Laxmi

Students can Download Maths Chapter 4 Geometry Ex 4.2 Questions and Answers, Notes Pdf, Samacheer Kalvi 7th Maths Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 7th Maths Solutions Term 2 Chapter 4 Geometry Ex 4.2

Question 1.
Given that ∆ABC = ∆DEF (i) List all the corresponding congruent sides
(ii) List all the corresponding congruent angles.
Solution:
Given ∆ABC ≅ DEF.

(i) Corresponding congruent sides.
\(\overline{A B}\) = \(\overline{D E}\); \(\overline{B C}\) = \(\overline{E F}\); \(\overline{A C}\) = \(\overline{D F}\)

(ii) Corresponding congruent angles.
∠ABC = ∠DEF; ∠BCA = ∠EFD ; ∠CAB = ∠FDE

Question 2.
If the given two triangles are congruent, then identify all the corresponding sides and also write the congruent angles.
(i)
(ii)
Solution:
Given ∆PQR ≅ ∆LNM
(i) (a) Corresponding sides
\(\overline{P Q}\) = \(\overline{L N}\) ; \(\overline{P Q}\) = \(\overline{L M}\) ; \(\overline{R Q}\) = \(\overline{M N}\)
(b) Corresponding angles
∠RPQ = ∠NLM; ∠PQR = ∠LNM; ∠PRQ = ∠LMN

(ii) Given ∆PQR ≅ ∆NML
(a) Corresponding angles
\(\overline{Q R}\) = \(\overline{L M}\) ; \(\overline{R P}\) = \(\overline{L N}\); \(\overline{P Q}\) = \(\overline{M N}\)
(b) Corresponding angles
∠PQP = ∠NMN; ∠QRP = ∠MLN; ∠RPQ = ∠LNM

Question 3.
Find the unit digit of expanded form.

(i) ∠A and ∠G
(ii) ∠B and ∠E
(iii) ∠B and ∠G
(iv) \(\overline{A C}\) and \(\overline{G F}\)
(v) \(\overline{B A}\) and \(\overline{F G}\)
(vi) \(\overline{E F}\) and \(\overline{B C}\)
Solution:
Given ∆ABC ≅ ∆EFG. Also from given triangles.
\(\overline{A B}\) = \(\overline{F G}\) \(\overline{B C}\) = \(\overline{G F}\) \(\overline{A C}\) = \(\overline{E F}\)
Also ∠A = ∠F ∠B = ∠G ∠C = ∠E
Answer:
(i) ∠A and ∠G are not corresponding angles.
(ii) ∠B and ∠E are not corresponding angles.
(iii) ∠B and ∠G are corresponding angles.
(iv) \(\overline{A C}\) and \(\overline{G F}\) are not corresponding sides.
(v) \(\overline{B A}\) and \(\overline{F G}\) are corresponding sides.
(vi) \(\overline{E F}\) and \(\overline{B C}\) are not corresponding sides.

Question 4.
State whether the two triangles are congruent or not. Justify your answer.

Solution:
(i) Let the given triangle be ∆ABC. \(\overline{A D}\) divides ∆ABC into two parts giving ∆ABD and ∆ACD.
In ∆ABD and ∆ACD

\(\overline{A B}\) = \(\overline{A C}\) (given)
\(\overline{B D}\) = \(\overline{A D}\) (common side)
∠BAD = ∠CAD (included angles)
∴ By SAS criterion ∆ABD ≅ ∆ACD.

(ii) Let the given triangles in the figure be ∆ABC and ∆DCB.
In both the triangles

\(\overline{B C}\) = \(\overline{B C}\) (Common side)
\(\overline{A B}\) = \(\overline{D C}\)
\(\overline{A C}\) = \(\overline{B D}\)
∴ By SSS Criterion ∆ABC ≅ ∆DCB

(iii) Let the given triangles be ∆ABC and ∆CDE.

Here \(\overline{A C}\) = \(\overline{C E}\) (given)
∠BAC = ∠DEC (given)
∠ACB = ∠DCE (vertically opposite angles)
Two angles and the included side are equal.
Therefore by ASA criterion ∆ABC ≅ ∆CDE.

(iv) Let the two triangles be ∆XYZ and ∆XYW

Here ∠W = ∠Z = 90°
\(\overline{X Y}\) = \(\overline{X Y}\) (Common Hypothenure)
\(\overline{X W}\) = \(\overline{X Z}\) (given)
By RHS criterion ∆XYZ ≅ ∆XYW

(v) Let the two triangles be ∆ABC and ∆ADC

In both the triangles \(\overline{A C}\) = \(\overline{A C}\) (common sides)
\(\overline{A D}\) = \(\overline{B C}\) (given)
\(\overline{A B}\) = \(\overline{D C}\) (given)
By SSS criterion ∆ABC ≅ ∆ADC.

Question 5.
To conclude the congruency of triangles, mark the required information in the following figures with reference to the given congruency criterion.

Solution:
(i) In the given triangles one angle is equal and a side is common and so equal.

To satisfy ASA criterion one more angle should be equal such that the common side is the included side of both angles of a triangle.
The figure will be as follows.

(ii) In the two given triangles two sides of one triangle is equal to two sides of the other triangle.

To satisfy SSS criterion the third sides mut be equal.

(iii) The given triangles have one side in common. They are right angled tringles.

To satisfy RHS criterion their hypotenuse must be equal.

(iv) In the given triangles two angles of one triangle is equal to two angles of the other triangles?

To satisfy ASA criterion included side of two angles must be equal.

(v) In both the triangles one of their sides are equal.

One of their angles are equal or they are vertically opposite angles.
To satisfy SAS criterion, one more side is to be equal such that the angle is the included of the equal sides.

Question 6.
For each pair of triangles state the criterion that can be used to determine the congruency?

Solution:
(i) Given two pair of sides are equal and one side is common to both the triangles.
∴ SSS congruency criterion is used.

(ii) One of the sides and one of the angles are equal.
∴ One more angle is vertically opposite angle and so it is also equal.
ASA criterion is used.

(iii) From the figure hypotenuse and one side are equal in both the triangles.
RHS congruency criterion is used. (∵ Considering ∆ABC and ∆BAD)
∠A = ∠B = 90°
AD = BC
AB = AB (common)
∴ AC = BD (hypotenuse)

(iv) By ASA criterion both triangles are congruent.

(v) By ASA criterion both triangles are congruent. Since two angles in one triangle are equal to two corresponding angles of the other triangle. Again one side is common to both triangle and the side is the included side of the angles.

(vi) Two sides are equal. One angle is vertically opposite angles and one equal.
By SAS criterion both triangles are cogruent.

Question 7.
I. Construct a triangle XYZ with the given conditions.

(i) XY = 6.4 cm, ZY = 7.7 cm and XZ = 5 cm
Solution:


Construction:
Step 1: Draw a line. Marked Y and Z on the line such that YZ 7.7 cm.
Step 2: With Y as centre drawn an arc of radius 6.4 cm above the line YZ.
Step 3: With Z as centre, drwan an arc or radius 5 cm to intersect arc drawn in steps. Marked the point of intersection as X.
Step 3: Joined YX and ZX. Now XYZ is the required triangle.

