31.
Give any two uses of aluminium.
Answer:

  • Aluminium metal is a corrosion – resistant and a good conductor of heat. So it is used in making utensils.
  • Aluminium is used in welding as thermite and a very good reducing agent.

Question 32.
What is the modern periodic table?
Answer:
The modem periodic table is a tabular arrangement of elements in rows and columns, highlighting the regular repetition of properties of the elements.

Question 33.
Explain the smelting process of iron in the Blast furnace.
Answer:
The charge consisting of roasted ore, coke and limestone in the ratio 8 : 4 : 1 is smelted in a blast furnace by introducing it through the cup and cone arrangement at the top.

Question 34.
What are the periodic properties?
Answer:
Properties such as atomic radius, ionic radius, ionisation energy, electronegativity, electron affinity, show a regular periodicity and hence they are called periodic properties.

Question 35.
Define Atomic radius.
Answer:
The atomic radius of an atom is defined as the distance between the centre of its nucleus and the outermost shell containing the valence electron.

Question 36.
Write the action of dil.HCl and dil.H2SO4 with iron.
Answer:
(i) Fe + 2HCl → FeCl2 + H2
(ii) Fe + H2SO4 → FeSO4 + H2

Question 37.
What is a covalent radius?
Answer:
It is defined as half the distance between the nuclei of two covalently bonded atoms of the same element in a molecule.

Question 38.
Define Ionisation energy.
Answer:
Ionisation energy is the minimum energy required to remove an electron from a gaseous atom in its ground state to form a cation.

Question 39.
What is an alloy?
Answer:
An alloy is a homogeneous mixture of two or more metals or of one or more metals with certain non-metallic elements. The properties of alloys are often different from the component metals.

SamacheerKalvi.Guru

Question 40.
What is Electronegativity?
Answer:
Electronegativity of an element is the measure of the tendency of its atom to attract the shared pair of electrons towards itself in a covalent bond.

Question 41.
Write the steps involved in metallurgical process.
Answer:
A metallurgical process involves three main steps as follows:

  • Concentration or Separation of the ore: It is the process of removal of impurities from the ore.
  • Production of the metal: It is the conversion of the ore into metal.
  • Refining of the metal: It is the process of purification of the metal.

Question 42.
Give a single term for each of the following:
(i) The process of extracting the ores from the Earth’s crust is called:
Answer:
Mining

(ii) The rocky impurities associated with an ore is called:
Answer:
Gangue or matrix

(iii) The substance added to the ore to reduce fusion temperature:
Answer:
Flux

(iv) Noble metals occur in this state:
Answer:
Native

Question 43.
How will you convert copper into copper carbonate?
Answer:
Copper reacts with oxygen in the presence of CO2 and moisture to give copper carbonate.
2Cu + O2 + CO2 + H2O → CuCO3. Cu(OH)2 (Copper Carbonate).

Question 44.
Mention the uses of iron.
Answer:
Uses of iron:

  1. Pig iron (Iron with 2 – 4.5 % of carbon): It is used in making pipes, stoves, radiators, railings, manhole covers and drain pipes.
  2. Steel (Iron with < 0.25 % of carbon): It is used in the construction of buildings, machinery, transmission cables and T.V towers and in making alloys.
  3. Wrought iron (Iron with 0.25 – 2 % of wrought carbon): It is used in making springs, anchors and electromagnets.

Question 45.
What are the chemical properties of metals in terms of

  1. valence electrons
  2. Atomicity.

Answer:

  1. Valence electrons: Metals usually have 1, 2 or 3 electrons in their outermost shell.
  2. Atomicity: Metals are usually monoatomic in their vapour state.

Question 46.
Why alloys are said to solid solutions?
Answer:
Alloys can be considered solid solutions in which the metal with high concentration is solvent and other metals are solute.
Example: brass is a solid solution of zinc (solute) in copper (solvent).

Question 47.
Write a note on Dry corrosion.
Answer:

  • The corrosive action in the absence of moisture is called dry corrosion.
  • It is the process of a chemical attack on a metal by corrosive liquids or gases such as O2, N2, SO2, H2S etc. in which O2 is more reactive.
  • It occurs at high temperature

Question 48.
Explain Wet Corrosion.
Answer:

  • The corrosive action in the presence of moisture is called wet corrosion.
  • It occurs as a result of the electrochemical reaction of metal with water or an aqueous solution of salt or acids or bases.

Question 49.
What is electroplating?
Answer:
Electroplating is a method of coating one metal over another metal by passing an electric current.

VII. Long Answer Questions.

Question 1.
Explain the variation of ionisation energy along the group and period.
Answer:

  • As the atomic size decreases from left to right in a period, more energy is required to remove the electrons. So, the ionisation energy increases throughout the period.
  • Down the group, the atomic size increases and hence the valence electrons are loosely bound. They require relatively less energy for the removal. Thus, ionisation energy decreases down the group in the periodic table.

Question 2.
Explain the electrolytic refining of copper.
Answer:
(i) Blister copper contains 98% of pure Cu and 2 % of impurities and is purified by electrolytic refining.
For electrolytic refining of Cu we use:
Cathode: A thin plate of pure Cu.
Anode: A block of impure Cu
Electrolyte: CuSO4 + dil H2SO4

(ii) When electric current is passed through the electrolytic solution, Pure Cu gets deposited at the cathode and the impurities settle at the bottom of the anode in the form of anode mud.

Question 3.
Explain Gravity separation method.
Answer:
Gravity Separation (or) Hydraulic method:
1. Principle: The difference in the densities or specific gravities of the ore and the gangue is the main principle behind this method. Oxide ores are purified by this method,
e.g., Haematite Fe2O3 the ore of iron.

2. Method: The ore is poured over a sloping, vibrating corrugated table with grooves and a jet of water is allowed to flow over it. The denser ore particles settle down in the grooves and lighter gangue particles are washed down by the water.

Question 4.
Discuss the magnetic separation methods.
Answer:
Magnetic separation method:
Principle: The magnetic properties of the ores from the basis of separation. When either the ore or the gangue is magnetic, this method is employed, e.g., Tinstone SnO2, the ore of tin.
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 21
Method: The crushed ore is placed over a conveyer belt which rotates around two metal wheels, one of which is magnetic. The magnetic particles are attracted to the magnetic wheel and fall separately apart from the nonmagnetic particles.

Question 5.
Explain the froth floatation process.
Answer:
Froth floatation Process:
Principle: This process depends on the preferential wettability of the ore with oil (pine oil) and the gangue particles by water. Lighter ores, such as sulphide ores, are concentrated by this method, e.g., Zinc blende (ZnS).
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 22
Method: The crushed ore is taken in a large tank containing oil and water and agitated with a current of compressed air. The ore is wetted by the oil and gets separated from the gangue in the form of froth. Since the ore is lighter, it comes on the surface with the froth and the impurities are left behind, e.g., Zinc blende (ZnS).

Question 6.
How will you extract aluminium from its ore?
Answer:
The extraction of aluminium from bauxite involves two steps:
(i) Conversion of bauxite into alumina – Baeyer’s Process
The conversion of Bauxite into Alumina involves the following steps:
Bauxite ore is finely ground and heated under pressure with a solution of concentrated caustic soda solution at 150° C to obtain sodium metal aluminate.
On diluting sodium meta aluminate with water, a precipitate of aluminium hydroxide is formed.
The precipitate is filtered, washed, dried and ignited at 1000°C to get alumina.
\(2 \mathrm{Al}(\mathrm{OH})_{3} \stackrel{1000^{\circ} \mathrm{C}}{\longrightarrow} \mathrm{Al}_{2} \mathrm{O}_{3}+3 \mathrm{H}_{2} \mathrm{O}\)

(ii) Electrolytic reduction of alumina – Hall’s Process
Aluminium is produced by the electrolytic reduction of fused alumina (Al2O3) in the electrolytic cell.
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 23
Cathode: Iron tank linked with graphite
Anode: A bunch of graphite rods suspended in a molten electrolyte.
Electrolyte: Pure alumina + molten cryolite + fluorspar (fluorspar lowers the fusion temperature of electrolyte)
Temperature: 900 – 950°C
The voltage used: 5 – 6 V
Aluminium is deposited at the cathode and oxygen gas is liberated at the anode. Oxygen combines with graphite to form CO2.

Question 7.
Explain the extraction of copper from copper pyrites.
Answer:
Extraction of copper from copper pyrites involves the following steps:
(i) The concentration of ore: The ore is crushed and then concentrated by froth floatation process.

(ii) Roasting: The concentrated ore is roasted in excess of air. During the process of roasting, the moisture and volatile impurities are removed. Sulphur, phosphorus, arsenic and antimony are removed as oxides. Copper pyrite is partly converted into sulphides of copper and iron.
\(2 \mathrm{CuFeS}_{2}+\mathrm{O}_{2} \rightarrow \mathrm{Cu}_{2} \mathrm{S}+2 \mathrm{FeS}+\mathrm{SO}_{2} \uparrow\)

(iii) Smelting: The roasted ore is mixed with powdered coke and sand and is heated in a blast furnace to obtain matte (Cu2S + FeS) and slag. The slag is removed as waste.

(iv) Bessemerisation: The molten matte is transferred to the Bessemer converter in order to obtain blister copper. Ferrous sulphide from matte is oxidized to ferrous oxide, which is removed as slag using silica.
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 24

(v) Refining: Blister copper contains 98% of pure copper and 2% of impurities and is purified A by electrolytic refining. This method is used to get metal of a high degree of purity. For electrolytic refining of copper, we use:
Cathode: A thin plate of pure copper metal.
Anode: A block of impure copper metal.
Electrolyte: Copper sulphate solution acidified with sulphuric acid.
When an electric current is passed through the electrolytic solution, pure copper gets deposited at the cathode and the impurities settle at the bottom of the anode in the form of sludge called anode mud.

Question 8.
Explain the metallurgy of iron.
Answer:
Iron is chiefly extracted from haematite ore (Fe2O3):
(i) Concentration by Gravity Separation: The powdered ore is washed with steam of water. As a result, the lighter sand particles and other impurities are washed away and the heavier ore particles settle down.

(ii) Roasting and Calcination: The concentrated ore is strongly heated in a limited supply of air in a reverberatory furnace. As a result, moisture is driven out and sulphur, arsenic and phosphorus impurities are oxidized off.

