Class 9

MP Board Class 9th Maths Solutions Chapter 7 Triangles Ex 7.4

Question 1.
Show that in a right angled triangle, the hypotenuse is the longest side.
Solution:
Given
ABC is a right angle A.
To prove:
AC > AB and AC > BC

Proof:
In ∆ABC
∠B = 90°
∴ ∠A + ∠C = 90° (by ASP)
and so ∠B > ∠A and ∠B > ∠C
AC > BC and AC > AB
(In a A, sides opposite to large angle are always longer).

Question 2.
In Fig. given below, sides AB and AC of ∆ABC are extended to points P and Q respectively. Also, ∠PBC < ∠QCB. Show that AC > AB.
Solution:
Given
∠PRC < ∠QCB To prove AC > AB

Proof:
In ∆ ABC
Exterior angle is equal to sum of two opposite angles
∠PBC = ∠1 + ∠3 and
∠QCB = ∠1 + ∠2
∠QCB > ∠PBC (given)
⇒ ∠1 + ∠2 > ∠1 + ∠3
⇒ ∠2 > ∠3
∴ AC > AB
(∴ In a A, side opposite to larger angle is always longer).

Question 3.
In Fig. below, ∠B < ∠A and ∠C < ∠D. Show that AD < BC.

Solution:
Given
∠B < ∠A i.e., ∠A > ∠B
∠C < ∠D i.e., ∠D> ∠C
To prove: AD > BC
i.e., BC > AD
Proof:
In ∆OCD
∠D > ∠C
OC > OD
(∴ In a ∆, sides opposite to larger angle are always longer) …(1)
In ∆OBA
∠A > AB
OB > OA
(∴ In a A, sides oppositedo larger angle are always longer) …(2)
Adding (1) and (2), we get
OC + OB > OD + OA
BC > AD

Question 4.
AB and CD are respectively the smallest and longest sides of a quadrilateral ABCD (see Fig. below). Show that ∠A > ∠C and ∠B > ∠D.
Solution:
Given
AB is the smallest siBe and CD is the longest side
To prove:

1. ∠A > ∠C and
2. ∠B > ∠D

Construction:
Join AC

1. Proof:
In, ∆ABC
BC > AB (∴ AB is the smallest side) ∠1 > ∠3
(∴ In a ∆ angle opposite to longer side is always larger) …..(1)
In ∆ACD
CD > AD (∴ CD is the largest side) ∠2 > ∠4
(∴ In a ∆ angles opposite to longer side are always larger) …(2)
Adding (1) and (2), we get
∠1 + ∠2 > ∠3 + ∠4
∠A > ∠C

2. To prove: AB > AD
Construction:
Join BD
Proof:
In ∆ABD
AD > AB (AB is the smallest side)
∠5 > ∠7 …(3)
In ∆BCD
CD > BC (CD is the longest side)

∠6 > ∠8 …(4)
Adding (3) and (4), we get
∠5 + ∠6 > ∠7 + ∠8
∠B > ∠D

Question 5.
In Fig. below, PR > PQ and PS bisects ∠QPR. Prove that ∠PSR > ∠PSQ.

Sol.
Given:
PR > PQ
∠1 = ∠2
To prove:
∠PSR > ∠PSQ
Proof:
In ∆PSQ
∠PSR = ∠1 + ∠Q (EAP)
In ∆PSR
∠PSQ = ∠2 + ∠R (EAP)
= ∠1 + ∠R (∠1 = ∠2)
In ∆PQR
PR > PQ (given)
∠Q > ∠R
(∴ In a ∆, angle opposite to longer side is always larger)
Adding ∠1 on both sides
∠Q + ∠l > ∠R + ∠1
∴ ∠PSR > ∠PSQ
(∴ ∠PSR = ∠1 + ∠Q and ∠PSQ = ∠1 + ∠R)

Question 6.
Show that of all the line segments drawn from a give point not on it, the perpendicular line segment is the shortest.
Solution:
Given
Let us consider the ∆PMN such that ∠M = 90°
Since, ∠M + ∠N + ∠P = 180° [Sum of angles of a triangle]

∠M = 90° [PM ⊥ l]
∠N < ∠M
PM < PN …..(1)
Similarly PM < PN₁ …..(2)
PM < PN₂ …..(3)
From (1), (2) and (3), we have PM is the smallest line segment drawn from P on the line l.
Thus, the perpendicular segment is the shortest line segment drawn on a line from a point not on it.

MP Board Class 9th Maths Solutions

MP Board Class 9th Maths Solutions Chapter 8 Quadrilaterals Ex 8.1

Question 1.
The angles of quadrilateral are in the ratio 3 : 5 : 9 : 13. Find all Ijbe angles of the quadrilateral.

Solution:
∠A = 3x, ∠B = 5x, ∠C = 9x, ∠D = 13x
In quadrilateral ABCD
∠A + ∠B + ∠C + ∠D = 360°
(∴ Sum of all the angles of ♢ is equal to 360°)

3x + 5x + 9x + 13x = 360°
30x = 360°
x = \(\frac{360^{\circ}}{30^{\circ}}\)
Let angle in ratio be x then angles are x= 12°
∠A = 3 x 12° = 36°
∠B = 5 x 12° = 60°
∠C = 9 x 12° = 108°
∠D = 13 x 12° = 156°

Question 2.
If the diagonals of a parallelogram are equal, then show that it is a rectangle.
Solution:
Given
ABCD is a parallelogram in which
AC =DB
To prove:
ABCD is a rectangle.
Proof
In ∆DAB and ∆CBA
DB = CA (given)
AB = BA (common)
AD = BC (∴ opposites sides of ∥^gm are equal)
∆DAB = ∆CBA (by SSS)
and so ∠DAB = ∠CBA
AD∥BC and AB is the transversal (by CPCT)
∴ ∠A + ∠B = 180° (CIA’s)
⇒ ∠A + ∠A = 180° (∴ ∠A = ∠B)
∴ ∠A = 90°
∠A = ∠C = 90°
and ∠B = ∠D = 90°
In ∥^gm ABCD, all the angles are right angles.
ABCD is a rectangle.

Question 3.
Show that if the diagonals ofa quadrilateral bisect each other at right angles, then it is a rhombus.
Solution:
Given
OA = OC, OB = OD and ∠AOD = 90°
To prove:
ABCD is a rhombus.
Proof:
In ∆AOD and ∆COB

OA = OC (given)
OD = OB (given)
∠1 = ∠2 (V.O.A.’s)
∴ ∆AOD = ∆COB (by SAS)
and so AD = CB (by CPC 7)
∠3 = ∠4 (by CPCT)
∠3 and ∠4 are A.I.A.’s and are equal
∴ AD ∥ PC (proved)
AD = BC
∴ ABCD is a parallelogram
In ∆AOD and ∆COD,
OA = OC (given)
OD = OD (common)
∠1 = ∠5 = 90°
(∴ ∠1 + ∠5 = 180° ⇒ 90° + ∠5 = 180° ∴ ∠5 = 90°)
∴ ∠AOD = ∠COD (by SAS)
and so AD = CD (by CPCT)
In ∥^gm APCD, all the sides are equal.
ABCD is rhombus.

Question 4.
Show that the diagonals of a square are equal and bisect each other at right angles.
Solution:
Given
ABCD is a square.
To prove:

1. AC = BD
2. OA = OC and OB = OD
3. ∠AOD = 90°

Proof:
In ∆DAB and ACBA,
DA = CB (given)
AB = BA (common)
∠A = ∠B (each 90°)
∴ ∆DAB = ∆CBA (by SAS)
and so BD =AC (by CPCT)

2. In ∆AOD and ∆COB, AD = CB(given)

∠4 = ∠5 (A.I.A.’s)
∠6 = ∠7 (A.I.A. ’s)
∆AOD = ∆COB (by ASA)
and so OA=OC , (byCPCT)
OD = OB (byCPCT)

3. In ∆AOD and ∆COD,
AO = CO (proved)
OD = OD (common)
AD = CD (given)
∆AOD = ∆COD (by SSS)
and so ∠1 = ∠3 (byCPCT)
∠1 + ∠3 = 180° (LPA’S)
⇒ ∠1 + ∠1 = 180° (∠1 = ∠3)
⇒ 2∠1 = 180°
∴ ∠1 = \(\frac{180^{\circ}}{2}\)

Question 5.
Show that if the diagonals of a quadrilateral are equal and bisect each other at right angles, then it is a square.
Solution:

Give
ABCD is in which
AC = BD
OA = OC
and OB = OD
∠AOD = 90°
To prove
ABCD is a square
Proof:
In ∆AOD and ∆COB,
OA = OC (given)
OD = OB (given)
∠7 = ∠8 (V.CXA.’s)
∴ ∆AOD = ∠COB
and so AD = BC
and ∠3 = ∠1 (byCPCT)
∠3 and ∠1 are A.I.A.’s and are equal
∴ AD ∥ BC
Similarly, AB ∥ CD
∴ ABCD is a parallelogram.
In ∆AOD and ∆COD,
OA = OC (given)
OD = OD (common)
∠7 = ∠9 (each 90°)
∆AOD = ∠COD (by SAS)
AD = CD (byCPCT)
In ∥^gmABCD, adjacent sidesAD = CD
∴ ABCD is a rhombus
In ∆DAB and ∆CBA,
DA = CB (proved)
AB = BA (common)
DB = CA (given)
∆DAB = ∆CBA (bySSS)
∠A = ∠B (by CPCT)
∠A + ∠B = 180° (CIA’s)
2∠A = 180°
∠A =90°
ABCD is a square.

Question 6.
Diagonals AC of a parallelogram ABCD bisects ∠A (see Fig). Show that

1. it bisects ∠C also,
2. ABCD is a rhombus.

Solution:
Given
ABCD is a parallelogram in which ∠1 = ∠2
To prove:

1. ∠3 = ∠4
2. ABCD is a rhombus.

Proof
1. ∠1 = ∠4 (A.I.A.’s) ….(i)
(∴ AD ∥ SC and AC is the transversal)
∠2 = ∠3 (A.I.A.’s) …(ii)
(∴ AB ∥ DC and AC is the transversal)
∠1 = ∠2 (given) …(iii)

From (i), (ii) and (iii), we get
∠4 = ∠3
(ii) From (ii) and (iii), we get,
∠1 = ∠3
In ∆ADC,
∠1 = ∠3
∴ AD = DC (In a A, sides opposites to equal angles are equal) and so ABCD is a rhombus
(∴ In a ∥^gm, if adjacent sides are equal then it is a rhombus)

Question 7.
ABCD is a rhombus, show that diagonal AC biusects ∠A as well as ∠C and diagonal BD biusects ∠B as well as ∠D.
Solution:
Given
ABCD is a rhombus.
To prove
∠1 = ∠2, ∠3 = ∠4, ∠5 = ∠6, ∠7 = ∠8.
Proof:
In ∆ADC and ∆ABC.

AD = AB (Adj. sides of a rhombus)
DC = BC (Adj. sides of a rhombus)
AC = AC (common)
∴ ∆ADC = ∆ABC (by SSS)
so ∠1 = ∠2 (by CPCT)
and ∠3 = ∠4 (by CPCT)
∴ AC bisects ∠A and ∠C
Similarly, ∠5 = ∠6 and ∠7 = ∠8
BD bisects ∠B and ∠D.

Question 8.
ABCD is a rectangle in which diagonal AC bisects ∠A as well as ∠C. Show that

1. ABCD is a square
2. diagonal BD bisects ∠B as well as ∠D.

Solution:
Given
ABCD is a rectangle.
∠1 = ∠2 and ∠3 = ∠4
To prove:

1. ABCD is a square
2. ∠5 = ∠6 and ∠7 = ∠8

Proof:
1. ∠A = ∠C
(∵ Rectangle is ∥^gm and in a ∥^gm opp. angles are equal.)

\(\frac{1}{2}\)∠A = \(\frac{1}{2}\)∠C
∠A = ∠C
∠2 = ∠4
In ∆ABC, ∠2 = ∠4
AB = BC
(In a A, sides opp. to equal angles are always equal)
ABCD is a rectangle in which adjacent sides are equal.
∴ ABCD is a square.

2. In ∆ABD,
AB = AD (∴ ABCD is a square)
∴ ∠5 = ∠7 (∴ In a A, angles opp. to equal sides are equal) ….(1)
AB ∥ DC and BD is the transversal
∴ ∠6 = ∠7 …(2)
AD ∥ BC and BD is the transversal.
∴ ∠5 = ∠8 …(3)
From (1) and (3), we get
∠7 = ∠8
From (1) and (2), we get
∠5 = ∠6
Diagonal BD bisects ∠B as well as ∠D.

Question 9.
In parallelogram ABCD, two points P and Q are taken on diagonal BD such that DP = BQ (see Fig.). Show that

1. ∆APD = ∆CQB
2. AP = CQ
3. ∆AQB = ∆CPD
4. AQ = CP A
5. APCQ is a parallelogram

Given
ABCD is a parallelogram.
∴ AD = BC, AB= DC and DP = BQ
To prove:

1. ∆APD = ∆CQB
2. AP = CQ
3. ∆AQB = ∆CPD
4. AQ = CP
5. APCQ is a parallelogram

Proof:
In ∆APD and ∆CQB
PD = QB (given)
AD = CB (given)
∠2 = ∠1 (AIA’s)
∆APD = ∆CQB (by SAS)
and so AP = CQ (by CPCT)

In ∆AQB and ∆CPD,
AB = CD (given)
∠3 = ∠4 (AIA’s)
BQ = DP (given)
∆AQB = ∆CPD (by SAS)
and so AQ = CP (by CPCT)
In quadrilaterals AQCP,
AP = CQ
AQ = CP
AQCP is a parallelogram.

Question 10.
ABCD is a parallelogram and AP and CQ are perpendicular from vertices A and C on diagonal BD (see Fig.). Show that

1. ∆APB = ∆CQD
2. AP = CQ

Solution:
Given
ABCD is a ∥^gm in which Ap ⊥ BD and CQ ⊥ BD.
To prove:

1. ∆APB = ∆CQD
2. AP = CQ

Proof:
In ∆APB and ∆CQD,
∠P = ∠Q (each 90°)
∠1 = ∠2 (AIA’s)
AB = CD (given)
∆APB ≅ ∆CQD (byAAS)
and so AP = CQ (by CPCT)

Question 11.
In ∆ABC and ∆DEF, AB = DE, AB ∥ DE, BC = EF and BC ∥ EE. Vertices A, B and C are joined to vertices, D,E and F respectively (see Fig.). Show that

1. quadrilateral ABED is a parallelogram
2. quadrilateral BEFC is a parallelogram
3. AD ∥ CF and AD = CF
4. quadrilateral ACFD is a parallelogram
5. AC = DF
6. ∆ABC = ∆DEF.

Solution:
Given
AB = DE and AB ∥ DE
BC = EF and BC ∥ EF
To prove

1. ABED is a ∥^gm
2. BEFC is a ∥^gm
3. AD ∥ CF and AD – CF
4. ACFD is a ∥^gm
5. AC =DF
6. ∆ABC ≅ ∆DEF

Proof:
1. AB = DE and AB ∥ DE (given)
ABED is ∥^gm
and so AD ∥ BE and AD = BE …(1)

2. BC = EF and BC ∥ FC (given)
BEFC is a ∥^gm
and so BE ∥ CF and BE = CF …..(2)

3. From (1) and (2), we get
AD ∥ CF and AD = CF

4. AD ∥ CF and AD = CF (proved)
ACFD is a ∥^gm

5. and so AC = DF
(In a parallelogram, opp. sides are equal)

6. In ∆ABC and ∆DEF,
AB = DE (given)
BC = EF (given)
AC = DF (proved)
∆ABC = ∆DEF (by SSS)

Question 12.
ABCD is a trapezium in which AB ∥ CD and AD = BC (see Fig.). Show that:

1. ∠A = ∠B
2. ∠C = ∠D
3. ∆ABC ≅ ∆BAD
4. Diagonal AC = diagonal BF)

[Hint: Extend AB and draw line through C parallel to DA intersecting AB produced at E.]
Solution:
Given
AB ∥ CD, AD = BC
To prove:

1. ∠A = ∠B
2. ∠C = ∠D
3. ∆ABC ≅ ∆BAD
4. diagonal AC = diagonal BD

Construction:
Draw a line CE ∥ DA which intersect AB produced at E.
Proof:
1. In quadrilateral ADCE,
AD ∥ EC (by const)
and AE ∥ DC ( AB ∥ DC)
∴ ADCE is a parallelogram
and so AD = EC (opp. sides of a ∥ are equal)…(i)
AD = BC (given) ….(ii)
From (i) and (ii), we get
BC = EC
In ∆BCE BC = EC (proved)
∠4 = ∠3
(∴ In a ∆, angles opp. to equal sides are equal)
∠2 + ∠3 = 180° (LPA’s) …(iii)
∠1 + ∠4 = 180° (CIA’s) …(iv)
From (iii) and (iv), we get
∠2 + ∠3 = ∠1 + ∠4
∠2 = ∠1 (∠3 = ∠4)
i.e., ∠A = ∠B

2. ∠3 = ∠5 (AIA’s) …(v)
∠6 = ∠4
(∴ ADCE is a ∥^gm and in a ∥^gm opp. angles are equal) …(vi)
∠4 = ∠3 (proved) …(vii)
From (v), (vi) and (vii), we get
∠5 = ∠6
i.e., ∠C = ∠D

3. In ∆ABC and ∆BAD,
AB = BA (common)
BC = AD (given)
∠2 = ∠1 (proved)
∆ABC ≅ ∆BAD (by SAS)
and so AC =BD (by CPCT)

4. diagonal AC = diagonal BD (proved)

Mid Point Theorem:
The line segment joining the mid-points of the sides of a triangle is parallel to the third side and equal to half of it.
Given.
ABC is a A in which D and E are the mid-points of sides AB and AC respectively.
To prove.
DE ∥ BC and DE = \(\frac{1}{2}\) BC
Construction:
Extend DE uptoFsuch that DE = EF. Join CF.
Proof:
In ∆AED and ∆CEE
AE = CE (E is the mid – point of AC)
∠AED = ∠CEF (VOA’s)
DE = FE (By constriction)
∆AED = ∆CEF , (By SAS)
and so ∠DAE = ∠FCE (By CPCT)
AD = CF (By CPCT)
∠DAE and ∠FCE are alternate interior angles and are equal.

AD ∥ FC
⇒ DB ∥ FC
Now, AD = DB and AD = FC
DB = FC
In BCFD, DB ∥ FC and DF = BC
BCFD is a ∥^gm
and so DF ∥ BC and DF = BC
⇒ DF ∥ BC and 2DF = BC
DE ∥ BC and DE = \(\frac{1}{2}\) BC

Converse of mid point theorem:
The line drawn through the mid – point of one side of a triangle and parallel to another side, bisects the third side.
Given
ABC is a A in which D is the mid-point of AB and DE ∥ BC.
To Prove:
E is the mid – point of AC.
Construction:
Mark a point F on AC and join DF.
Proof:
Let E be not the mid – point of AC. Let us assume that F be the mid – point of AC.
Then by mid-point theorem

DF ∥ BC
DE ∥ BC (Given)
From (i) and (ii), we get
DE ∥ DF
But lines DE and DF are intersecting lines, intersecting at D. This is a contradiction. So our supposition is wrong. Hence E is the mid – point of AC.

MP Board Class 9th Maths Solutions

MP Board Class 9th Special English Composition: Verbal Stimulus

an excursion to Fatehgarh in summer. She has made the following notes. Use these, notes together with your own ideas and write the brochure in your answer sheet in not more than 750 words. [10 marks]

What to see : Places, waterfalls, temples, gardens. Palaces : Maharani’s Palace includes Wax Palace — 540 AD — Whispering galleries, Sculptures — ancient rulers — limbs missing in a few. Waterfalls : Varsha — 500 feet, stream on the outskirts Gardens : Rose gardens — Orchards — Vineyards

Answer:
This summer, as usual, we have planned an excursion for the class — a visit to FATEHGARH which is not only beautiful but also has a historical significance.

Fatehgarh lies in the State of Uttar Pradesh. It is an eight-hour journey by bus. On reaching Fatehgarh we will be lounged in a Government Guest House. From there we shall proceed to visit the most famous place in Fatehgarh, the Maharani’s Palace, which includes the Wax Palace. It was built in 540 A.D. and it is known for its whispering galleries and the beautiful sculptures of ancient rulers. These sculptures are ancient so it is not surprising that the limbs of a few rulers in some of these sculptures may be found missing. This palace is indeed one of the few examples of ancient Indian art and gives us a peep into the glorious, rich cultural art of ancient Indian history.

To cool you in the summers we shall visit the Varsha waterfalls which fall from a height of 500 ft. It is a splendor to watch the water as it lashes down on to the ground and presents the most delightful sight. We also plan a visit to a stream which lies on the outskirts of Fatehgarh. Besides this our excursion will include a visit to the beautiful rose gardens, fruit orchards and vineyards to view the flowers and the fruits in their full bloom. It promises to be an excursion which should not be missed and. I can assure you that our visit to Fatehgarh will be most exciting and informative.

