Results for SSC JE

Basic Electrical Engineering MCQ-14

August 15, 2019

Basic Electrical Engineering MCQ-14




41. Which of the following statement about D.C. generators is false ?
(a) Compensating winding in a D.C. machine helps in commutation
(b) In a D. C. generator interpoles winding is connected in series with the armature
winding
(c) Back pitch and front pitch are both odd and approximately equal to the pole pitch
(d) Equilizing bus bars are used with parallel running of D.C. shunt generators
Ans: d
42. The demagnetising component of armature reaction in a D.C. generator
(a) reduces generator e.m.f.
(b) increases armature speed
(c) reduces interpoles flux density
(d) results in sparking trouble
Ans: a
43. Magnetic field in a D.C. generator is produced by
(a) electromagnets
(b) permanent magnets
(c) both (a) and (b)
(d) none of the above
Ans: a
44. The number of brushes in a commutator depends on
(a) speed of armature
(b) type of winding
(c) voltage
(d) amount of current to be collected
Ans: d
45. Compensating windings are used in D.C. generators
(a) mainly to reduce the eddy currents by providing local short-circuits
(b) to provide path for the circulation of cooling air
(c) to neutralise the cross-magnetising effect of the armature reaction
(d) none of the above
Ans: c
46. Which of the following components of a D.C, generator plays vital role for providing
direct current of a D.C. generator ?
(a) Dummy coils
(b) Commutator
(c) Eye bolt
(d) Equilizer rings
Ans: b
47. In a D.C. generator the ripples in the direct e.m.f. generated are reduced by
(a) using conductor of annealed copper
(b) using commutator with large number of segments
(c) using carbon brushes of superior quality
(d) using equiliser rings
Ans: c

48. In D.C. generators, lap winding is used for
(a) high voltage, high current
(b) low voltage, high current
(c) high voltage, low current
(d) low voltage, low current
Ans: b
49. Two generators A and B have 6-poles each. Generator A has wave wound armature
while generator B has lap wound armature. The ratio of the induced e.m.f. is generator A
and B will be
(a)    2 : 3
(b) 3 : 1
(c) 3 : 2
(d) 1 : 3
Ans: b
50. The voltage drop for which of the following types of brush can be expected to be least ?
(a) Graphite brushes
(b) Carbon brushes
(c) Metal graphite brushes
(d) None of the above
Ans: c
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Basic Electrical Engineering MCQ- 13

August 15, 2019


Basic Electrical Engineering MCQ- 13


31. D.C. generators are connected to the busbars or disconnected from them only under the
floating condition
(a) to avoid sudden loading of the primemover
(b) to avoid mechanicaljerk to the shaft
(c) to avoid burning of switch contacts
(d) all above
Ans: d
32. Eddy currents are induced in the pole shoes of a D.C. machine due to
(a) oscillating magnetic field
(b) pulsating magnetic flux
(c) relative rotation between field and armature
(d) all above
Ans: c
33. In a D.C. machine, short-circuited field coil will result in
(a) odour of barning insulation
(b) unbalanced magnetic pull producing vibrations
(c) reduction of generated voltage for which excitation has to be increased to maintain the
voltage
(d) all above
Ans:
34. Equilizer rings are required in case armature is
(a) wave wound
(b) lap wound
(c) delta wound
(d) duplex wound
Ans: b
35. Welding generator will have
(a) lap winding
(b) wave winding
(c) delta winding
(d) duplex wave winding
Ans: a
36. In case of D.C. machine winding, number of commutator segments is equal to
(a) number of armature coils
(b) number of armature coil sides
(c) number of armature conductors
(d) number of armature turns
Ans: a
37. For a D.C. machines laboratory following type of D.C. supply will be suitable
(a) rotary converter
(b) mercury are rectifier
(c) induction motor D.C. generator set
(d) synchronous motor D.C. generator set
Ans: c
38. The function of pole shoes in the case of D.C. machine is
(a) to reduce the reluctance of the magnetic path
(b) to spread out the flux to achieve uniform flux density
(c) to support the field coil
(d) to discharge all the above functions
Ans: d
39. In the case of lap winding resultant pitch is
(a) multiplication of front and back pitches
(b) division of front pitch by back pitch
(c) sum of front and back pitches
(d) difference of front and back pitches
Ans: d
40. A D.C. welding generator has
(a) lap winding
(b) wave moving
(c) duplex winding
(d) any of the above
Ans: a
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Basic Electrical Engineering MCQ- 12