(iii) Smelting (in a Blast Furnace): The charge consisting of roasted ore, coke and limestone in the ratio 8 : 4 : 1 is smelted in a blast furnace by introducing it through the cup and cone arrangement at the top. There are three important regions in the furnace.
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 25
a. The Lower Region (Combustion Zone):
The temperature is at 1500°C. In this region, coke bums with oxygen to form CO2 when the charge comes in contact with a hot blast of air.
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 26
It is an exothermic reaction since heat is liberated.

b. The Middle Region (Fusion Zone):
The temperature prevails at 1000°C. In this region, CO2 is reduced to CO.
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 27
Limestone decomposes to calcium oxide and CO2
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 28
These two reactions are endothermic due to absorption of heat. Calcium oxide combines with silica to form calcium silicate slag.
CaO + SiO2 → CaSiO3

c. The Upper Region (Reduction Zone): The temperature prevails at 400°C. In this region carbon monoxide reduces ferric oxide to form a fairly pure spongy iron.
\(\mathrm{Fe}_{2} \mathrm{O}_{3}+3 \mathrm{CO} \stackrel{400^{\circ} \mathrm{C}}{\longrightarrow} 2 \mathrm{Fe}+3 \mathrm{CO}_{2}\)
The molten iron is collected at the bottom of the furnace after removing the slag.
The iron thus formed is called pig iron. It is remelted and cast into different moulds. This iron is called cast iron.

Question 9.
Explain the types of alloys.
Answer:
Based on the presence or absence of Iron, alloys can be classified into:
1. Ferrous alloys: Contain Iron as a major component.
A few examples of ferrous alloys are Stainless Steel, Nickel Steel etc.

2. Non – ferrous alloys: These alloys do not contain Iron as a major component.
For example, Aluminium alloy, Copper alloy etc.
Copper Alloys (Non – ferrous):

Alloys Uses
Brass (Cu, Zn) Electrical fittings, medal, decorative items, hardware
Bronze (Cu, Sn) Statues, coins, bells, gongs

Aluminium Alloys (Non – ferrous):

Alloys Uses
Duralumin (Al, Mg, Mn, Cu) Aircraft tools, pressure cookers
Magnalium (Al, Mg) Aircraft, scientific instruments

Iron Alloys(Ferrous):

Alloys Uses
Stainless steel (Fe, C, Ni, Cr) Utensils, cutlery, automobile parts
Nickel steel (Fe, C, Ni) Cables, aircraft parts, propeller

VIII. HOT Questions.

Question 1.
What would be the atomic number of the next

  1. alkali metal
  2. alkaline earth metal
  3. Halogens
  4. inert gas, if discovered in future.

Answer:

  1. Alkali metal: 118 + 1 = 119
  2. Alkaline earth metal: 120
  3. Halogens: 117
  4. Inert gas: 118

Question 2.
Explain the mechanism of rusting?
Answer:
Rust is chemically known as hydrated ferric oxide (it is formulated as Fe2O3.xH2O).
Rusting results in the formation of scaling reddish – brown hydrated ferric oxide on the surface of iron and iron-containing materials.
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 29

Question 3.
All ores are minerals, but ait minerals are not ores. Why?
Answer:

  • The elements or compounds of the metals which occur in nature in the earth’s crust are called minerals whereas ore is a mineral from which the metal is profitably extracted.
  • For example, aluminium exists in the two mineral forms, that is clay and bauxite. But aluminium is mainly extracted from bauxite which contains 70 % aluminium oxide. So, bauxite is an ore of aluminium whereas clay is not ore.
  • So, all ores are minerals but all minerals need not be ores.

Question 4.
Why the graphite rods acting as anode in the Hall’s process should be replaced periodically?
Answer:
During Hall’s Process, the carbon electrodes get consumed, so they have to be replaced periodically.

Question 5.
Anionic radius Is higher than the corresponding neutral atom. Give reason.
Answer:
When an atom gains one or more electrons it forms an anion. During the formation of anion, the number of orbital electrons becomes greater than the nuclear charge. Hence, the electrons are not strongly attracted by the lesser number of nuclear charges. Hence anionic radius is higher than the corresponding neutral atom.

Question 6.
A reddish – brown metal A, when exposed to moist air, forms a green layer B. When A is heated at different temperatures in the presence of O2, it forms two types of oxides – C (black) and D (red). Identify A, B, C, D and write the balanced equation.
Answer:
(i) A reddish – brown metal A is a copper (Cu).

(ii) When copper (A) is exposed to moist air it forms a green layer (B) is copper carbonate.
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 30
(iii) When copper is heated at different temperature in the presence of oxygen, it forms two types of oxides CuO and Cu2O. (C and D)
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 31

Question 7.
A silvery – white metal on treatment with NaOH and HCl liberates H2 gas to form B and C respectively. The metal A will not react with acid D due to the formation of a passive film on the surface. Hence it is used for transporting acid D. Identify A, B, C, D and support your answer with balanced equations.
Answer:
(i) A silvery – white metal (A) is Aluminium (Al).
(ii) Aluminium reacts with NaOH to form B which is known as sodium meta aluminate with the liberation of H2 gas.
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 32
(iii) Aluminium reacts with HCl to form Aluminium chloride which is known as C with the liberation of H2 gas.
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 33
(iv) Aluminium does not react with conc. nitric acid (HNO3) which is known as D, due to the formation of a passive film on the surface.

A Aluminium Al
B Sodium meta aluminate NaAlO2
C Aluminium chloride AlCl3
D Nitric acid HNO3

Question 8.
Metal A belongs to period 4 and group 8. A in red hot condition reacts with steam to form B. A reacts with dilute HNO3 to give C. A again reacts with conc. H2SO4 to give D. Find A, B, C and D with suitable reaction.
Answer:
(i) Metal (A) belongs to period 4 and group 8 is iron (Fe).

(ii) Iron (A) reacts with steam to form magnetic oxide (B)
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 34

(iii) Iron (A) reacts with dilute HNO3 in cold condition to give ferrous nitrate (C).
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 35

(iv) Iron (A) reacts with conc.H2SO4 to form Ferric Sulphate (D).
Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements 36

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Samacheer Kalvi 10th English Grammar Modals

You can Download Samacheer Kalvi 10th English Grammar with Answers Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations. Attempt all english grammar practice sections covered in the Samacheer Kalvi 10th English Grammar Book and excel in reading, writing, and speaking english with great fluency.

Tamilnadu Samacheer Kalvi 10th English Grammar Modals

General Characteristics Of Modals
1. Modals are never used alone. A Principal verb is either present or implied;
as—
I can sing. He will help you.

2. Modals do not change according to the number or person of the subject;
as—
I can. We can. You can. He can. They can. etc.
I may. We may. You may. He may. They may. etc.

Samacheer Kalvi 10th English Grammar Modals

3. Modals have no Infinitive, Present Participle or Past Participle forms.
4. Modals cannot be used in all the tenses. When a modal does not fall in this pattern, it works as a Principal Verb;
as—
God willed so.
Heiny needs a pen.
Malathi dared to go into the dark forest.
(Here will, need and dare are used as main verbs)

Relationship of Modals with Tenses
(i) May, can, shall and will are in present forms while might, could, should and would are their past forms.
The two forms express different meanings, but usually no difference of time, e.g. the difference between may and might is often that of degree of probability,

as—
Sheela may come today. (possibility/likely to happen)
Sandra might come today. (remote possibility/less likely)

(ii) However, if the verb in the main clause is in the past tense, the forms might, could, should and would serve as regular past tenses;

as—

  1. He said, “I can help you.”
    He said that he could help her.
  2. You said, “She will come back soon.”
    You said that she would come back soon.
  3. Sheetal said, “May I use this pen, madam?”
    Sheetal asked her teacher if she might use that pen.

(iii) When we want to express the past time in verb phrases involving modals, we use the Present Perfect Tense of the Principal Verb;
as-
Senthil must have reached home by now.
You ought to have told me all the facts.

Samacheer Kalvi 10th English Grammar Modals

Quasi / Semi Modals
Quasi modals are also called semi-modals. There are four quasi modals: ‘used to’, ‘need to’, ‘dare to’ and ‘ought to’.

Fill in the blanks choosing the correct modal given within the brackets to suit the sentence.
1. They ……………………….. (can/might) be away for the weekend but I’m not sure.
2. You ……………………….. (may/might) leave now if you want to.
3. ……………………….. (Could/Might) you open the door a bit, please?
4. He ……………………….. (can/could) be a Bengali, judging by his accent.
5 ……………………….. (May/Can) you play the violin?
6. Listen, carefully, you (may not/might not) ……………………….. speak during this exam.
7. They ……………………….. (can’t/may not) still be out!
8. You ……………………….. (mustn’t/might not) smoke on the bus.
9. With luck, tomorrow ……………………….. (can/could) be a rainy day.
10. You (can/might) ……………………….. be right but I’m going back to check anyway.
11. I don’t know Hindi and so I ……………………….. (must/should) learn before I go to Delhi.
12. ……………………….. you stand upside down for a minute? No, I (can’t/could)
13. You ……………………….. leave small objects lying around. Children swallow it by mistake, (shouldn’t /may)
14. This is a public place. You ……………………….. (must/should) not smoke.
15. ……………………….. (May/Can) I ask a question?
16. He had been toiling for the past fifteen hours. He ……………………….. (must/should) be exhausted.
17. Drivers ……………………….. (must/should) stop the vehicle when they see the red signal.
18. According to the weather forecast, it ……………………….. (will/may) rain tomorrow.
19. Please try to reach the venue before me. I ……………………….. (will/may) be late.
20 ……………………….. (Could/Would) you mind lifting this box for me?
21. Anyone ……………………….. (can/could) come for a trial but it was up to Sir to decide who to accept.
22. Ajit was called aside and suggested that he ……………………….. (must/should) bring me back when I was a little older.
23. My induction into the Mumbai cricket circuit ……………………….. (could/may) have ended in failure.
24. I was delighted and I ……………………….. (must/should) say it was an opportunity that transformed my life.
25. The schedule was rigorous and Sachin ……………………….. (must/would) be exhausted by the end of the day.
26. I am sure that Zigzag ……………………….. (must/should) be Uncle Somu’s pet snake.
27. Some ……………………….. (might/can) be your best friend, but most of them were absolute nuisances!
28. You ……………………….. (may/can’t) deny that it was a great hit with everyone.
29. ……………………….. (Can/May) I take Zigzag to school, Papa?
30. He ……………………….. (can/could) even recite French Poetry!
Answer:
1. might 2. may 3. Could 4. could 5. Can 6. may not 7. can’t 8. mustn’t 9. could 10. might
11. must 12. Could/can’t 13. shouldn’t/may 14. must 15. May 16. must 17. should 18. will 19. may 20. Would
21. could 22. should 23. could 24. must 25. would 26. must 27. might 28. can’t 29. May. 30. can

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Samacheer Kalvi 10th English Vocabulary Clipped Words

You can Download Samacheer Kalvi 10th English Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Attempt all english grammar practice sections covered in the Samacheer Kalvi 10th English Grammar Book and excel in reading, writing, and speaking english with great fluency.