2. Sumit lives in a village. The entire village is worried about degradation of Nila Lake in the village. He writes an article for publication in the local newspaper highlighting various factors responsible for the degradation of the lake. Use the information given below and write the article in not more than 150-200 words. [10 marks]

Construction of roads and bridges	Deforestation of catchment area	Illegal occupation	Pollution
1. Hooding	1. decrease in water level	1. Blockage of canals	1. Loss of water organisms
2. Disturbing the natural drainage	2. increase in the growth of weeds	2. flooding	2. fewer visiting birds
	3. reduction of fish	3. shortage of drinking water

Answer:
I am being compelled to write this article to voice the concern of our entire village, Rampur, regarding the degradation of Nila Lake. This lake has been a part and parcel of our lives for numerous years and so it is very natural that out entire village, as a whole, is concerned about its degradation.

To provide easy access to our village the construction of numerous roads and bridges has been taken up in recent years. Unfortunately, this has led to flooding almost every year during the rainy season and has also disturbed the natural drainage system. Due to deforestation of a large portion of the catchment area around the lake the water level of the lake has decreased and there has been an increase in the growth of weeds. There is also a considerable amount of reduction of fish in the lake. Illegal occupation of land around the lake has led to blodsage of canals and shortage of drinking water. The lake water has become very polluted and there is a loss of water organisms. The number of migratory birds visiting the area has decreased. So, it is indeed pathetic to see this slow but sure degeneration of Nila Lake which has been a major source of sustenance of our entire village.

We sincerely hope that after going through this article in your esteemed newspaper concerned environmentalists will surely come forward to save Nila Lake from total degradation and effective measures will be taken up to improvise upon the present situation.

3. David of class IX-A is not coming to school because he is suffering from fever. He wants you to write an application to the Principal to excuse his absence from school for a week. Write this letter on his behalf taking help from the following notes. Your letter should not exceed 150 words. [10 marks]

Notes Suffering — unable to even write — taking medicine/will take about a week — grant leave — will makeup — friends’ help — home work class work — thanks.

Answer:
The Principal
Sr. Sec. School
XYZ Block
New Delhi
19 Dec. 20xx

Sir,
1 am a student of your school. My name is David and I am studying in class IX-A. I am writing this tetter to you to inform you that I have been unable to attend school from 17 Dec. 2Oxx as I have been suffering from typhoid fever. I have been taking strong medicines to relieve myself of the misery but it will still take me about one more week to get well. At present I am unable to even write, so my friend is writing this application on my behalf. Please grant me one week’s leave. I will make up for the classes I will be missing with the help of friends and keep my class-work and home-work up-to date. I am sure you will understand my plight and grant me leave. Thanking yoii.

Yours sincerely
David,
IX-A

4. Nitin of 8, Napier Town, Jabalpur is not happy with the sanitary conditions of his locality. He decides to write a letter to the Local Sanitary Inspector of the town to look into the sorry state of affairs. Using the following notes, write out a letter in about 150 words. [10 marks]
Answer:
The Sanitary Inspector
Jabalpur Municipal Corporation
Jabalpur
27 Nov. 20xx

Sir,
It is indeed appalling and unfortunate that the local civic bodies have remained indifferent towards the cleaning of our town. Our toivn presently is in a sorry state of affairs.

There are no sweepers to clear the heaps of garbage that lie unattended and start emitting foul smell. The garbage also attracts street dogs and pigs who scatter this garbage on the road. The drains of our locality are perpetually blocked and this creates totally insanitary and unhygienic conditions. Installation of dust- bins in the locality has not really helped to improve the situation because even if people make use of these dustbins to dispose of garbage, these dust-bins are rarely emptied. It is advisable to supply big polythene litter bags, instead of dust-bins, which make disposition of garbage easier. The water logging in the locality has proved an ideal breeding place for mosquitoes. The need of the hour is to have regular visits of officials from your department to inspect the locality and to have meetings with the residents of the locality in order to make our locality a better and hygienic place to live in.

I hope you will personally supervise this situation and we hope to hear from you soon.

Yours sincerely
Nitin

8, Napier Town
Jabalpur

5. You are required to write an article for your school magazine on ‘Importance of music in life.’ Write it with the help of these notes in about 150-175 words. [10 marks]
Answer:

5 March 20xx, 2 P.M.
On entering the examination hall to appear far my first public examination, the Science Olympiad, I had an extremely nervous feeling. The examination hall presented a rather dreary look. The only saving grace, in my opinion, was a beautiful and enchanting portrait of Virgin Mary

Note Fine Art — Vocal1 — Instrumental — All age groups — Natural gift — food for soul — Great musician — Western — Oriental — Classical — Pop — Light — Concerts — Competitions — Suggestions — School to provide facilities.

Answer:
Music, be it vocal or instrumental, has indeed assumed a place of importance in our complicated and hectic lives. It acts as a stimulant which activates our body and mind. Music is also regarded as a fine art which attracts people of all age-groups to pursue it not only as a hobby but also as a profession. A person endowed with musical capabilities regards this attribute as a natural gift which provides food for his soul. Some of the great musicians are held in very high esteem irrespective of the kind of music they propagate, whether Western, Oriental, Classical, bop or Light. These musicians organise their concerts which attract people from all walks of life. These concerts can also be of great benefit to the children, who are interested in pursuing music as a hobby or career in their lives to receive musical training at the school level itself. By receiving training in music from a very young age the basics of music will be instilled in a child and he will be able to relate to music very easily at a later stage in life. Therefore each school should have the facilities needed to give proper musical training to children. It is true that life these days is full of tension and worries at every age. If there is no stimulating diversion in the form of music for a person, his life will become dismal and monotonous.

6. John writes a page of his diaiy recording his first experience of a public examination. Below are listed his experiences. Using these notes write out a page of his diary in about 150-175 words. [10 marks]

Notes Nervous feeling — praying to God — lots of noises around — students rushing towards examination hall — finding the correct seats — a condition of the examination hall — receiving the question paper — instructions from the examiner — reading of the paper — beginning to write — revising — rewriting — finishing in time.

Answer:
5 March 2Oxx, 2 P.M
On entering the examination hail to appear for my first public examination, the Science Olympiad, 1 had an extremely nervous feeling. The examination hail presented a rather dreary look. T&e only saving grace, in my opinion, was a beautiful and enchanting portrait of Virgin Mary with Baby Jesus in her arms, hung inside the examination hall, to invoke a sense of confidence in the students and to remind us that we had the guidance and blessings of the Lord. I prayed to God fervently uncaring about the noise around me. The other students were rushing towards the examination hall and were busy in finding the correct seats in a hall that looked huge and overwhelmingly frightening. Once everyone had been seated, the examiner gave us some instructions regarding what toe were required to do and what we were strictly prohibited from doing.

Then I received the Question Paper and I sat thoughtfully reading and reflecting on it. After I had given a thorough reading to the Question Paper, I began to answer it keeping in mind the fact that I had three hours to complete the paper. I managed to complete the paper fifteen minutes before the stipulated time and then began revising my paper. I spotted and corrected the few silly mistakes and errors that I had made and rewrote some lines. After being totally satisfied with all that I had written, I finished my paper, took God’s name for yet another time and finally submitted it to the examiner.

-John

7. Gopal of 12, Raja Mandi, Agra wants to express his displeasure to the Newspaper Editor regarding the news that the bus stand near the railway station is being shifted to a new location. He feels that this would cause great hardship to the passengers. He made these notes for writing a letter to the Editor, The Times of India, New Delhi. Using these notes write a letter in about 750 words. [10 marks]

Notes The existing-bus Stand — convenient — travellers by train — travellers by bus — poor people to spend extra — wastage of time, money and energy — inconvenience to shopkeepers near the bus stand — closeness to the market also for visitors — suggested to add one more at a distance — if urgent.

Answer:
The Editor
The Times of India
New Delhi
19 Dec. 2Oxx

Sir,
Through the mediutr of this letter I wish to express my displeasure at the news that the bus stand, which is near the railway station, is being shfted to a new location.

This will indeeJ be a cause of great hardship to the passengers who are commuting daily by bus and train. The present location of the bus stand is very convenient for the people who have to travel by train from their homes to their place of work. These daily commuters find it extremely easy to board a bus from near the railway station where they disembarl from the train. If the bus stand is shifted, the common man will be forced to waste his time, energy and money unnecessarily. Many shops have also come up in the vicinity of the bus stand. These shopkeepers will also lose their earnings if the bus stand is shifted because their regular clients are those people who commute daily by bus and the tourists who come to visit Agra in order to see one of the Wonders of the world, The Taj Mahal. Even the commuters have an easy access to the market from where they can purchase the goods for their daily needs easily.

I suggest a solution to this problem. If the urgency is felt, it is advisable to add one more bus stop at a distance instead of shifting the present bus stand to a new location and causing a great deal of incon-venience to all.

Yours sincerely
Gopal
12, Raja Ki Mandi
Agra

8. Special repairs are required in your rented house. You have to write a letter to your landlord asking him to undertake the repair work immediately. Take the help of these notes and write your letter in not more than 150 words.[10 marks]

Notes Roof leaking — Wall plaster came out — Window panes broken — Floor has potholes — Switches loose — White washing — Paints on the doors and windows — Can share the cost — to be deducted from the rent — Urgent attention requested.

Answer:
A-394, XYZ Colony
ABC Block
11 June, 20xx
Dear Mr. Dev,
I had -written to you earlier also to get some repair work done in your house, which you have rented to me.

Now since the rainy season is at the onset, I reiterate my request to you to undertake this repair work immediately. The roof is leaking at various places and the wall plaster has also come off. Not only this, the floor has pot-holes which cause a lot of inconvenience. The window panes of three windows are broken making the house an easy prey to the warm winds and dust from outside. The switches too are loose and there is a danger of short circuit. The premises also needs white-wash and paint on the doors and windows. The house is indeed in a pathetic and appalling stale and requires urgent repairs. I am willing to share the cost of the repairs with you. With your permission I can get the repairs done myself and the expenditure can be later deducted in the rent in monthly instalments.

I request you to give priority attention to this matter and hope to hear from you at the earliest.

Yours sincerely
ABC

9. You had sent a Money Order of Rs. 100 to M/s Subroto Publishing House, 36 Tagore Gardens, Kolkata as per the details giveiu below, But it has not reached them till date. The details are : Money Order Registration No. 119 dated 2-l-20xx. Your address is 11, Teachers’ Colony, Naraingarh, (Punjab).
Write a letter of complaint to the Post Master in about 150 words. [10 marks]
Answer:
The Post Master
Naraingarh (Punjab)
31 January, 20xx

Sir,
I would like to give in a written complaint regarding a misplaced Money Order that I had sent from your Post Office to Kolkata.

The Money Order Registration No. is 119 dated 2nd January 20xx. I had sent this Money Order of Rs. 100 to M/s Subroto Publishing House, 36, Tagore Gardens, Kolkata for a book that I needed urgently. On enquiring from them yesterday 1 found out that they had not dispatched the book because they have not yet received the required payment, whereas I have already sent Rs. 100 through a Money Order to them almost one month ago. Due to some negligence on the part of the Post Office Department, my Money Order has not yet reached them. I need the book urgently to prepare for my exams scheduled to start in the middle’ of March. So, it is my earnest request to you to look personally into the matter and make sure that my Money Order is received in Kolkata as soon as possible.

I hope you will ensure that my complaint is attended to at the earliest.

Thanking you.
Sincerely vours
XYZ
11, Teachers’ Colony
Naraingarh (Punjab)

10. Gauri saw the following information about an exciting discovery. She is thrilled to read about it and decides to write a letter to her friend in the country-side, on the advancement in Scieiice and Technology. Write a letter using the information from the newspaper article. Your answer should not exceed 150 words. [10 marks]

Downsizing Transmitters

A radio transmitter, as small as a cigarette package that could be used to replace gigantic mobile telephone masts that are thought by’some to spoil the country-side, has been developed by Michael Roberts, an electronics expert at Leeds University, England.
Answer:
A -394 A Palam Colony
New Delhi
11th February, 20xx
Dearest Vandana,
I ant writing this letter to you to discuss the immense change that our whole life has undergone with the advancement of Science and Technology as a result of which we are able to bring a drastic change in our lifestyle.

Various new scientific discoveries and inventions in every sphere of life have brought people of the world closer. I read an article about an exciting discovery lately of downsizing transmitters through which a radio transmitter as small as a cigarette package could be used to replace gigantic mobile telephone masts. This device has been developed by Michael Roberts, on electronics expert at Leeds University, England. But some environmentalists feel that the installation of these transmitters will act as a foil to the naturalness and serenity of the country-side. Since you too live in the country-side, do write to me your opinion about this matter in your next letter. I am sure you are in a better position to realize the intensity of this drastic change made by the advancement of Science and Technology because even though you are living in the country-side you are connected amazingly well with the city through the excellent means of communication. Modern gadgets have indeed made the world jump forward with a leap, built up a glittering civilization, opened up innumerable avenues for growth of knowledge and added to the power of man to a great extent.

To conclude this letter I would just add that it now seems possible to conceive that man can actually triumph over and shape even his physical environment.
Yours lovingly
Gauri

11. Recently Geetha saw an advertisement in the newspaper that read “How to look young”. After reading it she feels strongly . about the use of synthetic creams and dyes to make people look young, and writes a letter about it io the Editor of the newspaper “The Herald” on ‘How to keep fit and be young’. Write this letter in about 150-200 words, using information from the newspaper advertisement together with your own ideas. [10 marks]
Answer:
The Editor
The Herald
22nd March 2Oxx

Sir,
I had. a chance of going through an advertisement in the newspaper about a certain cream that the advertisers claimed could make people look young. I was indeed astonished that in this day and age of modernisation there are people who are able to make a complete fool of others.

I am writing this letter to you to express my opinion about the use of synthetic creams and dyes that claim to have the ability to make a person look young. I strongly condemn the use of these creams and dyes which contain extremely harmful chemicals which can cause very severe adverse side-effects. Aging is a slow and gradual process and one must face it gracefully and should not be misled by false claims offered in the form of synthetic creams and dyes which do more harm than good. The real way to remain fit and healthy is to do regular exercise, eat balanced and the right kind of nutritious food and live a tension-free and happy life. This is the actual key to a fit and healthy life. The use of artificial products to look young on the contrary makes one look like a fool. We should always remember that these products contain many harmful ingredients that could possibly cause some severe allergic reaction.

Yours sincerely
Geetha

12. You feel that facilities for tourists could be improved in India. Write a letter to the Secretary, Department of Tourism in your State, highlighting the need for improving facilities for tourists to promote tourism in your region. Also suggest what facilities you would like to be extended to the tourists in your region. Your answer should not exceed 150 words. [10 marks]
Answer:
The Secretary
Department of Tourism
Uttar Pradesh
Date: 17 Jan. 20xx

Sir,
Recently, on reading an article about the tourist traffic to India and especially to our State which has one of the wonders of the world, I was quite perturbed to look at the figures. We are not getting enough tourists as we should get.

To get more tourists. We will have to develop the infrastructure and make the facilities world aass. A pleasant stay and easy access to the tourist spots are two may – factors that attract the tourists to a city. So, the tourism department shoved endeavor to improve upon the facilities provided by its lodges and bungalows and make access to these tourist spots from these lodges convenient. Furthermore, the tourist spots should be kept clean and a specific amount of money should be sanctioned for their maintenance. Last, but not the least, each and every one of us should make a sincere effort to keep our city clean, as a beautiful and clean city beckons the tourists.

By making these simple, but significant things possible, I am sure, tourism in our city can be improved.

Yours faithfully.
XYZ

13. In an inter-school debate, you have to speak in favour of the motion ‘Modem Gadgets have made us slaves to machines’, write a speech in favour of this motion. Write the speech in your answer sheet in not more than 150 words. [10 marks]
Answer:
Modern gadgets have made us slaves to machines without which we are certain that out lives will come to a standstill. They have made the world jump forward with a leap, built up a glittering civilization, opened up innumerable avenues for the growth of knowledge, and added to the power of man to such an extent that it is possible to conceive that man could triumph over and shape his physical environment. Through the astonishing discoveries of these modem gadgets, man has been able to give a definite form to his imagination. It is indeed a fact that as a result of the invention of modern gadgets the tone and temper of life has changed, beyond recognition. Through wireless telegraphs and fax machines messages can now be easily sent to any part of the world. Modem gadgets incorporate all the comforts and highest standards in engineering innovation and reliability that have greatly contributed to man’s welfare. New equipment for navigation, data-processing, computer-controlled radar system providing information on a variety of new products for use at construction sites are only some of the advantages of modern gadgets. They have also greatly contributed to our entertainment as radios, televisions, compact discs both audio and visual — are now no longer considered as luxury items but have assumed the status of being referred to as necessities. Indeed the advantages of these gadgets are so many that they appear to have revolutionised every phase life.

14. Anita John of class X has just returned from a visit to Ooty which is in the grip of a severe water crisis. She finds that her hometown is also facing the same problem. She had picked up the following pamphlet from her hotel room and wants it to be publicised. [10 marks]

Water Is Life

Washing hands and face	✓ DOS Half fill basin—2 litres	✗ DONTS Wash under running tap for 3 minutes-27 litres
Brushing teeth	Use a glass of water— reuse—1/2 litre	Let tap run for 5 minutes— 45 litres
Showering	Turn off tap before soap­ing then rinse down— 20 litres	Let tap run while soaping— 90 litres
Bathing	Take a shower instead	Fill bath tub—110 litres
Leaky tap	Get it repaired	Let it drip Slow drip—400 litres a day Fast drip—3000 litres a day

She decides to write a letter to the editor of the local newspaper highlighting ways and means of saving water. Write this letter in your answer sheet using information from the pamphlet together ’ with your own ideas in not more than 150 words. [10 marks]
Answer:
13, Baird Road
Pune (Maharashtra)
The Editor
National Herald
Pune
11 June 20xx

Sir,
I have returned from a visit to Ooty recently, which was in the grip of a severe water crisis. On returning to Pune, I found that the water problem is equally pathetic here. So, I would like to suggest certain measures to save water. I had picked up a pamphlet from the hotel where we were staying at Ooty which highlighted ways to save water and I want it to be publicised through your esteemed newspaper. Washing our hands and face under a running tap for only two minutes wastes about 27 lities of water whereas a half filled basin can do this work with only 2 litres of water. While brushing our teeth if we let the tap run for five minutes we waste 45 litres of water but if we use a glass of water, we consume only half a litre of water. If we turn off the tap while soaping our body before bathing we use only 20 litres of water, whereas if we let it run we waste about 90 litres. We should avoid using bath-tubs as a filled bath tub wastes 110 litres of water. A leaky tap must be repaired immediately because if the tap is allowed to leak slowly it wastes 400 litres of water a day and a fast drip wastes 3000 litres of water a day.

If each and every one of us understands it and decides to follow this simple but very important rule, we are sure to remedy our present water crisis to a great extent.

Yours sincerely
Anita Johri

15. Read the following extra from an article in a magazine and then using your own ideas as well, write- an article for your school magazine on the Delights and Usefulness of Walking. Write your answer in about 150-200 words. [10 marks]

‘Walking has its own delights. in India walking is associated with deprivation and poverty. “If you have a car why walk?” asked the professor, revving up his Fiat for the few metres from his house to the college building. Pavements and pedestrians get second class treatment.
Answer:
The saying aptly goes, ‘A healthy body has a healthy mind’. So, it is imperative for each one of us to keep good health if we want our mind to be alert. In today’s hectic and busy life it may at times seem difficult to devote time for activities that keep us fit. This is where walking proves to be the most useful and easy activity.

Walking not only keeps our body healthy by the circulation of blood but also provides a delightful respite for us by the sheer delight it gives. But, it is indeed a pity that some people who are most interested in walking refrain from it because in India walking is associated with deprivation and poverty. Their false pride and wrong thinking make them travel by car for even the shortest of distance. They would prefer to miss out on the delights of walking and prefer not to care about the good it would do to their health so as not to endanger their false prestige. It. is high time that the educated lot of Indians put aside these petty notions and live their life for themselves and live it according to what they feel is best for them. Walking does not indicate deprivation and poverty and it is only the thinking of certain narrow-minded people who have categorised the people walking or pedestrians as second class people.

Walking should be enjoyed as it gives pleasure and provides a wonderful opportunity for us to be in direct contact with nature, unlike at times irksome and suffocating journey in a closed vehicle.

16. Read the following summary of a study conducted titled The Impact of Television Advertising on Children. Then based on the information in the summary and your own ideas on the subject, write an article for the school magazine titled Children and T.V. Advertising. Write your answer in about 150-200 words. [10 marks]

One Year Out Of Ten Is Spent
Watching Tv

• On an average, children in Delhi watch 17 hours of TV every week. Children spend more time in front of the small screen than on hobbies and other activities, including home work and meals.
• The average 8-year old spends about 68 hours every month, 30 days (of 24 hours each) every year, and one entire year i out of 10 exclusively on watching television.
• Seventy five percent of children said they loved watching ads, on TV
• Children below eight like advertisements better than the programmes and see them as pictures with storylines. Only older children understand the ad’s intention on sell.

Source : The Impact of Advertising on Children by Namita Unnikrishnan and Shailaja Bajpai.
Answer:

Children And Tv Advertising

Television has become a very popular mode of entertainment which, is unfortunately also making children more and more addicted to watching J it. The television programmes pose to dominate their daily routine and many a time children do not even hesitate to ignore their studies because, of their passion to stay glued to the television sets.

Almost seventy-five percent of the children, who watch television most ; eagerly, are essentially interested in seeing the advertisements on the television. Children in the younger age group, below ten years of age, view the advertisements with more interest and enthusiasm than they watch any other programme on television. This is so because they see these advertisements as wonderful and short pictures with story lines. Their impatient nature is able to endure these short ad films with a lot of patience. These young children are totally taken in by the vibrant and glorious world shown in the various ad films.