August 15, 2019

Basic Electrical Engineering MCQ- 12
21. In D.C. generators, current to the external circuit from armature is given through
(a) commutator
(b) solid connection
(c) slip rings
(d) none of above
Ans: a
23. Brushes of D.C. machines are made of
(a) carbon
(b) soft copper
(c) hard copper
(d) all of above
Ans: a

24. If B is the flux density, I the length of conductor and v the velocity of conductor, then
induced e.m.f. is given by
(a)Blv
(b)Blv2
(c)Bl2v
(d)Bl2v2
Ans: a
25. In case of a 4-pole D.C. generator provided with a two layer lap winding with sixteen
coils, the pole pitch will be
(a) 4
(b) 8
(c) 16
(d) 32
Ans: b

26. The material for commutator brushes is generally
(a) mica
(b) copper
(c) cast iron
(d) carbon
Ans: d
27. The insulating material used between the commutator segments is normally
(a) graphite
(b) paper
(c) mica
(d) insulating varnish
Ans: c
28. In D.C. generators, the brushes on commutator remain in contact with conductors
which
(a) lie under south pole
(b) lie under north pole
(c) lie under interpolar region
(d) are farthest from the poles
Ans: c
29. If brushes of a D.C. generator are moved in order to bring these brushes in magnetic
neutral axis, there will be
(a) demagnetisation only
(b) cross magnetisation as well as magnetisation
(c) crossmagnetisation as well as demagnetising
(d) cross magnetisation only
Ans: c

30. Armature reaction of an unsaturated D.C. machine is
(a) crossmagnetising
(b) demagnetising
(c) magnetising
(d) none of above
Ans: a

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RRB JE Previous Questions|RRB JE Solved Paper Set 13

April 17, 2019

RRB JE Previous Questions|RRB JE Solved Paper Set 13



81. If ` 1440 is divided into two parts in which one part is  of the second, then 9 the smaller part is
1) ` 405 2) ` 630 3) ` 810 4) ` 1035


82. If √4*n = 1024, then the value of n is
1) 5 2) 8 3) 10 4) 12 

84. A man covers half of his journey at 6 km/ hr and the remaining half at 3 km/ hr. His average speed is
1) 4 km/ hr 2) 4.5 km/ hr 3) 9 km/ hr 4) 3 km/ hr


85. The average weight of 8 boys is increased by 1.5 kg when one of the boys, who weights 65 kg, is replaced by a new boy. The weight of the new boy is1) 70 kg 2) 74 kg 3) 76 kg 4) 77 kg


4 86. The 4/5 th of a certain number is 64. Half of the number is-
1) 40 2) 32 3) 80 4) 16


87. The ratio between the present ages of Ravi and Jai is 3:2. If Ravi was 6 years older than Jai, four years back, how old is Jai now?
1) 6 years 2) 12 years 3) 18 years 4) Data inadequate



89. The length of a rectangle is increased by 60%. By what perent would the width have to be decreased to maintain the same area?
1 2 1) 37  % 2) 60% 3) 75% 4) 66 % 2 3


90. By selling a tape-recorder for ` 950, I lose 5%. What percent shall I gain by selling it for a 1040?
1) 4% 2) 4.5% 3) 40% 4) 5%

91. When 1 is added to each of the given two numbers, their ratio becomes 3 : 4 and when 5 is subtracted from each, the ratio becomes 7 : 10. The numbers are:
1) 8, 11 2) 11, 15 3) 26, 35 4) 27, 36


92. 5 men or 9 women can do a piece of work 19 days. In how many days will 3 men and 6 women working together will finish the work?
1) 10 days 2) 15 days 3) 87 days 4) 38 days

93. Two pipes can fill a tank in 20 minutes will 30 minutes respectively. If both the pipes are opened simultaneously, then the tank will be filled in
1) 10 minutes 2) 12 minutes 3) 15 minutes 4) 25 minutes


94. A train 132 metre long passes a telegraph post in 6 seconds. The speed of the train is

1) 70 km/ hr 2) 72 km/ hr 3) 79.2 km/ hr 4) 80 km/ hr

95. The radius of the wheel of a vehicle is 70 cm. The wheel makes 10 revolutions in 5 seconds. The speed of the vehicle is
1) 29.46 km/ hr 2) 31.68 km/ hr 3) 36.25 km/ hr 4) 32.72 km/ hr