Tamilnadu Samacheer Kalvi 10th English Vocabulary Clipped Words

Some examples of clipped words

1. aeroplane plane
2. agriculture Agri
3. alchemist chemist
4. alumni/alumna alum
5. amend mend
6. apollinaris Polly
Samacheer Kalvi 10th English Vocabulary Clipped Words
7. automobile auto
8. beautiful beauty
9. biology bio
10. botany bot
11. brassiere bra
12. brother bro
13. burst bust
14. buttocks butt
15. cablegram cable
16. cafeteria cafe
17. calculus calc
18. cellphone cell
19. centum cent
20. champion champ
21. chemistry chem
22. chimpanzee chimp
23. cleric clerk
24. coattails tails
25/ coca-cola / cocaine coke
26. coeducational coed
27. comprehensive comp
28. condominium condo
29. co-operative co-op
30. cousin cous
31. cucumber cuke
32. daddy dad
33. daily paper daily
34. delicatessen / delicacy deli
35. dental / dentistry dent
36t, detective tec
37. differential diff
Samacheer Kalvi 10th English Vocabulary Clipped Words
38. disport sport
39. distill still
40. doctor doc
41. dormitory dorm
42. drapery drape
43. earthquake quake
44. ecology eco
45. electronic mail e-mail
46. enthusiasm enthu
47. examination exam
48. fabulous fab
49. faggot fag
50. fraternity frat
51. gabble gab
52. gasoline gas
53. gentleman gent
54. graduate grad
55. Gypsy gyp
56. hackney hack
57. head-shrinker shrink
58. hippopotamus hippo
59. homosexual homo
60. information info
61. internet net
62. jet aircraft jet
63. laboratory lab
64. lavatory lav
65. limousine limo
66. literature lit
Samacheer Kalvi 10th English Vocabulary Clipped Words
67. lubricate lube
68. luncheon lunch
69. mathematics maths
70. maximum max
71. medical medic
72. memorandum memo
73. mistress miss
74. mobile vulgus mob
75. modem mod
76. mommy mom
77. motorcar car
78. moving picture movie
79. non-vegetarian non-veg
80. oleomargarine margarine
81. parachute chute
82. parole d’honneur parole
83. penitentiary pen
88. photograph photo
89. pianoforte piano
90. popular pop
91. president pres
92. professional pro
93. professor prof
94. promenade prom
95. psychology psych
96. public house pub
97. pugnacious pug
98. pyjamas jams / jammies
99. quadrangle / quadraphonic quad
100. raccoon coon
101. referee/reference ref
Samacheer Kalvi 10th English Vocabulary Clipped Words
102. refrigerator fridge
103. representative rep
104. revolution / reverend rev
105. rhinoceros rhino
106. robot bot
107. saxophone sax
108. schizophrenic schizo
109. scramble scram
110. squadron squad
111.. specifications specs
112. statistics stats
113. sweat suit sweats
114. synchronise sync
115. teacher teach
116. technical tech
117. teenager teen
118. telephone phone
119. television tele
120. trigonometry trig
121. triumph trump
122. trombone bone
123. turnpike pike
124. tuxedo tux
125. tympani tymps
126. universal joint U joint
127. university varsity
128. vegetarian veg
129. veteran / veterinarian vet
130. website web
131. zoological garden zoo

Samacheer Kalvi 10th English Vocabulary Clipped Words

Unclipped Words

1. vet veterinarian
2. typo typographical error
3. taxi taxicab
4. sub submarine
5. sopho sophomore
6. pop music popular music
7. mike microphone
8. perm permanent wave
9. sci-fi science fiction
10. car carriage
11. mum chrysanthemum
12. croc crocodile
Samacheer Kalvi 10th English Vocabulary Clipped Words
13. deb debutante
14. curio curiosity
15. fax facsimile
16. iron flatiron
17. pant pantaloon
18. burger hamburger
19. ID identification
20. recap recapitulate
21. mart market
22. gym gymnasium
23. mini minimum
24. stereo stereophonic

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Samacheer Kalvi 10th English Vocabulary Singular & Plural Forms

You can Download Samacheer Kalvi 10th English Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations. Attempt all english grammar practice sections covered in the Samacheer Kalvi 10th English Grammar Book and excel in reading, writing, and speaking english with great fluency.

Tamilnadu Samacheer Kalvi 10th English Vocabulary Singular & Plural Forms

Question 1.
The plural form of ‘matrix’ is ………………………………. .
Answer:
matrices

Question 2.
The plural form of “criterion” is ………………………………. .
Answer:
criteria

Samacheer Kalvi 10th English Vocabulary Singular & Plural Forms

Question 3.
The plural form of “series” is ………………………………. .
Answer:
series

Question 4.
The plural form of ‘lady’ ………………………………. .
Answer:
ladies

Question 5.
The plural form of ‘erratum’ is ………………………………. .
Answer:
errata

Question 6.
The plural form of ‘cupful’ ………………………………. .
Answer:
cupfuls/cupsful

Question 7.
The plural form of ‘deer’ is ………………………………. .
Answer:
deer/deers

Question 8.
The plural form of ‘innings’ ………………………………. .
Answer:
innings

Question 9.
The plural form of ‘curriculum’ ………………………………. .
Answer:
curricula

Question 10.
The plural form of ‘medium’ ………………………………. .
Answer:
media

Question 11.
The plural form of ‘abyss’ ………………………………. .
Answer:
abysses

Question 12.
The plural form of ‘sister-in-law’ ………………………………. .
Answer:
sisters-in-law

Question 13.
The plural form of ‘ aquarium’ ………………………………. .
Answer:
aquaria

Question 14.
The plural form of ‘ arch ’ ………………………………. .
Answer:
arches

Question 15.
The plural form of ‘chateau’ ………………………………. .
Answer:
chateaux

Samacheer Kalvi 10th English Vocabulary Singular & Plural Forms

Question 16.
The plural form of ‘cod’ ………………………………. .
Answer:
cod

Question 17.
The plural form of ‘crisis’ ………………………………. .
Answer:
crises

Question 18.
The plural form of ‘hoax’ ………………………………. .
Answer:
hoaxes

Question 19.
The plural form of ‘foot’? ………………………………. .
Answer:
feet

Question 20.
The plural form of ‘oasis’ ………………………………. .
Answer:
oases

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Samacheer Kalvi 10th English Vocabulary Abbreviations and Acronyms

You can Download Samacheer Kalvi 10th English Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Attempt all english grammar practice sections covered in the Samacheer Kalvi 10th English Grammar Book and excel in reading, writing, and speaking english with great fluency.

Tamilnadu Samacheer Kalvi 10th English Vocabulary Abbreviations and Acronyms

1. AAA Amateur Athletic Association
2. AAFI Amateur Athletic Federation of India
3. ACR Annual Confidential Report
4. ADC Aide-de-camp (Assistant)
5. AFI Athletics Federation of India
6. AFMC Armed Forces Medical College
7. AICTE All India Council for Technical Education
8. AIFF All India Football Federation
9. AITUC All India Trade Union Congress
10. ANC African National Congress
11. AOC Air Officer Commanding
12. ASAP As Soon As Possible
13. ASEAN Association of South East Asian Nations
14. ASLV Augmented Satellite Launch Vehicle
15 ASSOCHAM