It is only the older and mature children who understand that the ad films’ mere intention is to lure the consumer into buying their products by elevating their goods to a high scale where they appear most appealing and attractive. So, it is our moral responsibility to make sure that the young children’s innocent and ignorant minds are not impressed by what 1 the ad films have to offer, but they view them solely for their entertainment.

17. Maria of 7, Gandhi Road, Jaipur, is very interested in sports and concerned about the state of sports in the country. She decides to write a letter to the editor of The Herald, Jaipur, on Why can’t we win an Olympic Gold? She made some notes for her letter. Using the notes and your own ideas, write out the letter in not more than 150 words. [10 marks]

No sports ‘culture’ — not enough emphasis on sports in schools — facilities for training and coaches lacking — funds/sports scholarships very few — talented do not get sponsors or jobs — public, selectors and trainers not interested enough — plenty of talent in the nation — only we are unable to spot and nurture 4. Answer:
The Editor
The Herald Jaipur
12 Sept. 20xx

Sir,
I write this letter to you as a concerned spgrts enthusiast to express my anguish at the poor state of sports in our country as a result of which we have been unable to win a gold medal in the Olympic Games held so far.

I feel that there is no sports culture m our country, in general, and so we are not able to nurture and groom the plenty of talent that our nation has. When the sportspersons of our country have to play and compete with international players in the World Olympics, their training and coaching should also match to that available to their international counterparts. Whereas in our country, the facilities for training and coaching are lacking and to a certain extent expenditure to enhance these facilities is sometimes considered as not necessary. We may fail to realize the importance of coaching centres in our day to day life but our inability to win a gold medal at the Olympic Games so far should make us realize the importance of training centres. It is also very unfortunate that the funds and sports scholarships available to budding sportspersons are very few. Political intervention at the time of selection alSo at times prevents the selectors in selecting the better players to play at the international level. Last but not the least the public in general and the selectors and trainers in particular do not seem to be affected by the lack of this “sports culture’ in our country.

Through your esteemed newspaper I wish to appeal to the people in general and specially the sports enthusiasts to give the sports culture in our country the boost and enhancement that has been long due.

Yours sincerely
Maria
7, Gandhi Road
Jaipur

18. Vijay witnessed an accident near the school gate where a child fell down and was hurt quite badly. Many people were standing around but did not know what to do. Finally, someone who had a car quickly took him to hospital. However, Vijay felt that at least some of the students should have been able to render first-aid. He decided to write a letter to the editor about the importance of knowing first-aid. Using your own ideas write out Vijay’s letter in not more than 150 words. [10 marks]
Answer:
The Editor
News Week
17th October, 20xx

Sir,
Last week, 1 witnessed an accident near the school gate where a child fell down and hurt himself badly. The people standing around were unable to do anything except look on helplessly. It was at this moment that I realized the importance of knowing first-aid.

I feel that it is imperative for students especially and the people in general to at least have the basic knowledge of rendering first-aid in case of an emergency. The use of first-aid often helps us to sustain a life till proper medical aid is available. The knowledge of first-aid will prove helpful not only in case of an accident, but also to treat a bum victim, help a drowned casualty and at times just to stop one from bleeding. The importance of first-aid should be instilled into the minds of children at the school – stage itself so that they do not panic in an accidental situation but cautiously and sensibly put their knowledge about rendering first-aid to the person who requires it into practice. Nothing is more precious to a person than his life and if timely use of first-aid can help someone till the time professional medical help is available, it can prove to be the life-saving remedy.

Sincerely yours
Vijay

19. Gaurav read the following in a newspaper article At the heart of the literacy campaign is the volunteer, who as instructor, resource person or local organiser, gives freely of her or his time and puts in enormous effort to make the campaign succeed.

He decided to speak at the school assembly on the experience of students who volunteer to take literacy classes. Using your own ideas write out his speech in about 150-200- words.
[10 marks]
Answer:
Illiteracy is one of the major problems that confront our country.

This problem assumes ala ming proportions because of the democratic rule in our country. Democracy, which postulates enlightenment, is by and large a blessing, and illiteracy, “which implies ignorance, is therefore a curse.

To eradicate illiteracy to some extent, barious students volunteer to take literacy classes and feel proud to help their unfortunate countrymen who have been deprived of the privilege of being educated. These voluntary workers, after receiving certain incentives and being provided with the requisite facilities ensure better results in the social arena. They have adopted new paths and motivated a large section of masses towards their literacy classes. This voluntary service on the part of students, has proven to be an effective measure for reaching out to the uneducated masses and thereby further helped the illiterate persons to eradicate their constant exploitation and humiliation at the hands of society. The students have helped these people to become aware as to why they have been deprived and motivated them to move towards change.

By undertaking this creditable, but herculean task, these students feel a sense of pride in being able to make their contribution to take their country oh the path of fast growth and progress.

20. You are required to speak on ‘Pollution’ in the school morning assembly. Prepare your speech taking help from the following points. You may use ideas contained in the unit ‘Environment’. Write your speech in not more than 150 words. [10 marks]

Points Environment — air — water — noise Sources of pollution — traffic — garbage Ecological balance — felling of trees — building of dams — congested localities Suggestions — Plantation — pooling — shifting of factories and mills.

Answer:

Environment

Environmental pollution is one of the major hazards that are threatening the ecological balance. The air that we inhale is polluted, the water we drink is contaminated and noise pollution has managed to take away the calmness and serenity from our otherwise hectic and tense lives. One of the main sources of pollution is the heavy and congested traffic which causes. concentration of smoke and harmful particles in the atmosphere which is a permanent or chronic cause of various respiratory disorders. The incessant felling of trees, building of dams and the upcoming unplanned congested localities have disturbed the ecological balance to an alarmingly high level. To remedy this situation the urgent need of the hour is to plant as many trees wherever possible and to shift the factories and mills to places where their effect on pollution of the environment is minimised. To control traffic, car pools must be made so that-the emission- levels from vehicular traffic can be reduced to the desired levels.

MP Board Class 9th English Solutions

MP Board Class 9th Science Solutions Chapter 14 Natural Resources

Natural Resources Intext Questions

Natural Resources Intext Questions Page No. 193

Question 1.
How is our atmosphere different from the atmospheres on Venus and Mars?
Answer:
Earth’s atmosphere has mixture of nitrogen (79%), oxygen (20%), and a small fraction of carbon dioxide, water vapours and other gases which makes the existence of life possible on Earth while the atmospheres on Venus and Mars mainly has carbon dioxide. Approximately, 95% to 97% is carbon dioxide is present on these planets which do not support existence of life.

Question 2.
How does the atmosphere act as a blanket?
Answer:
Atmosphere is a mixture of various gases along with vapour and submerged particles. It surrounds the earth and separates it from outer space. As a blanket stop interaction between body covered inside and atmosphere outside, in similar way atmosphere stops interaction between earth and space.
The most important isolations done by atmosphere are:

1. It keeps the average temperature of the Earth fairly constant during day time and even during the course of whole year.
2. It prevents a sudden increase in the temperature during day time.
3. It slows down the escape of heat from the surface of the Earth into outer space during night time.

Question 3.
What causes winds?
Answer:
Atmospheric pressure and temperature difference generates wind. As earth surface is not similar everywhere even at some places it is occupied by huge water bodies, lava emitting volcanoes, moist forest etc., a difference in temperature and pressure arises and to maintain equilibrium wave of pressure moves which we feel or notice as wind.

Question 4.
How are clouds formed?
Answer:
During day time, a large amount of water evaporates from various water bodies and of earth surface and through biological activities such as transpiration and respiration and mix up into the air. This causes the air in the atmosphere to heat up and since air is a bad conductor of heat, when this heated air rises, it expands and cools, which results in the condensation and formation of water droplets. The presence of dust and other suspended particles in air also facilitates cloud formation. The gathering of water droplets leads to the formation of clouds.

Question 5.
List any three human activities that you think would lead to air pollution.
Answer:
Three human activities leading to air pollution are:

1. Smoke from industrial and manufacturing activities etc.
2. Burning of fossil fuels for household and commercial purpose.
3. Spreading farming chemicals such as crop dusting, insect / pest killers, fertilizer dust etc.

Natural Resources Intext Questions Page No. 194

Question 1.
Why do organisms need water?
Answer:
Water is the major component of living organism some of the living organism has up to 90% of water of their body weight. Water is a wonderful liquid, it helps in performing most of the functions of our body like digestion, cell sap and oilier content formation, transportation of substance from one place to another inside the body etc.

Question 2.
What is the major source of fresh water in the city’town/ village where you live?
Answer:
The major source of fresh water near me is river.

Question 3.
Do you know of any activity which may be polluting this water source?
Answer:
Dumps from industrial activities, household works for various purpose in the fresh water sources are main activities which causes pollution. Air pollution which generates acid rain and spread submerged dust is also responsible for polluting water resources.

Natural Resources Intext Questions Page No. 196

Question 1.
How is soil formed?
Answer:
The process of soil formation is termed ‘paedogenesis’. Soil is formed mainly by the weathering of rocks through various physical chemical and biological processes with the help of various factors such as the sun, water, wind, and living organisms. It is made up of mineral particles, organic materials, air, water and living organisms. During day time, the rocks are heated up by solar rays. This causes the rocks to expand. During night time, these rocks cool down and contracts. It causes weathering of rock and formation of soil.

1. Water: It helps in breaking of rocks in two ways:
   • It goes into the cracks and crevices formed in the rocks. When this water freezes, its volume increases. As a result, the size of the cracks also increases. This helps in the weathering of rocks.
   • Water moving at fast speed carries big and small particles of rock downstream. These rocks rub against each other, resulting in breaking down of rocks. These smaller particles are carried away by running water and deposited down its path.
2. Wind: Strong winds carry away rocks, which causes rubbing of rocks. This results in the breaking down of rocks into smaller and smaller particles.
3. Living Organism: Some living organisms like lichens help in the formation of soil. Lichens grow on rock surfaces and converts them into powdery form and make soil layer. In the same way, the plants like moss also helps in the making of fine soil particles.

Question 2.
What is soil erosion?
Answer:
The blowing away or washing away of land surface by wind or water is known as soil erosion.

Question 3.
What are the methods of preventing or reducing soil erosion?
Answer:
The methods of preventing or reducing soil erosion are:

1. Plantation of tress and plants.
2. Prevention of deforestation.
3. Prevent excessive grazing.

Natural Resources Intext Questions Page No. 201

Question 1.
What are the different states in which water is found during the water cycle?
Answer:
Water is found in three different states during the water cycle:

1. Solid (snow, ice).
2. Liquid water (ground water, river water, etc.)
3. Gaseous state (water vapours).

Question 2.
Name two biologically important compounds that contain both oxygen and nitrogen.
Answer:
Two biologically important compounds that contain both oxygen and nitrogen are:

1. Amino acids.
2. Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA).

Question 3.
List any three human activities which would lead to an increase in the carbon dioxide content of air.
Answer:
Three Human activities are:

1. Burning of fuels in various processes like heating, cooking, transportation and industry.
2. Human induced forest fires.
3. The process of deforestation includes the cutting down of trees. This decreases the uptake of carbon dioxide for photosynthesis. Eventually, the content of carbon dioxide increases.

Question 4.
What is the greenhouse effect?
Answer:
Some gases like carbon dioxide, methane, nitrous oxide prevent the escape of heat from the Earth’s surface by trapping it. This increases the average temperature of the Earth. This is called the green house effect.

Question 5.
What are the two forms of oxygen found in the atmosphere?
Answer:
The two forms of oxygen found in the atmosphere are:

1. Diatomic molecular form with chemical formula O₂.
2. Triatomic molecular form with chemical formula O₃ known as ozone.

Natural Resources NCERT Textbook Exercise

Question 1.
Why is the atmosphere essential for life?
Answer:
The atmosphere is essential for life because it maintains an appropriate climate for the sustenance of life by carrying out the following activities:

1. Atmosphere keeps the average temperature of the earth fairly constant during day time.
2. It prevents a sudden increase in temperature during day time.
3. It also slows down the escape of heat from the surface of the earth into outer space during night time.

Question 2.
Why is water essential for life?
Answer:
Water is essential for life because of the following reasons:

1. Most biological reactions occur when substances are dissolved in water. Thus, all cellular processes need water as a medium to take place.
2. Transportation of biological substances needs water as a medium.

Question 3.
How are living organisms dependent on the soil?
Or
Are organisms that live in water totally independent of soil as a resource?
Answer:
Almost all living organisms are dependent on soil. Some depends directly, while some depends indirectly. Plants need soil for getting support as well as nutrients to prepare their food. On the other hand, organisms depend on plants for food and other substances that are essential for life. Herbivores depend directly upon plants and carnivores depend upon animals, which in turn depend upon plants for food. This makes them depend on soil indirectly.

Organisms that live in water are not totally independent of soil as a resource. These organisms depend on aquatic plants for food and other substances. These aquatic plants in turn require minerals for their sustenance. These minerals are carried to water bodies from soil by rivers, rain water etc. Without the supply of minerals from the soil to the water bodies, it is impossible to imagine aquatic life.

Question 4.
You have seen weather reports on television and in newspapers. How do you think we are able to predict the weather?
Answer:
The meteorological department of the government collects data on the elements of weather such as maximum and minimum temperatures, maximum and minimum humidity, rainfall, wind speed etc. They are able to study these elements using various instruments. The maximum and minimum temperature of a day is measured by a thermometer known as the maximum – minimum thermometer. Rain fall is measured by an instrument known as the rain gauge. Wind speed is measured by anemometers. There are various instruments used to measure humidity.

Question 5.
We know that many human activities lead to increasing levels of pollution of the air, water-bodies and soil. Do you think that isolating these activities to specific and limited areas would help in reducing pollution?
Answer:
Yes. Isolating human activities to specific areas would help in reducing levels of pollution. For example, setting up of industries in isolated regions will control pollution to some extent. The pollution caused by these industries will not contaminate water resources, agriculture land, fertile land, etc.

Question 6.
Write a note on how forests influence the quality of our air, soil and water resources.
Answer:
Forests influence the quality of our air, soil, and water resources in various ways. Some of them are:

1. Forests balance the percentages of carbon dioxide and oxygen in the atmosphere. The increasing amount of carbon dioxide caused by human activities is balanced by a larger intake of carbon dioxide by plants during
   the process of photosynthesis. Simultaneously, a large amount of oxygen is released.
2. Forests prevent soil erosion. Roots of plants bind the soil tightly in a way that the surface of the soil cannot be eroded away by wind, water etc.
3. Forests help in the replenishment of water resources. During the process of transpiration, a huge amount of water vapour goes into the air and condenses to form clouds. These clouds cause rainfall that recharge water bodies.

Natural Resources Additional Questions

Natural Resources Multiple Choice Questions

Question 1.
The atmosphere of the earth is heated by radiations which are mainly ___________ .
(a) radiated by the sun
(b) re – radiated by land
(c) re – radiated by water
(d) re – radiated by land and water.
Answer:
(d) re – radiated by land and water.

Question 2.
If there were no atmosphere around the earth, the temperature of the earth will ___________ .
(a) increase.
(b) go on decreasing.
(c) increase during day and decrease during night.
(d) be unaffected.
Answer:
(c) increase during day and decrease during night.

Question 3.
What would happen, if all the oxygen present in the environment is converted to ozone?
(a) We will be protected more.
(b) It will become poisonous and kill living forms.
(c) Ozone is not stable, hence it will be toxic.
(d) It will help harmful sun radiations to reach earth and damage many life forms.
Answer:
(b) It will become poisonous and kill living forms.

Question 4.
One of the following factors does not lead to soil formation in nature ___________ .
(a) the sun
(b) water
(c) wind
(d) polythene bags.
Answer:
(d) polythene bags.

Question 5.
The two forms of oxygen found in the atmosphere are ___________ .
(a) water and ozone
(b) water and oxygen
(c) ozone and oxygen
(d) water and carbon – dioxide.
Answer:
(c) ozone and oxygen

Question 6.
The process of nitrogen – fixation by bacteria does not take place in the presence of ___________ .
(a) molecular form of hydrogen
(b) elemental form of oxygen
(c) water
(d) elemental form of nitrogen.
Answer:
(b) elemental form of oxygen

Question 7.
Rainfall patterns depend on ___________ .
(a) the underground water table.
(b) the number of water bodies in an area.
(c) the density pattern of human population in an area.
(d) the prevailing season in an area.
Answer:
(b) the number of water bodies in an area.

Question 8.
Among the given options, which one is not correct for the use of large amount of fertilisers and pesticides?
(a) They are eco – friendly.
(,b) They turn the fields barren after sometime.
(c) They adversely affect the useful component from the soil.
(d) They destroy the soil fertility.
Answer:
(a) They are eco – friendly.

Question 9.
The nitrogen molecules present in air can be converted into nitrates and nitrites by ___________ .
(a) a biological process of nitrogen fixing bacteria present in soil.
(b) a biological process of carbon fixing factor present in soil.
(c) any of the industries manufacturing nitrogenous compounds.
(d) the plants used as cereal crops in field.
Answer:
(a) a biological process of nitrogen fixing bacteria present in soil.

Question 10.
One of the following processes is not a step involved in the water – cycle operating in nature ___________ .
(a) evaporation
(b) transpiration
(c) precipitation
(d) photosynthesis.
Answer:
(d) photosynthesis.

Question 11.
The term “water – pollution” can be defined in several ways. Which of the following statements does not give the correct definition?
(a) The addition of undesirable substances to water – bodies.
(b) The removal of desirable substances from water – bodies.
(c) A change in pressure of the water bodies.
(d) A change in temperature of the water bodies.
Answer:
(c) A change in pressure of the water bodies.

Question 12.
Which of the following is not a green house gas?
(a) Methane
(b) Carbon dioxide
(c) Carbon monoxide
(d) Ammonia.
Answer:
(d) Ammonia.

Question 13.
Which step is not involved in the carbon – cycle?
(a) Photosynthesis
(b) Transpiration
(c) Respiration
(d) Burning of fossil fuels.
Answer:
(b) Transpiration

Question 14.
‘Ozone – hole’ means
(a) a large sized hole in the ozone layer.
(b) thinning of the ozone layer.
(c) small holes scattered in the ozone layer.
(d) thickening of ozone in the ozone layer.
Answer:
(b) thinning of the ozone layer.

Question 15.
Ozone – layer is getting depleted because of ___________ .
(a) excessive use of automobiles.
(b) excessive formation of industrial units.
(c) excessive use of man – made compounds containing both fluorine and chlorine.
(d) excessive deforestation.
Answer:
(c) excessive use of man – made compounds containing both fluorine and chlorine.

Question 16.
Which of the following is a recently originated problem of environment?
(a) Ozone layer depletion.
(b) Green house effect.
(c) Global warming.
(d) All of the above.
Answer:
(d) All of the above.

Question 17.
When we breathe in air, nitrogen also goes inside along with oxygen. What is the fete of this nitrogen?
(a) It moves along with oxygen into the cells.
(b) It comes out with the CO₂ during exhalation.
(c) It is absorbed only by the nasal cells.
(d) Nitrogen concentration is already more in the cells so it is not at all absorbed.
Answer:
(b) It comes out with the CO₂ during exhalation.

Question 18.
Top – soil contains the following ___________ .
(a) Humus and living organisms only.
(b) Humus and soil particles only.
(c) Humus, living organisms and plants.
(d) Humus, living organisms and soil particles.
Answer:
(d) Humus, living organisms and soil particles.

Question 19.
Choose the correct sequences ___________ .
(a) CO₂ in atmosphere → decomposers → organic carbon in animals → organic carbon in plants.
(b) CO₂  in atmosphere → organic carbon in plants → organic carbon in animals → inorganic carbon in soil.
(c) Inorganic carbonates in water → organic carbon in plants → organic carbon in animals → scavengers.
(d) Organic carbon in animals → decomposers → CO₂ in atmosphere → organic carbon in plants.
Answer:
(b) CO₂  in atmosphere → organic carbon in plants → organic carbon in animals → inorganic carbon in soil.

Question 20.
Major source of mineral in soil is the ___________ .
(a) parent rock from which soil is formed.
(b) plants.
(c) animals
(d) bacteria.
Answer:
(a) parent rock from which soil is formed.

Natural Resources Very Short Answer Type Questions

Question 1.
Name the factor responsible for rainfall patterns in India.
Answer:
North – East or South – West Monsoons.

Question 2.
Name any two organisms. Which play important role in nitrogen – fixation.
Answer:
Rhizobium and Nitrosomonas.

Question 3.
State the process and the form by which carbon enters in the living system.
Answer:
Respiration.

Question 4.
Write any one difference between oxygen and ozone.
Answer:
Oxygen is diatomic (O₂) whereas ozone is triatomic (O₃).

Question 5.
What is the temperature range on the surface of moon?
Answer:
-190°C to 110°C.

Natural Resources Short Answer Type Questions

Question 1.
Rivers from land, add minerals to sea water. Discuss, how?
Answer:
Water is wonderful solvent. As water flows over the rocks which containing soluble minerals and these mineral get dissolved in the water. Thus, Rivers from land, add minerals to sea water.

Question 2.
How can we prevent the loss of top soil?
Answer:
Loss of top soil can be prevented by stopping the falling of trees and excessive grazing by animals, growing more the vegetation cover.

Question 3.
How is the life of organisms living in water affected when water gets polluted?
Answer:
When water gets polluted, oxygen does not dissolves in water properly, which effects the aquatic organisms adversely. Also, due to undesirable chemicals and waste discharge from factories and households cause diseases to the aquatic organisms.