(ii) An equilateral triangle of side 7.5 cm
Solution:

Construction:
Step 1: Drawn a line. Marked X and Y on the line such that XY = 7.5 cm.
Step 2: With X as centre, drawn an arc of radius 7,5 cm above the line XY.
Step 3: With Y as centre, drawn an arc of radius 7.5 cm to intersect arc drawn in steps. Marked the point of intersection as Z.
Step 4: Joined XZ and YZ. Now XYZ in the required triangle.

(iii) An isosceles triangle with equal sides 4.6 cm and third side 6.5 cm
Solution:

Construction: .
Step 1: Drawn a line. Marked X and Y on the line such that XY = 6.5 cm.
Step 2: With X as centre, drawn an arc of radius 4.6 cm above the line XY
Step 3: with Y as centre, drawn an arc of radius 4.6 cm to intersect arc drawn in steps. Marked the point of intersection as Z.
Step 4: Joined XZ and YZ. Now XYZ is the required triangle.

II. Construct a triangle ABC with given conditions.

(i) AB = 7 cm, AC = 6.5 cm and ∠A = 120°.
Solution:

Construction:
Step 1: Drawn a line. Marked A and B on the line such that AB = 7 cm.
Step 2: At A, drawn a ray AX making an angle of 120° with AB.
Step 3: With A as centre, drawn an arc of radius 6.5 cm to cut the ray AX. Marked the point of intersection as C.
Step 4: Joined BC.
ABC is the required triangle.

(ii) BC = 8 cm, AC = 6 cm and ∠C = 40°.
Solution:


Construction:
Step 1: Drawn a line. Marked B and C on the line such fhat BC = 8 Cm.
Step 2: At C, drawn a ray CY making an angle of 40° with BC.

Step 3: With C as centre, drawn an arc of radius 6 cm to cut the ray CY, marked the point of intersection as A.
Step 4: Joined AB.
AB is the required triangle.

(iii) An isosceles obtuse triangle with equal sides 5 cm
Solution:

Construction:
Step 1: Drawn a line. Marked B and C on the line such that BC = 5 cm.
Step 2: At B drawn a ray BY making on obtuse angle 110° with BC.
Step 3: With B as centre, drawn an arc of radius 5 cm to cut ray BY. Marked the point of intersection as C.
Step 4: Joined BC. ABC is the required triangle.

III. Construct a triangle PQR with given conditions.

(i) ∠P = 60°, ∠R = 35° and PR = 7.8 cm
Solution:

Construction:
Step 1: Drawn a line. Marked P and R on the line such that PR = 7.8 cm.
Step 2: At P, drawn a ray PX making an angle of 60° with PR.
Step 3: At R, drawn another ray RY making an angle of 35° with PR. Mark the point of intersection of the rays PX and RY as Q.
PQR is the required triangle.

(ii) ∠P = 115°, ∠Q = 40° and PQ = 6 cm
Solution:

Construction:
Step 1: Drawn a line. Marked P and Q on the line such that PQ = 6 cm.
Step 2: At P, drawn O ray PX making an angle of 115° with PQ.
Step 3: At Q, drawn another ray QY making an angle of 40° with PQ. Marked the point of intersection of the rays PX and Q Y as R.
PQR is the required triangle.

(iii) ∠Q = 90°, ∠R = 42° and QR = 5.5 cm
Solution:

Construction:
Step 1: Drawn a line. Marked Q and R on the line such that QR = 5.5 cm.
Step 2: At Q, drawn a ray QX making an angle of 90° with QR.
Step 3: At R, drawn another ray RY making an angle of 42° QR. Marked the point of intersection of the rays QX and RY as P.
PQR is the required triangle.

Objective Type Questions

Question 8.
If two plans figures are congruent then they have
(i) same size
(ii) same shape
(iii) same angle
(iv) same shape and same size
Answer:
(iv) same shape and same size

Question 9.
Which of the following methods are used to check the congruence of plane figures?
(i) translation method
(ii) superposition method
(iii) substitution method
(iv) transposition method
Answer:
(ii) superposition method

Question 10.
Which of the following rule is not sufficient to verify the congruency of two triangles.
(i) SSS rule
(ii) SAS rule
(iii) SSA rule
(iv) ASA rule
Answer:
(iii) SSA rule

Question 11.
Two students drew a line segment each. What is the condition for them to be congruent?
(i) They should be drawn with a scale.
(ii) They should be drawn on the same sheet of paper.
(iii) They should have different lengths.
(iv) They should have the same length.
Answer:
(iv) They should have the same length.

Question 12.
In the given figure, AD = CD and AB = CB. Identify the other three pairs that are equal.

(i) ∠ADB = ∠CDB, ∠ABD = ∠CBD, BD = BD
(ii) AD = AB, DC = CB, BD = BD
(iii) AB = CD, AD = BC, BD = BD
(iv) ∠ADB = ∠CDB, ∠ABD = ∠CBD, ∠DAB = ∠DBC
Answer:
(i) ∠ADB = ∠CDB, ∠ABD = ∠CBD, BD = BD

Question 13.
In ∆ABC and ∆PQR, ∠A = 50° = ∠P, PQ = AB, and PR = AC. By which property ∆ABC and ∆PQR are congruent?
(i) SSS property
(ii) SAS property
(iii) ASA property
(iv) RHS property
Answer:
(ii) SAS property

Students can Download Maths Chapter 2 Algebra Intext Questions and Answers, Notes Pdf, Samacheer Kalvi 8th Maths Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 2 Algebra Intext Questions

Exercise 2.1
Try These (Text book page no. 32)

Question 1.
Identify which among the following are linear equations.

1. 2 + x = 19 – Linear as degree of the variable x is 1
2. 7x² – 5 = 3 – not linear as highest degree of x is 2
3. 4p³ = 12 – not linear as highest degree ofp is 3
4. 6m + 2 – Linear, but not an equation
5. n = 10 – Linear equation as degree of n is 1
6. 7k – 12= 0 – Linear equation as degree of Hs 1
7. \(\frac{6x}{8}\) + y = 1 – Linear equation as degree ofx & y is 1
8. 5 + y = 3x – Linear equation as degree ofy & x is 1
9. 10p + 2q = 3 – Linear equation a& degree ofp & q is 1
10. x² – 2x-4 – not linear equation as highest degree of x is 2

Think (Text book page no. 32)

Question 1.
Is t(t – 5)= =10 a linear equation? Why?
Solution:
t(t – 5) = 10
= t x t – 5 x t = 10
= t² – 5t = 10
This is not a linear equation as the highest degree of the variable ‘t’ is 2

Question 2.
Is x² = 2x, a linear equation? Why?
Solution:
x² = 2x
= x² – 2x = 0
This is not a linear equations as the highest degree of the variable ‘x’ is 2

Try These (Text book page no. 33)

Convert the following statements into linear equations:

Question 1.
On subtracting 8 from the product of 5 and a number, I get 32.
Solution:
Convert to linear equations:
Given that on subtracting 8 from product of 5 and a, we get 32
5 × x – 8 = 32
5x – 8 = 32

Question 2.
The sum of three consecutive integers is 78.
Solution:
Sum of 3 consecutive integers is 78
Let 1st integer be ‘x’
∴ x + (x + 1) + (x + 2) = 78
∴ x + x + 1 + x + 2 = 78
3x + 3 = 78

Question 3.
Peter had a Two hundred rupee note. After buying 7 copies of a book he was left with ₹ 60.
Solution:
Let cost of one book be ‘x’
∴ Given that 200 – 7 × x = 60
∴ 200 – 7x = 60

Question 4.
The base angles of an isosceles triangle are equal and the vertex angle measures 80°.
Solution:
Let base angles each be equal to x & vertex bottom angle is 80°. Applying triangle
property, sum of all angles is 180°
∴ x + x + 80 = 180°
2x + 80 = 180°

Question 5.
In a triangle ABC, ∠A is 10° more than ∠B. Also ∠C is three times ∠A. Express the equation in terms of angle B
Solution:
Let ∠B = b
Given ∠A = 10° + ∠B = 10 + b
Also given that ∠C = 3 x ∠A = 3 x (10 + 6) = 30 + 3b
Sum of the angles = 180°
∠A + ∠B + ∠C = 180°
10 + b + b + 30 + 3b = 180°
∴ 5b + 40 = 180°

Think (Text book page no. 34)

Question 1.
Can you get more than one solution for a linear equation?
Solution:
Yes, we can get. Consider the below line or equation
x + y = 5
here, when x = 1, y = 4
when x = 2, y = 2
x = 3, y = 2
x = 4, y = 1
Hence, we get multiple solutions for the same linear equation.