Samacheer Kalvi 10th English Vocabulary Abbreviations and Acronyms

Associated Chambers of Commerce and Industry of India
16. ATC Air Traffic Control
17. ATM Automated Teller Machine
18. ATR Action Taken Report
19. ATS Anti Tetanus Serum
20. AWACS Airborne Warning and Control Systems
21. AMIE Associate Member of the Institute of Engineers
22. AIR All India Radio
23. AIDS Acquired Immuno Deficiency Syndrome
24. AIIMS All India Institute of Medical Sciences
25. BA Bachelor of Arts
26. BARC Bhabha Atomic Research Centre
27. BBC British Broadcasting Corporation
28. BCCI Board of Cricket Control in India
29. B.Ed. Bachelor of Education
30. BHEL Bharat Heavy Electricals Limited
31. BIOS Basic Input Output System
32. BMA British Medical Association
33. BPCL Bharat Petroleum Corporation Limited
34. BS Bachelor of Science
35. BS British Standard
36. BSNL Bharat Sanchar Nigam Limited
37. CAD
Samacheer Kalvi 10th English Vocabulary Abbreviations and Acronyms
Computer-Aided Design
38. CAG Comptroller and Auditor General of India
39. CAT Common Aptitude Test
40. CBI Central Bureau of Investigation
41. CDAC Centre for the Development of Advanced Computing
42. CEO (a)Chief Educational Officer (b)Chief Executive Officer
43. CFC Chlorofluorocarbon
44. CFL Compact Fluorescent Lamps
45. CFO Chief Financial Officer
46. CGST Central Goods and Services Tax
47. CIA Central Intelligence Agency
48. CID Criminal Investigation Department
49. CIS Commonwealth of Independent States
50. CISF Central Industrial Security Force
51. CLRI Central Leather Research Institute
52. CNN Cable News Network
53. COD Cash On Delivery
54. COPRA Consumer Protection Act
55 CPI Communist Party of India
56. CPU Central Processing Unit
57. CPWD Central Public Works Department
58. CRPF Central Reserve Police Force
59. CRY Child Relief and You
60. CSIR Council of Scientific and Industrial Research
61. CSO Central Statistical Organisation
62. CTBT Comprehensive Test Ban Treaty
63. CVC Central Vigilance Commission
64. DA
Samacheer Kalvi 10th English Vocabulary Abbreviations and Acronyms
Dearness Allowance
65. DARE Documentation Automatic Retrieval Equipment
66. DC Deputy Commissioner
67. DIG Deputy Inspector General
68. DNA Deoxyribo Nucleic Acid
69. DoT Department of Telecommunications
70. DPEP District Primary Education Programme
71. DRDO Defence Research and Development Organisation
72. DSLR Digital Single Lens Reflex
73. DTH Direct-to-Home
74. DTP Desk Top Publishing
75. DVD Digital Video Disc
76. ELISA Enzyme-Linked Immuno-Sorbent Assay
77. EMI Equated Monthly Installment
78. EPABX Electronic Private Automatic Branch Exchange
79. ESA European Space Agency
80. ESMA Essential Services Maintenance Act
81. EWS Economically Weaker Section
82. FAO Food and Agricultural Organisation
83. FBI Federal Bureau of Investigation
84. FDI Foreign Direct Investment
85. FERA Foreign Exchange Regulation Act
86. FIFA Federation International de Football Association
87. FIR First Information Report
88. FRCS Fellow of the Royal College of Surgeons
89. FRS Fellow of the Royal Society
.90. FTCL Fellowship Trinity College of London
91. GAME Global Energy Water Cycle Asian Monsoon Experiment
92. GATE Graduate Aptitude Test in Engineering
93. GATT General Agreement on Tariffs and Trade
94. GMT Greenwich Mean Time
95. GPO General Post Office
96. GPS Global Positioning System
97. GRE Graduate Record Examination
98. GSI Geological Survey of India
99. GSLV Geo-Synchronous Satellite Launch Vehicle
100. GST Goods and Services Tax
101. HIV Human Immunodeficiency Virus
102. HRD
Samacheer Kalvi 10th English Vocabulary Abbreviations and Acronyms
Human Resource Development
103. HTML Hyper Text Mark-up Language
104. HTTP Hyper Text Transfer Protocol
105. IAAI International Airport Authority of India
106. IAEA International Atomic Energy Agency
107. IAS Indian Administrative Service
108. ICAR Indian Council for Agricultural Research
109. ICBM Inter Continental Ballistic Missile
110. ICMR Indian Council of Medical Research
111. ICS Indian Civil Service
112. ICSE Indian Certificate of Secondary Education
113. ICT Information and Communication Technology
114. IDBI Industrial Development Bank of India
115. IELTS International English Language Testing System
116. IFS Indian Forest Service
117. IFSC Indian Financial System Code
118. IIM Indian Institute of Management
119. IIT Indian Institute of Technology
120. IMD India Meteorological Department
121. IMF International Monetary Fund
122. INA Indian National Army
123. INSAT Indian National Satellite
124. IPKF Indian Peace Keeping Force
125. IPL Indian Premier League
126. IPS Indian Police Service
127. IREP The Integrated Rural Energy Programme
128. IRS Indian Revenue Service/ Indian Remote Sensing Satellite
129. ISP Internet Service Provider
130. ISRO Indian Space Research Organisation
131. 1ST Indian Standard Time
132. IVP Intravenous Push
133. JD Juris Doctor
134. JRF Junior Research Fellowship
135. KVIC Khadi and Village Industries Commission
136. LBW Leg Before Wicket
137. LCM Lowest Common Multiple
138. LoC Line of Control
139. LPG Liquefied Petroleum Gas
140. LTCL Licentiateship Trinity College of London
141. MA Master of Arts
142. MCA Master of Computer Applications
143. MD Managing Director
144. M.Ed Master of Education
145. MLA Member of the Legislative Assembly
146. MLC Member of the Legislative Council
147. MLF Multi-Lateral Funding
148. M.Phil. Master of Philosophy
149. MRTS Mass Rapid Transit System
150. MS Master of Surgery
151. MTC Metro Transport Corporation
152. NASA National Aeronautics and Space Administration
153. NATo North Atlantic Treaty Organization
154. NBT National Book Trust
155. NCERT National Council of Educational Research and Training
156. NCO Non-Commissioned Officer
157. NCTE National Council for Teacher Education
158. NDDB
Samacheer Kalvi 10th English Vocabulary Abbreviations and Acronyms
National Dairy Development Board
159. NEET National Eligibility-cum-Entrance Test
160. NGO Non-Governmental Organisation
161. NIC National Informatics Centre
162. NIFT National Institute of Fashion Technology
163. NLC Neyveli Lignite Corporation
164. NOC No Objection Certificate
165. NPCIL Nuclear Power Corporation of India Limited
166. NPT Nuclear Non-Proliferation Treaty
167. NSC National Savings Certificate
168. NSE National Stock Exchange
169. NTA National Testing Agency
170. NTPC National Thermal Power Corporation
171. NTSE National Talent Search Examination
172. ODI One Day International / Open Datalink Interface
173. ODS Ozone Deleting Substances
174. OIGS On India Government Service
175. ONGC Oil and Natural Gas Corporation
176. OPAC Online Public Access Catalogue
177. OPEC Organisation of Petroleum Exporting Countries
178. PA Personal Assistant
179. PAC Public Accounts Committee
180. PAN Permanent Account Number
181. PDA Personal Digital Assistant
182. PERT Project Evaluation and Review Technique
183. PETA People for Ethical Treatment of Animals
184. PIL Public Interest Litigation
185. PIN Postal Index Number
186. POTA Prevention of Terrorism Act
187. POW Prisoner of War
188. PRO Public Relations Officer
189. PSLV Polar Satellite Launch Vehicle
190. PSU Public Sector Units
191. PTA Parents Teachers Association
192. PTI Press Trust of India
193. PTO Please Turn Over
194. PWD Public Works Department
195. RAC Reservation Against Cancellation
196. RAM Random Access Memory
197. RAW Research and Analysis Wing
198. RLWL Remote Location Wait List
199. RTE Right To Education
200. RTI Right To Information
201. RTO Regional Transport Officer
202. SAARC South Asian Association for Regional Cooperation
203. SAIL Steel Authority of India Limited
204. SAM Surface to Air Missile
205. SARS Severe Acute Respiratory Syndrome
206. SASE Self Addressed Stamped Envelope
207. SBI State Bank of India
208. SEZ Special Economic Zone
209. SGST State Goods and Services Tax
210. SIM Subscriber Identity Module
211. SMS Short Message Service
212. ‘SPCA Society for the Prevention of Cruelty to Animals
213. SSC Staff Selection Commission
214. START Strategic Arms Reduction Treaty
215. SWOT Strength, Weakness, Opportunity, and Threat
216. TADA Terrorist and Disruptive Activities
217. TAPS
Samacheer Kalvi 10th English Vocabulary Abbreviations and Acronyms
Tarapur Atomic Power Station
218. TELCO Tata Engineering and Locomotive Company
219. TESMA Tamilnadu Essential Services Maintenance Act
220. TISCO Tata Iron and Steel Company
221. TLC Total Literacy Campaign
222 TNEB Tamil Nadu Electricity Board
223 TNPSC Tamil Nadu Public Service Commission
224. TOEFL Test of English as a Foreign Language
225. TPS Thermal Power Station
226. TQM Total Quality Management
227. TT(E)I Traveling Ticket Examiner/ Inspector
228. TTTI Technical Teachers Training Institute
229. UDC Upper Division Clerk
230. UFO Unidentified Flying Objects
231. UGC University Grants Commission (India)
232. ULFA United Liberation Front of Asom/Assam
233. UNICEF United Nations International Children’s Emergency Fund
234. UNO United Nations Organisation
235. UPSC Union Public Service Commission
236. uv Ultra Violet
237. VAO Village Administrative Officer
238. VAT Value Added Tax
239. VHF Very High Frequency
240. VHS Video Home System / Voluntary Health Services
241. VIP Very Important Person
242. VPP Value Payable Post
243. VSNL Videsh Sanchar Nigam Limited
244. WHO World Health Organisation
245. Wi-Fi Wireless Fidelity
246. WTO World Trade Organisation
247. WWW World Wide Web
248. YMCA Young Men’s Christian Association
249. YWCA Young Women’s Christian Association
250. ZIP Zone Improvement Plan

SamacheerKalvi.Guru

Contractions

“Am/Are” Samacheer Kalvi 10th English Vocabulary Abbreviations and Acronyms “Here is/has” Here’s Who would/had Who’d
I am I’m One is/has One’s That would/had That’d
You are You’re “Will (Or Shall)” “Us” Samacheer Kalvi 10th English Vocabulary Abbreviations and Acronyms
We are We’re I will I’ll Let us Let’s
They are They’re You will You’ll “Not”
Who are Who’re She will She’ll Cannot Can’t
“Have” He will He’ll Do not Don’t
I have I’ve It will It’ll Is not Isn’t
You have You’ve We will We’ll Will not Won’t
We have We’ve They will They’ll Should not Shouldn’t
They have They’ve That will That’ll Could not Couldn’t
Could have Could’ve There will There’ll Would not Wouldn’t
Would have Would’ve This will This’ll Are not Aren’t
Should have Should’ve What will What’ll Does not Doesn’t
Might have Might’ve Who will Who’ll Was not Wasn’t
Who have Who’ve “Would, Had” Were not Weren’t
There have There’ve I would/had – I’d Has not Hasn’t
“Is, Has” Samacheer Kalvi 10th English Vocabulary Abbreviations and Acronyms You would/had You’d Have not Haven’t
He is/has He’s He would/had He’d Had not Hadn’t
She is/has She’s She would/had She’d Must not Mustn’t
It is/has It’s We would/had We’d Did not Didn’t
What is/has What’s They would/had They’d Might not Mightn’t
That is/Has That’s It would/had It’d Need not Needn’t
Who is/has Who’s There would/had There’d
There is/has There’s What would/had What’d Samacheer Kalvi 10th English Vocabulary Abbreviations and Acronyms

Samacheer Kalvi 10th English Vocabulary Abbreviations and Acronyms Read More »

Samacheer Kalvi 10th English Vocabulary Slang Expressions

You can Download Samacheer Kalvi 10th English Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations. Attempt all english grammar practice sections covered in the Samacheer Kalvi 10th English Grammar Book and excel in reading, writing, and speaking english with great fluency.

Tamilnadu Samacheer Kalvi 10th English Vocabulary Slang Expressions

Give the correct expression for the highlighted slang like expression:
1. I am gonna speed up my work.
2. Do you wanna join us to Ooty next week?
3. Whatcha going to do?
4. D’ya wanna come?
5. Can you gimme a hand?
6. She hasn’t gotta penny.
7. She’s kinda cute.
8. Please lemme be informed without fail.
9. Who saw ya?
10. You ain’t my boss.
11. I ain’t your boss.
12. He ain’t your boss.
13. I ain’t done it.
14. She is sorta tired.
15. We hafta go immediately.
16. I dunno if its all that good.
17. Dontcha know it?
18. I’m outta country next month.
19. Ya needa know ‘bout it.
20. I coulda come.
Answer:
1. going to 2. want to 3. What are you 4. Do you want to 5. give me
6. got a 7. kind of 8. let me 9. you 10. aren’t
11. am not 12. isn’t 13. haven’t 14. sort of 15. have to 16. don’t know
17. Don’t you 18. out of 19. You need to, about 20. could have

Samacheer Kalvi 10th English Vocabulary Slang Expressions

Observe the following Slang expressions and fill in the blanks given below.