Question 4.
During summer, if you go near the lake, you feel relief from the heat, why?
Answer:
Due to evaporation of water, air nearby water bodies become cooler.

Question 5.
In coastal area, wind current moves from the sea towards the land during day; but during night it moves from land to the sea. Discuss the reason.
Answer:
Air above the land gets heated quickly during day and starts rising. This creates a region of low pressure as a result air over sea rushes into this area of low pressure. This movement of air from one region to the other creates winds. During night, as water cools down slowly, the air above water is warmer than the air on land. So, air moves from land to sea creating winds.

Question 6.
Following are a few organisms: (a) lichen (b) mosses (c) mango tree (d) cactus.
Which among the above can grow on stones; and also help in formation of soil? Write the mode of their action for making soil.
Answer:
Lichens and Mosses: (a) and (b).
Lichens and mosses release materials which break down the stones causes formation of soil.

Question 7.
Soil formation is done by both abiotic and biotic factors. List the names of these factors by classifying them as abiotic and biotic?
Answer:

1. Sun, water and wind are abiotic factors that forms soil.
2. Lichens, mosses and trees are biotic factors which form soil.

Question 8.
All the living organisms are basically made up of C, N, S, P, H and O. How do they enter the living forms? Discuss.
Answer:
In 1952, Stanley Miller along with Harold C. Urey designed an experiment to see how complex organic molecules might have formed under the conditions of early Earth. From long experimental method he developed organic matter from non living things. And, concluded that on specific environmental conditions non living things grow up to living form.

Question 9.
Why does the percentage of gases like oxygen, nitrogen and carbon dioxide remain almost the same in the atmosphere?
Answer:
The percentage of gases like oxygen, nitrogen and carbon dioxide remain almost the same in the atmosphere because cycling of these gases maintains consistency.

Question 10.
Why does moon have very cold and very hot temperature variations e.g., from -190°C to 110°C even though it is at the same distance from the sun as the earth is?
Answer:
No atmosphere exists on the moon thus, moon have very cold and very hot temperature variations e.g., from -190°C to 110°C even though it is at the same distance from the sun as the earth.

Question 11.
Why do people love to fly kites near the seashore?
Answer:
People love to fly kites near the seashore because air gets heated quickly during day and creates wind, which helps them to fly kites easily.

Question 12.
Why does Mathura refinery pose problems to the Taj Mahal?
Answer:
Polluted environment of Mathura due to refinery and other infrastructural facilities, industries etc. release toxic gases (like oxides of sulphur) which causes acid rain and corrode the marbles of Taj Mahal.

Question 13.
Why does water need conservation even though large oceans surround the land masses?
Answer:
Marine water is not useful for human and plant life directly. Hence fresh water need conservation. Uneven distribution of limited fresh water resources need conservation to ft ever rising demands.

Question 14.
There is mass mortality of fishes in a pond. What ma) the reasons?
Answer:

1. Thermal pollution
2. Addition of poisonous (mercury) compounds in water
3. Due to blockage of gills with any pollutant.

Natural Resources Long Answer Type Questions

Question 1.
How do fossil fuels cause air pollution?
Answer:
Most of air pollution of our environment is caused by the burning of fossil fuels, such as coal, oil natural gas and gasoline to produce electricity and power out vehicles. Carbon dioxide (CO₂) is a good indicator of how much fossil fuel is burnt and how much of other pollutants are emitted as a result. When fossil fuels are burnt, they release primarily nitrogen oxides into the atmosphere, which leads to the formation of smog and simultaneously acid rain.

The most common nitrogen – related compounds emitted into the air by human activities are collectively referred to as nitrogen oxides. Ammonia is also a harmful nitrogen compound emitted to the air, agricultural activities also contribute in air pollution but fossil fuels are most common reason for its increase day by day.

Question 2.
What are the causes of water pollution? Discuss how you can contribute in reducing water pollution.
Answer:
Domestic and industrial waste dump to water – bodies are main reason of water pollution. Industries produce huge amount of waste which contains toxic chemicals and pollutants which can cause air pollution and damage us and our environment. They contain pollutants such as lead, mercury, sulphur, asbestos, nitrates and many harmful chemicals.

Prevention of water pollution:
Stop dumping waste in water – bodies is the only way to get clear water resources. Do not throw chemicals, oils, paints and medicines down the sink drain or the toilet. If you use chemicals and pesticides for your gardens and farms, be mindful not to overuse pesticides and fertilizers. This will reduce run offs of the chemical into nearby water sources.

Natural Resources Higher Order Thinking Skills (HOTS)

Question 1.
If decomposers are removed completely from the Earth, what will be the result? Give reasons.
Answer:
Decomposers are the organisms that feed on dead and decaying matter present on the Earth. These organisms decompose the dead plants and animals returning the complex nutrients present in them in available form to the nature.

Question 2.
Why is nitrogen – fixing bacteria found only in the roots of leguminous plants?
Answer:
The roots of leguminous plants contains root nodules. These nodules provide shelter to nitrogen fixing bacteria like Rhizobium.

Natural Resources Value Based Questions

Question 1.
Manisha lived near industrial area in Delhi. During winters . she saw that the smoke has reduced the visibility in the area. Manisha requested the industries to fit in chimney the precipitators that would not release smoke particulates in air.

1. What is smog?
2. Name two disease caused due to air pollution.
3. What values are displayed by Manisha?

Answer:

1. When smoke is added to fog, smog is formed.
2. Air – pollution causes respiratory problem and allergies.
3. Manisha showed the value of self-awareness, and responsible behaviour.

Question 2.
Radha saw a child sleeping in a car parked with closed doors and glass rolled up in the open area on a sunny day near the market. She immediately raised an alarm and with the help of police, she got the window glass rolled down.

1. Why was it not safe to keep the doors with window glass rolled Up for a child inside the car?
2. Name two gases that can lead to above effect.
3. What values are exhibited by Radha?

Answer:

1. It was not safe for the child in the car with locked doors and window rolled up, the sunlight would result in the green house effect in the car. This would increase the temperature in the car and also result in the increase in CO₂ level which would lead to suffocation.
2. Carbon dioxide gas and methane gas can lead to green house effect.
3. Radha displayed the value of aware citizen and responsible behaviour.

MP Board Class 9th Science Solutions

MP Board Class 9th Special English Postcard Writing

1. Aditya, who lives in Delhi, left for Shimla on a week’s holiday on SUNDAY. On the train he realised that he had forgotten to return his local library books due on Saturday. The library is closed on Wednesday. lie decided to write his brother a postcard from Shimla requesting him to return the books which he had left on his table. Write the postcard for him in your answer sheet giving all details. Do not add any new information. Write your answer in about 50 words or less.(5 marks)
Answer:

Shimla 17 June 20xx Dear Lalit I reached Shimla safely. On my way I realized I had forgotten to return three books of my local library due to be returned on Saturday. These books are lying on my study table. Please return these books to the librarian any day
except on Wednesday because the library is closed on Wednesday. Yours lovingly Aditya	Lalit AS 122, S.J. Enclave New Delhi Pin : 110029

2. Ramganesh has invented a new software for learning languages. You can see his notes below. He writes a postcard to his friend Ravi about it. Use the information to write the postcard. Do not exceed 50 words. Copy the format of the post card from the question paper in your answer sheet’ (5 marks)

Notes

Cirrus Electronic Systems – provide – multi-lingual software solution – launched – ‘India Speaks’ – Helps to learn any Indian language from another language – learn 15 languages from 210 combinations – possess-four parts – 150 terms – day to day needs – 400 sentences covered – helps get around everywhere.
Answer:

New Delhi 18-4-20xxDear Ravi You will be glad to know that the Cirrus Electronic Systems has launched ‘India Speaks’, a multi-lingual software solution invented by me. It will help to learn any Indian language from another language. It possesses in four parts some 150 terms of
day to day needs. It covers 400 sentences and can help one get around anywhere. What do you think about it? Waiting for your reply. Regards, Ramganesh.	To Mr. Ravi 425, New Colony, Colaba, Mumbai Pin : 400001

3. You are attending a Tennis coaching camp in Bangalore. Write a postcard in not more than 50 words to your mother on your experiences in the camp. Copy the format of the postcard from the question paper in your answer sheet. (5 marks)
Answer:

1st October, 20xx Dearest Mummy I am glad I decided to attend this Tennis Coaching Camp. It is indeed very enriching and productive in terms of learning and understanding the technical aspects of the game. Even the practical training imparted in this camp is very good. I am very sure by the end of two weeks I will

4. You are Shipra, do Shri Ram Naresh and are in Delhi to receive “The Bravery Award” for the .year 2004. The rehearsal for the function that is to take place on the 26th of January is over. Write a post-card to your parents who are living at 15, Esplanade Road, Cochin, telling them about the rehearsal in not more than 50 words. Copy the format of the post-card from the question paper in you answer sheet. (5 marks)
Answer:

21st January, 2008 Dear Mama and Papa Yesterday I went for the rehearsal of the function of the Bravery Award that I will receive on ~’6th of January: There were 18 more recipients and even during the rehearsal my spirits were soaring high and a sense of pride overwhelmed me. We were told about
our positions and how to conduct ourselves. Now we all are waiting for the final day. Do reach the venue on time. Yours lovingly Shipra	Shri Ram Naresh 15, Esplanade Road Cochin

5. You are Akash. During your holidays you went to Lucknow to visit your cousin. You took part in a hiking expedition, to Nainital, with your cousin and his friends. Write a post¬card to your friend Gaurav, B-21, Pandav Nagar, Delhi, about your expedition, in not more than 50 words. Copy the format of the post-card from the question paper in your answer sheet.
(5 marks)
Answer:

12th December, 20xx Dearest Gaurav, I went on a very adventurous trip during the holidays. I had gone to Lucknow to visit my cousin. There I took part in a hiking expedition to Nainital with him and his friends. It was a most exciting and wonderful experience. I got a unique opportunity to view the natural beauty of Nainital from a totally new
perspective. I have lots more adventure stories to share when we meet. With love Akash	Gaurav B-21, Pandav Nagar Delhi-110006.

MP Board Class 9th English Solutions

MP Board Class 9th Science Solutions Chapter 6 Tissues

Tissues Intext Questions

Tissues Intext Questions Page No. 69

Question 1.
What is a tissue?
Answer:
A group of cells that are similar in structure and / or work together to achieve a particular function form a tissue.

Question 2.
What is the utility of tissues in multi – cellular organisms?
Answer:
In multi – cellular organisms, different types of tissues perform different functions. Since a particular group of cells carry out only a particular function, they do it very efficiently. So, multi – cellular organisms possess a specific division of labour.

Tissues Intext Questions Page No. 74

Question 1.
Name types of simple tissues.
Answer:

1. Parenchyma
2. Collenchyma and
3. Sclerenchyma

Question 2.
Where is apical meristem found?
Answer:
At root tip and shoot tip.

Question 3.
Which tissue makes up the husk of coconut?
Answer:
Sclerenchymatous tissue.

Question 4.
What are the constituents of phloem?
Answer:
Phloem is made up of four types of elements: Sieve tubes, companion cells, phloem fibres and the phloem parenchyma.

Tissues Intext Questions Page No. 78

Question 1.
Name the tissue responsible for movement in our body.
Answer:
Muscular, tissue.

Question 2.
What does a neuron look like?
Answer:
A neuron is the unit of nervous tissue. It is elongated in shape and consists of three parts viz., dendrites, cell body and axon.

Question 3.
Give three features of cardiac muscles.
Answer:

1. Cardiac muscle cells are cylindrical, branched and uninucleate.
2. They show rhythmic contraction and relaxation throughout life.
3. They are involuntary muscles.

Question 4.
What are the functions of areolar tissue?
Answer:
Areolar tissue fills space inside the organs, supports internal organs and helps in repair of the tissues.

Tissues NCERT Textbook Exercises

Question 1.
Define the term ‘tissue’.
Answer:
The group of cells similar in structure that work together to achieve a particular function forms a tissue. This group of cells has a common origin.

Question 2.
How many types of elements together make up the xylem tissue? Name them.
Answer:
Xylem is formed of four types of elements.
They are:

1. tracheids
2. vessels
3. xylem parenchyma
4. xylem fibre.

Question 3.
How are simple tissues different from complex tissues in plants?
Answer:
Simple tissues are made of one type of cells which coordinate to perform a common function.
Complex tissues are made of more than one type of cells. All these coordinate to perform a common function.

Question 4.
Differentiate between parenchyma, collenchyma and sclerenchyma on the basis of their cell wall.
Answer:

Question 5.
What are the functions of the stomata?
Answer:
Functions of stomata:

1. Exchange of gases, particularly CO₂ and O₂ with atmosphere.
2. Loss of water in the form of vapours during transpiration.

Question 6.
Diagrammatically show the difference between the three types of muscle fibres.
Answer:

Question 7.
What is the specific function of the cardiac muscle?
Answer:
The specific function of cardiac muscle is to contract and relax rhythmically throughout life.

Question 8.
Differentiate between striated, unstriated and cardiac muscles on the basis of their structure and site / location in the body.
Answer:

Question 9.
Draw a labelled diagram of a neuron.
Answer:

Question 10.
Name the following:

1. Tissue that forms the inner lining of our mouth.
2. Tissue that connects muscle to bone in humans.
3. Tissue that transports food in plants.
4. Tissue that stores fat in our body.
5. Connective tissue with a fluid matrix.
6. Tissue present in the brain.

Answer:

1. Squamous epithelium.
2. Tendons.
3. Phloem.
4. Adipose tissue.
5. Blood.
6. Nervous tissue.

Question 11.
Identify the type of tissue in the following: skin, bark of tree, bone, lining of kidney tubule, vascular bundle.
Answer:

1. Skin: Striated squamous epithelium
2. Bark of tree: Cork (protective tissue)
3. Bone: Connective tissue
4. Lining of kidney tubule: Cuboidal epithelium tissue
5. Vascular bundle: Conducting tissue (xylem and phloem).

Question 12.
Name the regions in which parenchyma tissue is present.
Answer:
Parenchyma is found in cortex and pith of both root and stem. When it contains chlorophyll, it is called chlorenchyma, found in green leaves.

Question 13.
What is the role of epidermis in plants?
Answer:
Cells of epidermis form a continuous layer without intercellular spaces. It protects all the parts of the plant.

Question 14.
How does the cork act as a protective tissue?
Answer:
In older plants, the secondary meristem forms on its outerside several layered thick cork or the bark. Cork acts as a protective tissue because:

1. Its cells are dead and compactly arranged without intercellular spaces
2. Its cells also have deposition of suberin in their walls that makes them impervious to gases and water.

Thus, cork protects the underlying tissues from excessive loss of water, adverse external environment and mechanical injuries.

Question 15.
Complete the table:

Answer:

Tissues Additional Questions

Tissues Multiple Choice Questions

Question 1.
The spindle shaped cells, uninucleated and unbranched are present in muscular tissue of _________.
(a) Striated muscles
(b) Smooth muscles
(c) Cardiac muscles
(d) Both (a) and (b).
Answer:
(b) Smooth muscles

Question 2.
The size of the stem increases in the width due to _________.
(a) Apical meristem
(b) Intercalary meristem
(c) Primary meristem
(d) Lateral meristem.
Answer:
(d) Lateral meristem.

Question 3.
The cells of cork are dead and have a chemical in their walls that makes them impervious to gas and water. The chemical is _________.
(a) Lignin
(b) Suberin
(c) Cutin
(d) Wax.
Answer:
(b) Suberin

Question 4.
The tissue that helps in the movement of our body are _________.
(a) Muscular tissue
(b) Skeletal tissue
(c) Nervous tissue
(d) All of the above.
Answer:
(d) All of the above.

Question 5.
The connective tissue that connects muscle to bone is called _________.
(a) Ligament
(b) Tendon
(c) Cartilage
(d) Areolar.
Answer:
(b) Tendon

Question 6.
Cartilage and bone are types of _________.
(a) Muscular tissue
(b) Connective tissue
(c) Meristematic tissue
(d) Epithelial tissue.
Answer:
(b) Connective tissue

Question 7.
A tissue whose cells are capable of dividing and re – dividingis called _________.
(a) Complex tissue
(b) Connective tissue
(c) Permanent tissue
(d) Meristematic tissue.
Answer:
(d) Meristematic tissue.

Question 8.
The tissue that helps in the secretion and absorption and is found in the inner lining of the alimentary canal is?
(a) Ciliated epithelium
(b) Cuboidal epithelium
(c) Squamous epithelium
(d) Columnar epithelium.
Answer:
(d) Columnar epithelium.

Question 9.
The flexibility in plants is due to a tissue called?
(a) Chlorenchyma
(b) Parenchyma
(c) Sclerenchyma
(d) Collenchyma.
Answer:
(d) Collenchyma.

Question 10.
The tissue present in the lining of kidney tubules and ducts of salivary glands is?
(a) Squamous epithelium tissue
(b) Glandular epithelium tissue
(c) Cuboidal epithelium tissue
(d) Columnar epithelium tissue.
Answer:
(d) Columnar epithelium tissue.

Tissues Very Short Answer Type Questions

Question 1.
Name two main groups of plant tissue.
Answer:
Two groups are:

1. meristematic tissues and
2. permanent tissues.

Question 2.
Where will you look for meristematic cells in a plant body?
Answer:
The meristematic cells are present only at the growing regions such as shoot tips, root tips and at the base of the leaves or internodes.

Question 3.
What are simple permanent tissues?
Answer:
Simple permanent tissues consist of one type of cells which look like each other.

Question 4.
Name two types of simple permanent plant tissues.
Answer:
Simple permanent plant tissues are:

1. Parenchyma
2. Collenchyma and
3. Sclerenchyma.

Question 5.
Write four elements of xylem.
Answer:

1. Tracheids
2. Vessels
3. Xylem parenchyma
4. Xylem fibres.

Question 6.
What are the three types of muscle fibres (muscle cells)?
Answer:
Three types of muscle fibres are:

1. Striated muscle (skeletal muscle or voluntary muscle).
2. Unstriated muscle (smooth muscle or involuntary muscle).
3. Cardiac muscle.

Question 7.
What are the various functions of all types of epithelial tissues?
Answer:
Epithelial tissues help in

1. protection
2. absorption
3. excretion
4. exchange of respiratory gases
5. secretion.

Question 8.
What is basement membrane?
Answer:
It is a very thin non – cellular membrane on which cells of epithelial tissue rest. It also separates the epithelial tissue from the underlying tissues.

Question 9.
Of which type of muscles the stomach wall is made of? Whether they are voluntary or involuntary?
Answer:
Smooth or non-striated. They are involuntary muscles.

Question 10.
What is the function of connective tissue?
Answer:
Connective tissue connects different tissues and organs. It provides support to different parts of the body by forming packing around different organs of the body

Question 11.
What are the two main features of connective tissue?
Answer:

1. Cells are loosely spaced and are embedded in matrix.
2. Matrix may be jelly – like, fluid, dense or rigid.

Question 12.
Name one animal whose whole skeleton is made of cartilage.
Answer:
Shark fish.

Question 13.
List seven examples of connective tissue.
Answer:

1. Bone
2. Cartilage
3. Tendons
4. Ligaments
5. Areolar tissue
6. Adipose tissue and
7. Blood.

Question 14.
What are blood platelets?
Answer:
Blood platelets are minute (about 2 to 4μ in diameter), anucleated, disc like bodies. The main function of platelets is to help in clotting of blood.

Question 15.
Name the connective tissue that is found between skin and muscles.
Answer:
Areolar connective tissue fills the space between skin and muscles.

Question 16.
How would you recognize that the slide given to you is of striated muscle? Give only two important points.
Answer:

1. Striated muscles have light and dark bands (which gives it a striped look).
2. Striated muscle fibres are not branched like cardiac muscles.

Question 17.
From which part of a nerve cell, dendrites arise?
Answer:
The cell body.

Question 18.
Name the tissue present in the brain.
Answer:
Nervous tissue (formed of neuron cells).

Question 19.
Which cell is the longest in the body of an animal?
Answer:
Neuron (Nerve cell) which may be upto 1m long (in special cases).

Question 20.
Name a fluid, except blood, which circulates in the body.
Answer:
Lymph.

Question 21.
Why are striated muscles generally called skeletal muscles?
Answer:
In general, striated muscles are attached with the bones. They help in the movement of the bones. So, they are also called skeletal muscles.

Question 22.
Name one muscle which does not fatigue and works throughout life in normal conditions.
Answer:
Cardiac muscles.

Question 23.
How are ligaments different from tendons?
Answer:
Ligaments are elastic connective tissues which attach bones with each other to keep them in then placer Tendons arc less elastic connective tissues which attach, muscles to a bone.

Question 24.
What is the main function of meristematic tissue?
Answer:
The mam function of meristematic tissue is to form continuously new cells for increasing cell number, length and the girth of the plant.

Tissues Short Answer Type Questions

Question 1.
How do tissues formed in multicellular organisms?
Answer:
During development from zygote (formed by the union of egg and sperm), a large number of cells are formed. These cells undergo differentiation to produce various specialised tissues to perform different functions in the living body.

Question 2.
What are the characteristics of plant tissues?
Answer:
Plants are stationary or fixed, they do not need much energy. So, most of the tissues they have are supportive, which provide them with structural strength. Most of these tissues are dead; they do not contain living protoplasm.

Question 3.
What are structural and functional differences between plants and animals?
Answer:
As plants do not move, they do not need much energy. So, most of the tissues they have are dead and supportive. But animals need energy as they move around in search of food, mate and shelter. So, most of the animal tissues are living.