Think (Text book page no. 35)

Question 1.
“An equation is multiplied or divided by a non zero number on either side.” Will there be any change in the solution?
Solution:
Not be any change in the solution

Question 2.
“An equation is multiplied or divided by two different numbers on either side”. What will happen to the equation?
Solution:
When an equation is multiplied or divided by 2 different numbers on either side, there will be a change in the equation & accordingly, solution will also change.

Exercise 2.2
Think (Text book page no. 37)

Question 1.
Suppose we take the second piece to be x and the first piece to be (200 – x), how will the steps vary. Will the answer be different?
Solution:
Let 2nd piece be V & 1st piece is 200 – x
Given that 1st piece is 40 cm smaller than hence the other piece
∴ 200 – x = 2 × x – 40

200 + 40 = 2x + x
240 = 3x
∴ x = \(\frac{240}{3}\) = 80
∴ 1st piece = 200 – x = 200 – 80 = 120 cm
2nd piece = x = 80 cm
The answer will not change

Exercise 2.3
Think (Text book page no. 43)

Question 1.
If instead of (4, 3), we write (3, 4) and try to mark it, will it represent ‘M’ again?
Solution:
Let 3, 4 be M, when we mark, we find that it is a different point and not ‘M’

Try These (Text book page no. 45)

Question 1.
Complete the table given below.

Solution:

Question 2.
Write the coordinates of the points marked in the following figure

• A – (-3, 2)
• B – (5, 2)
• C – (5, -3)
• D – (-3, 3)
• E – (-1,4)
• F – (1, 2)
• G – (7, 4)
• H – (0, 2)
• i – (o, 3)
• J – (-3, 0)
• K – (5, 0)
• L – (-1, 0)
• M – (-2, 0)
• N – (-2, -1)
• O – (0, 0)
• P – (-1, -1)
• Q – (1, -1)
• R – (2, -1)
• S – (0, -3)
• T – (7, 0)
• U – (7, -2)

Exercise 2.4
Think (Text book page no. 49)

Question 1.
Which of the points (5, -10) (0, 5) (5, 20) lie on the straight line X = 5?
Solution:
All points on the line X = 5 will have X – coordinate as 5.
Therefore, any point with X – coordinate as 5 will lie on X = 5 line.
Hence the points (5, – 10) & (5,20) will lie on X = 5

Think (Text book page no. 54)

Question 1.
Why is it given that the speed is ‘constant’? If the speed is not constant, will the graph be the same? The graph is named as y = 80 x algebraically. Why?
Solution:

or in other words, the slope of a line in a distance – time graph. We observe that the slope of the graph is constant hence, speed is constant. If the speed is not constant, the graph will be different as slope of the line would change.

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

Tamilnadu Samacheer Kalvi 9th Science Solutions Chapter 16 Applied Chemistry

Samacheer Kalvi 9th Science Applied Chemistry Textbook Exercises

I. Choose the correct answer.

Question 1.
One Nanometre is ………………
(a) 10^{– 7} metre
(b) 10^{– 8} metre
(c) 10^{– 6} metre
(d) 10^{– 9} metre
Answer:
(d) 10^{– 9} metre

Question 2.
The antibiotic Penicillin is obtained from …………………
(a) plant
(b) microorganism
(c) animal
(d) sunlight
Answer:
(b) microorganism

Question 3.
1 % solution of Iodoform is used as ……………..
(a) antipyretic
(b) antimalarial
(c) antiseptic
(d) antacid
Answer:
(c) antiseptic

Question 4.
The cathode of an electrochemical reaction involves …………….
(a) oxidation
(b) reduction
(c) neutralisation
(d) catenation
Answer:
(b) reduction

Question 5.
The age of a dead animal can be determined by using an isotope of ………………..
(a) carbon
(b) iodine
(c) phosphorous
(d) oxygen
Answer:
(a) carbon

Question 6.
Which of the following does not contain natural dyes?
(a) Potato
(b) Beetroot
(c) Carrot
(d) Turmeric
Answer:
(a) Potato

Question 7.
This type of food protect us from deficiency diseases.
(a) Carbohydrates
(b) Vitamins
(c) Proteins
(d) Fats
Answer:
(b) Vitamins

Question 8.
Radiochemistry deals with ……………….
(a) oxidants
(b) batteries
(c) isotopes
(d) nanoparticles
Answer:
(c) isotopes

Question 9.
The groups responsible for the colour of an organic compound is called ………………….
(a) isotopes
(b) auxochrome
(c) chromogen
(d) chromophore
Answer:
(d) chromophore

Question 10.
Chlorinated hydrocarbons are used as ……………..
(a) fertilizers
(b) pesticides
(c) food colourants
(d) preservatives
Answer:
(b) pesticides

II. Fill in the blanks.

1. ……………. is an electrochemical cell which converts electrical energy into chemical change (Reaction).
2. Painkiller drugs are called ……………..
3. Aspirin is an …………….
4. …………. , …………….. and …………… are macronutrients required for plant growth.
5. ……………. is a chemical used in fingerprint analysis.

Answer:

1. Electrolytic cell
2. Analgesic
3. Analgesics
4. Nitrogen, Phosphorous, Potassium
5. Ninhydrin

III. Match the following.

Answer:

1. (c) Fever
2. (e) Electroplating
3. (b) Iodine – 131
4. (a) Large surface area
5. (d) Cancer cell identification

IV. Answer in brief.

Question 1.
What is Chemotherapy?
Answer:
Treatment of certain diseases by destroying the invading organism without damaging the cells of the host, by the use of certain organic compounds is known as Chemotherapy.

Question 2.
What are called Anaesthetics? How are they classified?
Answer:
The drugs which cause loss of sensation are called Anaesthetics.
Types of Anaesthetics

General anaesthetics: They are the agents, which bring about loss of all modalities of sensation, particularly pain along with ‘reversible’ loss of consciousness.
Local anaesthetics: They prevent the pain sensation in localised areas without affecting the degree of consciousness.

Question 3.
What is the need for chemical fertilizers in crop fields?
Answer:
Chemical fertilizers provide the essential micro and macronutrients for crop growth that may not be sufficiently available in the soil.

Question 4.
What is Forensic chemistry related to?
Answer:
Forensic chemistry applies scientific principles, techniques, and methods to the investigation of crime.

