Structural Clay Products
Solved Objective Questions (S K Duggal)
1. Consider the following statements:
Good soil for making bricks should contain
(1) about 30% alumina
(2) about 10% lime nodules
(3) a small number of iron oxides
(4) about 15% magnesia
Of these statements
(a) 1 and 2 are correct (b) 1 and 3 are corect
(c) 1, 3 and 4 are correct (d) 2, 3 and 4 are correct
Answer:- (a) 1 and 2 are correct
2. If L is the length and B the width of the brick and t the thickness of mortar, the relation
between these is
(c) L = B + 2 t (d) L = 2B + t
between these is
(a) L = 2B (b) L = B + t
(c) L = B + 2 t (d) L = 2B + t
Answer:- (d) L=2B+t
3. The weight of a standard brick should be
(a) 1000 g (b) 1500 g
(c) 2500 g (d) 3000 g
Answer:- (d)3000g
4. Frog is provided in
(i) 9 cm high bricks only
(ii) 4 cm high bricks only
(iii) extruded bricks only
Of the above
(a) only (i) is correct (b) only (ii) is correct
(c) (i) and (iii) are correct (d) (i), (ii) and (iii) are correct
Answer:- (a) only (i) is correct
5. The most important purpose of frog in brick is to
(a) emboss manufacturer's name
(b) reduce the weight of brick
(c) form keyed joint between brick and mortar
(d) improve insulation by providing 'hollows'
Answer:- (c) form keyed joint between brick and motor
6. Consider the following statements :
(1) About 25% of alumina in brick earth imparts the plasticity necessary for moulding bricks into the required shape
(2) Iron pyrite present in brick earth preserves the form of the bricks at high temperatures.
(3) Presence of weeds in brick earth makes the bricks unsound.
Which of these statements are correct?
(a) 1 and 2 (b) 1 and 3
(c) 2 and 3 (d) 1, 2 and 3
Answer:- (b) 1 and 3
7. Water absorption for Ist class bricks should not be more than
(a) 12% (b) 15%
(c) 20% (d) 25%
Answer:- (b) 15%
8. For hidden masonry works the bricks used should be
(a) Ist Class (b) IInd Class
(c) IIIrd Class (d) for any of the above
Answer:- (a) IInd Class
9. For centring of R.C.C. structures, the bricks used should be
(a) Ist Class (b) IInd Class
(c) IIIrd Class (d) IVth Class
(a) Ist Class (b) IInd Class
(c) IIIrd Class (d) IVth Class
Answer:- (b) IInd Class
10. Match List-I (Constituents of bricks) with List-II (Corresponding influence) and select the
correct answer using the codes given below the lists :
List-I List-II
(Constituents of bricks) (Corresponding influence)
A. Alumina 1. Colour of brick
B. Silica 2. Plasticity recovery for moulding
C. Magnesia 3. Reacts with silica during burning and causes particles to unite together and development of strength
D. Limestone 4. Preserves the form of brick at high temperature and prevents shrinkage
Codes :
(a) A B C D (b) A B C D
2 1 4 3 3 4 1 2
(c) A B C D (d) A B C D
2 4 1 3 3 1 4 2
correct answer using the codes given below the lists :
List-I List-II
(Constituents of bricks) (Corresponding influence)
A. Alumina 1. Colour of brick
B. Silica 2. Plasticity recovery for moulding
C. Magnesia 3. Reacts with silica during burning and causes particles to unite together and development of strength
D. Limestone 4. Preserves the form of brick at high temperature and prevents shrinkage
Codes :