97. The area of the base of a rectangular tank is 6500 cm2 and the volume of water contained in it is 2.6 cubic metres. The depth of the water tank is
1) 2.5 metre 2) 3 metre 3) 5.5 metre 4) 4 metre


98. Two angles are complementary, if the sum of their measures is1) 90° 2) 100° 3) 180° 4) 360°


Answers:

81-2; 82-3; 83-3; 84-1; 85-4; 86-1; 87-2; 88-4; 89-1; 90-1; 91-3; 92-2; 93-2; 94-3; 95-2; 96-4; 97-4; 98-1; 99-3; 100-1

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RRB JE Previous Questions|RRB JE Solved Paper Set 12

April 17, 2019


RRB JE Previous Questions|RRB JE Solved Paper Set 12

61. In the alternatives given below, three are alike in some manner while the fourth
one is different. Choose the odd one.
1) Garo 2) Khasi 3) Kangra 4) Jaintia
62. In the alternatives given below, three are alike in some manner while the fourth
one is different. Choose the odd one.
1) Triangle 2) Tangent 3) Square 4) Rhombus
63. In the alternatives given below, three are alike in some manner while the fourth
one is different. Choose the odd one.
1) Up 2) Down 3) Above 4) Small
64. In the alternatives given below, theree are alike in some manner while the fourth
one is different. Choose the odd one.
1)      Run 2) Walk 3) Think 4) Jump
65. 'Flower' is related to 'Essence' in the same way as 'Oven' is related to1) Vapour 2) Fire 3) Heat 4) Steam
66. 'Gravity' is related to 'Pull' in the same way as 'Magnetism' is related to1) Repulsion 2) Separation 3) Attraction 4) Push
67. Choose the correct alternative that will continue the same pattern and replace the
question mark (?) in the given series.
120, 99, 80, 63, 48, ?
1) 35 2) 38 3) 39 4) 40
68. Choose the correct alternative that will continue the same pattern and replace the
question mark (?) in the given series.
1, 5, 14, 30, 55, 91, ?
1) 130 2) 140 3) 150 4) 160
69. Choose the correct altrnative that will continue the same pattern and replace the
question mark (?) in the given series.
2, 12, 36, 80, 150, ?
1)      194 2) 210 3) 252 4) 258
70. Choose the correct alternative that will continue the same pattern and replace the
question mark (?) in the given series.
1) KSU 2) LMN 3) SOV 4) SOW
71. Choose the correct alternative that will continue the same pattern and replace the
question mark (?) in the given series.
M, N, O, L, R, I, V, ?
1) A 2) E 3) F 4) H
72. A and B are brothers. C and D are sisters. A's son is D's brother. How is B
related to C?
1) Father 2) Brother 3) Grandfather 4) Uncle
73. Introducing a man, a woman said, 'His wife is the only daughter of my father'.
How is that man related to the woman?
1) Brother 2) Father-in-law
3) Husband 4) Maternal Uncle
74. A man is facing West. He turns 45° in the clock-wise direction and then another
180° in the same direction and then 270° in the anti-clockwise directon. Which
direction is he facing now?
1) South 2) North-West 3) West 4) South-West
75. A man starts from a point 'X' and walks 3 km southwards, then he turns left and
walks 6 km. In which direction is he from the starting point?
1) South-West 2) South-East 3) West 4) South
76. The H.C.F. of 595 and 252 is1) 1 2) 7 3) 11 4) 17
77. The L.C.M. of 26, 56, 104 and 182 is1) 456 2) 728 3) 748 4) 1274
78. 6.5 × 4.7 + 6.5 × 5.3)/( 1.3 × 7.9 - 1.3 × 6.9) = ?
1) 3.9 2) 39 3) 34.45 4) 50
79. A student was asked to divide a number by 3. But, instead of dividing it, he
multiplied it by 3 and got 29.7. What was the correct answer?
1) 3.3 2) 9.3 3) 9.8 4) 9.9
80. 5852 ÷ 28 × ? - 1653 = 1064
1) 9 2) 13 3) 15 4) 18


Answers :