V. Answer in detail.

Question 1.
Explain the types of dyes based on their method of application.
Answer:
Dyes are classified in two ways, one, based on the method of application and other on their parent structure.

Based on method of application:

• Acid dyes: These are acidic in nature and used for dyeing animal fibres and synthetic fibres. These can be used for protein fibre such as wool and silk. E.g. Picric acid, Naphthol yellow-s
• Basic dyes: These are basic dyes containing basic group (- NH₂,- NHR, – NR₂). They are used for dyeing animal fibres and plant fibres.
• Mordant dyes or Indirect dyes: These dyes have a poor affinity for cotton fabrics and hence do not dye directly. They require pretreatment of the fibre with a mordant. Mordant (latin: mordere = to bite) is a substance which can be fixed to the fibre and then can be combined with the dye to form an insoluble complex called lake. Aluminium, chromium, and iron salts are widely used as mordants. E.g. alizarin.
• Direct dyes: They have high affinity for cotton, rayon and other cellulose fibre. So they are applied directly as they fix firmly on the fabric. E.g. Congo red
• Vat dyes: It can be used only on cotton and, not on silk and wool. This dyeing is a continuous process and is carried out in a large vessel called vat. So it is called as vat dye. E.g. Indigo

Question 2.
Name various food additives and explain their functions.
Answer:

VI. HOTS

Question 1.
Batteries that are used in mobile phone can be recharged. Likewise, can you recharge the batteries used in watches? Justify your answer.
Answer:
A primary cell cannot be recharged. Watch batteries have a primary cell. In a primary cell, chemical energy is converted into electrical energy when current is drawn from it.

Whereas mobile phones use secondary cells. In secondary cells electrical energy is converted to chemical energy when current is passed through it and chemical energy is converted to electrical energy when current is drawn from it.

Question 2.
Sudha met with a fire accident. What kind of drug(s), she must take?
Answer:
Analgesics are to be administered to reduce the pain followed by antibiotics to prevent infection by microbes.

Question 3.
The soil pH of a cropland is 5. What kind of fertilizers should be used in that land?
Answer:
Organic fertilizer like compost can be used to maintain pH of soil at 6.5, which is ideal for soil and to moderate the acidity.

Samacheer Kalvi 9th Science Applied Chemistry Additional Questions

I. Answer briefly.

Question 1.
Explain the structure of an electrolytic cell.
Answer:

• It is an electrochemical cell which converts electrical energy into chemical energy i.e. in electrolytic cells, electricity is used to bring about chemical reactions.
• Here, both anode and cathode are in contact with Anode same electrolyte and thus the half-cells are not separated. As seen in galvanic cells, electrolytic cell also involves redox reaction. We get electricity from galvanic cells. But electrolytic cells use electricity.
• In electrolytic cells, when electricity is passed to the electrolyte, it dissociates into its constituent ions. These ions undergo redox reaction forming the respective elements. This phenomenon is called Electrolysis. So electrolysis is a process by which an electrolyte is decomposed into its constituent elements by passing electricity through its aqueous solution or fused (molten) state.

Question 2.
How does galvanic cell produce electricity?
Answer:
In a galvanic cell, at anode oxidation takes place which releases electrons. These electrons are attracted by cathode and hence the electrons flowing from anode to cathode are gained in reduction reaction. As long as the redox reaction proceeds, there is a flow of electrons and hence electricity.

Question 3.
What are drugs? What are their characteristics?
Answer:
The chemicals used for treating diseases are termed as drug.
Characteristics of drugs: A drug must possess the following;

1. It should not be toxic
2. It should not cause any side effects.
3. It should not affect the receptor tissue
4. It should not affect the normal physiological activities
5. It should be effective in its action.

Question 4.
Write the applications of Nanochemistry.
Answer:
Some applications of Nanochemistry are:

1. The metallic nanoparticles can be used as very active catalysts.
2. Chemical sensors from nanoparticles and nanowires enhance the sensitivity and sensor selectivity.
3. Nanocoatings and nanocomposites are found useful in making a variety of products such as sports equipment, bicycles and automobiles etc.
4. These are used as novel UV-blocking coatings on glass bottles which protect beverages from being damaged by sunlight.
5. Nanotechnology is being applied in the production of synthetic skin and implant surgery.
6. Nanomaterials that conduct electricity are being used in electronics as minute conductors to produce circuits for microchips.
7. Nanomaterials have extensive applications in the preparation of cosmetics, deodorants and sunscreen lotion and they are used to improve moisturizers without making them too oily.
8. Nanoparticle substances are incorporated in fabrics to prevent the growth of bacteria.
9. Biomedical devices like drug infusion pumps, microneedles and glucometer are made from nanomaterials.
10. Nanochemistry is used in making space, defence and aeronautical devices

Question 5.
What are the applications of Radiochemistry?
Answer:
Important applications of radioisotopes are as under –

• Radiocarbon dating – its a method by which the age of fossil wood or animal is determined using C-14 isotope.
• Study of chemical reactions – the nature of some chemical reactions can be studied by mixing a radioisotope with a non-radioactive isotope of the reactants. The radioisotope used for this purpose is radiotracer.
• Diagnosis – Radioisotope is found very useful to diagnose and understand many diseases.

Question 6.
Write a note on Natural dyes.
Answer:
Many natural dyes have been known from a long time. These are obtained from vegetable sources.

• Henna: It is a reddish-brown dye obtained from plant Lawsonia inermis (Tamil: Maruthondri). A paste of these leaves is used as a hair dye and also for colouring palms.
• Turmeric: It is the traditional natural cosmetic in India. It is obtained from the plant Curcuma. longa. It also acts as an antiseptic. Turmeric is mostly used in India for colouring food.

Question 7.
What is electroplating? Why is it done?
Answer:
The process of depositing a thin layer of one metal over another metal by the process of electrolysis is called electroplating.

It is done to protect the metal from corrosion. For example, metals like iron are electroplated with tin, nickel or chromium to protect from rusting.

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

Tamilnadu Samacheer Kalvi 9th English Vocabulary Idioms

An idiom is an expression in English with a special meaning of its own. Idioms do not give the literal meaning of the individual words used in them.

Here are a few sentences with idioms (meanings are given in brackets):

• Business is going from bad to worse, (deteriorate further)
• They always do things in a big way, (on a large scale)
• The government has taken a very hard line (not giving in) against illegal quarrying.
• Orders for the new product are coming in thick and fast, (in large numbers)
• How can any one make ends meet (manage with the money) with just ? 2000/- a month?
• Your son’s behavior is a matter of concern, (something to worry about)
• The name sounds familiar but I can’t call her face to mind, (recall something from memory; recognise)
• My uncle loves to tell us how to play cricket. He is an armchair expert.
  (one who gives advice in an area in which he was not actively involved)
• Ravi is our sincere employee. He has had a clean slate (a past record without discredit) for over twenty years.
• The policeman went near the damaged car to have a look at close quarters, (very near)
• Dr. Jacob is at the helm (in charge) of affairs in this hospital.
• No one can make a break even (make no profit or loss) in the first year of business.
• Because of the steep rice in prices, people living on pension feel the pinch, (feeling unpleasant change in one’s standard of living)
• Let us settle the bill for the damage fair and square, (in a fair way)
• I can hear you over phone loud and clear, (very clearly)
• By and by (as time goes by) he will realise that my going to Delhi was the right decision.