Question 4.
Why do meristematic cells lack vacuoles?
Answer:
Meristematic cells divide frequently to give rise to new cells. So, they need dense cytoplasm and soft cell wall. Vacuoles cause hindrance in cell division as they are full of cell sap and provide turgidity and rigidity to the cell.

Question 5.
What are characteristic structural features of meristematic cells ?
Answer:
Meristematic cells have:

1. Thin cell walls.
2. Abundant or dense cytoplasm and single large nucleus.
3. Spherical, oval, polygonal or rectangular shape.
4. No intercellular spaces between them.
5. Either no vacuoles at all or a few vacuoles.

Question 6.
List any four salient features of meristematic tissue.
Answer:

1. This tissue consists of actively dividing cells.
2. This tissue is present in growing regions of plants.
3. In this tissue, cells are packed closely without intercellular spaces.
4. Cells of this tissue have thin cell walls, dense cytoplasm and prominent nuclei.

Question 7.
What are permanent tissues?
Answer:
The cells of meristematic tissue lose the ability to divide and get differentiated into specialised cells. These differentiated cells form different types of tissues which are known as permanent tissues.
Some examples: permanent tissues are

• parenchyma
• sclerenchyma etc.

Question 8.
With the help of only schematic line diagram, show classification of main permanent tissues.
Answer:

Question 9.
Write the characteristics of collenchyma.
Answer:
The cells in this type of tissue are living, elongated and thickened with cellulose at the corners. There is very little intercellular space. This tissue provides flexibility and mechanical support to plants. It is found in hypodermis of stems and leaf stalks.

Question 10.
What are protective tissues?
Answer:
All parts of plants e.g., leaves, flowers, stems and roots are covered by a single outermost protective layer called epidermis. It consists of rectangular, closely fitted relatively flat cells which lack intercellular spaces. Usually, it is one cell thick and is covered with cutin. Epidermis protects internal tissues of the plant.

Question 11.
Does the outer most protective layer is throughout, continuous? If not, what interruptions are usually foundation leaves and herbaceous parts of the plant?
Answer:
Epidermis is the outermost layer of cells in leaves and green herbaceous stems. It is not a continuous layer as it contain numerous minute pores called stomata.

Question 12.
Write major functions of stomata present in the epidermis.
Answer:
Major functions of stomata:

1. Stomata are essential for exchange of gases – oxygen and carbon dioxide between the plant and the atmosphere.
2. Normally, plants remove excessive water in the form of vapour through stomata. This process is called transpiration.

Question 13.
What is the main function of vascular tissues in plants?
Answer:
Vascular tissues transport:

1. Water and dissolved minerals from toots to various parts of the plant (xylem).
2. Prepared food material from leaves to different plant parts (phloem).

Question 14.
What ire vascular bundles?
Answer:
In plants, complex tissues xylem and phloem altogether constitute a structure called vascular bundle. Their main function is transportation of water, salts and food materials within the plant body.

Question 15.
List four elements of phloem. Which one of them is most important and why?
Answer:
Phloem consists of following four elements:

1. Sieve tubes
2. Companion cells
3. Phloem parenchyma
4. Phloem fibres.

The most important element of phloem is sieve tubes because they translocate food materials from leaves to other parts of plant.

Question 16.
What is muscular tissue? What is their function?
Answer:
1. Muscular tissue: This is a specialised tissue which is composed of contractile, fibre – like cells. This tissue is responsible for movement in our body.

2. Function: The movement of the body or limbs is brought about by contraction and relaxation of contractile proteins present in the muscle cells.

Question 17.
In desert plants, epidermis is covered by waxy substances. Can you think why?
Answer:
Waxy substances which cover epidermis are waterproof and hence, they check loss of water during transpiration. Besides this, they also aid in protection against mechanical injury and invasion by parasitic fungi.

Question 18.
What are the four important types of tissues found in animals?
Answer:
The four animal tissues found in animals are:

1. Epithelial tissues.
2. Connective tissues.
3. Muscular tissues and.
4. Nervous tissue.

Question 19.
State one important function of each of the following:

1. Areolar tissue
2. Cuboidal epithelium.

Answer:

1. Areolar tissue: It fills the space inside the organs, supports internal organs and helps in repair of tissues.
2. Cuboidai epithelium: it forms the lining of kidney tubules and ducts of salivary glands where it provides mechanical support.

Question 20.
What are the two main components of blood? Why is blood considered a type of connective tissue?
Answer:
Blood has two main components:

1. Fluid (liquid) matrix called plasma.
2. Suspended red blood cells (RBCs), white blood cells (WBCs) and platelets.

Blood is considered as a connective tissue because:

1. It has the same Origin as the other connective tissues.
2. It flows to different parts of the body and thus, connects different parts of the body with one another to exchange materials and gases.

Question 21.
Why do blood and lymph called as connective tissues?
Answer:
The fluid tissue (blood and lymph) connects various parts (cells) of the body. It supplies nutritive materials, oxygen and hormones collected from different organs to the body tissues. It also collects waste materials from different body tissues and delivers to excretory organs.

Question 22.
Why is blood called as fluid connective tissue?
Answer:
Blood is considered as a connective tissue because it connects different parts of the body. It contains plasma as matrix in which blood cells remain suspended. Being matrix (plasma) in liquid state, blood is called fluid connective tissue.

Question 23.
Explain how the bark of a tree is formed. How does it act as a protective tissue?
Answer:
As trees grow old, a strip of secondary meristem replaces the epidermis of the stem. Cells on the outside are cut off from this layer. This forms the several layer thick cork or the bark of the tree. Bark is a mass of dead tissue lying in the peripheral region of the plant body as a hard dry covering. Its function is protection. It protects the inner tissues against the attack of fungi and insects, against loss of water by evaporation etc.

Question 24.
What is the difference between voluntary and involuntary muscles? Give example of each.
Answer:
Voluntary muscles are those which are directly under control of our will
e.g.

• skeletal muscle.

They work or contract on our command. Involuntary muscles are not under the command of our will. We cannot control contraction and relaxation of these muscles. They are of two types – smooth muscles and cardiac muscles. Smooth muscles are found in stomach, intestine, iris of eye, in ureters and in the bronchi of lungs. Another type of involuntary muscles that is, cardiac muscles are found in heart.

Tissues Long Answer type Questions

Question 1.
The following diagrams are of L.S. of shoot apex and L.S. of root apex. Observe the diagrams and answer the questions given below:

1. What type of cells shoot apex and root apex consists of?
2. What are the main characteristics of these cells?
   

Answer:

1. Meristematic cells.
   • (a) Cells have big nucleus and dense cytoplasm.
   • (b) These cells lack intercellular spaces and vacuoles.

Question 2.
How many types of meristems are present in plants, on the basis of position?
Answer:
On the basis of location of meristem, it is classified into three types:

1. Apical meristem: It is present at the tip of stem, root and their branches.

2. Intercalary meristem: It is found at the leaf base, above the nodes (i.e. at the base of internodes as in grasses) or below the nodes (i.e. at the upper most region of internode as in mint.)

3. Lateral meristem: Vascular cambium and cork cambium are the examples of lateral meristem. Vascular cambium is found in vascular bundles while cork cambium is found underneath the bark of trees. Both of these cause increase in the girth of plants.

Question 3.
Draw a labelled diagratn of shoot to show location of meristematic tissues in the plant body and write the functions of each of them.
Answer:
Functions:

1. Apical meristem: It increases the length of the stem and the root.
2. Lateral meristem (cambium): It increases the girth of the stems and roots.
3. Intercalary meristem: It is present at the base of the leaves or internode (on either side of the node).

It produces buds which develop in auxiliary branches or auxiliary floral branches.

Question 4.
Explain the structure of parenchyma. What are its major modifications?
Answer:
Parenchyma: It is the basic or fundamental tissue found in plants. Cells of this tissue are thin walled, circular or polygonal. They are living with a nucleus and a vacuole. Intercellular spaces are present between the cells of this tissue. Two modifications of parenchyma are chlorenchyma and aerenchyma.

Chlorenchyma: Sometimes cells of the parenchyma contain chlorophyll and perform photosynthesis. This kind of parenchyma is known as chlorenchyma.

Aerenchyma: In aquatic plants, parenchyma contains big air spaces in between them. Such a parenchyma tissue is known

(a) Parenchyma with intercellular spaces.
(b) Aerenchyma with big spaces

Question 5.
Write the main functions of parenchyma.
Answer:
Functions of the parenchyma:

1. They store food.
2. They provide temporary support by retaining the turgid condition of cells.
3. Chlorenchyma containing chloroplasts prepare food through photosynthesis.
4. In aquatic plants, aerenchyma gives buoyancy to plants and hence they can float easily.

Question 6.
Describe the structure of selerenchyma. Write its major functions.
Answer:
Selerenchyma: Selerenchyma is the chief mechanical tissue of plants. The cells of this tissue are usually long, narrow and pointed at both ends. Due to deposition of lignin, their walls are often very highly thickened. Hence, the lumen of cell cavity is nearly obliterated. They are usually provided with simple pits which may be oblique or straight.
The selerenchyma cells are dead cells and their main function is to provide strength and rigidity to the plant.

Question 7.
What is xylem? Explain its structure. Which one of its component is very important and why?
Answer:
Xylem is a complex plant tissue which transports water and dissolved minerals from roots to all other plant parts.

Structure: Xylem consists of four kinds of cells (also known as elements):
(i) Tracheids: A tracheid is an elongated, hollow cell with its both ends tapering. The walls of these cells are thickened by the deposition of lignin. At certain spots lignin is not present. These spots are termed as pits. The tracheids are dead cells.

(ii) Vessels: These are tube like structures formed by a number of cells placed end to end with their transverse walls dissolved. The side walls of these tubes also have deposition of lignin. The thickening of the walls show various kinds of patterns. They are also dead cells.

(iii) Xylem parenchyma: These are parenchymatous, thin walled, living cells. They help in lateral conduction of water and sap. They also store food.

(iv) Xylem fibres: They are lignified dead fibres which provide mechanical support to plant. The most important element of xylem is vessel because most of the water and minerals are carried upward through this component of xylem.

Question 8.
Describe the structure of phloem.
Answer:
Structure of phloem: The main conducting part of the phloem is sieve tube which is formed of elongated cylindrical cells arranged in vertical rows. The walls between the cells have many minute pores through which food material can pass from one cell to the next. The porous walls between the cells is termed as sieve plate. Each sieve tube is supported by a long parenchymatous cell called the companion cell which helps the sieve tubes in the conduction of food material.

The above figure shows that phloem also contains phloem fibres, which provide mechanical support. Another component of phloem is parenchyma cells which stores food.

Question 9.
What is epithelial tissue?
Answer:
Epithelial Tissue: Epithelial tissue forms covering of entire surface of the body and lines the internal organs. Because of this, epithelial tissue is also called protective tissue. It also forms a barrier to keep different body systems separate. In this tissue cells are closely associated and arranged on a very thin extracellular fibrous basement membrane. Epithelial tissue may be composed of one (simple epithelium) or more layers of cells (compound epithelium). The skin, lining of mouth and alimentary canal, lung alveoli etc. are made of epithelial tissues.

Question 10.
What are the four main functions of epithelial tissue?
Answer:
The four main functions of epithelial tissue are:

1. It forms the outer layer of skin and hence it protects the underlying cells from drying, injury, bacterial and chemical effects..
2. It forms lining of mouth, alimentary canal and other internal organs and thus protects these organs.
3. It helps in absorption of water and other nutrients in alimentary canal.
4. Some of them are greatly specialised and perform secretory function.

Question 11.
What are the categories of epithelial tissue depending upon the shape and function of epithelial cells?
Answer:
Depending upon the shape and function of the cells, epithelial tissue is classified as:

Question 12.
What are the various forms of epithelial tissues? Describe briefly.
Answer:
(i) Squamous epithelium: The cells of this tissue are thin and flat forming a delicate lining. It is found in the alveoli and blood vessels. Tongue, oesophagus and lining of mouth also made up of squamous epithelium.

(ii) Cuboidal epithelium: The cells of this tissue are cube like in appearance. It is found in the lining of kidney tubules and ducts of salivary glands etc.

(iii) Columnar epithelium: The cells of this tissue are more tall and wide, placed side by side. Their nuclei are situated near the bases. They may have finger like . projections – the microvilli on their free surfaces. This tissue usually lives in the internal surface of stomach and intestine.

(iv) Ciliated epithelium: The cells of this tissue are modifications of columnar epithelial cells. They have many small hair like projections called cilia on their free ends. This type of epithelium is found in trachea and oviduct.

(v) Striated squamous epithelium: Cells of this tissue are similar to squamous epithelial cells but in this tissue they are arranged in many layers to prevent wear and tear of parts. In skin, striated squamous epithelium is found.

(vi) Glandular epithelium: In this type of epithelium, cells secrete substances at the epithelial surface. Such type of epithelium is found in glands.

Question 13.
Explain the structure of three types of muscle fibres. Also write the locations where they are found in the body.
Answer:
The following are the three types of muscle cells:
(i) Unstriated muscles: (Also known as smooth, involuntary muscles). This type of muscular tissue consists of spindle – shaped, long uninucleate cells. These muscles are present in alimentary canal, blood vessels, iris of eye, in ureters and bronchi of lungs etc.

(ii) Striated muscles: Also known as voluntary muscles because of their function being in our control or will. This type of muscular cells are long multi – nucleated and, enclosed in a membrane known as sarcolemma. Each fibre has several longitudinal filaments embedded in cytoplasm. These filaments give these muscles striated appearance. These muscles are attached to the skeleton; so they are also called skeletal muscles.

(iii) Cardiac muscles: These muscles are found in heart. They are not under the control of the will. They contract rhythmically and involuntarily throughout life without the sign of fatigue. Structurally they show the characters of both unstriated and striated muscles. They are made up of branched fibres. These fibres are uninucleated and show alternate light and dark bands (striations).

Question 14.
What are three main categories of connective tissue?
Answer:
Categories of Connective Tissue:
(i) Connective tissue: There is a matrix in which generally two types of (white and yellow) fibres are present. In between these fibres some connective tissue cells are present.
Examples of this kind of connective tissues are

• areolar tissue and
• adipose tissue.

(ii) Skeletal tissue: This type of tissue forms the skeleton of an organism. It is of two types – cartilage and bone Cartilage has solid matrix, called chondrin, in which fibres and cells known as chondrocytes are present. Usually, cells are present in clusters of 2 – 3 cells in small spaces called lacunae. Cartilage is found in the regions of pinna, nose, trachea and larynx. In bones, matrix is formed of a protein called ossein impregnated with phosphate and carbonates of calcium and magnesium.

(iii) Fluid tissue: Blood and lymph are examples of fluid connective tissue. These are specialized connective tissues. It consists of liquid matrix with no fibres. In liquid matrix called plasma corpuscles remain suspended. Blood transports food material, gases and other substances to the various parts of the body.

Question 15.
What are fibrous connective tissue?
Answer:
Fibrous connective tissue. It is of two types:
(i) The white fibrous connective tissue: It consists of white, non-elastic, unbranched fibres which unite to form bundles called tendons. Tendons are strong, tough and smooth, rope like structures which serve to attach muscles with the bones.

(ii) The yellow fibrous connective tissue: It also consists of fibres which are fine thread like structures. These fibres are quite elastic. Like white elastic fibres, these fibres also form cords called ligaments. These ligaments connect two bones.

Question 16.
Describe the structure of cartilage and bone.
Answer:
1. Cartilage: It is a solid but semi – rigid and flexible connective tissue. It has large, bluntly angular cartilage cells called chondrocytes. They occur in clusters of 2 or 3 in small spaces (lacunae) scattered in the matrix. Cartilage smoothens bone surfaces at joints and is also present in the nose, ear, trachea and larynx.

2. Bone: Bone is a solid, rigid and strong connective tissue. Its matrix become hard due to the deposition of salts of calcium and phosphorus. Osteocytes or bone cells are present in irregular spaces – lacunae in the matrix, interconnected by fine canals called canaliculi. In this tissue, matrix deposits in concentric rings around narrow longitudinal cavities called Haversian canals. These canal carries blood vessels and nerves.

Question 17.
Explain the structure of a fluid connective tissue.
Answer:
Blood is a fluid connective tissue consists of:

1. Blood plasma: It is the fluid matrix which contains 85% to 90% water, 7% different types of proteins, 0.9% of salts, about 0.1% glucose and a very small amount of hormones, wastes etc. In the plasma, blood corpuscles (cells) are suspended.
2. Blood cells. Three kinds of blood cells are found suspended in the blood plasma.

These are:
(a) Red blood corpuscles (erythrocytes) or RBC
(b) White blood corpuscles (leucocytes) or WBC and
(c) Blood platelets.

(a) Red blood corpuscles (erythrocytes) or RBC:
The red blood corpuscles are biconcave, disc – like cells which are devoid of nucleus. They contain a substance called haemoglobin because of this they appear red in colour. The most important function of the RBC is the transport of oxygen and carbon dioxide.

(b) White blood corpuscles (leucocytes) or WBC: These cells are comparatively larger in size, colourless and irregular in appearance. They are devoid of haemoglobin. They protect our body from diseases by destroying germs.

(c) Blood platelets: These are small, 2 – 4μ in diameter. They are without nucleus. Their main function is to liberate some substances which helps in blood clotting.

Question 18.
What are areolar tissue and adipose tissue? Where are they located?
Answer:

1. Areolar tissue: It is a connective tissue which consists of matrix, several types of cells, collagen and elastin fibres.
2. Location: They are found between the skin and muscles, around blood vessels and nerves and in the bone marrow.
3. Functions: It fills space inside the organs, support internal organs and helps in repair of the tissues.
   
4. Adipose tissue: It consists of cells (adipocytes) which are filled with fat globules. These cells remain scattered in a matrix.
5. Location: It is found below the skin and between internal organs.
6. Function: It stores fats and act as insulator.
   

Question 19.
(i) What is a nervous tissue?
(ii) Draw a well labelled diagram of neuron. (label any 4 parts).
Answer:
(i) Nervous Tissue: Nervous tissue is made up of specialised cells called nerve cells or neurons. Each nerve cell is elongated in shape and consists of three parts: cell body, dendrites and axon.The cell body contains a distinct nucleus and has a special kind of granules, called Nissel’s granules in the cytoplasm. From the cell body a single long part called the axon and many branched parts called dendrites arise. In some nerve cells, the axon has a thick white covering called medullary sheath. The terminal end of axon is without sheath and branched. Each nerve cell receives message through the dendrites and sends them to the axon (see Fig. below).
(ii)

Tissues Higher Order Thinking Skills (HOTS)

Question 1.
Cutting of rose plant is done timely in gardens, but still it regain its length. Give reason.
Answer:
In rose plant, intercalary meristeim is present at the base of leaves or internodes. The cells of these tissues, therefore divide and increase the length of plant.

Question 2.
Why does water hyacinth floats on water?
Answer:
A type of parenchyma called aerenchyma is present in water hyacinth. This encloses a lot of air and makes the plant lighter than water. Therefore, it floats on water.

Tissues Value Based Question

Question 1.
A patient suffering from paralysis was unable to walk. His family members took the utmost care of him:

1. Name two tissues responsible for the movement of body?
2. What are the tissues present in brain and spine?
3. What value of the family members is seen in the above case?

Answer:

1. Two tissues responsible for movement of the body are nervous tissue and muscular tissue.
2. The tissues present in brain and spine are nervous tissues.
3. His family members showed the value of being kind, caring, dutiful and responsible.

MP Board Class 9th Science Solutions

MP Board Class 9th Special English Unseen Passages Factual

Passage-1

Camps To Tap Creativity

1. As the dreaded examinations crawl to a halt, students look forward to the much-awaited “creative outlets”, the summer camps, to let off steam and spend their holidays. A summer camp is conducted over a short period of four to five weeks involving interesting and fun-filled activities. The colorful spectrum of summer camps provides a wide variety of activities which include artistic skills, such as painting, origami, art, music, craft and also spoken English, cookery and computer courses. Not only this, the summer camps keep the child “fit as a fiddle” by imparting lessons in yoga, cricket, tennis and swimming.

2. With changing, times and trends parents have become productivity-oriented. They want their children to learn through productive play unlike in the past when play was just played. Today, the parents want to tap the potential of their children to the fullest. To achieve this aim, the summer camps afford an ideal opening for children to develop their hobbies and talents. The importance of creative, play is often underestimated whereas the fact is that art and craft projects can excite even a young child’s imagination and promote a sense of great achievement. The little things that children make and take home give them a sense of achievement and pride when they show them to their parents.

3. Summer camps develop a child’s confidence and his ideas. They also encourage children to do things on their own. The camps are beneficial for hyperactive and aggressive children as they help channel their energies fruitfully by drawing out the best in them. They also promote mutual understanding not only among teachers and children but also bring about .interaction between the taught. This provides a good experience for a better future— a future of confidence.