61-3; 62-2; 63-4; 64-3; 65-3; 66-3; 67-1; 68-2; 69-3; 70-1; 71-2; 72-4; 73-3; 74-4; 75-2; 76-2; 77-2; 78-4; 79-1; 80-2

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RRB JE Previous Question paper| Solved paper RRB JE Set 11

April 17, 2019

RRB JE Previous Question paper| Solved paper RRB JE  Set 11



41. 'Jamini Roy' was a famous1) Dance 2) Magician 3) Cartoonist 4) Painter


42. 'NCERT' stands for1) National Committee of Educational Research and Training
2) National Council of Educational Research and Training
3) National Council for Educational Research and Teaching
4) National Council of Employment Resources and Training



43. Who directed the film 'Slumdog Millionaire'?
1) Anil Kapoor 2) Prakash Jha
3) Danny Boyle 4) Simon Beautoy


44. Who is the first female amputee to climb Mount Everest?
1) Samina Baig 2) Arunima Sinha
3) Bachhendri Pal 4) Raha Moharrak


45. Who was declared 'Man of the Series' in the ICC Champions Trophy 2013?
1) Shikhar Dhawan 2) Virat Kohli
3) Ravindra Jadeja 4) MS Dhoni


46. Which among the following States is considered India's most flood-prone State?
1) Uttarakhand 2) Jharkhand
3) Bihar 4) Nagaland


47. Who among the following is the author of the book 'Mudra Rakshasa'?
1) Kalidasa 2) Kalhana 3) Kautilya 4) Vishakhadatta


48. 'Vishnupad Temple' is situated in
1) Gaya 2) Varanasi 3) Rajgir 4) Nalanda


49. 'Jiradei', the birthplace of Dr. Rajendra Prasad comes under which district of Bihar?
1) Patna 2) Madhubani 3) Gaya 4) Siwam


50. Indian Space Research Organisation (ISRO) is situated in
1) Bengaluru 2) Hyderabad 3) Ahmedabad 4) Mumbbai


51. X is mightier than Y and Y is mightier than Z. P is mightier than Q but inferior to Y. Q is mightier than Z. Who is the weakest among all?
1) X 2) Z 3) Q 4) P


52. If each of the digits in the number '92581473' are arranged in ascending order, what will be the difference between the digits, which are fourth from the right and third from the left in the new arrangement?
1) One 2) Two 3) Three 4) Four


53. In a certain code, EAT is written as 318 and CHAIR is written as 24156. How will TEACHER be written in that code?
1) 8812346 2) 8321436 3) 8312436 4) 8313426


54. If NOIDA is written as 39658, how will INDIA be written?
1) 36568 2) 63568 3) 63569 4) 65368


55. In a certain code language, '253' means 'books are old', '546' means 'man is old'
and '378' means 'buy good books'. What stands for 'are' in that code?
1) 2 2) 4 3) 5 4) 6


56. If 'oranges' are 'apples', 'bananas' are 'apricots', 'apples' are 'chillies', 'apricots' are
'oranges' and 'chillies' are 'bananas', then which of the following are green in
colour?
1) Apricots 2) Apples 3) Chillies 4) Bananas


57. In a certain code, ROAD is written as URDG. How will SWAN written in that
code?
1) VXDQ 2) VZDQ 3) VZCP 4) UXDQ


58. If '+' means '÷', '×' means '÷' '÷' means '+' and '-' means '×', then which of the
following will be the value of the expressions?
252 × 9 - 5 + 32 ÷ 92
1) 95 2) 168 3) 192 4) 200


59. If P denotes '÷', Q denotes '×' R denotes '+' and S denotes '-', then.
18 Q 12 P 4 R 5 S 6 = ?
1) 95 2) 53 3) 51 4) 57


60. The following equation may be corrected by interchanging which two signs?
5 × 15 ÷ 7 - 20 + 4 = 77
1) - and + 2) × and ÷ 3) + and ÷ 4) + and ×


Answers:

41-4; 42-2; 43-3; 44-2; 45-1; 46-3; 47-4; 48-1; 49-4; 50-1; 51-2; 52-2; 53-3; 54-2; 55-1; 56-4; 57-2; 58-4; 59-2; 60-3

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RRB JE previous Questions|RRB JE Solved paper Set 10