1. Bee’s knees (someone who loves themselves)
2. dough (related to money)
3. telly (television)
4. Beeb (British Broadcasting Corporation)
5. Skiving (avoiding work or school)
6. dossing (lazing around doing nothing)
7. Killing me (really hurting)
8. Chap (a man) Samacheer Kalvi 10th English Vocabulary Slang Expressions
9. Bits and bobs (collection of small things/bits and pieces)
10. Nicked (stolen)
11. Dodgy (unreliable)
12. Chuffed (well pleased)
13. Ace (excellent)
14. Veg (vegetables)
15. Sarnie (food-related slang word/sandwich)
16. bickie (a biscuit or a chocolate biscuit)
17. Miffed (annoyed)
18. Kip (short sleep or nap)
19. Arm and a leg (extremely expensive)
20. Stuffed (unable to eat more) Samacheer Kalvi 10th English Vocabulary Slang Expressions

1. “Oh no! They have …………………….. petrol from my motorbike!”
2. All this routine work is ……………………..
3. Almost every day, my mom gives us …………………….. for breakfast.
4. Beverley and Sharon are …………………….. today to watch the IPL match.
5. Chandan is a bit of a …………………….. character.
6. Come on, Beno, stop …………………….. around and get some work done.
7. He thinks he’s the ……………………..
8. I am broke and not one …………………….. I have in hand.
9. Iam not too sure if I met this …………………….. the other day.
10. I don’t think I can have the dessert, I’m already ……………………..
11. I have only had an hour’s ……………………..
12. I need to keep track of the updates on ……………………..
13. Mithwin was really …………………….. at his birthday present.
14. My friend gave me a …………………….. when I was really hungry.
15. Our family counts on …………………….. for more accurate weather forecast.
16. Select your favorite fruit or …………………….. and pickle them while they are still fresh.
17. Silvi is an …………………….. singer.
18. There was a large collection of tools and other to …………………….. look at.
19. These shoes cost me ……………………..
20. We were a bit …………………….. about the news report on bombing at Srilanka.
Answer:
1. nicked 2. killing me 3. sarnie 4. skiving 5. dodgy
6. dossing 7. Bee’s knee 8. dough 9. chap 10. stuffed
11. kip 12. telly 13. chuffed 14. bickie 15. beep 16. veg
17. ace 18. bits and bobs 19. arm and a leg 20. miffed

Samacheer Kalvi 10th English Vocabulary Slang Expressions

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Samacheer Kalvi 10th English Vocabulary Confusables & Homophones

You can Download Samacheer Kalvi 10th English Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Attempt all english grammar practice sections covered in the Samacheer Kalvi 10th English Grammar Book and excel in reading, writing, and speaking english with great fluency.

Tamilnadu Samacheer Kalvi 10th English Vocabulary Confusables & Homophones

Homophones are one of the groups of words pronounced alike but differ in meaning and spelling or both. (e.g.) carat,
carrot; week, weak and hear, here.
Rewrite the following sentences by using the correct homophones for the underlined words:

Samacheer Kalvi 10th English Vocabulary Confusables & Homophones

Question 1.
He did not here any foot steps.
Answer:
He did not hear any foot steps.

Question 2.
Gita met her old classmate on her weigh to the ATM.
Answer:
Gita met her teacher on her wav to the ATM.

Question 3.
Ice cream with brownie was served as desert.
Answer:
Ice cream was served as dessert.

Question 4.
The old lady took wrest for an hour.
Answer:
The old lady took rest for an hour.

Question 5.
Tirupathi is a grate pilgrim spot.
Answer:
Tirupathi is a great pilgrim spot.

Question 6.
Never pause unhealthy comments.
Answer:
Never pass unhealthy comments.

Question 7.
My mom wood be pleased to help you during this festival time.
Answer:
My mom would be pleased to help you during this festival time.

Question 8.
You are not aloud inside the room.
Answer:
You are not allowed inside the room.

Question 9.
There was a cheque dam in Holland.
Answer:
There was a check dam in Holland.

Question 10.
If Himalayan eves disappear, few states will suffer.
Answer:
If Himalayan ice disappears, few states will suffer.

Samacheer Kalvi 10th English Vocabulary Confusables & Homophones

Question 11.
Her shoes are two small.
Answer:
Her shoes are too small.

Question 12.
Time may heel some wounds.
Answer:
Time may heal some wounds.

Question 13.
Mom advised me to prey regularly.
Answer:
Mom advised me to pray regularly.

Question 14.
Don’t loose your temper.
Answer:
Don’t lose your temper.

Question 15.
Some believe, “Mite is right”.
Answer:
Some believe, “Might is right”.

Question 16.
She new the way to the supermarket.
Answer:
She knew the way to the supermarket.

Question 17.
King Solomon was always faring in his judgment.
Answer:
King Solomon was always fair in his judgment.

Question 18.
Marina beach is the longest in Asia.
Answer:
Marina beach is the longest in Asia.

Question 19.
An engineer was arrested who had hordes of 2000 rupee notes.
Answer:
An engineer was arrested who had hoards of 2000 rupee notes.

Question 20.
The due seated on the top of a grass sparkled like a diamond.
Answer:
The dew seated on the top of a grass sparkled like a diamond.

Samacheer Kalvi 10th English Vocabulary Confusables & Homophones

Fill in with the right confusable to make a meaningful sentence
1. ……………………………. is a big clock, (ours/hours)
2. The colour of your ……………………………. is black, (hare/hair)
3. Gold is measured in ……………………………. (carrot/carat)
4. I sent a ……………………………. to my friend, (mail/male)
5. The ……………………………. seated on the top of the flowers and made the flower look more beatiful. (due/dew)
6. Sparrows were ……………………………. here long ago. (scene/seen)
7. Give me a ……………………………. when you reach home, (wring/ring)
8. How the youngest bird flies across the ……………………………. is a puzzle! (see/sea)
9. Last ……………………………. he did not attend school since he was ……………………………. (weak/week)
10. Those who are ……………………………. of their ……………………………. dare not do mistakes.(conscience/conscious)
11. Nivedha’s ……………………………. son ……………………………. himself to the new environment, (adapted/adopted)
12. The book which has been ……………………………. for the BA class has been ……………………………. for containing some
marks against a particular religion, (proscribed/prescribed)
13. Tommy was walking around the forest with his ……………………………. feet when he was attacked by the ……………………………. (bear/bare).
14. In the story, St.Michael, a ……………………………. was seated in a ……………………………. (ferry/fairy).
15. I wanted to buy a ……………………………. of bangles but I ended buying ……………………………. (pair/pears)
16. Every ……………………………. my grandmother would tell be a story about a ……………………………. to help me grow courageous, (knight/night)
17. We had to ……………………………. patiently, in spite of carrying a heavy ……………………………. (weight/wait)
18. The ……………………………. of the ……………………………. is always soft and silky, (hare/hair)
19. When teaching my son how to drive, I told him if he didn’t hit the ……………………………. in time he would ……………………………. the car’s side mirror, (break/brake)
20. If you ……………………………. drugs, you will get arrested and end up in a prison ……………………………. (cell/sell)
21. Karthik won’t spend one ……………………………. on a bottle of perfume until he knows that he loves the ……………………………. (sent/scent/cent) SamacheerKalvi.Guru
22. If you accidentally drink a bottle of fabric ……………………………. you might ……………………………. (die/dye)
23. To bake a ……………………………. shaped cake, you’ll need some all-purpose ……………………………. (flour/flower)
24. If the ……………………………. breaks on your sandal, you might fall. However, your injuries will ……………………………. in a week’s time, (heal/heel)
25. I wanted to sit ……………………………. so I could ……………………………. the mimicry performance without any distractions, (hear/here)
Answer:
1. ours
2. hair
3. carat
4. nail
5. dew
6. seen
7. ring
8. sea
9. week/weak
10. conscious/conscience
11. adopted/adapted
12. prescribed/proscribed
13. bare/bear
14. fairy/ferry
15. pair/pears
16. knight/night
17. wait/weight
18. hair/hare
19. brake/break
20. sell/cell
21. cent/scent
22. dye/die
23. flower/flour
24. heel/heal
25. here/hear

Samacheer Kalvi 10th English Vocabulary Confusables & Homophones

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Samacheer Kalvi 10th Science Solutions Chapter 5 Acoustics

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Tamilnadu Samacheer Kalvi 10th Science Solutions Chapter 5 Acoustics

Samacheer Kalvi 10th Science Acoustics Textual Solved Problems

Question 1.
At what temperature will the velocity of sound in the air be double the velocity of sound in air at 0° C?
Solution:
Let T° C be the required temperature. Let v1 and v2 be the velocity of sound at temperatures T1K and T2K respectively.
T1 = 273K (0°C) and T2 = (T°C + 273)K
\(\frac{v_{2}}{v_{1}}=\sqrt{\frac{\mathrm{T}_{2}}{\mathrm{T}_{1}}}=\sqrt{\frac{273+\mathrm{T}}{273}}=2\)
Here, it is given that, v2/v1 = 2
So \(\frac{273+\mathrm{T}}{273}=4\)
T = (273 × 4) – 273 = 819° C.

Question 2.
A source producing a sound of frequency 90 Hz is approaching a stationary listener with a speed equal to (1 / 10) of the speed of sound. What will be the frequency heard by the listener?
Solution:
When the source is moving towards the stationary listener, the expression for apparent frequency is
\(n^{\prime}=\left(\frac{v}{v-v_{s}}\right) n\)
\(\begin{array}{l}{=\left(\frac{v}{v-\left(\frac{1}{10}\right) v}\right) n=\left(\frac{10}{9}\right) n} \\ {=\left(\frac{10}{9}\right) \times 90=100 \mathrm{Hz}}\end{array}\)

Question 3.
A source producing a sound of frequency 500 Hz is moving towards a listener with a velocity of 30 ms-1. The speed of the sound is 330 ms-1. What will be the frequency heard by the listener?
Solution:
When the source is moving towards the stationary listener, the expression for apparent frequency is
n’ = \(\left(\frac{v}{v-v_{\mathrm{s}}}\right) n\)
= \(\left(\frac{330}{330-30}\right) \times 500\)
= 550 Hz.