Idioms from the Textual Exercises
Idiom – Meaning
1. alarm bells ringing – a sign of something going wrong
2. back to the wall – in serious difficulty
3. below the belt – unfair or unsporting behavior
4. by the skin of one’s teeth – a narrow escape.
5. drive one up the wall – to annoy or irritate someone
6. asp / clutch at straws – try any method to overcome a crisis
7. hang out to dry – abandoning one who is in difficulty
8. have cold feet – feel nervousness and anxiety
9. hit the road – to begin one’s journey
10. in a nice pickle – in a troublesome or difficult situation
11. in our corner – on your side in an argument or dispute
12. in panic mode – in a frightening state
13. on the ropes – state of near collapse or defeat
14. right up to one’s alley – ideally suited to one’s interest
15. saved by the bell – help at the last moment rescuing one from a difficult situation
16. shot his bolt – to exhaust one’s effort
17. square off – prepare for a conflict
18. take (one) for a ride – to deceive someone
19. throw in the towel – to give up
20. tight corners – difficult situations

Some more idioms and meanings :

1	a bolt from the blue	unexpected event; complete surprise (usually unwelcome)
2	a drop in the ocean	a very small amount compared with what is needed or expected
3	a great deal	plenty of
4	a penny for your thoughts	a way of asking what someone is thinking.
5	a stone’s throw	a very short distance
6	a storm in a teacup	a big fuss about a small problem
7	a wild goose chase	a worthless hunt or chase
8	a yellow streak	cowardice in one’s character
9	above board	honest, not a secret
10	add insult to injury	to worsen an unfavorable situation
11	armchair expert	one who gives advice in an area in which he was not actively involved
12	at close quarters	very near
13	at hand	very near
14	at loggerheads	to disagree strongly
15	at snail’s pace	very slowly
16	at the drop of the hat	without any hesitation
17	at the eleventh hour	at the last moment
18	at the end of one’s tether	to have no power, patience or endurance left
19	at the helm	in charge
20	at the mercy of	under the control of
21	barking up the wrong tree	accusing the wrong person
22	be armed with	be equipped with
23	be fit for	suitable
24	be part of	belong to
25	beat around the bush	avoiding the main topic
26	bed of roses	comfortable position
27	best of both worlds	all the advantages
28	big way	on a large scale
29	bite the bullet	to get something over with because it is inevitable
30	blessing in disguise	something good that isn’t recognized at first.
31	bolt from the blue	something that happened without warning
32	break even	make no profit or loss
33	break the ice	make people feel more comfortable
34	break through	penetrate
35	bring forth	produce
36	burst into	enter suddenly
37	by and by	as time goes by
38	by nature	because of natural habits
39	call it a day	stop working on something
40	can’t judge a book by its cover	cannot judge something primarily on appearance.
41	clean slate	a past record without discredit
42	comparing apples to oranges	comparing two things that cannot be compared
43	costs an arm and a leg	very expensive
44	curiosity killed the cat	being inquisitive can lead you into an unpleasant situation.
45	devil’s advocate	to present a counter argument
46	draw a blank	unable to get information
47	every cloud has a silver lining	good-things come after bad things
48	eyesore	ugly sight
49	eyewash	something to deceive
50	fair and square	in a fair way
51	fall a prey to	become a victim
52	far cry from	very different from
53	far from	distant
54	feel the pinch	feeling unpleasant change in one’s standard of living
55	fit as a fiddle	in good health
56	fortune favours the bold	take risks
57	give (someone) a piece of one’s mind	to tell someone frankly what one thinks especially when one disapproves of the other’s behaviour
58	give someone the cold shoulder	ignore someone
59	go down in flames	fail spectacularly
60	go on a wild goose chase	to do something pointless
61	going from bad to worse	deteriorate further
62	good-for-nothing	worthless
63	hang around	someone strongly to loiter
64	hang in there	don’t give up
65	hard to come by	difficult to find
66	have a hand	to get involved
67	have no hand in	does not take part in an activity
68	head back	return
69	herculean task	difficult task
70	hit the nail on the head	do or say something exactly right
71	hit the sack	go to sleep
72	holds good	valid at the time of discussion
73 ,	honour bound (to do something)	required to do something as a moral duty but not by law
74	in a nutshell	briefly
75	in all walks of life	all social groups
76	in deep waters	in trouble
77	in hot pursuit	following closely
78	in short supply	Not enough / scarce
79	in the hands of	in the care of
80	in the service of	available for
81	it is a piece of cake	it is easy
82	it’s Taining cats and dogs	it’s raining hard
83	keep pace with	to move with same speed
84	keep something at bay	keep something away
85	kicked the bucket	passed away
86	leave no stone unturned	look everywhere
87	let the cat out of the bag	give away a secret
88	lion’s share	major share
89	look down upon	treat with contempt                        .
90	loud and clear	very clearly
91	make both ends meet	live within means
92	make fun of	ridicule
93	make up one’s mind	decide, determine
94	matter of concern	something to worry about
95	miss the boat	it’s too late
96	muffle up	to cover
97	not playing with a full deck	someone who lacks intelligence
98	note of hand	promissory note
99	null and void	invalid
100	on cloud nine	to be extremely happy
101	once and for all	completely and finally
102	once in a blue moon	vary rarely
103	one thing leads to another	series of events in which each event was caused by the previous one.
104	out of place	unsuitable
105	pink of health	extremely healthy, in perfect condition
106	play an important role	to have a significant position
107	pull yourself together	calm down
108	put on airs	behave in an unnatural way to impress others
109	shadow of one’s self	not having the strength, former self influence, etc., that one once had
110	side by side	along with
111	speak volumes	to express something very clearly and completely
112	spill the beans	give away a secret
113	take to one’s heels	to run away
114	taken a very hard line	not giving in
115	the ball is in your court	it’s your decision
116	the burning question	a crucial issue
117	the whys and wherefores	the reasons for something
118	thick and fast	in large numbers
119	tit for tat	revenge
120	told him flat	expressed opinion directly
121	tread on	walk with difficulty
122	trial and error	to try many times to succeed
123	tricks of the trade	the expertise of doing business
124	well-balanced	well adjusted
125	whole nine yards	everything, all of it
126	wouldn’t be caught dead	would never like to do something
127	with a bang	in a very exciting way

Exercises
(i) Choose the correct option to complete the given idioms.
1. A bolt from _________.
(a) the white (b) the sky (c) the green (d) the blue
Answer:
(d) the blue

2. A storm _________.
(a) at sea (b) in the ocean (c) in a coffee cup (d) in a tea cup
Answer:
(d) in a tea cup

3. Can’t judge a book, _________.
(a) by the colour (b) by its cover (c) by its pages (d) by its author
Answer:
(db) by its cover

4. Every cloud _________.
(a) is dark (b) hides the sun (c) has a silver lining (d) brings rain
Answer:
(c) has a silver lining

5. Casts an arm _________.
(a) and a face (b) and a finger (c) and a leg (d) and some money
Answer:
(c) and a leg

6. Add insult to _________.
(a) friend (b) enemy (c) neighbor (d) injury
Answer:
(d) injury

7. A penny for _________.
(a) a picture (b) honesty (c) hard work (d) your thoughts
Answer:
(d) your thoughts

8. Fortune favors
(a) the hardworking (b) the poor (c) the rich (d) the bold
Answer:
(d) the bold

9. Hit the nail _________.
(a) on the wall (b) on the door (c) in the bench (d) on the head
Answer:
(d) on the head

10. Once in a _________.
(a) blue moon (b) in a tea cup (c) new moon (d) full moon
Answer:
(a) blue moon

(ii) Give a suitable idiom for the given meanings.