April 17, 2019

RRB JE previous Questions|RRB JE Solved paper Set 10

21. Which of the following is a scalar quantity?
1) Electric Field 2) Average Velocity
3) Power 4) Magnetic Momentum


22. If the velocity of a body is doubled
1) Its Kinetic Energy is doubled 2) Its potential Energy is doubled
3) Its Momentum is doubled 4) Its Acceleration is doubled


23. Clothes keep us warm in winter because they1) supply heat
2) do not rediate heat
3) prevent air from contacting the body
4) prevent the heat of the body from escaping


24. Permanent magnet can be made from
1) Cobalt 2) Aluminum 3) Zinc 4) Lead


25. Who among the following is known as 'Father of Biology'?
1) Aristotle 2) Darwin 3) Lamark 4) Hippocrates


26. Spiral shape bacteria is called
1) Diplococus 2) Bacillus 3) Cocus 4) Spirillum


27. Which of the folloiwng bones is not found in human leg?
1) Tibia 2) Humerus 3) Femur 4) Fibula


28. The enzyme found in human saliva is
1) Renin 2) Ptylin 3) Tenin 4) Resin


29. Virus of 'Bird Flu' is also known as
1) NH51 2) NH15 3) H5N1 4) N5H1


30. 'Gypsum' is an ore of
1) Iron 2) Calcium 3) Sodium 4) Magnesium


31. Which of the folloiwng is used for killing rats?
1) Zinc Phosphide 2) Duralumin 3) Zinc Oxide 4) Sodium Nitrate


32. Which of the following is not an isotope of Hydrogen?
1) Protium 2) Eritium 3) Deuterium 4) Tritium


33. Which of the following is not an Input Device?
1) Keyboard 2) Scanner 3) Mouse 4) Printer


34. http://www.discovery.com is an example of
1) Web brower 2) Website
3) Web page 4) Internet Service Provider


35. A prescribed set of well-defined instructions for solving mathematical problems
is called1) A Compiler 2) A code
3) A description 4) An algorithm


36. Which part of the Indian Constitution deals with the Directive Principles of the
State Policy?
1) Part I 2) Part III 3) Part IV 4) Part V


37. The 44th amendment in the Constitution of India removed which one of the
following rights from the category of Fundamental Rights?
1) Freedom of Speech 2) Equality before Law
3) Right of Property 4) Freedom of Religion


38. Who was the first Chief Minister of Bihar?
1) Krishna Singh 2) K.B. Sahay
3) Mahamaya Prasad Sinha 4) Karpoori Thakur


39. Who was the Prime Minister of India just before Dr. Manmohan Singh?
1) H.D. Deve Gowda 2) I.K. Gujral
3) P.V. Narasimha Rao 4) Atal Bihari Vajpayee


40. Japan's Parliament is known as

1) Diet 2) Dail 3) Yuan 4) Tokyo House

Answers:

21-3; 22-3; 23-4; 24-2; 25-1; 26-4; 27-2; 28-2; 29-3; 30-2; 31-1; 32-2; 33-4; 34-2; 35-4; 36-3; 37-3; 38-1; 39-4; 40-1

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RRB JE Previous Questions|RRB JE Solved Paper Set 9

April 17, 2019

RRB JE Previous Questions|RRB JE Solved Paper Set 9
1. Which of the following was the capital of 'Kuru' Mahajanapada?
1) Mathura 2) Indraprastha 3) Videha 4) Mithila

2. Out of the following remains excavated in Indus Valley, which one indicates the commercial and econimic development?

1) Pottery 2) Seals 3) Boats 4) Houses

3. Which of the folliwng is not an example of literature of Vedic tradition?
1) Vedas 2) Puranas 3) Vedangas 4) Purvas

4. The Indian king who opposed Alexander was
1) Ambhi 2) Porus 3) Dhananand 4) Mahapadmananda

5. Who laid the foundation of the city Patliputra?
1) Udayan 2) Ashoka
3) Bimbisara 4) Mahapadmananda

6. What was the name of Budha's Charioteer?
1) Manna 2) Channa 3) Devadata 4) Raghu

7. The most famous Kushan ruler was1) Rudradaman 2) Vasudeva I
3) Kanishka 4) Ashoka

8. Between which two rulers was the first Battle of Panipat fought?
1) Akbar and Bahlol Lodi 2) Babur and Ibrahim Lodi
3) Bairam Khan and Sikandar Lodi 4) Shahjahan and Daulat Khan Lodi