Question 4.
A source of sound is moving with a velocity of 50 ms-1 towards a stationary listener. The listener measures the frequency of the source as 1000 Hz. what will be the apparent frequency of the source when it is moving away from the listener after crossing him? (velocity of sound in the medium is 330 ms-1)
Solution:
When the source is moving towards the stationary listener, the expression for apparent frequency is
\(\begin{aligned} n^{\prime} &=\left(\frac{v}{v-v_{\mathrm{s}}}\right) n \\ 1000 &=\left(\frac{330}{330-50}\right) n \\ n &=\left(\frac{1000 \times 280}{330}\right) \end{aligned}\)
n = 848.48 Hz.
The actual frequency of the sound is 848.48 Hz. When the source is moving away from the stationary listener, the expression for apparent frequency is
\(\begin{aligned} n^{\prime} &=\left(\frac{v}{v+v_{\mathrm{s}}}\right) n \\ &=\left(\frac{330}{330+50}\right) \times 848.48 \end{aligned}\)
= 736.84 Hz.
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Question 5.
A source and listener are both moving towards each other with a speed v/10 where v is the speed of sound. If the frequency of the note emitted by the source is f, what will be the frequency heard by the listener?
Solution:
When source and listener are both moving towards each other, the apparent frequency is
\(\begin{aligned} n^{\prime} &=\left(\frac{v+v_{l}}{v-v_{s}}\right) n \\ n^{\prime} &=\left(\frac{v+\frac{v}{10}}{v-\frac{v}{10}}\right) n \\ n^{\prime} &=\frac{11}{9} \cdot f \\ &=1.22 f \end{aligned}\)

Question 6.
At what speed should a source of sound move away from a stationary observer so that the observer finds the apparent frequency equal to half of the original frequency?
Solution:
When the source is moving away from the stationary listener, the expression for the apparent frequency is
\(\begin{array}{l}{n^{\prime}=\left(\frac{v}{v+v_{\mathrm{s}}}\right) n} \\ {\frac{n}{2}=\left(\frac{v}{v+v_{\mathrm{s}}}\right) n} \\ {v_{\mathrm{s}}=v}\end{array}\)

Samacheer Kalvi 10th Science Acoustics Textual Evaluation

I. Choose the best Answer

Question 1.
When a sound wave travels through air, the air particles _____.
(a) vibrate along the direction of the wave motion
(b) vibrate but not in any fixed direction
(c) vibrate perpendicular to the direction of the wave motion
(d) do not vibrate.
Answer:
(a) vibrate along the direction of the wave motion

Question 2.
Velocity of sound in a gaseous medium is 330 ms-1. If the pressure is increased by 4 times without causing a change in the temperature,
the velocity of sound in the gas is:
(a) 330 ms-1
(b) 660 ms1
(c) 156 ms-1
(d) 990 ms-1
Answer:
(a) 330 ms-1

Question 3.
The frequency, which is audible to the human ear is _____.
(a) 50 kHz
(b) 20 kHz
(c) 15000 kHz
(d) 10000 kHz.
Answer:
(b) 20 kHz
Hint: Audible frequency hearing the human ear range between 20 Hz to 20 kHz

Question 4.
The velocity of sound in air at a particular temperature is 330 ms-1. What will be its value when temperature is doubled and the pressure is halved?
(a) 330 ms-1
(b) 165 ms-1
(c) 330 × √2 ms-1
(d) 320 × √2 ms-1
Answer:
(a) 330 ms-1

Question 5.
If a sound wave travels with a frequency of 1.25 × 104 Hz at 344 ms-1, the wavelength will be _____.
(a) 27.52 m
(b) 275.2 m
(c) 0.02752 m
(d) 2.752 m.
Answer:
(c) 0.02752 m
Hint: Velocity of sound = frequency × wavelength
v = nλ
\(\lambda=\frac{v}{n}=\frac{344}{1.24 \times 10^{4}}\)
λ = 0.02752 m.
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Question 6.
The sound waves are reflected from an obstacle into the same medium from which they were incident. Which of the following changes?
(a) speed
(b) frequency
(c) wavelength
(d) none of these.
Answer:
(d) none of these.
Hint: If there is the same medium of a reflected obstacle is used, there is no change in speed, frequency and wavelength of the sound.

Question 7.
Velocity of sound in the atmosphere of a planet is 500 ms-1. The minimum distance between the sources of sound and the obstacle to hear the echo, in point Is is:
(a) 17 m
(b) 20 m
(c) 25 m
(d) 50 m
Answer:
(c) 25 m

II. Fill in the blanks

Question 1.
The rapid back and forth motion of a particle about its mean position is called _____.
Answer:
vibrations.

Question 2.
If the energy in a longitudinal wave travels from south to north, the particles of the medium would be vibrating in _____.
Answer:
both north and south.

Question 3.
A whistle giving out a sound of frequency 450 Hz, approaches a stationary observer at a speed of 33 ms-1. The frequency heard by the observer is (speed of sound = 330 ms-1) ______.
Answer:
Data:
v = 330 ms-1
vS = 33 ms-1
n = 450 Hz
n’ =?
Apparent frequency
\(\begin{aligned} n^{\prime} &=\left(\frac{v}{v-v_{\mathrm{S}}}\right) n \\ &=\left(\frac{330}{330-33}\right) \times 450=1.11 \times 450 \end{aligned}\)
n’ = 500 Hz.

Question 4.
A source of sound is travelling with a velocity 40 km/h towards an observer and emits a sound of frequency 2000 Hz. If the velocity of sound is 1220 km/h, then the apparent frequency heard by the observer is _____.
Answer:
2068 Hz
Hint: Apparent frequency heard by the observer.
Data:
v = 1220 km/h (or) 339 ms-1
vS = 40 km/h (or) 11.1 ms-1
n = 2000 Hz
\(\begin{aligned} n^{\prime} &=\left(\frac{v}{v-v_{\mathrm{s}}}\right) n \\ &=\left(\frac{339}{339-11.1}\right) \times 2000 \end{aligned}\)
= 1.03385 × 2000
n’ = 2068 Hz.

III. True or False. If false give the reason

Question 1.
Sound can travel through solids, gases, liquids and even vacuum.
Answer:
False.
Reason: Sound can not travel in a vacuum. This is because sound waves are vibrating waves. In vacuum, where there are no atoms or molecules to vibrate.

Question 2.
Waves created by Earth Quake are Infrasonic.
Answer:
True.
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Question 3.
The velocity of sound is independent of temperature.
Answer:
False.
Reason: For an ideal gas the velocity of sound depends on its temperature and is independent of gas pressure.

Question 4.
The velocity of sound is high in gases than liquids.
Answer:
False.
Reason: Velocity of a sound wave is maximum in solids because they are more elastic in nature than liquids and gases. Since gases are least elastic in nature, the velocity of sound is the least in a gaseous medium.
So VS > VL > VG.

IV. Match the following

Question 1.

1. Infrasonic (a) Compressions
2. Echo (b) 22 kHz
3. Ultrasonic (c) 10 Hz
4. High-pressure region (d) Ultrasonography

Answer:
1. (c) 10 Hz
2. (d) Ultrasonography
3. (b) 22 kHz
4. (a) Compressions

V. Assertion and Reason Type Questions

Mark the correct choice as
(a) If both the assertion and the reason are true and the reason is the correct explanation of the assertion.
(b) If both the assertion and the reason are true but the reason is not the correct explanation of the assertion.
(c) The assertion is true, but the reason is false.
(d) The assertion is false, but the reason is true.

Question 1.
Assertion: The change in air pressure affects the speed of sound.
Reason: The speed of sound in a gas is proportional to the square of the pressure
Answer:
(d) The assertion is false, but the reason is true.

Question 2.
Assertion: Sound travels faster in solids than in gases.
Reason: Solid posses a greater density than that of gases.
Answer:
(b) If both the assertion and the reason are true but the reason is not the correct explanation of the assertion.

VI. Answer very briefly

Question 1.
What is a longitudinal wave?
Answer:
If the particles of the medium vibrate along the direction of propagation of the wave.

Question 2.
What is the audible range of frequency?
Answer:
Audible range of frequency is from 20 Hz to 20000 Hz.

Question 3.
What is the minimum distance needed for an echo?
Answer:

  1. The minimum distance required to hear an echo is 1/20th part of the magnitude of the velocity of sound in air.
  2. If you consider the velocity of sound as 344 ms-1, the minimum distance required to hear an echo is 17.2 m.

Question 4.
What will be the frequency sound having 0.20 m as its wavelength, when it travels with a speed of 331 m s-1?
Answer:
Speed v = 331 m/s
Let the wave length be λ = 0.2 m
Let the frequency be n
∴ Frequency n = \(\frac{v}{λ}\) = \(\frac{331}{0.2}\) = \(\frac{3310}{2}\)
∴ Frequency = 1655 Hz

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Question 5.
Name three animals, which can hear ultrasonic vibrations.
Answer:
Mosquitos, bats and dogs are the three animals that can hear ultrasonic vibrations.

VII. Answer briefly

Question 1.
Why does sound travel faster on a rainy day than on a dry day?
Answer:
When humidity increases, the speed of sound increases. That is why you can hear sound from long distances clearly during rainy seasons.

Question 2.
Why does an empty vessel produce more sound than a filled one?
Answer:
In an empty vessel, multiple reflections of sound takes place. Hence more sound is produced in an empty vessel than tilled one.

Question 3.
Air temperature in the Rajasthan desert can reach 46°C. What is the velocity of sound in air at that temperature? (v0 = 331 ms-1)
Answer:
Velocity of sound, v0 = 331 ms-1
Air temperature, T = 46° C
Velocity of sound in air temperature vT = (v0 + 0.61T) ms-1
= 331 + (0.61 × 46)
= 331 + 28.06
vT = 359.06 ms-1.

Question 4.
Explain why the ceilings of concert halls are curved.
Answer:
The ceilings of concert halls are curved so that multiple reflections of sound waves can take place.
The parabolic surfaces are used to focus the sound at a particular point. Hence sound will be louder.

Question 5.
Mention two cases in which there is no Doppler effect in sound?
Answer:

  1. When source (S) and listener (L) both are at rest.
  2. When S and L move in such a way that distance between them remains constant.
  3. When source S and L are moving in mutually perpendicular directions.
  4. If the source is situated at the centre of the circle along which the listener is moving.

VIII. Problem Corner

Question 1.
A sound wave has a frequency of 200 Hz and a speed of 400 ms-1 in a medium. Find the wavelength of the sound wave.
Solution:
A sound wave of frequency, n = 200 Hz
Speed, v = 400 ms-1
The wavelength of the sound wave, λ = \(\frac{v}{n}\)
λ = \(\frac{400}{200}\) = 2 m.

Question 2.
The thunder of cloud is heard 9.8 seconds later than the flash of lightning. If the speed of sound in air is 330 ms-1, what will be the height of the cloud?
Answer:
Speed of sound in air v = 330 m/s
Time to hear thunder t = 9.8 s
∴ Height of the cloud = v × t
= 330 × 9.8
= 3234 m.

Question 3.
A person who is sitting at a distance of 400 m from a source of sound is listening to a sound of 600 Hz. Find the time period between successive compressions from the source?
Solution:
Frequency = \(\frac{1}{\text { Time period }}\)
Time period = \(\frac{1}{\text { Frequency }}=\frac{1}{600}\)
T = 0.00167 seconds
The time period between successive compressions from the source is 0.00167 seconds.

Question 4.
An ultrasonic wave is sent from a ship towards the bottom of the sea. It is found that the time interval between the transmission and reception of the wave is 1.6 seconds. What is the depth of the sea, if the velocity of sound in the seawater is 1400 ms-1?
Solution:
Samacheer Kalvi 10th Science Solutions Chapter 5 Acoustics 1
The depth of the sea is 1120 m.