1. Say something exactly right.
Answer:
To hit the nail on the head.

2. All social groups.
Answer:
All walks of life.

3. It’s raining hard.
Answer:
Its raining cats and dogs.

4. Passed away.
Answer:
Kicked the bucket.

5. Live within means.
Answer:
To make both ends meet.

6. Invalid.
Answer:
Null and void.

7. Extremely healthy.
Answer:
Pink of health.

8. Give away a secret.
Answer:
To let the cat out of the bag.

9. Revenge.
Answer:
Tit for that.

10. In trouble.
Answer:
In deep waters.

Students can Download Maths Chapter 2 Algebra Ex 2.4 Questions and Answers, Notes Pdf, Samacheer Kalvi 8th Maths Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 2 Algebra Ex 2.4

Question 1.
Fill in the blanks:

Question (i)
y = px where p ∈ Z always passes through the ………
Answer:
Origin (0, 0)
Hint:
[When we substitute x = 0 in equation, y also becomes zero. (0,0) is a solution]

Question (ii)
The intersecting point of the line x = 4 and y = – 4 is ………
Answer:
4, -4
Hint:
x = 4 is a line parallel to the y – axis and
y = – 4 is a line parallel to the x – axis. The point of intersection is a point that lies on both lines & which should satisfy both the equations. Therefore, that point is (4, -4)

Question (iii)
Scale for the given graph, on the x – axis 1 cm = ……… units y – axis 1 cm = ………. units

Answer:
3 units, 25 units
Hint:
With reference to given graph,
On the x – axis, 1cm = 3 units
y axis, 1cm = 25 units

Question 2.
Say True or False:

Question (i)
The points (1, 1) (2, 2) (3, 3) lie on a straight line.
Answer:
True
Hint:
The points (1, 1), (2, 2), (3, 3) all satisfy the equation y = x
which is straight line. Hence, it is true

Question (ii)
y = – 9x not passes through the origin.
Answer:
False
Hint:
y = – 9x substituting forx as zero, we get y = – 9 x 0 = 0
∴ for x = 0, y = 0. Which means line passes through (0, 0), hence statement is false.

Question 3.
Will a line pass through (2, 2) if it intersects the axes at (2, 0) and (0, 2).
Solution:
Given a line intersects the axis at (2, 0) & (0, 2)
Let line intercept form be expressed as
ax + by = 1 Where a & b are the x & y intercept respectively.
Since the intercept points are (2, 0) & (0, 2)
a = 2, b = 2
∴ 2x + 2y = 1
When the point (2, 2) is considered & substituted in the equation
2x + 2y = 1 we get
2 x 2 + 2 x 2 = 4 ≠ 1
∴ The point (2, 2) does not satisfy the equation. Therefore the line does not pass through (2, 2)
Alternatively graphical method:
as we can see the line doesn’t pass through (2, 2)

Question 4.
A line passing through (4, – 2) and intersects the Y – axis at (0, 2). Find a point on the line in the second quadrant.
Solution:

Line passes through (4, – 2)
y – axis intercept point – (0, 2)
using 2 point formula,
\(\frac { y-y_{ 1 } }{ x-x_{ 1 } } \) = \(\frac { { y }_{ 2 }-{ y }_{ 1 } }{ { x }_{ 2 }-{ x }_{ 1 } } \)
\(\frac{y-2}{x-0}\) = \(\frac{1-2-2}{4-0}\)
∴ \(\frac{y-2}{x}\) = \(\frac{-4}{4}\) = – 1
y – 2 = – 1 × x

∴ x + y = 2 is the equation of the line.
Any point in II quadrant will have x as negative & y as positive.
So let us take x value as – 2
∴ – 2 + y = 2
y = 2 + 2 = 4
∴ Point in II Quadrant is (-2, 4)

Question 5.
If the points P (5, 3) Q(- 3, 3) R (- 3, – 4) and S form a rectangle then find the coordinate of S.
Solution:
Plotting the points on a graph (approximately)

Steps:

1. Plot P, Q, R approximately on a graph.
2. As it is a rectangle, RS should be parallel to PQ & QR should be parallel to PS
3. S should lie on the straight line from R parallel to x – axis & straight line from P parallel to y – axis
4. Therefore, we get S to be (5, -4)

[Note: We don’t need graph sheet for approximate plotting. This is just for graphical understanding]

Question 6.
A line passes through (6, 0) and (0, 6) and an another line passes through (- 3, 0) and (0, – 3). What are the points to be joined to get a trapezium?
Solution:
In a trapezium, there are 2 opposite sides that are parallel. The other opposite sides are non-parallel.
Now, let us approximately plot the points for our understanding [no need of graph sheet]

1. Plot the points (0, 6), (6, 0), (-3, 0) & (0, – 3)
2. Join (0, 6) & (6, 0)
3. Join (-3, 0) & (0, -3)
4. We find that the lines formed by joining the points are parallel lines.
5. So, for forming a trapezium, we should join (0, 6), (-3, 0) & (0, -3), (6, 0)

Question 7.
Find the point of intersection of the line joining points (- 3, 7) (2, – 4) and (4, 6) (- 5, 7). Also find the point of intersection of these lines and also their intersection with the axis.
Solution:

Equation of line joining 2 points by 2 point formula is given by
\(\frac { y-y_{ 1 } }{ x-x_{ 1 } } \) = \(\frac { { y }_{ 2 }-{ y }_{ 1 } }{ { x }_{ 2 }-{ x }_{ 1 } } \)
∴ \(\frac{y-7}{x-(-3)}\) = \(\frac{-4-7}{2-(-3)}\)
\(\frac{y-7}{x+3}\) = \(\frac{-11}{2+3}\)
∴ \(\frac{y-7}{x+3}\) = \(\frac{-11}{5}\)
Cross multiplying, we get

Transposing the variables, we get
11x + 5y = 35 – 33 = 2
11x + 5y = 2 – Line 1
Similarly, we should find out equation of second line

∴ 9y – 54 = 13x – 52
9y – 13x = 2 – Line 2
For finding point of intersection, we need to solve the 2 line equation to find a point that will satisfy both the line equations.
∴ Solving for x & y from line 1 & line 2 as below
11x + 5y = 2 ⇒ multiply both sides by 13,
11 x 13x + 5 x 13y = 26
Line 2:
9y – 13x = 2 ⇒ multiply both sides by 11
9 x 11y – 13 x 11x = 22