9. When and where was the 'Ghadar Party' founded?
1) America, 1913 2) England, 1917
3) Denmark, 1921 4) Scotland, 1925

10. Gandhiji's movement of boycotting the foreign goods aimed at
1) Promotion of Welfare State 2) Creating anti-British sentiments
3) Promotion of Cottage Industry 4) Full independence


11. Which one of the following leaders belonged to the extremist wing of the
Congress?
1) Aurobindo Ghosh 2) Dadabhai Naoroji
3) G.K.Gokhale 4) S.N.Banerjee

12. At the Second Round Table Conference, the Indian National Congress was
represented by1) Jawaharlal Nehru 2) Rajendra Prasad
3) M.K.Gandhi 4) Vallabh Bhai Patel

13. Earth's gravitational pull in minimum in
1) Troposphere 2) Stratosphere
3) Thermosphere 4) Exosphere

14. The most abundant element in the Earth's Crust is
1) Aluminum 2) Silica 3) magnesium 4) Sodium

15. Which of the following is not a Kharif crop?
1) Rice 2) Maize 3) Cotton 4) Barley

16. 'Palghat' is a division of which of the following Railways?
1) Southern Railway 2) South Eastern Railway
3) South Central Railway 4) South Western Railway

17. Which of the following Unin Terriotories of India has the lowest population?
1) Pondicherry 2) Daman and Diu
3) Lakshadweep 4) Andaman and Nicobar

18. 'Kakolat Water fall' is situated in which of the following States?
1) Bihar 2) Uttar Pradesh
3) Himachal Pradesh 4) Uttarakhand

19. Which one of the following longitudes determines the Indian Standard Time?
1) 85.5°E 2) 86.5°E 3) 84.5°E 4) 82.5°E

20. The Nagarjunasagar Dam is built across which ofthe following rivers?
1) Krishna 2) Chambal 3) Kosi 4) Sutlej

Answers : 1-2; 2-2; 3-2; 4-2; 5-3; 6-2; 7-3; 8-2; 9-1; 10-2; 11-1; 12-3; 13-4; 14-1; 15-4; 16-2; 17-3; 18-1; 19-4; 20-1


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Building Materials- BRICKS Basic Civil Engineering Industrial Extension officer Coaching

March 09, 2019

Building Materials- BRICKS Basic Civil Engineering Industrial Extension officer Coaching



INDUSTRIAL EXTENSION OFFICER|EEEMADE EASY|BIBIMOHANAN


For Free Coaching Classes Visit EEE Made Easy Youtube Channel

Download PDF; link at the bottom of this page

Basic Civil Engineering-set 4

BRICKS

Contents




Brick


obtained by mouldinggood clay into a block, which is dried and then burnt.
oldest building block to replace stone
Manufacture of brick started with hand moulding, sun drying and
burning in clamps


Size


The size of the bricks are of 90 mm ×90 mm ×90 mm and 190 mm ×90 mm ×40 mm.
With mortar joints, the size of these bricks are taken as 200 mm ×100 mm ×100 mm and 200 mm ×100 mm×50 mm

Types of Bricks



Bricks may be broadly classified as:
(i) Building bricks
(ii) Paving bricks
(iii) Fire bricks
(iv) Special bricks

(i) Building Bricks: These bricks are used for the construction of walls.
(ii) Paving Bricks: These are vitrified bricks and are used as pavers.
(iii) Fire Bricks: These bricks are specially made to withstand furnace temperature. Silica bricks
belong to this category.

(iv) Special Bricks: These bricks are different from the commonly used building bricks with
respect to their shape and the purpose for which they are made. Some of such bricks are listed below:
(a) Specially shaped bricks
(b) Facing bricks
(c) Perforated building bricks
(d) Burnt clay hollow bricks
(e) Sewer bricks
( f ) Acid resistant bricks.

Properties of Bricks


(i) Colour: Colour should be uniform and bright.
(ii) Shape: Bricks should have plane faces. They should have sharp and true right-angled corners.
(iii) Size: Bricks should be of standard sizes as prescribed by codes.