(“The Young World” The Hindu”)

Question 1.
On the basis of your reading of the passage complete the following sentences. Write the answers in your answer sheet against the correct blank number : (8 marks)
(a) Activities in summer camps are …………….. and …………….. sentences.
(b) Summer camps keep the children healthy since ……………..
(c) Now-a-days pare’ its Bunk play should be ……………..
(d) “To achieve this aim”. Wliat aim is the writer referring to here?
(e) “They also promote mutual understanding.” They’ refers, to ……………..
(f) Summer camps are particularly helpful for problem children who are …………….. and …………….. Give the list of qualities
(g) …………….. and
(h) …………….. apart from the ones given below, which camps help to develop in children: confidence; creativity; .talents
Answer:
(a) fun-filled and interesting. ;
(b) they impart lessons in yoga, cricket, tennis and swimming.
(c) productivity-oriented.
(d) The aim is the parent’s desire to tap the potential of their children to the fullest.
(e) ‘They’ refers to the summer camps.
(f) hyperactive and aggressive.
(g) independence
(h) mutual understanding

Passage-2

The Rabbits Who Caused All The Troubles

1. Within the memory of the youngest child there was a family of rabbits who lived near a pack of wolves. The wolves announced that they did not like the way the rabbits were living. One night several wolves were killed in an earthquake and this was blamed on the rabbits, for it is well known that rabbits pound on the ground with their hind legs and cause earthquakes. On another night one of the wolves was killed by a bolt of lightning and this also was blamed on the rabbits, for it is well known that lettuce-eaters cause lightning.

2. The wolves threatened to civilise the rabbits if they did not behave, and the rabbits decided to run away to a desert island. But the other animals, who lived at a great distance, shamed them saying, “You must stay where you are and be brave. This is no world for escapists. If the wolves attack you, we will come to your aid, in all probability.” So the rabbits continued to live near the wolves. And one day there was a terrible flood which drowned a great many wolves. This was blamed on the rabbits, for it is well known that carrot nibblers with long ears cause floods. The wolves descended on the rabbits for their own good, and imprisoned them in a dark cave, for their own protection,

3. When nothing was heard about *the rabbits for some weeks, the other animals demanded to know what had happened to them. The wolves replied that the rabbits had been eatem and since they had been eaten the affair was a purely internal matter. “They were trying to escape,” said the wolves, “and, as you know, this is no world for escapists.”amey Thurber

Question 1.
On the basis of your reading of the passage above, complete the following sentences. Write the answers in your answer sheet agaipst the correct numbers.
(a) According to the wolves, the earthquake was caused by the rabbits ……………..
(b) The rabbits did not run away from their place of living to other safe places because ……………..
(c) Pick up two words from the passage which the wolves have used to indicate the nature of rabbits.
(d) What characteristic of the wolves does the phrase for their own good’ reveal?
(e) The wolvesustified their action to the other animals by saying ……………..
(f) The final fate of the rabbits was ……………..
(g) a purely Internal matter’ is humorous because ……………..
(h) The title ‘The Rabbits Who Caused All the Troubles’ is significant because ……………..
Answer:
(a) for it is well known that rabbits pound on the ground with their hind legs and cause earthquakes.
(b) they did not want to be shamed for being escapists.
(c) (i) lettuce-eaters (ii) carrot-nibblers
(d) This phrase reveals the self-centered nature of the wolves
(e) that the rabbits were trying to escape and this is no world for escapists
(f) imprisonment in a dark cave and being devoured by the wolves.
(g) the matter is not at all an internal one
(h) it is ironical as it was only the wolves who thought that the rabbits caused all the troubles

Passage-3

Medical Problems

1. By the end of the 15th century, European explorers had considerable experience of long-distance ocean voyaging. In particular, they had learned that the greatest danger, apart from storms and hurricanes, was lack of food and water. If a ship was becalmed supplies could quickly run low.

2. European navigators had also learned that there were other problems besides hunger and thirst. They noticed that ship crews often became very sick, even though they were eating and drinking regularly, but they did not understand why this happened. In fact, the crews were suffering from a disease called scurvy, caused by a lack of vitamin C. As a result, their gums became sore, their teeth fell out and many eventually died.

3. Scurvy affected crews throughout the Age of Discovery and beyond. Not until the 18th century did the British navy discover an effective way of preventing scurvy to issue a daily dose of lime juice, which is rich in vitamin C. This soon earned British sailors the nickname ‘Limeys’. (167 words)

Question 1.
On the basis of your reading of the passage answer the following questions. Write the answers in your answer sheet against the correct blank number.
(a) Two problems sailors faced on long-distance voyages in the 15th century were
(b) Supplies on ships sometimes ran low because
(c) Find words from para number one that mean
1. a lot of
2. being without
Answer:
1 the danger of storms and hurricanes, and the lack of food and water.
(b) of the ship being becalmed.
(c) 1. considerable
2. lack

Question 2.
On the basis of your reading of the passage answer the following notes on scurvy appropriately. Do not add any extra information. Write the answers in your answer sheet against the correct blank numbers.
(a) What it is ……………..
(b) Cause ……………..
(c) Symptoms ……………..
(d) Cure ……………..
Answer:
(a) disease
(b) lack of Vitamin C
(c) souring of gums and falling of teeth,
(d) drinking lime juice daily.

Passage-4

About Computers

1. There is a myth that there is something magical about computers * and those who run them. The legend has got about that computers are ‘electronic brain is’ and that programmers are some sort of supermen. The facts are that computers are very stupid and the people who program them are normal human beings. Anyone who can count from 0 to 7 on his or her fingers and make eight can learn to be a programmer. The business is not difficult, just tricky.

2. It is very misleading to imagine that computers can ‘think’ like people. They cannot. They have no more a mind of their own than a lawn-mower. However, they make it possible for people to ‘bottle’ thought. You work out how to do a particular job or solve a problem, write a program and the computer will apply your thinking to that of or problem as long and as often as you like. In this sense, computers are half alive because they perpetuate the thinking of their creators. (167 words)

Question 1.
On the basis of your reading of the passage above complete the notes given below. Write the answers in your answer sheet against the correct blank numbers.

Fact and Fiction about Computers.
(a) What Computers cannot do?
(b) What Computers can do?
(c) Programmers are not
(i) They are
(ii) who
(iii) logically or clearly.
Answer:
(a) Computers cannot think.
(b) They perpetuate the thinking of their creators.
(c)
(i) some sort of supermen,
(ii) normal human beings
(iii) can solve a problem

Question 2.
Complete the following statement on the basis of your reading the passage. Write the answers in your answer sheet against the correct blank numbers.
2 Computers are like lawn-mowers because (a) …………….. .
(b) The ‘business’ in para 1 refers to ……………..
(c) To ‘bottle’ in para 2 means ……………..
Answer:
(a) like lawn-mower, they do not have a mind of their own.
(b) the job of being a programmer.
(c) to store or to accommodate.

Passage-5

1. Advertising is a dose companion of market economy. Yet it is an unpleasant feature of modern life. Sometimes strange but sensational commercials on T.V. can cost heavily to one’s pocket Not only do they cost heavily to one’s pocket, they also cost heavily to one’s life. Not long before, an innocent student tried to imitate the acrobatics of a young man in a commercial ad- 1 Vertisement and lost his precious life for nothing.

2. In some cases advertising has started to erode individual privacy, in the name of educating and enlightening the consumer about his rights to choose the right product. The magazines, TV and movies keep dinning into the ears of everyone that material things are what life is about. Advertising has invaded every aspect of human existence. It includes sponsoring of events like sports etc. on a global basis. Advertising sells not only goods; it sells ideas also. Ideas – good ideas, like national integration and communal harmony, have been spread through advertising.

3. In addition to commercial advertising we have social advertising. Social advertising refers to the advertisements which deal with social causes. They aim at the welfare and well-being of the people. Its target audience is not a specific class. It aims at masses who can be educated about issues like health, family welfare, literacy, national security etc. They are so important that even the government falls back upon them very often to highlight issues of immediate and national concern.

Question 1.
On the basis of your reading of the passage, complete the following statements as briefly as possible. Write the answers in your answer sheet against the correct blank numbers.

Do not copy the whole sentence.
(a) In some cases advertisements affect individual
(b) Advertising sells not only good stisement is
(d) Sometimes advertisements are good because
Answer:
(a) privacy
(b) it sells ideas also.
(c) that it may cost heavily tp one’s life also.
(d) they spread ideas like national integration and communal harmony.

Question 2.
Fill in the missing words in the spaces that are left blank. .Write the answers in your answer sheet against the correct blank numbers.
(a) Instead of the word “companion” (para 1) we can use the word.
(b) Instead of the phrase “Not long before” (para 1) we can- use the word
(c) According to the passage the greatest danger of adver.
(c) The two types of advertisement are
(1) …………….. (2) ……………..
Answer:
(a) “associate”
(b) ‘recently’.
(c)
(i) Commercial advertising;
(ii) Social advertising

Passage-6

If we would see our dream of Panchayat Raj, i.e., true democracy realized, we would regard the humblest and lowest Indian as being the ruler of India with the tallest in the land This presupposes that all are pure, or will become pure if they are not. And purity must go hand-in-hand with wisdom. No one would then harbor any distinction between community and community, caste and out-caste. Everybody would regard all as equal with oneself and hold them together in the silken net of love. No one would regard another as untouchable. We would hold as equal the toiling laborer and the rich capitalist. Everybody would know how to earn an honest living by the sweat of one’s brow, and make no distinction between intellectual and physical labour. To hasten this consummation, we would voluntarily turn ourselves into scavengers. No one who has wisdom will ever touch opium liquor or any intoxicants. Everybody would observe Swadeshi as the rule of life and regard every woman not being his wife, as his’ mother, sister or daughter according to her age, never lust after her in his heart. He would be ready to lay down his life when occasion demands it, never want to take another’s life. If he is a Sikh in terms of the commandment of the Gurus he would have the heroic courage to stand single-handed and alone—without yielding an inch of ground against the “one lakh an a quarter” enjoined by them. Needless to say, such a son of India will not want to be told what his duty in the present hour is.

Question 1.
On the basis of your understanding of the poem above complete the following sentences. Write the answers in your answer sheet against the correct blank numbers.
(a) Panchayat Raj is true democracy because
(b) When purity goes hand-in-hand with wisdom there will not be any
(c) A man of wisdom will never use in democracy.
Answer:
(a) the humblest and lowest Indian would be the ruler of India.
(b) distinction on the lines of community and caste.
(c) opium, liquor or any Toxicants

Question 2.
On the basis of your reading the passage answer the following questions:
(a) The Panchayat Raj will eradicate untouchability. How?
(b) How will Swadeshi promote patriotism and a sense of national pride?
Answer:
(a) Panchayat Raj will ensure no distinction between caste and community. Everybody would regard all as equal with oneself and this ideology will help to eradicate untouchability.
(b) Swadeshi will promote patriotism as the rule of life, and each Indian would be ready to lay down his life when the occasion demands and will .want to do his duty for the nation as demanded by the present hour.

Passage-7

Getting a good night’s sleep can help you cope with stress more effectively. But not getting enough sleep can cause more stress. Insomniacs have higher concentrations of stress hormones than others.

Women are prone to sleep disturbances. Their sleep problems frequently interfere with their daily activities.

Experts believe that sleep, especially .deep sleep, enables our nervous system to function well. Without it, we lose our ability to concentrate, remember or analyse. Some experts speculate that during deep sleep, cells manufacture more proteins, which are essential for cell growth and repair of damage from things like stress and ultraviolet rays.

Scientists believe that activity in the area of the brain that controls emotions and social interactions lessens during sleep and that deep sleep may help people be emotionally and socially adept when awake.

Sleep may also help our brain to store a newly learned activity in its memory bank. In a study, Canada, students deprived of sleep after learning a complex logic game showed a 30 percent learning deficit when tested a week later compared with students not deprived of sleep.

The effects of sleep deprivation on other bodily functions are just as alarming. In studies from five medical centres across the country, researchers established that individuals with insomnia were also more likely to have poor health, including chest pain, arthritis and depression and to have difficulty accomplishing daily tasks. Another breakthrough study revealed that even temporary loss of sleep can affect the body’s ability to break down carbohydrates, interfere with the function of various hormones and worsen the severity of ailments such as diabetes and high blood pressure.

So whatever works to help you sleep well, whether its regular exercise earlier in the day, weekly massages, yoga, meditation or a lavender-scented bath, make time for it today. (300 words)

Question 1.
On the basis of your understanding of the passage above complete the following sentences. Write the answers in your answer sheet against the correct blank numbers.

While good sleep helps to (a) …………………. lack of it can (b) …………………. (2) Deep sleep makes the nervous system (c) …………………. so that we can (d) …………………. well. (2)

A Canadian research on students’sleep has proved that (e) (2)
Answer:
(a) cope with stress
(b) cause more stress
(c) to function well
(d) concentrate, remember and analyse
(e) students deprived of sleep showed a 30 percent learning deficit than students not deprived of sleep.
(f) poor health.
(g) weakens body’s ability to break down carbohydrates.
(h) interferes with junction of various hormones.
(i) worsens severity of diabetes and high blood pressure.

III-effects of Insomnia

Question 2.
Any two ways suggested in the passage to promote good sleep are:
(i) …………………. (ii) ………………….
Answer:
(i) regular exercise earlier in the day.
(ii) yoga or meditation

Passage-8

1. We’ve just left the dinner table, when I hear music coming from my daughter’s computer. It surprises me that my daughter Ida is listening to music from a time she refers to as the very old days. “What are you playing?” I ask. “It’s Phi Collins,” is her prompt reply, while she shows how, with a few strokes, she can download almost any song from the Internet. limes have certainly been changing since I scratched my first Beatles record. Tactfully I don’t mention that I had bought the record she’s listening to before she was bom. The concept of a phonograph record belongs to a bygone age and I don’t want to spoil the pleasure she’ll get from discovering her “own” new favorite musician.

2. The music brings memories flooding back. I have a sudden urge to bring back my record collection from the attic, where it has moldered for almost a decade. Only one thing stops me: my turntable succumbed to the damp air in a cellar where I stored it for a good ten years. No, I don’t care if turntables are ancient technology: I will find one. And I will restore my long lost record collection which took up a good amount of shelf space to its former glory. Buying something as uncool as a turntable takes courage and planning. I find a promising TV and radio store in the phone book but I am expecting a mountain of questions from the clerk, who will most certainly have been born and raised after the demise of the turntable.

3. “A turntable? Coming right up!” says the young man behind the counter. He disappears into the storeroom and before I can say long-playing record, he’s back with a small cardboard under his arm. It’s too good to be true. An hour later my new acquisition is in the living room and a respectful atmosphere descends. I’ve sorted my records into piles all over the floor, I find a Beatles album.

4. Behind the wonderful music now flowing through the loudspeaker is die unmistakable sound of vinyl. It doesn’t take long for my twelve-year-old son’s* eagle eye to spot the turntable and he has to try it out.onas is technically minded, a child * of the computer age, yet I sense a certain reverence as he picks up the tonearm and tries to place it in the middle of the record. Brought up in the CD age how could he know what’s wrong?

I say in a soothing voice: “The starting, groove is on-die edge of the record.” “Does it matter which side is up?” queried my daughter. “It does matter,” I replied. Soon we were listening to a Phil Collins number we both like. The generation gap vanishes as the music takes over. I relish the moment to the full and cast a glance at Ida. She’s relaxed and smiling.

Question 1.
Fill in the following summary using only one word for each blank. Write the answers in your answer sheet against the correct blank number. (1/2 6 = 3 marks)

It was a moment of surprise for the author to (a) ………………….. that his daughter had the same (b) ………………….. for music as he had. This brought back (c) ………………….. of his (d) ………………….. collection in the attic. Though, a (e) ………………….. task, he was (f) ………………….. in locating a turntable.
Answer:
(a) discover
(b) passion/interest
(c) memories
(d) record
(e) difficult
(f) successful

Question 2.
Complete the following sentences. Write the answers in your answer sheet.
(a) Tonas did not know how to handle the turntable as
(b) Music could bridge the generation gap as
(c) The author was reluctant to bring out his turntable from the cellar because
Answer:
(a) he was seeing it for the first time and he was a technically minded computer age child.
(b) it takes over the complete atmosphere and makes one relish each moment to the full.
(c) it had mouldered there for almost a decade and might have succumbed to the damp air in a cella

Question 3.
Find words from the passage which mean the same as the following
(a) skillfully avoiding giving offense (para 1).
(b) a feeling of respect (para 4)
Answer:
(a) tactfully
(b) reverence

Passage-9

1. Papaya is the healthiest fruit with a list of properties that is long and exhaustive. Belonging to the family of Caricaceae fruit, it is commonly kown as Papaw.in Australia and Mamao in Brazil.

It first originated in southern Mexico and neighboring Central America, but is now available in every tropical and subtropical’ country. Papaya favors digestion as well as cures skin irritation, and sun bums. You can munch on it as a salad, have it cooked or boiled or just drink it up as milkshake juices. Modern science confirms the age-old beliefs that papaya has much to contribute to die health cause. The most important of these virtues is the protein-digesting enzyme in the milky juice or latex. The enzyme is similar to pepsin in its digestive action and is said to be so powerful that it can digest 200 times its own weight in protein. It assists the body in assimilating the maximum nutritional value from food to provide energy and body building materials.

2. Papain in raw papaya makes up for the deficiency of gastric juice and fights excess of unhealthy mucus in the stomach, dyspepsia and intestinal irritation. The ripe fruit, if eaten regularly corrects habitual constipation, bleeding piles and chronic diarrhea. The juice of the papaya seeds also assists in the above- mentioned ailments.

3. The ’juice, used as a cosmetic, removes freckles or brown spots due to exposure to sunlight and makes the skin smooth and delicate. A paste of papaya seeds is applied in skin diseases like those caused by ringworm. The black seeds of the papaya are highly beneficial in the treatment of cirrhosis of the liver caused by alcoholism, malnutrition, etc. A tablespoonful of its juice, combined with a hint of fresh lime juice, should be consumed once or twice daily for a month. The fresh juice of raw papaya mixed with honey can be applied over inflamed tonsils, for diphtheria and other throat disorders. It dissolves the membrane and prevents infection from spreading.

Question 1.
Complete the following :
(a) The other names for papaya are ;
(b) Though now found in every tropical country
(c) One of the most important virtues of papaya is
(d) Intestinal irritation can be overcome
(e) Diseases cured by papaya are
(f) Throat disorders can be cured if
Answer:
(a) Papaw and Mamao.
(b) it first originated in Southern Mexico and neighboring Central America.
(c) the protein-digesting enzyme in the milky juice or latex.
(d) by the papain in raw-papaya.
(e) habitual constipation, bleeding piles and chronic diarrhea.
(f) fresh juice of raw papaya mixed with honey is applied over inflamed tonsils.

Question 2.
Complete the table below :

Portion / extract Juice (b) ____________________ Black seeds

treatment for (a) ___________________ Skin diseases (d) ___________________

caused by exposure to sunlight (c) ____________________ Alcoholism

Answer:
(a) freckles or brown spots
(b) Paste of Papaya seeds
(c) ringworm
(d) cirrhosis of the liver

Passage-10

1. Set in the declining but still green Western Ghats m the southwest of Karnataka, Coorg is the heart of India’s coffee country coffee being the world’s most heavily traded commodity after crude oil. Coorg boasts a land area four times larger than Hong Kong and seven times the area of Singapore, most of it is under tree cover because unlike tea plants, the coffee bush requires shade.

2. India is acknowledged as the producer of the finest mild coffees. With their tropical climate, high altitude, abundant rainfall and fertile soil, Coorg and the neighboring Chickmagalur districts in Karnataka have consistently produced and exported high-quality ^ coffee for over 150 years. The coffee output of these two districts accounts for 70 percent of the total coffee produced in the country. Coorg coffee is valued for its blue colour, clean beans and fine liquoring qualities and hence is in demand in the international markets.

3. In March and April is the coffee blossom time in Coorg. When . blossoms transform into berries, the bushes are cropped. The cherry-red fruit is then pulped; the seeds separated, dried and sent for curing. Coorg or Kodagu is the district which is one of the largest producers of pepper, cardamom and honey in the world.

4. Not much is known about early history of Coorg. Recorded history is available only from 1600 AD onwards when Kodava rajas ruled over the region and established their capital at Mercara by constructing a mud-walled fort. The martial Kodavas troubled Hyder Ali and his son Tipu Sultan who ruled the Mysore region in the, 18lh century by way of sporadic rebellions. But in 1785, Tipu’s large army marched into Kodagu and devastated the kingdom. Fourteen years later, with the help of the British who defeated Tipu Sultan following the historic siege of Srirangapatana in 1799, Coorg regained independence and under the leadership of Raja Veerarajendra rebuilt die capital. Later in 1834, the British exiled its ruler Chikkaveera Rajendra and assumed administrative charge of the district. The British left India in 1947, leaving behind a legacy of coffee plantations* colonial buildings and well- planned road networks.

Question 1.
Complete the following:
(a) The tea plants are unlike coffee plants as the latter
(b) Coorg coffee is internationally acclaimed for its
(c) Coorg is famous not only for coffee but also for
(d) After crude oil, coffee is the
Answer:
(a) require shade
(b) blue colour, clean beans and fine liquoring qualities
(c) pepper, cardamom and honey
(d) world’s most heavily traded commodity

Question 2.
Complete the table given below:

Year	Events
(a) …………………………………..	Recorded history.of Coorg
1785 AD	available from
	(b) …………………………………..
(c) …………………………………..	Coorg regained independence
1834 AD	(d) …………………………………..

Answer:
(a) 1600 AD
(b) Tipu’s large army marched into Kodagu and devastated the kingdom.
(c) 1799
(d) British exiled the ruler Chikkaveera Rajendra and assumed ad-ministrative charge of the district.