Substituting this value of y in line 1 we get
11x + 5y = 2
11x + 5 x \(\frac{12}{41}\) = 2
11x = 2 – \(\frac{60}{41}\) = \(\frac{82-60}{41}\) = \(\frac{22}{41}\)
x = \(\frac{2}{41}\)
∴ Point of intersection is (\(\frac{2}{41}\) \(\frac{12}{41}\))
To find point of intersection of the lines with the axis, we should substitute values & check
Line 1:
11x + 5y = 2
Point of intersection of line with x – axis, i.e y coordinate is ‘0’
∴ put y = 0 in above equation
∴ 11x – 5 x 0 = 2
11x + 0 = 2
x = \(\frac{2}{11}\)
∴ Point is (\(\frac{2}{11}\), 0)
Similarly, point of intersection of line with y – axis is when x – coordinate becomes ‘0’
∴ put x = 0 in above equation
∴ 11 x 0 + 5y = 2
∴ 0 + 5y = 2
y = \(\frac{2}{5}\)
∴ Point is (0, \(\frac{2}{5}\))
Similarly for line 2,
9y – 13x = 2
For finding x intercept, i.e point where line meets x axis, we know thaty coordinate becomes ‘0’
∴ Substituting y – 0 in above eqn. we get
9 x 0 – 13x = 2
∴ 0 – 13x = 2
x = \(\frac{-2}{13}\)
∴ Point is (\(\frac{-2}{13}\), 0)
Similarly for y – intercept, x – coordinate becomes ‘0’,
∴ Substituting for x = 0 in above equation, we get
9y – 13 x 0 = 2
9y – 0 = 2
9y = 2
y = \(\frac{2}{9}\)
Point is (0, \(\frac{2}{9}\))

Question 8.
Draw the graph of the following equations:

1. x = – 7
2. y = 6

Solution:

Question 9.
Draw the graph of

1. y = – 3x
2. y = x – 4

Solution:
To draw graph, we need to find out some points.
1. for y = – 3x, let us first substituting values & check
put x = 0
y = – 3 x 0 = 0 ∴ (0,0) is a point
put x = 1
y = – 3 x 1 = – 3 ∴ (1, – 3) is a point
If join these 2 points, we will get the line

2. for y = x – 4
put x = 0
y = 0 – 4 = -4 ∴ (0, – 4) is a point
x = 4
y = 4 – 4 = 0 ∴ (4, 0) is a point
Now let us plot the points & join them on graph

Question 10.
Find the values

Solution:
Let y = x + 3
(i) if x = 0
y = 0 + 3 = 3
∴ y = 3

(ii) y = 0
0 = x + 3
∴ x = – 3

(iii) x = – 2
y = – 2 + 3
∴ y = 1

(iv) y = -3
-3 = x + 3
∴ x = -6

Let 2x + 7 – 6 = 0
(i) x = 0
2 x 0 + y – 6 = 0
∴ 7 = 6

(ii) y = 0
2x + 0 – 6 = 0
2x = 6
x = 3

(iii) x = – 2
2 x (- 2) + y – 6 = 0
y – 10 = 0
y = 10

(iv) y = -3
2x – 3 – 6 = 0
2x = 9
x = \(\frac{9}{2}\)

Question 11.
The following is a table of , values connecting the radii of a few circles and their circumferences (Taking π = \(\frac{22}{7}\)) Illustrate the relation with a graph and find

1. The radius when the circumference is 242 units.
2. The circumference when the radius is 24.5 units.

Solution:

r = 24.5 Circumference?

Steps :

1. Draw the axis, x – axis = radius & y – axis = circumference
2. Mark the points by choosing scale of 1 cm = 7 units for x axis & 1 cm = 44 units for y – axis
3. Join the points to form a line.
4. Now for r value = 24.5 (mid value between 21 & 28), draw vertical line to touch the main line & from there drop line parallel to x axis and note where it meets y axis.

It meets between 132 & 176. Taking the mid value
i.e \(\frac{132+176}{2}\) = 154, we get circumference of 154 when r = 24.5.
Similarly, for circumference of 242, we get r value to be 38.5

Question 12.
An over-head tank is full with water. Water leaks out from it, at a constant rate of 10 litres per hour. Draw a “time-wastage” graph for this situation and find

1. The water wasted in 150 minutes
2. The time at which 75 litres of water is wasted.

Solution:
From over head tank, water leaks out at 10 l/hr.
∴ Let us see how much leakage happens with time
Time     Leakage
1 hr        10 ltrs.
2 hrs       20 ltrs.
3 hrs       30 ltrs.
4 hrs       40 ltrs.. and so on
150 min = 120 min + 30 min
= 2 hr 30 min = 2 \(\frac{1}{2}\) hrs
Now let us plot a graph between time & water leakage

Water wasted in 150 min (2\(\frac{1}{2}\) hrs) = 25 litres
Time at which 75 litre of water is wasted = 7\(\frac{1}{2}\) hrs = 450 minutes.

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

Tamilnadu Samacheer Kalvi 9th English Grammar Phrasal Verbs

A phrasal verb is a verb that is made up of a main verb together with an adverb or a preposition or both, to create a completely new meaning.

Exercises

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

Tamilnadu Samacheer Kalvi 9th English Grammar Auxiliaries Verbs

A phrasal verb is a verb that is made up of a main verb together with an adverb or a preposition or both, to create a completely new meaning.

• Modals are special verbs which behave irregularly in English.
• These verbs perform several important functions in the formation of sentences.
• They have multiple uses that need to be understood for efficient use of the English language both for written and spoken purposes.

Modals Are Used In/To

• Indicate Tenses
• Frame Questions
• Short answers
• Question Tag
• Active & Passive Voice
• Direct & Indirect speech Negatives

Here Are Some Characteristics Of Modal Verbs :

• They never change their form. You can’t add “s”, “ed”, “ing”…
• They are always followed by an infinitive without “to” (i.e. the bare infinitive.)
• They are used to indicate modality allow speakers to express certainty, possibility, willingness, obligation, necessity, ability etc.,

Examples Of Modal Verbs
Here Is A List Of Modals With Examples:

Exercise
(i) Fill in the blanks with appropriate modal auxiliary verbs.
1. My grandmother is eighty-five, but she _________ still read and write without glasses
Answer:
can

2. _________ I come with you?
Answer:
Shall

3. _________ you help me with the housework, please?
Answer:
Could

4. There was a time when I _________ stay up very late.
Answer:
used to

5. you _________ lose any more weight. You are already slim.
Answer:
need not

6. we _________ not make the first move.
Answer:
must

7. It is snowing outside so I _________ stay at home.
Answer:
should

8. I _________ get you a shawl from Kashmir.
Answer:
shall

9. _________ you mind if I borrowed your car?
Answer:
Would

10. _________ you take care of my dog for a day?
Answer:
Can I Could

11. Our country _________ become a super power by 2025.
Answer:
may

12. She _________ sell her home because she needs money.
Answer:
might

13. _________ we visit Ajanta and Ellora?
Answer:
Shall

14. _________ you come with us?
Answer:
Will

15. The Captain said, ‘Players _________ assemble at the ground at 4 P.M.’
Answer:
must

16. I _________ not be unfair to him.
Answer:
should

17. We _________ do all the work for the common good.
Answer:
ought to

18. You _________ tell the truth.
Answer:
should

19. Excuse me _________ you tell me where the bus station is?
Answer:
can

20. She _________ play the flute and the guitar.
Answer:
can

21. When we were younger, we _________ watch movies all afternoon!
Answer:
used to

22. If you want to camp in the park, you _________ to pay for a permit first.
Answer:
need

23. He _________ go inside, or he will get a terrible sunburn!
Answer:
should

24. He _________ stop drinking so much coffee, or he will make himself sick!
Answer:
must

25. He _________ bring the food very soon.
Answer:
will

26. We _________ definitely win the championship game.
Answer:
must

27. I _________ rather have a cup of tea.
Answer:
would

28. You _________ stop eating pizzas because it is bad for you.
Answer:
should

29. _________ I sit down now?
Answer:
Mav

30. I _________ go now
Answer:
must

31. I _________ tell the truth to the teacher.
Answer:
ought to

32. _________ you pass me the ketchup?
Answer:
Could

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

Tamilnadu Samacheer Kalvi 9th English Grammar Non-finite verbs (Gerund, Infinitives, Participles)

A non-finite verb (also known as a verbal) is the term used to describe a verb that does not indicate tense. The non-finite verbs are called gerunds, infinitives, and participles.