Question 5.
A man is standing between two vertical walls 680 m apart. He claps his hands and hears two distinct echoes after 0.9 seconds and 1.1 seconds respectively. What is the speed of sound in the air?
Solution:
Given data is
d = 680 m
t1 = 0.9 s
t2 = 1.1 s
v = ?
\(\text { Velocity }=\frac{\text { Distance travelled by sound }}{\text { Time taken }}\)
\(v=\frac{2 d}{t}\)
Samacheer Kalvi 10th Science Solutions Chapter 5 Acoustics 2

Question 6.
Two observers are stationed in two boats 4.5 km apart. A sound signal sent by one, under water, reaches the other after 3 seconds. What is the speed of sound in the water?
Answer:
Distance of boats d = 4.5 × 103 m
= 4500 m.
Time t = 3 s
Speed of sound in water = \(\frac{d}{t}\)
= \(\frac{4500}{3}\)
= 1500 m/s

Question 7.
A strong sound signal is sent from a ship towards the bottom of the sea. It is received back after 1 s What is the depth of sea given that the speed of sound in water 1450 ms-1?
Solution:
Velocity of sound in water \(=\frac{\text { Distance travelled by sound }}{\text { Time taken }}\)
Depth of the sea, d = velocity × time
\(d=\frac{v t}{2}=\frac{1450 \times 1}{2}\) = 725 m.

IX. Answer in Detail

Question 1.
What are the factors that affect the speed of sound in gases?
Answer:
In the case of gases, the following factors affect the velocity of sound waves.
Effect of density : The velocity of sound in a gas is inversely proportional to the square root of the density of the gas. Hence, the velocity decreases as the density of the gas increases.
v ∝\(\sqrt{\frac{1}{d}}\)

Effect of temperature : The velocity of sound in a gas is directly proportional to the square root of its temperature. The velocity of sound in a gas increases with the increase in temperature v ∝ √T. Velocity at temperature T is given by the following equation:
Vr = (vo + 0.61 T)ms-1.
Here, vo is the velocity of sound in the gas at 0° C. For air, vo = 331 ms-1. Hence, the velocity of sound changes by 0.61 ms-1 when the temperature changes by one degree Celsius.

Effect of relative humidity : When humidity increases, the speed of sound increases. That is why you can hear sound from long distances clearly during rainy seasons.

Question 2.
What is mean by the reflection of sound? Explain.
Answer:
Reflection of Sound:
The bouncing of sound waves from the interface between two media is termed as the reflection of sound.
(a) Reflection at the boundary of a rarer medium

  • Consider a wave travelling in a solid medium striking on the interface between the solid and the air. The compression exerts a force F on the surface of the rarer medium.
  • As a rarer medium has smaller resistance for any deformation, the surface of separation is pushed backwards.
  • As the particles of the rarer medium are free to move, a rarefaction is produced at the interface. Thus, compression is reflected as rarefaction and a rarefaction travels from right to left.

Samacheer Kalvi 10th Science Solutions Chapter 5 Acoustics 3

(b) Reflection at the boundary of a denser medium

  • A longitudinal wave travels in a medium in the form of compressions and rarefactions. Suppose a compression travelling in the air from left to right reaches a rigid wall.
  • The compression exerts a force F on the rigid wall. In turn, the wall exerts an equal and
    opposite reaction R = -F on the air molecules. This results in a compression near the rigid wall.
  • Thus, a compression travelling towards the rigid wall is reflected back as a compression. That is the direction of compression is reversed.

Samacheer Kalvi 10th Science Solutions Chapter 5 Acoustics 4

(c) Reflection at sound in curved surfaces

  • When the sound waves are reflected from the curved surfaces, the intensity of the reflected waves is changed.
  • When reflected from a convex surface, the reflected waves are diverged out and the intensity is decreased.
  • When sound is reflected from a concave surface, the reflected waves are converged and focused at a point. So the intensity of reflected waves is concentrated at a point.
  • Parabolic surfaces are used when it is required to focus the sound at a particular point. Hence, many halls are designed with parabolic reflecting surfaces.
  • In elliptical surfaces, sound from one focus will always be reflected the other focus, no matter where it strikes the wall.

Question 3.
(a) What do you understand by the term ‘ultrasonic vibration’?
(b) State three uses of ultrasonic vibrations.
(c) Name three animals which can hear ultrasonic vibrations.
Answer:
(a) Ultrasonic vibrations are the vibration with frequency greater than 20 KHz. Human ear cannot detect the ultrasonic vibration.

(b) (i) Ultrasonic waves are used in ultrasonography.
(ii) It is used to get signal images of a developing embryo in the mother’s uterus.
(in) They are used to forecast about tsunami and earthquake.

(c) Certain creatures like dog, bats, dolphins and mosquito can detect the waves.

Question 4.
What is an echo?
(a) State two conditions necessary for hearing an echo.
(b) What are the medical applications of echo?
(c) How can you calculate the speed of sound using echo?
Answer:
Echo: An echo is the sound reproduced due to the reflection of the original sound from various rigid surfaces such as walls, ceilings, surfaces of mountains, etc.

(a) (i) The persistence of hearing for human ears is 0.1 second. This means that we can hear two sound waves clearly if the time interval between the two sounds is at least 0.1 s. Thus, the minimum time gap between the original sound and an echo must be 0.1 s.

(ii) The above criterion can be satisfied only when the distance between the source of the sound and the reflecting surface would satisfy the following equation:
\(\begin{aligned} \text { Velocity } &=\frac{\text { Distance travelled by sound }}{\text { Timetaken }} \\ v &=\frac{2 d}{t} \\ d &=\frac{v t}{2} \end{aligned}\)
Since, t = 0.1 second, then \(d=\frac{v \times 0.1}{2}=\frac{v}{20}\)

(b) (i) The principle of echo is used in obstetric ultrasonography, which is used to create real – time visual images of the developing embryo or fetus in the mother’s uterus.
(ii) This is a safe testing tool, as it does not use any harmful radiations.

(c) Apparatus required:
A source of sound pulses, a measuring tape, a sound receiver and a stopwatch.
Calculation of speed of sound:
The sound pulse emitted by the source travels a total distance of 2nd while travelling from the source to the wall and then back to the receiver.
The time taken for this has been observed to be ‘t’. Hence, the speed of the sound wave is given by:
\(\text { Speed of sound }=\frac{\text { Distance travelled }}{\text { Timetaken }}=\frac{2 d}{t}\).

X. HOT Questions

Question 1.
Suppose that a sound wave and a light wave have the same frequency, then which one has a longer wavelength?
(a) Sound
(b) Light
(c) both (a) and (b)
(d) data not sufficient.
Answer:
(b) light
Explanation: The light wave has a longer wavelength because it has much greater speed.
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Question 2.
When sound is reflected from a distant object, an echo is produced. Let the distance between the reflecting surface and the source of sound remain the same. Do you hear an echo sound on a hotter day? Justify your answer.
Answer:
Echo of sound is heard with less velocity and intensity on a hotter day. Because the velocity of sound is directly proportional to temperature of air. On a hotter day temperature will be higher so velocity of sound will be changed by higher values.

Samacheer Kalvi 10th Science Acoustics Additional Questions

I. Choose the best answer

Question 1.
Light can travel in a vacuum but not sound because of ______.
(a) speed of sound is very slow than light.
(b) light waves are electromagnetic in nature.
(c) sound waves are electromagnetic in nature.
(d) light waves are not electromagnetic in nature.
Answer:
(a) speed of sound is very slow than light.
Hint: Light can travel in a vacuum because light waves are electromagnetic in nature.

Question 2.
In a longitudinal wave there is a state of maximum compression at a point at an instant. The frequency of wave is 50 Hz. After what time will the same point be in the state of maximum rarefaction:
(a) 50 s
(b) 25 s
(c) 0.01 s
(d) 0.002 s
Answer:
(c) 0.01 s

Question 3.
When sound travels from air to water, which parameter does not change?
(a) Wavelength
(b) Frequency
(c) Velocity
(d) Temperature.
Answer:
(b) Frequency
Hint: Frequency remains unchanged when sound travels from air to water.

Question 4.
When a wave passes from one medium to another, there is a change of:
(a) Wavelength and velocity
(b) Wavelength and frequency
(c) Velocity and frequency
(d) Velocity only
Answer:
(a) Wavelength and velocity

Question 5.
At what temperature, the speed of sound in the air will become double of its value at 27°C?
(a) 54° C
(b) 627° C
(c) 327° C
(d) 927° C.
Answer:
(d) 927° C.
Hint:
\(\frac{v_{1}}{v_{2}}=\sqrt{\frac{\mathrm{T}_{1}}{\mathrm{T}_{2}}} \Rightarrow \frac{v_{1}}{2 v_{1}}=\sqrt{\frac{\mathrm{T}_{1}}{\mathrm{T}_{2}}}\)
⇒ \(\frac{1}{4}=\frac{27+273}{\mathrm{T}_{2}}\)
⇒ T2 = 300 × 4 = 1200 K
⇒ T2 = 1200 – 273 = 927° C.
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Question 6.
Sound waves from a point source are propagating in all directions. What will be the ratios of amplitude at a distance 9 m and 25 m from the source?
(a) 9 : 25
(b) 25 : 9
(c) 3 : 5
(d) 81 : 625
Answer:
(b) 25 : 9

II. Fill in the blanks:

Question 1.
Sound waves in a gas are ______.
Answer:
Longitudinal.

Question 2.
The velocity of sound is the largest in ______.
Answer:
Steel.

Question 3.
Hertz is the unit of ______.
Answer:
Frequency.

Question 4.
Sound travels in rocks in the form of ______.
Answer:
Both longitudinal and transverse elastic waves.

Question 5.
The velocity of sound varies directly as the square root of the ______.
Answer:
The absolute temperature of the gas.

Question 6.
Reflection of sound waves obey the ______.
Answer:
Laws of reflection.

Question 7.
RADAR is the short form of ______.
Answer:
Radio Detection and Ranging.
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Question 8.
The abbreviation of SONAR is ______.
Answer:
Sound Navigation and Ranging.

III. Match the following

Question 1.

Medium Speed of Sound (m/s)
(i) Copper (a) 343
(ii) Water (b) 331
(iii) Air (0° c) (c) 5010
(iv) Air (at 20° c) (d) 1493

Answer:
(i) (c) 5010
(ii) (d) 1493
(iii) (b) 331
(iv) (a) 343.

Question 2.

Waves Range
(i) Audible (a) 340 m/s
(ii) Sound (b) greater than 20kHz
(iii) Infrasonic (c) 20Hz – 20 kHz
(iv) Light (d) below 20 Hz
(v) Ultrasonic (e) 3 × 108 m/s

Answer:
(i) (c) 20 Hz – 20 kHz
(ii) (a) 340 m/s
(iii) (d) below 20 Hz
(iv) (e) 3 × 108 m/s
(v) (b) greater than 20 kHz.

IV. Assertion and Reason Questions

Question 1.
Assertion: Sound wave cannot propagate through a vacuum but light can.
Reason: Sound wave cannot be polarised but light can.
(a) Both assertion and reason are true and the reason is the correct explanation of the assertion.
(b) Both assertion and reason are true but the reason is not the correct explanation of the assertion.
(c) Assertion is true but the reason is false.
(d) Both assertion and reason are false.
Answer:
(b) Both assertion and reason are true but the reason is not the correct explanation of the assertion.
Explanation: Sound waves, being mechanical waves, cannot travel through a vacuum. Light waves, electromagnetic waves, can travel through a vacuum.