MP Board Class 9th English Solutions

MP Board Class 9th Special English Notice Writing

1. A notice on the Students Notice Board is to be prepared regarding an ensuing tree plantation ceremony to be held on 7th July, 20xx in the school premises inviting students to participate in it by contributing at least five plants from each class. The notice, should not have more than 50 words. Put your notice in a box. (5 marks)

Notice A tree plantation ceremony will be held on the school premises on 7th July, 20xx. Students are invited to participate in it whole-heartedly to make it a grand success A minimum of five plants should be contributed by each class. Our endeavour is for a green and clean environment for our school.

2. The school has decided to hold a fete in the school playground, the Principal has asked you to write, as the Headboy/Headgirl of the school, a notice about this fete, inviting the students and the teachers to participate in it. The notice should include all the necessary details.

Writer out the notice in box in not more than 50 words excluding the heading. (5 marks)
Answer:

School ‘Fete’ The school is organising a fete in the school-lawns on the 16th and 17th Oct., 20xx. Students and Teachers are requested to give in their names for booking of stalls. Wholehearted contribution and co-operation is needed from all to make this fete a grand success. For other details contact the members of the cabinet. XYZ (Head Girl)

3. Write a notice for the school notice board informing students about school inspection to be held on l-3-20xx by the District Education Officer. The notice should be of 50 words asking for punctuality, cleanliness and discipline. Put your notice in a box. (5 marks)
Answer:

School ‘Inspection’ A School inspection will be held on the 1st of March, 20xx by the District Education Officer. Students are requested to maintain punctuality, cleanliness and discipline so as to keep up the good reputation of our school and live up to the expectations of our respected teachers and Principal. XYZ (Head Girl)

4. Rahul of X-A is a theatre enthusiast and is interested in entering an inter-school play competition being held to celebrate 50 years of Indian Independence. His teacher has told him the school could enter the competition if he finds enough volunteers before 10 September to take care of all the work — acting, directing, costumes, props, lights etc. He decides to write a notice for the notice board asking for participants or volunteers. Write the notice for him in not more than 50 words. Put the notice in a box. Give the notice an appealing heading. (5 marks)
Answer:

Let’s Celebrate 50 Years Of Independence To commemorate 50 years of India’s Independence, an InterSchool Play Competition is being organised. All theatre enthusiasts interested to participate or volunteer for work related to acting, directing, costumes, props, lights etc. should give in their names before 10 September to Rahul in class X- A during lunch break.

5. You are Anupam, the editor of the school magazine, and want to hold an interclass competition to collect poems and cartoons for the magazine before Sept.’ 20xx. Draft a notice (in not more than 50 words) for the students’ notice board inviting entries. Mention all details required like entry dates, prizes etc. Give your notice an appealing heading. Put your notice in a box. (5 marks)
Answer:

Test Your Creativity An interclass competition is being organised for a collection of poems and cartoons for the school magazine. Submit your entries by the 6th of August to the members of the editorial board in Room No. 112. The three best entries will raceme cash prizes of Rs. 500, Rs. 250 and Rs. 150 respectively. Anupam Editor (School Magazine)

6. You are Manav/Mansi, Secretary of die School Cultural Committee. You have to write a notice for die Cultural Fiesta to be held in your school. Write the notice in not more than 50 words mentioning the date, venue, time and items to be held. (5 marks)
Answer:

Valley School
Notice

5 September, 20xx
The Cultural Committee of our School is organising a Cultural. Fiesta which will be held in our School Ground on 20 September from 6 p.m. to 8.30 p.m. A variety of folk dances, folk music and other regional programmes will be presented on the occasion.

Manav
Secretary

7. Reuben is the head boy of City Public School, Lucknow. He was given the following letter and told to put up a notice on the school notice board. Including details from the letter write the notice in not more than 50 words. Do not give any extra information. Put the notice in a box. (5 marks) Arpana Clinic,
Rajaji Street,
Lucknow,
20 Sep. 2007
The Principal,
City Public School,
Lucknow,

Sir,
I acknowledge receipt of your letter and accept your invitation to speak to the children on dental care. Your effort to make children aware of dental hygiene should be appreciated.

The 25th of this month would be a convenient day for me. I will speak to them for an hour and make it interesting through demonstrations and slides. I hope you will inform them of the same.

Thank you very much.

Yours faithfully,
Dr. C.eline
Answer:

City Public School, Lucknow Notice 20th Sep, 2007 Dr. Celine, a dental surgeon from Arpanet Clinic will be visiting our school to speak to the students on dental care* She will make us aware of dental hygiene in an hour’s talk on the 25th of this month. She will also be using demonstrations and slides to make her talk interesting and cohesive. Students are requested to be present in the Common Room by 9 A.M.

8. You are Rekha / Rahul of National Public School, Bilaspur. Being incharge of the cultural committee of your school, you are given the following letter by your Principal about an Inter-school Cultural Fiesta your school has to take part in. Write a notice, in not more than 50 words, including relevant details from the letter, asking students to appear for selection. Do not give extra information. Put the notice in a box. (5 marks)
Hill Mount School,
Bilaspur.
20 Oct., 2007 .
The Principal,
National Public School,
Bilaspur.
Madam,
Our school is conducting a cultural fiesta on the 26th of this month. The events for the competition include music, dance and skit. We would appreciate if the students of your prestigious. institution participate and make our show a grand success. Attractive prizes will be awarded to the winners.

Thank you very much.
Yours faithfully,
Gayathri Sundaram
Principal
Answer:

National Public School, Bilaspur Notice 20th Oct., 2007 Hill Mount School is conducting a cultural fiesta on the 26th of this month. The events for competition are music, dance and skit. Interested students are requested to give in their names by the 22th of February. Attractive prizes mil be awarded to the winners. Rahul Incharge Cultural Committee

9. You are Ajay/Ajitha, the organizer of the Inter School FootbaL Competition to be held in your school. Write a notice in not more than 50 words to be put on the School Notice Board asking the students of Class X to me£t you to discuss the details regarding the conduct of the competition. Put your notice in a box. (5 Marks)
Answer:

Notice ABC Senior Secondary School 15th Sept. The Inter School Football Competition is being held in our school from 22nd Sept to 1st Oct. Students of class X are requested to come for a meeting in Room No. 10 on the 19th of Sept, during the Activity period to discuss the details and other arrangements regarding the conduct of the competition. Ajay (Organiser)

10. You are the Secretary, Cultural Club of your school. The school is celebrating its Annual Cultural Day on the 25th of March. Draft a notice to be put on the notice boird of your school informing the badge holders and house captains of a meeting you are conducting to take decisions on some important matters regarding the conduct of the programme. The notice should not exceed 50 words. Put your notice in a box. (5 marks)
Answer:

Notice Board XYZ High School 3rd March, 20xx Our school is celebrating its Annual Day on the 25th of March. A meeting of the badge holders and house captains will be held on the 5th of March in the Music Room during ‘zero’ period to discuss important matters regarding the conduct of the programme for the Annual Day. Secretary Cultural Club

11. Your school has decided to choreograph a dance drama for the school annual day. You are the cultural secretary of Are school. Write a notice in not more than 50 words for your school notice board inviting talented students to assemble on 12th Nov. in the audit6rium. They will be selected by the famous dancer Sarala Nagpal. Put your notice in a box. (5 marks )
Answer:

XYZ Senior Secondary School Notice Our school is presenting a Dame Drama for its Annual Day to be held on the 27th November. We invite talented students to assemble on 12th November in the auditorium for an audition. Students will be selected by the famous dancer Sarala Nagpal. ABC Cultural Secretary

12. National Television Co. is looking for a new face to play the role of Netaji Subhash Chandra Bose in their serial ‘Life and Times of Great Leaders’. They want a man in his forties who bears close resemblance to Netaji Subhash Chandra Bose in all respects. The person should also possess good voice. Those who have acted earlier will be given preference. You have been given charge of looking for talented people for the above mentioned role. Write a notice for this to be displayed at various places (in not more than 50 words in all). Put your notice in a box. (5 marks)
Answer:

National Telivision Company K.G.Marg, New Delhi Great Opportunity for Amateur Actors 16 August 20xx We are looking fot a new face to play the part of Netaji Subhash Chandra Bose in the serial ‘Life and Times of Great Leaders’. The person should be in his 40’s, should bear a close resemblance to Netaji and should possess a good voice. Preference will be given to those who have acted earlier. Interested persons may contact the Production Manager, with complete Bio-data by the 28th of August, between 9 AM. to 1P.M., ………………………….. Production Incharge

13. You are Mridul, the Head Boy of Vidya Public School. An Air Force officer has agreed to conduct an orientation camp In your school for-those Interested in joining the Air Force after school. Put up a notice informing the students of the programme and encouraging them to participate. Write the notice in not more than 50 words and put the notice in a box. (5 marks)
Answer:

Vidya Public School Notice 17th January, 20xx An Air Force Officer has consented to conduct an Orientation Camp in our school for those interested in joining the Air Force after school. Students of classes XI & XII are requested to make this camp a success by being present in full strength. The camp will be held on 27th January, 8 a.m. to 12 p.m. in the Mini Auditorium. Mridul Head Boy

14. You are Ramesh, the Organizing Secretary of “The Ooty Flower Show.” A notice is to be circulated among the participants of the Flower Show informing them about the different categories in which they can take part (Home Garden, Institutional Garden etc.) A ‘Flower King and Queen’ competition for children below the age of 10 will also be held. Draft the notice in not more than 50 xvords. (5 marks)
Answer:

The Ooty Flower Show Notice 22nd September, 20xx The participants of the Floxoer Show are hereby informed about the different categories in which they can take part. These include Home Garden, Institutional Garden etc. A ‘Flower King and Queen’ competition will also be held for children below the age of 10 years on the day of the Flower Shaw on 1st October, between 4 to 5 P.M. Ramesh (Organising Secretary)

15. You are Sharat, President of the Interact Club of your school. You wish to organize a snack bar on the Sports Day of your school. The proceeds of the sale will go for charity. You put up a notice on the notice board of your school calling for a meeting to discuss the same. 17 s ft the notice giving all the details in not more than 50 xvords. Put the notice in a box. (5 marks)
Answer:

Xyz Senior Secondary School Notice Meeting of Interact Club 15th October, 20xx The Interact Club is organising a snack bar on Sports Day of our school to be held on 22nd October. The proceeds of the sale will go for chanty. The members of the club are called for a meeting on 4th October in the Activity Room to discuss the same. Sharat (President)

16. Your school has received the following letter from the Director of Health:
The Principal
Grammar School
Lovedale

Dear Principal,
1 am writing to highlight the fact that many young children are still suffering from polio because people do not realize the importance of the vaccine. Hence I request you to tell your school students to encourage people in your area to take their children who are 5 years and below for the Immunization Camp to be held in the Community Centre in your locality on Sunday, 2 September 2006 from 8 a.m. to 4 p.m. The Chief Minister will personally administer the polio drops between 10 a.m. and 11 a.m. The student who encourages the maximum number of people will be awarded a certificate.

Yours faithfully
AK Walia

17. You are Vartica, Secretary of the NSS in your school. You decide to make out a notice. Using the information given in the above letter, write the notice in not more than 50 words.
Answer:

Grammar School
Lovedale
Notice

29 August, 2006
Polio Camp

The State Government is organising a Polio-Immunization Camp in the Community Centre on 2nd September 2006 from 8 a.m. to 4 p.m. The Chief Minister will personally admin. ister these drops between 10 a.m. and 11 a.m. Students should encourage people to take their children under 5 years, for this Camp. A certificate will be awarded to the student bringing the maximum number of people.

Vertica Secretary, NSS

MP Board Class 9th English Solutions

MP Board Class 9th Maths Solutions Chapter 7 Triangles Ex 7.3

Question 1.
∆ABC and ∆DBC are two isosceles triangles on the same base BC and vertices A and D are on the same side of BC (see Fig. below). If AD is extended to intersect BC at P, show that

1. ∆ABD = ∆ACD
2. ∆ABP = ∆ACP
3. AP bisects ∠A as well as ∠D.
4. AP is the perpendicular bisector of BC.

Solution:
Given
AB = AC
DB = DC
To prove:

1. ∆ABD = ∆ACD
2. ∆ABP = ∆ACP
3. ∠1 = ∠2 and ∠5 = ∠6
4. ∠3 = ∠4 = 90° and BP = PC

Proof
1. In ∆ABD and ∆ACD
AB = AC (given)
BD = CD (given)
AD =AD (common)
∆ABD = ∆ACD (by SSS)
and so ∠1 = ∠2 (by CPCT)

2. In ∆ABP and ∆ACP
AB = AC (given)
∠1 = ∠2 (proved)
AP = AP (common)
∆ABP ≅ ∆ACP (by SAS)
and so ∠3 = ∠4
and BP = CP (by CPCT)

∠1 = ∠2 AP bisects ∠A

3. In ∆DBP and ∆DCP
BP = CP (proved)
∠3 = ∠4 (proved)
DP = DP (common)

∆DBP ≅ ∆DCP (by SAS)
and so ∠5 = ∠6 (by CPCT)
∴ AP bisects ∠D.

4. BP = CP (proved)
∠3 = ∠4 (proved)
∠3 + ∠4 = 180° (LPA’s)
∠3 + ∠3 = 180° (∠3 = ∠4)
2∠3 = 180°
∠3 = 90°
∠3 = ∠4 (each 90°)
and therefore, AP is the perpendicular bisector of BC

Question 2.
AD is an altitude of an isosceles triangle ABC in which AB = AC. Show that

1. AD bisects BC
2. AD bisects ∠A.

Solution:
Given
AB = AC and AD ⊥ BC
To prove
∠1 = ∠2 and
BD = CD
Proof:
In ∆ABD and ∆ACD
AB = AC
AD = AD
∠3 = ∠4
∆ABD = ∆ADC
and so BD = CD and ∠1 = ∠2

Question 3.
Two sides AS and BC and median AM on one triangle ABC are respectively equal to sides PQ and QR and median PN of ∆PQR (see-Fig. below). Show that:

1. ∆ABM ≅ ∆PQN
2. ∆ABC ≅ ∆PQR

Solution:
Given
AB = PQ
BC = QR
AM = PN
To prove:

1. ∆ABM ≅ ∆PQN
2. ∆ABC ≅ ∆PQR

Proof:
BC = QR (given)
\(\frac{1}{2}\) BC = \(\frac{1}{2}\)QR
BM = QN

1. In ∆ABM and ∆PQN
AB = PQ (given)
BM = QN (proved)
AM = PN (given)
∆ABM ≅ ∆PQN (by SSS)
and so ∠ABC = ∠PQR (by CPCT)

2. In ∆ABC and ∆PQR
AB = PQ (given)
BC = QR (given)
∠B = ∠Q (proved)
∆ABC ≅ ∆PQR by (SAS)

Question 4.
BE and CF are two equal altitudes of a triangle ABC. Using RHS congruence rule, prove that triangle ABC is isosceles.

Solution:
Given
∠E = ∠F
BE = CF
To prove
AB = AC
Proof:
In ∆FBC and ∆ECB
BE = CF (given)
∠F = ∠E (each 90°)
BC = CB (common)
∴ ∆FBC = ∆ECB (by RHS)
and so ∠B = ∠C (by CPCT)
In ∆ABC, ∠B = ∠C
AB = AC
(sides opposite to equal angles of a A are equal)
and so ABC is isosceles.

Question 5.
ABC is an isosceles triangle with AB = AC. Draw AP ⊥ BC to show that ∠B = ∠C.
Solution:
Given
AB = AC
∠APB = ∠APC = 90°
To prove:
∠B = ∠C

Proof:
In ∆ABP and ∆ACP
AP = AP (common)
∠APB = ∠APC (each 90°)
AB = AC (given)
∴ ∆ABP = ∆ACP (by RHS)
and ∠B = ∠C (by CPCT)

Theorem 7.6.
If two angles of a triangle are equal, then the sides opposite to them are also equal.
Given
In ∆ABC, ∠C = ∠B

To prove: AB = AC
Construction:
Draw the bisector of ∠A and let it meet BC an D
Proof:
In ∆s ABD and ACD, we have ∠B = ∠C (Given)
∠BAD = ∠CAD (Construction)
AD = AD (Common)
∴ ∆ABD ≅ ∆ACD (AAS Cong. Criterion)
Hence, AB = AC (CPCT)

Theorem 7.7.
If two sides of a triangle are unequal, the longest side has greater angle opposite to it.
Given:
In ∆ABC; AC > AB
To prove: ∠ABC > ∠ACB.

Construction:
Mark point D on AC such that AB = AD. Join BD.
Proof:
In ∆ABD,
AB = AD
∴ ∠1 = ∠2 (Const. As opp. equal sides) ….(1)
But ∠2 is an exterior angle of ABCD.
∠2 > ∠ACB (Exterior Angle Theorem) …(2)
From (1) and (2), we have
∠1 > ∠ACB (Const.)
But ∠ABC > ∠1
∴ ∠ABC > ∠ACB

Theorem 7.8. (Converse of Theorem 7.7)
In a triangle the greater angle has the longer side opposite to it.
Given:
In ∆ABC, ∠ABC > ∠ACB
To prove: AC > AB

Proof:
For ∆ABC, there are only three possibilities of which exactly one must be true.

1. AC = AB
2. AC < AB (iii) AC > AB.

Case 1:
If AC = AB, then ∠ABC = ∠ACB, which is contrary to what is given.
AB ≠ AC

Case 2:
If AC < AB, the longer side has the greater angle opposite to it.
∴ ∠ACB > ∠ABC.
This is also contrary to what is given.

Case 3:
We are left with the only possibility, namely AC > AB which is true.
AC > AB.

MP Board Class 9th Maths Solutions

MP Board Class 9th Science Solutions Chapter 9 Force and Laws of Motion

Force and Laws of Motion Intext Questions

Force and Laws of Motion Intext Questions Page No. 118

Question 1.
Which of the following has more inertia:

1. a rubber ball and a stone of the same size?
2. a bicycle and a train?
3. a five – rupees coin and a one – rupee coin?

Answer:
As we know, inertia is the calculated value for the mass of the body. It is proportional to mass of the body:

1. Inertia of the stone is greater than that of a rubber ball as mass of a stone is more than the mass of a rubber ball for the same size.
2. Inertia of the train is greater than that of the bicycle. As mass of a train is more than the mass of a bicycle.
3. Mass of a five rupee coin is more than that of a one – rupee coin. Hence, inertia of the five – rupee coin is greater than that of the one – rupee coin.

Question 2.
In the following example, try to identify the number of times the velocity of the ball changes: “A football player kicks a football to another player of his team who kicks the football towards the goal. The goalkeeper of the opposite team collects the football and kick it towards a player of his own team”. Also, identify the agent supplying the force in each case.
Answer:
Four times:

• First, when a football player kicks to another player. Agent supplying the force: First case – First player. Second when that player kicks the football to the goalkeeper. Agent supplying the force. Second case – Second player.
• Third when the goalkeeper stops the football. Agent supplying the force: Third case – Goalkeeper.
• Fourth when the goalkeeper kicks the football towards a player of his own team. Agent supplying the force: Fourth case – Goalkeeper.

Question 3.
Explain why some of the leaves may get detached from a tree if we vigorously shake its branch.
Answer:
When we shake any tree’s branches vigorously some leaves of that tree get detached because branches comes in motion while the leaves tend to remain at rest due to inertia of rest.

Question 4.
Why do you fall in the forward direction when a moving bus brakes to a stop and fall backwards when it accelerates from rest?
Answer:
Due to inertia of motion, we fall in the forward direction when a moving bus brakes to a stop and fall backwards when it accelerates from rest.

1. Case I: Since the driver applies brakes and bus comes to rest. But, the passenger tries to maintain its inertia of motion. As a result, a forward force is exerted on him.
2. Case II: The passenger tends to fall backwards when the bus accelerates from rest because when the bus accelerates, the inertia of rest of the passenger tends to oppose the forward motion of the bus.

Force and Laws of Motion Intext Questions Page No. 126

Question 1.
If action is always equal to the reaction, explain how a horse can pull a cart.
Answer:
According to Newton’s third law of motion, a force is exerted by the Earth on the horse in the forward direction while horse pushes the ground in the backward direction. As a result, the cart moves forward.

Question 2.
Explain, why is it difficult for a fireman to hold a hose, which ejects large amounts of water at a high velocity.
Answer:
According to Newton’s third law of motion, a reaction force is exerted over fireman by the ejecting water in the backward direction when a fireman holds a hose, which is ejecting large amounts of water at a high velocity. As a result of the backward force, the stability of the fireman get affected. Hence, it is difficult for him to remain stable while holding the hose.

Question 3.
From a rifle of mass 4kg, a bullet of mass 50g is fired with an initial velocity of 35 ms^-1. Calculate the initial recoil velocity of the rifle.
Answer:
Given,
Mass of the rifle, m₁ = 4kg
Mass of the bullet, m₂ = 50g = 0.05kg
Recoil velocity of the rifle = v₁
Bullet is fired with an initial velocity, v₂= 35 m/s
Condition:
Initially, the rifle is at rest.
Thus, its initial velocity, v = 0
Total initial momentum of the rifle and bullet system = (m₁+ m₂)v = 0
Total momentum of the rifle and bullet system after firing = m₁v₁ + m₂v₂
= 0.05 × 35 = 4v₁ + 1.75
As per law of conservation of momentum:
Total momentum after the firing = Total momentum before the firing
⇒ 4v₁ + 1.75 = 0
v₁ = –\(\frac { 1.75 }{ 4 }\) = -0.4375 m/s
So, the rifle recoils backwards with a velocity of 0.4375 m/s because value is negative.