• Finite verb : A verb that indicates tense and changes according to the subject
• Non-Finite verb : A verb that does not indicate tense and does not change according to the subject

Finite verb
Finite verbs change tense and number according to the subject.

• Arun invited Suresh to his daughter’s birthday.
• Her friends presented the girl with a toy.
• His friend presented a watch.

Non-finite verbs
Non-finite verbs have no subject and do not change according to the tense or number.

Non-finite verbs are broadly classified as follows:
i. Gerunds 1. Viking Is a healthy habit (Present participle used as a noun)
ii. Infinitive 2. I like to walk early in the morning. (lo infinitive)
iii. Present participle 3. These are my walking shoes. (Present participle used as an adjective)
iv. Past participle 4. Having walked a long distance I felt tired

Infinitives and Gerunds
The infinitive is often called as ‘to verb’. It functions as a subject or object.
SUBJECT : (e.g.) To swim is a good exercise. – Subject
OBJECT : (e.g.) I like to swim – Object

Infinitives may be used without to and we call such infinitives plain infinitives or bare infinitives.
(e.g.) She made me do my project.
We use plain/bare infinitives with these models.

shall will do did would make need
may might could must let dare see

The infinitive may function as a subject, direct object, subject complement, adjective, or adverb in a sentence. Although an infinitive is easy to locate because of the to+verb form, deciding what function it has in a sentence depends on the meaning.

(e.g.) To wait seemed foolish when decisive action was required, (subject)
(e.g.) Everyone wanted to go (direct object)
(e.g.) His ambition is to fly, (subject complement)
(e.g.) He lacked the strength to resist, (adjective)
(e.g.) We must study to learn, (adverb)

Gerunds

A gerund is an action word that ends in – ing but functions as a noun

Exercises
(i) Identify the finite and non-finite verbs in the following sentences.
1. I like (finite) to play (non-finite) with my puppy.
2. She works (finite) hard to pass (non-finite) the test.
3. Smoking (non-finite) is prohibited (finite) in the kitchen.
4. He went (finite) to the city to find (non-finite) work.
5. The boy saved (finite) the cat from the dogs.
6. The teacher asked (finite) the students to submit (non-finite) their assignments before they go (finite) home.

(ii) Identify the finite and non-finite verbs in the following sentences and state whether they are infinitives, participles or gerunds.
1. Singing (non-finite – gerund) is (finite verb) his pastime.
2. I like (finite verb) to read (non-finite).
3. It is (finite verb) easy to find (non-finite – infinitive) faults with others.
4. He went (finite verb) to work (non-finite – infinitive) in London.
5. She doesn’t like (finite verb) to do (non-finite – infinitive) anything.
6. I enjoy (finite verb) reading.

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

Tamilnadu Samacheer Kalvi 9th English Grammar Prepositional Phrases

A prepositional phrase is a modifying phrase consisting of a preposition and its object. Example prepositions: across, in, under, around, beneath, over, up, without etc.

A Prepositional phrase is a group of words that begin with a preposition and help to explain the relationship between two things.

• on the boat
• over the tree
• in the school

Example :
The present inside the big box is mine.

Exercises
Underline the prepositional phrase in each sentence below.

1. We walked op the stairs.
2. My mom took a walk around the block.
3. I looked under my bed.
4. The girl looked behind the door for her friend who was hiding.
5. Don’t leave without your coat.

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

Tamilnadu Samacheer Kalvi 9th English Grammar Clauses and Phrases

A clause is a group of words that contains both a subject and a predicate (or a verb). There are two types of clauses. They are independent clauses and dependent clauses.

Examples
1. Kalpana wants to buy a phone, but she does not have enough money.
(Independent Clause) (Independent Clause)

2. If you don’t study well, you won’t pass the exam.
(Dependent Clause) (Independent Clause)

3. Kavin bought a car which was too expensive.
(Independent Clause) (Dependent Clause)

4. San Jai is a talented player though he is out of form.
(Independent Clause) (Dependent Clause)

Independent Clauses also known as main clauses, are complete sentences. They can stand alone and express a complete thought.

Examples :

• I need a book.
• Mary prefers coffee.
• Ram is a good volleyball player.

Dependent Clauses also known as subordinate clauses contain a subject and a predicate, but they do not express a complete thought.

Examples:

• When it is raining
• Because you were late
• After you go to school

There are three main types of dependent clauses: adjective, adverb, and noun.

An adjective clause describes or gives more information about a noun—tells us which one, what kind, or how many.
Example :
The book that I left on the bus belongs to Mr. Baskar.

An adverb clause describes or gives more information about the verb—tells us when, where, how, to what extent, or under what condition something is happening.

Example :
She was happy because her father gave her a watch.
A noun clause takes the place of a noun in the sentence.

Example :
This is the best route that I know.

Phrases
A phrase is a group of words that forms a meaningful unit, but it is not a complete sentence. In other words, it does not have a subject or a verb.

• the black hat
• blown away
• in the wind

Example :
The red umbrella was blown away in the wind.

There are several kinds of phrases in the English language. Some of the common phrases are described below.

NOUN PHRASES
A Noun Phrase is a group of words made up of a noun and its modifiers.

• the white car
• my English teacher
• the book shop

Example :
The pink house is for sale.

VERB PHRASES
A Verb phrase is a group of words made up of a verb, helping verbs, and modifiers.

• ran quickly to catch
• filled with horror
• dedicated to

Example :
You have woken up everyone in the house.

Exercises
(i) Choose either phrase or clause from the group of words.
1. He works hard every day. (Clause / Phrase)
Answer:
Clause

2. After a good day. (Clause / Phrase)
Answer:
Phrase

3. If I need to call you. (Clause / Phrase)
Answer:
Clause

4. In a dark and dangerous hallway. (Clause / Phrase)
Answer:
Phrase

5. Before the next light. (Clause / Phrase)
Answer:
Phrase

6. Because it’s the right thing to do. (Clause / Phrase)
Answer:
Clause

7. As quickly as possible. (Clause / Phrase)
Answer:
Phrase

8. This car’s not working. (Clause / Phrase)
Answer:
Clause

9. Working for himself. (Clause / Phrase)
Answer:
Phrase

10. Whenever it gets cold. (Clause / Phrase)
Answer:
Clause

Choose either Dependent or Independent for the group of words.
1. Because it’s the best solution. (Independent / Dependent)
Answer:
Dependent

2. Working at this job is a lot of fun. (Independent / Dependent)
Answer:
Independent

3. It doesn’t really interest me. (Independent / Dependent)
Answer:
Independent

4. I should have given her a ride. (Independent / Dependent)
Answer:
Independent

5. After the movie is over. (Independent / Dependent)
Answer:
Dependent

6. If he ever calls. (Independent / Dependent)
Answer:
Dependent

7. Whenever I have the time. (Independent / Dependent)
Answer:
Dependent

8. There could be a problem. (Independent / Dependent)
Answer:
Independent

9. Since the last time they visited. (Independent / Dependent)
Answer:
Dependent

10. Whenever it gets cold (Independent / Dependent)
Answer:
Dependent