Question 2.
Assertion: The velocity of sound increases with increase in humidity.
Reason: Velocity of sound does not depend upon the medium.
(a) both assertion and reason are true and the reason is the correct explanation of the assertion.
(b) both assertion and reason are true but reason is not the correct explanation of the assertion.
(c) Assertion is true but reason is false.
(d) Assertion is false but the reason is true.
Answer:
(c) The assertion is true but the reason is false.
Explanation: Velocity of sound increases with increase in humidity. The velocity of sound depends upon medium.

V. Answer Very Briefly

Question 1.
What is sound? Is it a force or energy?
Answer:
Sound is a vibration that typically propagates as an audible wave of pressure, through a transmission medium such as a gas, liquid or solid. Sound is not a force, it is an energy.

Question 2.
In which type of media, can longitudinal waves be propagated?
Answer:
Longitudinal waves can be propagated through solids, liquids and gases.

Question 3.
How does sound reach our ears from various sources?
Answer:
Sound reaches our ears in the form of transverse waves or vibrations from its source of production.

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Question 4.
What is the minimum distance between two points in a wave having a phase difference of 2π?
Answer:
The minimum distance is the wavelength.

Question 5.
Suppose you and your friend are on the Moon. Will you be able to hear any sound produced by your friend?
Answer:

  • As the Moon does not have air, you will not be able to hear any sound produced by your friend.
  • Hence, you understand that the sound produced due to the vibration of different bodies needs a material medium like air, water, steel, etc, for its propagation.
  • Hence, sound can propagate through a gaseous medium or a liquid medium or a solid medium.

Question 6.
What is the effect of pressure on the speed of sound in gas?
Answer:
The increase of pressure has no effect on the speed of sound in a gas.

Question 7.
Write down the difference between the sound and light waves.
Answer:

Sound Light
1. Medium is required for the propagation 1. Medium is not required for the propagation.
2. Sound waves are longitudinal. 2. Light waves are transverse.
3. Wavelength ranges from 1.65 cm to 1.65 m. 3. Wavelength ranges from 4 × 10-7 m to 7 × 10-7 m.
4. Sound waves travel in the air with a speed of about 340 ms-1 at NTP. 4. Light waves travel in the air with a speed of 3 × 108 ms-1

Question 8.
Define particle velocity.
Answer:
The velocity with which the particles of the medium vibrate in order to transfer the energy in the form of a wave is called particle velocity.

Question 9.
Define wave velocity.
Answer:
The velocity with which the wave travels through the medium is called wave velocity.

Question 10.
Define velocity of a sound wave.
Answer:
The distance travelled by a sound wave in unit time is called the velocity of a sound wave.
\(\text { Velocity }=\frac{\text { Distance }}{\text { Time taken }}\)

Question 11.
State the laws of reflection of sound.
Answer:
The incident wave, the normal to the reflecting surface and the reflected wave at the point of incidence lie in the same plane.
The angle of incidence ∠i is equal to the angle of reflection ∠r.

Question 12.
State ‘Laws of reflection’.
Answer:

  • The incident wave, the normal to the reflecting surface and the reflected wave at the point of incidence lie in the same plane.
  • The angle of incidence ∠i is equal to the angle of reflection ∠r.

Question 13.
What is meant by rarer and denser medium?
Answer:

  1. Rarer medium: The medium in which the velocity of sound increases compared to other medium is called rarer medium. (Water is rarer compared to air for sound).
  2. Denser medium: The medium in which the velocity of sound decreases compared to other medium is called denser medium. (Air is denser compared to water for sound)

VI. Problem Corner

Question 1.
A wave of length 0.60 cm is produced in air and travels with a velocity of 340 ms-1. Will it be audible to the human ear?
Solution:
Wavelength, λ = 0.6 × 10-2 m
Velocity of sound, v = 340 ms-1
Frequency, n = \(\frac{v}{\lambda}\)
⇒ n = \(\frac{340}{0.6 \times 10^{-2}}\)
⇒ n = 566.66 × 102
⇒ n = 567 × 102 Hz.

Question 2.
Consider a source moving towards a listener at a speed of 0.9 v. Where v is the velocity of sound. Calculate the apparent frequency if the actual frequency is 600 Hz.
Solution:
Samacheer Kalvi 10th Science Solutions Chapter 5 Acoustics 5

Question 3.
Audible frequencies have a range of 20 Hz to 20,000 Hz. Express it in terms of wavelength in air.
Answer:
Let the velocity of sound in air be 340 m/s
Initial frequency v1 = 20 Hz
Initial wavelength λ1 = \(\frac{v}{V_1}\)
= \(\frac{340}{20}\) = 17 m
Final frequency v2 = 20 × 10³ Hz
Final wavelength λ2 = \(\frac{340}{20×10³}\)
= 17 × 10-3 = 0.017 m
The range of wavelength is from 17 m to 0.017 m

VII. Answer in detail.

Question 1.
Write down the applications of echo?
Answer:
Applications of echo:

  • Some animals communicate with each other over long distances and also locate objects by sending the sound signals and receiving the echo as reflected from the targets.
  • The principle of echo is used in obstetric ultrasonography, which is used to create real – time visual images of the developing embryo or fetus in the mother’s uterus. This is a safe testing tool, as it does not use any harmful radiations.
  • Echo is used to determine the velocity of sound waves in any medium.

Question 2.
Classify sound waves based on their frequencies.
Answer:
(i) Audible waves : These are sound waves with a frequency ranging between 20 Hz and 20,000 Hz. These are generated by vibrating bodies such as vocal cords, stretched strings etc.

(ii) Infrasonic waves : These are sound waves with a frequency below 20 Hz that cannot be heard by the human ear. eg: waves produced during earth quake, ocean waves, sound produced by whales, etc.

(iii) Ultrasonic waves : These are sound waves with a frequency greater than 20 kHz, Human ear cannot detect these waves, but certain creatures like mosquito, dogs, bats, dolphins can detect these waves, eg: waves produced by bats.

Question 3.
Write down the concept of Ear trumpet and Megaphone.
Answer:
Ear trumpet:

  • Ear trumpet is a hearing aid, which is useful by people who have difficulty in hearing.
  • In this device, one end is wide and the other end is narrow. The sound from the sources fall into the wide end and are reflected by its walls into the narrow part of the device. This helps in concentrating the sound and the sound enters the eardrum with more intensity. This enables a person to hear the sound better.

Megaphone:

  • A megaphone is a horn – shaped device used to address a small gathering of people.
  • It’s one end is wide and the other end is narrow. When a person speaks at the narrow end, the sound of his speech is concentrated by the multiple reflections from the walls of the tube. Thus, his voice can be heard loudly over a long distance.

Question 4.
What is the Doppler effect? Derive the formula for the change in apparent frequency
1. Both source and listener move towards and away from each other.
2. Both source and listener move one behind the other source follows the listener and listener follows the source.
3. A source at rest, listener moves towards and away from the source.
4. A listener at rest, the source moves towards and away from the listener.
Answer:
1.

Position of source and listener Note Expression for apparent frequency
(i) Both source and listener move
(ii) They move towards each other
(a) Distance between source and listener decreases.
(b) Apparent frequency is more than actual frequency.
\(n^{\prime}=\left(\frac{v+v_{\mathrm{L}}}{v-v_{\mathrm{S}}}\right) n\)
(i) Both source and listener move
(ii) They move away from each other
(a) Distance between source and listener increases.
(b) Apparent frequency is less than actual frequency.
(c) vS and vL become opposite to that in case-1.
\(n^{\prime}=\left(\frac{v-v_{\mathrm{L}}}{v+v_{\mathrm{S}}}\right) n\)

2.

Position of source and listener Note Expression for apparent frequency
(i) Both source and listener move
(ii) They move one behind the other
(iii) Source follows the listener
(a) Apparent frequency depends on the velocities of the source and the listener.
(b) vS becomes opposite to that in case-2.
\(n^{\prime}=\left(\frac{v-v_{\mathrm{L}}}{v-v_{\mathrm{S}}}\right) n\)
(i) Both source and listener move
(ii) They move one behind the other
(iii) The listener follows the source
(a) Apparent frequency depends on the velocities of the source and the listener.
(b) vS and vL become opposite to that in case-3.
\(n^{\prime}=\left(\frac{v+v_{\mathrm{L}}}{v+v_{\mathrm{s}}}\right) n\)

3.

Position of source and listener Note Expression for apparent frequency
(i) Source at rest
(ii) Listener moves towards the source
(a) Distance between source and listener decreases.
(b) Apparent frequency is more than actual frequency.
(c) vS = 0 in case-1.
\(n^{\prime}=\left(\frac{v+v_{\mathrm{L}}}{v}\right) n\)
(i) Source at rest
(ii) Listener moves away from the source
(a) Distance between source and listener increases.
(b) Apparent frequency is less than actual frequency.
(c) vS = 0 in case-2.
\(n^{\prime}=\left(\frac{v-v_{\mathrm{L}}}{v}\right) n\)

4.

Position of source and listener Note Expression for apparent frequency
(i) Listener at rest
(ii) Source moves towards the listener
(a) Distance between source and listener decreases.
(b) Apparent frequency is more than actual frequency.
(c) vL = 0 in case-1.
\(n^{\prime}=\left(\frac{v}{v-v_{\mathrm{S}}}\right) n\)
(i) Listener at rest
(ii) Source moves away from the listener
(a) Distance between source and listener increases.
(b) Apparent frequency is less than actual frequency.
(c) vL = 0 in case-2.
\(n^{\prime}=\left(\frac{v}{v+v_{\mathrm{S}}}\right) n\)

Question 5.
Explain echo method to measure velocity’ of sound.
Answer:
Apparatus required: A source of sound pulses, a measuring tape, a sound receiver, and a stop watch.
Procedure:

  1. Measure the distance ‘d’ between the source of sound pulse and the reflecting surface using the measuring tape.
  2. The receiver is also placed adjacent to the source. A sound pulse is emitted by the source.
  3. The stopwatch is used to note the time interval between the instant at which the sound pulse is sent and the instant at which the echo is received by the receiver. Note the time interval as ‘t’.
  4. Repeat the experiment for three or four times. The average time taken for the given number of pulses is calculated.

Calculation of speed of sound : The sound pulse emitted by the source travels a total distance of 2d while travelling from the source to the wall and then back to the receiver. The time taken for this has been observed to be ‘t’. Hence, the speed of sound wave is given by:
Speed of sound = \(\frac{distence Travelled}{Time Taken}\)
= \(\frac{2d}{t}\)

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