(iv) Texture: They should possess fine, dense and uniform texture. They should not possess fissures, cavities, loose grit and unburnt lime.
(v) Soundness: When struck with a hammer or with another brick, it should produce metallic sound.
(vi) Hardness: Finger scratching should not produce any impression on the brick

. (vii) Strength: Crushing strength of brick should not be less than 3.5 N/mm2. A field test for strength is that when dropped from a height of 0.9 m to 1.0 mm on hard ground, the brick should not break into pieces.

(viii) Water Absorption: After immersing the brick in water for 24 hours, water absorption should not be more than 20 per cent by weight. For class-I works, this limit is 15 per cent.

(ix) Efflorescence: Bricks should not show white patches when soaked in water for 24 hours and then allowed to dry in shade. White patches are due to the presence of sulphate of calcium, magnesium and potassium. They keep the masonry permanently in damp and wet conditions

. (x) Thermal Conductivity: Bricks should have low thermal conductivity so that buildings built with them are cool in summer and warm in winter.

(xi) Sound Insulation: Heavier bricks are poor insulators of sound while lightweight and hollow bricks provide good sound insulation.

(xii) Fire Resistance: Fire-resistance of bricks is usually good. In fact, bricks are used to encase steel columns to protect them from fire.

Tests on Bricks


to find their suitability:
(i) Crushing strength
(ii) Absorption
(iii) Shape and size and
(iv) Efflorescence.


(i) Crushing Strength:

The brick specimen is immersed in water for 24 hours.
The frog of the brick is filled flush with 1:3 cement mortar and the specimen is stored in a damp jute bag for 24 hours
and then immersed in clean water for 24 hours.
The specimen is placed in a compression testing machine with 6 mm plywood on top and bottom of it to get a uniform load on the specimen.
Then the load is applied axially at a uniform rate of 14 N/mm2.
The crushing load is noted. Then the crushing strength is the ratio of crushing load to the area of brick loaded. Average of five specimens is taken as the crushing strength.

(ii) Absorption Test:

The brick specimen is weighed dry. Then they are immersed in water for a period of 24 hours. The specimen is taken out and wiped with a cloth. The weight of each specimen in a wet condition is determined. The difference in weight indicates the water absorbed. Then the percentage absorption is the ratio of water absorbed to dry weight multiplied by 100. The average of five specimens is taken. This value should not exceed 20 per cent.

(iii) Shape and Size:

Bricks should be of standard size and edges should be truly rectangular with sharp edges. To check it, 20 bricks are selected at random and they are stacked along the length, along the width and then along with the height.
For the standard bricks of size 190 mm ×90 mm ×90 mm.
IS code permits the following limits:
Lengthwise: 3680 to 3920 mm
Widthwise: 1740 to 1860 mm
Heightwise: 1740 to 1860 mm

field tests help in ascertaining the good quality bricks:
(i) uniformity in size
(ii) uniformity in colour
(iii) structure
(iv) hardness test
(v) sound test
(vi) strength test


Classification of Bricks Based on their Quality

(i) First-class bricks
(ii) Second class bricks
(iii) Third class bricks and
(iv) Fourth class bricks

(i) First Class Bricks:

These bricks are of standard shape and size. They are burnt in kilns. They fulfil all the desirable properties of bricks.

(ii) Second Class Bricks:

These bricks are ground moulded and burnt in kilns. The edges may not be sharp and uniform. The surface may be somewhat rough. Such bricks are commonly used for the construction of walls which are going to be plastered.

(iii) Third Class Bricks:

These bricks are ground moulded and burnt in clamps. Their edges are somewhat distorted. They produce dull sound when struck together. They are used for temporary and unimportant structures.

(iv) Fourth Class Bricks:

These are the over burnt bricks. They are dark in colour. The shape is irregular. They are used as aggregates for concrete in foundations, floors and roads

Uses of Bricks

Bricks are used in the following civil works:
(i) As building blocks.
(ii) For the lining of ovens, furnaces and chimneys.
(iii) For protecting steel columns from fire.
(iv) As aggregates in providing waterproofing to R.C.C. roofs.
(v) For pavers for footpaths and cycle tracks.
(vi) For lining sewer lines


Detailed Syllabus of Industrial Extension officer Watch HERE


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Building Materials- BRICKS Basic Civil Engineering Industrial Extension officer Coaching Building Materials- BRICKS Basic Civil Engineering Industrial Extension officer Coaching Reviewed by Sikha on March 09, 2019 Rating: 5
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