Question 4.
Two objects of masses 100g and 200g are moving along the same line and direction with velocities of 2 ms^-1 and 1  ms^-1, respectively. They collide and after the collision, the first object moves at a velocity of 1.67 ms^-1. Determine the velocity of the second object.
Answer:
Given,
m₁ = 100g = 0.1kg
m₂ = 200g = 0.2kg
Velocity of m₁ before collision, v₁ = 2 m/s
Velocity of m₂ before collision, v₂ = 1 m/s
Velocity of m₁ after collision, v₃ = 1.67 m/s
Velocity of m₂ after collision = v₄
As per the law of conservation of momentum:
Total momentum before collision = Total momentum after collision
Hence,
m₁v₁ + m₂v₂ = m₁v₃+ m₂v₄
Putting values
2(0.1) + 1(0.2) = 1.67(0.1) + v₄(0.2)
0.4 = 0.167 + 0.2v₄
v₄ = 1.165 m/s
Velocity of the second object = 1.165 m/s.

Force and Laws of Motion NCERT Textbook Exercises

Question 1.
An object experiences a net zero external unbalanced force. Is it possible for the object to be travelling with a non –  zero velocity? If yes, state the conditions that must be placed on the magnitude and direction of the velocity. If no, provide a reason.
Answer:
Yes, an object may travel with a non – zero velocity even when the net external force on it is zero. A rain drop falls down with a constant velocity. The weight of the drop is balanced by the upthrust and the viscosity of air. The net force on the drop is zero.

Question 2.
When a carpet is beaten with a stick, dust comes out of it Explain.
Answer:
When we beat the carpet with a stick, it comes into motion. But the dust particles continue to be at rest due to inertia and get detached from the carpet.

Question 3.
Why is it advised to tie any luggage kept on the roof of a bus with a rope?
Answer:
Due to sudden jerks or due to the bus taking sharp turn on the road, the luggage may fall down from the roof because of its tendency to continue moving in the original direction. To avoid this, the luggage is tied with a rope on the roof.

Question 4.
A batsman hits a cricket ball which then rolls on a level ground. After covering a short distance, the ball comes to rest The ball slows to a stop because
(a) the batsman did not hit the ball hard enough.
(b) velocity is proportional to the force exerted on the ball.
(c) there is a force on the ball opposing the motion.
(d) there is no unbalanced force on the ball, so the ball would come to rest.
Answer:
(c) there is a force on the ball opposing the motion.

Question 5.
A truck starts from rest and rolls down a hill with a constant acceleration. It travels a distance of 400 m in 20 s. Find its acceleration. Find the force acting on it if its mass is 7 metric tonnes (Hint: 1 metric tonne = 1000 kg.)
Answer:
Here, u = 0, s = 400m, t = 20 s, a = ?, F = ?.
m = 7 tonnes
= 7 × 1000kg
= 7000kg
⇒ s = ut + \(\frac { 1 }{ 2 }\)at²
400 = (0 + 20) + \(\frac { 1 }{ 2 }\)a(20)²
a = \(\frac { 400\times 2 }{ { 20 }^{ 2 } } \)
∴ a = 2 m/s²
Force,
F = ma
= 7000 × 2 = 14,000 N.

Question 6.
A stone of 1kg is thrown with a velocity of 20 ms^-1 across the frozen surface of a lake and comes to rest after travelling a distance of 50m. What is the force of friction between the stone and the ice?
Answer:
m = 1kg, u = 20 m/s, s = 50m, v = 0, F = ? a = ?.
⇒ v² – u² = 2as
(0)² – (20)² = 2a (50)
∴ – 400 = 100a
= \(\frac { 400 }{ 100 }\) – 4 m/s²
Force of friction, F = m × a
= 1kg × -4 m/s² = -4 N

Question 7.
A 8000kg engine pulls a train of 5 wagons, each of 2000kg, along a horizontal track. If the engine exerts a force of 40,000 N and the track offers a friction force of 5000 N, then calculate:
(a) the net accelerating force;
(b) the acceleration of the train; and
(c) the force of wagon 1 on wagon 2.
Answer:
m = 8,000 + 5 × 2,000 = 18,000kg
(a) The net accelerating force,
F = Engine force – friction force
= 40,000 – 5,000 = 35,000 N.

(b) The acceleration of the train,
a = \(\frac { F }{ m }\) = \(\frac { 35,000 }{ 18,000 }\) = \(\frac { 35 }{ 18 }\) = 1.94 ms^-2

(c) The force of wagon 1 on wagon 2
= The net accelerating force – mass of wagon × acceleration
= 35,000 – 2,000 × \(\frac { 35 }{ 18 }\)
= 35,000 – 3888.8 = 31,111.2 N.

Question 8.
An automobile vehicle has a mass of 1500kg. What must be the force between the vehicle and road if the vehicle is stopped with a negative acceleration of 1.7 ms^-2?
Answer:
Here, mass = 1500kg
a = -1.7 ms²
F = m × a
= 1500 × (-1.7)
= -2550 N
The force between the vehicle and the road is 2,550 is, m a direction opposite to the direction of the vehicle.

Question 9.
What is the momentum of an object of mass m, moving with a velocity v? Choose correct option.
(a) (mv)²
(b) mv²
(c) \(\frac { 1 }{ 2 }\) × mv²
(d) mv.
Answer:
(d) mv.

Question 10.
Using a horizontal force of 200 N, we intend to move a wooden cabinet across a floor at a constant velocity. What is the friction force that will be exerted on the cabinet?
Answer:
The cabinet will move with constant velocity only when the net force on it is zero.
Force of friction on the cabinet = 200 N, in a direction opposite to the direction of motion of the cabinet.

Question 11.
Two objects, each of mass 1.5kg, ate moving in the same straight line but in opposite directions. The velocity of each object is 2.5 ms^-1 before the collision during which they stick together. What will be the velocity of the combined object after collision?
Answer:
Here, m₁ = m₂ = 1.5kg,
u₁ = 2.5 ms^-1, u₂ = – 2.5 ms^-1
Let v be the velocity of the combined object after the collision.
By conservation of momentum,
Total momenta after collision = Total momenta before collision
= (m₁ + m₂) v = m₁u₁ + m₂u₂
= (1.5 + 1.5) v = 1.5 × 2.5 + 1.5 × (-2.5)
= 3.0 v = 0
or
⇒ v = 0 ms^-1

Question 12.
According to the third law of motion when we push on an object, the object pushes back on us with an equal and opposite force. If the object is a massive truck parked along the roadside, it will probably not move. A student justifies this by answering that the two opposite and equal forces cancel each other. Comment on this logic and explain why the truck does not move.
Answer:
Action and reaction always act on different bodies, so they cannot cancel each other. When we push a massive truck, the force of friction between its tyres and the road is very large and so, the truck does not move.

Question 13.
A hockey ball of mass 200g travelling at 10 ms^-1 is struck by a hockey stick so as to return it along its original path with a velocity at 5 ms^-1. Calculate the change of momentum occurred in the motion of the hockey ball by the force applied by the hockey stick.
Answer:
Here, m = 200g = 0.2kg,
u = 10 ms^-1,
v = -5 ms^-1
change in momentum = m (v – u)
= 0.2 (- 5 – 10) = -3kg ms^-1.

Question 14.
A bullet of mass 10g travelling horizontally with a velocity of 150 ms^-1 strikes a stationary wooden block and comes to rest in 0.03 s. Calculate the distance of penetration of the bullet into the block. Also calculate the magnitude of the force exerted by the wooden block on the bullet.
Answer:
Here m = 10g = 0.01kg,
u = 150 ms^-1,
v = 0, t = 0.03 s
a = \(\frac { v-u\quad }{ t } \) = \(\frac { 0-150\quad }{ 0.03 } \) = -5,000 ms^-1
The distance of penetration of the bullet into the block,
s = ut + \(\frac { 1 }{ 2 }\)at²
150 × 0.03 + \(\frac { 1 }{ 2 }\) × (-5,000) × (0.03)
= 4.5 – 2.25 = 2.25
The magnitude of the force exerted by the wooden block on the bullet
= ma = 0.01 × 5,000 = 50 N.

Question 15.
An object of mass 1kg travelling in a straight line with a velocity of 10 ms^-1 collides with, and sticks to, a stationary wooden block of mass 5kg. Then, they both move off together in the same straight line. Calculate the total momentum just before the impact and just after the impact. Also, calculate the velocity of the combined object.
Answer:
Here, m₁ = 1kg, u₁ = 10 ms^-1, m₂ = 5kg, u₂ = 0
Let v be the velocity of the combined object after the collision.
Total momentum just before the impact
= m₁u₁ + m₂u₂  = 1 × 10 + 5 × 0 = 10kg ms^-1
Total momentum just after the impact = (m₁ + m₂)v = (1 + 5)v
= 6v kg ms^-1 by conservation of momentum,
6v = 10
= v = \(\frac { 10 }{ 6 }\) = \(\frac { 5 }{ 3 }\) ms^-1
∴ Total momentum just after the impact
= 6 × \(\frac { 5 }{ 3 }\) = 10 ms^-1

Question 16.
An object of mass 100kg is accelerated uniformly from a velocity of 5 ms^-1 to 8 ms^-1 in 6 s. Calculate the initial and final momentum of the object. Also, find the magnitude of the force exerted on the object.
Answer:
Here, m = 100kg,
u = 5 ms^-1,
v = 8 ms^-1,
t = 6 s
Initial momentum, P₁ = mu = 100 × 5 = 500kg ms^-1
Final momentum, P₂ = mu = 100 × 8 = 800kg ms^-1
The magnitude of the force exerted on the object.
F = \(\frac { { P }_{ 2 }-{ P }_{ 1 } }{ t } \) = \(\frac { 800-500 }{ 6 }\) = \(\frac { 300 }{ 6 }\) = 50 N.

Question 17.
Akhtar, Kiran and Rahul were riding in a motorcar that was moving with a high velocity on an expressway when an insect hit the windshield and got stuck on the windscreen. Akhtar and Kiran started pondering over the situation. Kiran suggested that the insect suffered a greater change in momentum as compared to the change in momentum of the motorcar (because the change in the velocity of the insect was much more than that of the motorcar). Akhtar said that since the motorcar was moving with a larger velocity, it exerted a larger force on the insect And as a result the insect died. Rahul while putting an entirely new explanation said that both the motorcar and the insect experienced the same force and a change in their momentum. Comment on these suggestions.
Answer:
Both, the motorcar and insect experience the equal force and hence, a same change in their momentum. So, we agree with Rahul. But due to smaller mass or inertia, the insect dies.

Question 18.
How much momentum will a dumb – bell of mass 10kg transfer to the floor if it falls from a height of 80cm? Take its downward acceleration to be 10 ms^-2.
Answer:
Here, m = 10kg, u = 0,
s = 80cm = 0.80m,
a = 10 m/s^-2
Let v be the velocity gained by the dumb-bell as it reaches the floor.
As v² – u² = 2as
v² – 0² = 2 × 10 × 0.80 = 16
or
v = 4 ms^-1
Momentum transferred by the dumb-bell to the floor
p = mv = 10 × 4 = 40kg ms^-1

Force and Laws of Motion Additional Questions

Force and Laws of Motion Multiple Choice Questions

Question 1.
Which of the following statements is not correct for an object moving along a straight path in an accelerated motion?
(a) Its speed keeps changing.
(b) Its velocity always changes.
(c) It always goes away from the earth.
(d) A force is always acting on it.
Answer:
(c) It always goes away from the earth.

Question 2.
According to the third law of motion, action and reaction ________ .
(a) Always act on the same body.
(b) Always act on different bodies in opposite directions.
(c) Have same magnitude and directions.
(d) Act on either body at normal to each other.
Answer:
(b) Always act on different bodies in opposite directions.

Question 3.
A goalkeeper in a game of football pulls his hands backwards after holding the ball shot at the goal. This enables the goal keeper to ________ .
(a) Exert larger force on the ball.
(b) Reduce the force exerted by the ball on hands.
(c) Increase the rate of change of momentum.
(d) Decrease the rate of change of momentum.
Answer:
(b) Reduce the force exerted by the ball on hands.

Question 4.
The inertia of an object tends to cause the object ________ .
(a) To increase its speed.
(b) To decrease its speed.
(c) To resist any change in its state of motion.
(d) To decelerate due to friction.
Answer:
(c) To resist any change in its state of motion.

Question 5.
A passenger in a moving train tosses a coin which falls behind him. It means that motion of the train is ________ .
(a) Accelerated
(b) Uniform
(c) Retarded
(d) Along circular tracks.
Answer:
(a) Accelerated

Question 6.
An object of mass 2kg is sliding with a constant velocity of 4 ms^-1 on a frictionless horizontal table. The force required to keep the object moving with the same velocity is ________ .
(a) 32 N
(b) 0 N
(c) 2 N
(d) 8 N.
Answer:
(b) 0 N

Question 7.
Rocket works on the principle of conservation of ________ .
(a) Mass
(b) Energy
(c) Momentum
(d) Velocity.
Answer:
(c) Momentum

Question 8.
A water tanker filled up to \(\frac { 2 }{ 3 }\) of its height is moving with a uniform speed. On sudden application of the brake, the water in the tank would ________ .
(a) Move backward
(b) Move forward
(c) Be unaffected
(d) Rise upwards.
Answer:
(b) Move forward

Question 9.
Which of the following represents example(s) of potential energy?
(a) A moving car
(b) A moving fan
(c) A book resting on the table
(d) Both (a) and (c).
Answer:
(d) Both (a) and (c).

Question 10.
Unit of force is ________ .
(a) Ampere
(b) Volt
(c) Joule
(d) Hertz.
Answer:
(c) Joule

Question 11.
Product of mass and acceleration of a body is called ________ .
(a) Acceleration
(b) Work
(c) Power
(d) Energy.
Answer:
(b) Work

Question 12.
Which of the following is correct about energy?
(a) Energy is not required to do work.
(b) Work can be expressed as Force × Displacement.
(c) Unit of power is joule.
(d) Power is the amount of work done per unit time.
Answer:
(c) Unit of power is joule.

Question 13.
An object of mass 3kg is falling from the height of 1m. The kinetic energy of the body will be when it touches the ground ________ .
(a) 29.4 N
(b) 29.4 J
(c) 30 N
(d) 15 J
Answer:
(b) 29.4 J

Question 14.
Two objects with masses 1kg and 9kg, and equal momentum. Calculate the ratios of their kinetic energies ________ .
(a) 3 : 1
(b) 9 : 1
(c) 1 : 1
(d) 1 : 2
Answer:
(b) 9 : 1

Question 15.
Considering air resistance negligible, the sum of potential and kinetic energies of the free falling body would be ________ .
(a) zero
(b) infinite
(c) would decrease
(d) remains fixed.
Answer:
(d) remains fixed.

Force and Laws of Motion Very Short Answer Type Questions

Question 1.
What do we call to the product of mass and velocity of an object?
Answer:
Momentum.

Question 2.
Define inertia.
Answer:
The property by which an object tends to remain in the state of rest or of uniform motion unless acted upon by some force is called inertia.

Question 3.
Which property has S.I. unit kilogram metres per second i.e., 1kg m/s?
Answer:
Momentum.

Question 4.
Give an example of scalar quantity.
Answer:
Mass.

Question 5.
Give an example of vector quantity.
Answer:
Momentum.

Question 6.
Calculate the total momentum of the bullet and the gun before firing.
Answer:
For both, it would be zero because both of them are at rest.

Question 7.
Which force slows down a moving bicycle when we try to stop?
Answer:
The force of friction.

Question 8.
Which kind of force of gravity work when an object is under free fall?
Answer:
Unbalanced force.

Question 9.
Which property of an object resist a change in their state of rest or motion?
Answer:
Inertia.

Question 10.
Which law of Newton is also known as Galileo’s law of inertia?
Answer:
First law.

Question 11.
Is force a vector quantity?
Answer:
Yes.

Question 12.
Which force of motion opposes motion of an object?
Answer:
Force of friction.

Question 3.
When action and reaction forces act on two different bodies, what kind of magnitude they have?
Answer:
Action and reaction forces act on two different bodies but they are equal in magnitude.

Question 14.
When gun moves in the backward direction, which kind of velocity is generated?
Answer:
Recoil.

Question 15.
Which factor of body is dependent on its mass?
Answer:
Inertia of a body depends on its mass.

Force and Laws of Motion Short Answer Type Questions

Question 1.
There are three solids made up of aluminium, steel and wood, of the same shape and same volume. Which of them would have highest inertia?
Answer:
Steel has highest inertia because it has greatest density and greatest mass, therefore, it has highest inertia.

Question 2.
Two balls of the same size but of different materials, rubber and iron are kept on the smooth floor of a moving train. The brakes are applied suddenly to stop the train. Will the balls start rolling? If so, in which direction? Will they move with the same speed? Give reasons for your answer.
Answer:
If the breaks are applied suddenly then, the balls will start rolling in the direction in which the train was moving. Due to the application of the brakes, the train comes to rest but due to inertia the balls try to remain in motion, therefore, they begin to roll. Direction and speed of all balls will not be same because the masses of the balls are not the same, therefore, the inertial forces are not same on both the balls. Thus, the balls will move with different speeds.

Question 3.
Two identical bullets are fired, one by a light rifle and another by a heavy rifle with the same force. Which rifle will hurt the shoulder more and why?
Answer:
According to law of conservation of momentum or explanation by Newton’s laws of motion, light rifle will hurt the shoulder more.

Question 4.
A horse continues to apply a force in order to move a cart with a constant speed. Explain why?
Answer:
The force applied by the horse balances the force of friction

Question 5.
Suppose a ball of mass m is thrown vertically upward with an initial speed v, its speed decreases continuously till it becomes zero. Thereafter, the ball begins to fall downward and attains the speed v again before striking the ground. It implies that the magnitude of initial and final momentums of the ball are same. Yet, it is not an example of conservation of momentum. Explain.
Answer:
Law of conservation of momentum is applicable to isolated system (no external force is applied). In this case, the change in velocity is due to the gravitational force of earth.

Question 6.
In which of the following conditions work done will be equal to zero?
Answer:
In the absence of any one of the two conditions given below, work done will be equal to zero, that is work is not considered to be executed:

1. Force should act on the object.
2. Object must be displaced.

Question 7.
Define energy and explain its forms.
Answer:

1. Energy: Energy is the capacity of doing work. More the power, more will be energy and vice – versa. For example, a motorcycle has more energy than a bicycle.
2. Forms of energy: There are many forms of energy, such as kinetic energy, potential energy, mechanical energy, chemical energy, electrical energy etc.

Force and Laws of Motion Long Answer Type Questions

Question 1.
Give the formulation of work. In which conditions work can occur?
Answer:
Work = Force × Displacement
or W = F × s
where, W is work ‘F’ is force and ‘s’ is displacement.
If force, F = 0
Therefore, work done, W = 0, s = 0
If displacement, s = 0
Therefore, Work done, W = F × 0 = 0
It proves that, there are two conditions for work to occur or be done:

1. Force should act on the object.
2. Object must be displaced.

Question 2.
Give the conditions when work done become positive and negative.
Answer:
When force is applied in the direction of displacement, the work done is considered as positive.
i.e., W = F × s
When force is applied in opposite direction of displacement, the work done is considered as negative.
i.e., W = -F × s = -Fs.

Question 3.
Explain positive and negative work.
Answer:
1. Positive work:
If a force displaces the object in its direction, then the work done is positive.
Here,
W = Fd
Example:
Motion of ball falling towards ground where displacement of ball is in the direction of force of gravity.

2. Negative work. If the force and the displacement are in opposite directions, then the work is said to be negative.
Here,
W = -Fd.
Example:
If a ball is thrown in upward direction but the force due to earth’s gravity is in the downward direction.

Question 4.
A cyclist moving along a circular path of radius 63m completes three rounds in 3minutes.
1. The total distance covered by him during this time.
2. Net displacement of cyclist.
3. The speed of the cyclist
Answer:
1. Total distance covered
s = 2πr × t
s = 2πr × 3
= 2 × \(\frac { 22 }{ 7 }\) × 63 × 3 = 1188m

2. Displacement = Zero

3. Speed = \(\frac { Distance }{ Time }\)
= \(\frac { 1188 }{ 180 }\)
= 6.6 m/s.

Force and Laws of Motion Higher Order Thinking Skills (HOTS)

Question 1.
As per Newton’s third law, every force is accompanied by equal and opposite force. How then can anything move?
Answer:
According to the Newton’s third law, action and reaction are two equal and opposite forces but they act on different bodies. This make the motion of a body possible.

Question 2.
The passengers travelling in a bus fall ahead when a speeding bus stops suddenly. Why?
Answer:
When the speeding bus stops suddenly lower part of the body, a long with the bus comes to rest while the upper part tends to remain in motion due to inertia of motion. That is why passengers fall ahead.

Question 3.
A player always runs some distance before taking a jump. Why?
Answer:
A player always runs for some distance before taking a jump because inertia of motion helps him to take a longer jump.

Force and Laws of Motion Value Based Question

Question 1.
Sushil saw his karate expert breaking a slate. He tried to break the slate but Sushil’s friend stopped him from doing so and told him that it would hurt, one needs lot of practice in doing such activity.

1. How can a karate expert break the slate without any injury to his hand?
2. What is Newton’s third law of motion?
3. What value of Sushil’s friend is seen in the above case?

Answer:

1. A karate expert Sushil applies the blow with large velocity in a very short interval of time on the slate, therefore large force is exerted on the slate and it breaks.
2. To every action, there is an equal and opposite reaction, both act on different bodies.
3. Sushil’s friend showed the value of being responsible and caring friend.

MP Board Class 9th Science Solutions