(a) A B C D (b) A B C D
2 1 4 3 3 4 1 2
(c) A B C D (d) A B C D
2 4 1 3 3 1 4 2
Answer:- (c) A B C D
2 4 1 3
2 4 1 3
11. The IS classification of bricks is based on
(i) compressive strength
(ii) water absorption
(iii) dimensional tolerance
Of the above
(a) only (i) is correct (b) (i) and (ii) are correct
(c) (i) and (iii) are correct (d) (i), (ii) and (iii) are correct
(i) compressive strength
(ii) water absorption
(iii) dimensional tolerance
Of the above
(a) only (i) is correct (b) (i) and (ii) are correct
(c) (i) and (iii) are correct (d) (i), (ii) and (iii) are correct
Answer:- (c) (i) and (iii) are correct
12. Which of the following constituent in the earth gives plasticity to mould bricks in suitable shape?
(a) Silica (b) Lime
(c) Alumina (d) Magnesia
Answer:- (c) Alumina
13. The raw bricks shrink during drying and warp during burning because of
(a) less lime in brick earth
(b) less silica and excess magnesia in brick earth
(c) excess of alumina and silica in brick earth
(d) alkalis in brick earth
(a) less lime in brick earth
(b) less silica and excess magnesia in brick earth
(c) excess of alumina and silica in brick earth
(d) alkalis in brick earth
Answer:- (c) excess of silica and excess magnesia in brick earth
14. The moulded bricks are dried before burning to an approximate moisture content of
(a) 3% (b) 6%
(c) 10% (d) 20%
(a) 3% (b) 6%
(c) 10% (d) 20%
Answer:- (a) 3%
15. In the process of brick manufacturing, the pug mill is used in which of the following operation?
(a) Weathering (b) Blending
(c) Tempering (d) Burning
Answer:- (c) Tempering
16. Consider the following statements :
For the manufacture of good quality bricks, it is essential to
(1) use a reverberatory kiln
(2) blend the soil with clay or sand as deemed appropriate
(3) knead the soil in a Ghani
(4) temper the soil in a pug mill
Of these statements
(a) 1 and 3 are correct (b) 2 and 4 are correct
(c) 1, 3 and 4 are correct (d) 2, 3 and 4 are correct
For the manufacture of good quality bricks, it is essential to
(1) use a reverberatory kiln
(2) blend the soil with clay or sand as deemed appropriate
(3) knead the soil in a Ghani
(4) temper the soil in a pug mill
Of these statements
(a) 1 and 3 are correct (b) 2 and 4 are correct
(c) 1, 3 and 4 are correct (d) 2, 3 and 4 are correct
Answer:- (b) 2 and 4 are correct
17. Bricks are burnt at a temperature range of
(a) 500° to 700° C (b) 700° to 900° C
(c) 900° to 1200° C (d) 1200° to 1500° C
(a) 500° to 700° C (b) 700° to 900° C
(c) 900° to 1200° C (d) 1200° to 1500° C
Answer:- (c) 900° to 1200° C
18. Match List-I with List-II and select the correct answer using the codes given below the lists :
List-I List-II
(Ingredients) (%)
(A) Silica (1) 50 – 60%
(B) Lime (2) 20 – 30%
(C) Alumina (3) 10%
(D) Alkalis (4) <10%
Codes :
(a) A B C D (b) A B C D
1 2 3 4 1 3 2 4
(c) A B C D (d) A B C D
1 2 4 3 2 1 4 3
Answer:- (b) A B C D
1 3 2 4
19. Match List-I with List-II and select the correct answer using the codes given below the lists :
List-I List-II
(Ingredients) (Property)
A. Silica 1. imparts durability, prevents shrinkage
B. Alumina 2. softens clay
C. Lime 3. renders clay plastic
D. Ferric Oxide 4. lowers fusing point
Codes :
(a) A B C D (b) A B C D
1 3 2 4 1 4 2 3
(c) A B C D (d) A B C D
1 3 4 2 4 3 1 2
List-I List-II
(Ingredients) (Property)
A. Silica 1. imparts durability, prevents shrinkage
B. Alumina 2. softens clay
C. Lime 3. renders clay plastic
D. Ferric Oxide 4. lowers fusing point
Codes :
(a) A B C D (b) A B C D
1 3 2 4 1 4 2 3
(c) A B C D (d) A B C D
1 3 4 2 4 3 1 2
Answer:- (c) A B C D
1 3 4 2
1 3 4 2
20. Excess of silica makes brick
(a) brittle on burning (b) to melt on burning
(c) to crack on drying (d) to warp
(a) brittle on burning (b) to melt on burning
(c) to crack on drying (d) to warp
Answer:- (a) brittle on burning
21. Which of the following is harmful in the clay used for making bricks?
(a) Iron oxide (b) Iron pyrite
(c) Alkali (d) Magnesia
(a) Iron oxide (b) Iron pyrite
(c) Alkali (d) Magnesia
Answer:- (b) Iron pyrite
22. When carbonaceous materials in the form of bituminous matter of carbon are present in
the clay, the bricks will
the clay, the bricks will
(a) be spongy (b) have a black core
(c) be porous (d) have cracks
Answer:- (b) have a black core
23. Swollen structure and white blotches will be found in bricks when
(a) carbon (b) bituminous matter
(c) organic matter (d) sulphur
is present in clay used for making bricks.
Answer:- (d) Sulphur
24. Consider the following properties
1. Strength development during firing
2. Drying shrinkage
3. Shaping
When fly ash is used as an additive with clay in brick manufacturing the improved properties are
(a) 1 only (b) 2 only
(c) 1 and 2 (d) 1 and 3
1. Strength development during firing
2. Drying shrinkage
3. Shaping
When fly ash is used as an additive with clay in brick manufacturing the improved properties are
(a) 1 only (b) 2 only
(c) 1 and 2 (d) 1 and 3
Answer:- (c) 1 and 2
25. Consider the following stages in the manufacturing of bricks :
1. Weathering 2. Moulding
3. Tempering
The correct sequence of these stages in the manufacturing of the bricks is
(a) 1, 2, 3 (b) 2, 3, 1
(c) 1, 3, 2 (d) 3, 2, 1
1. Weathering 2. Moulding
3. Tempering
The correct sequence of these stages in the manufacturing of the bricks is
(a) 1, 2, 3 (b) 2, 3, 1
(c) 1, 3, 2 (d) 3, 2, 1
Answers:- (c) 1,3,2
26. Consider the following operations of preparation of brick earth
1. Digging 2. Weathering
3. Tempering 4. Blending
5. Unsoiling
The correct sequence of these operations are
(a) 5, 1, 2, 4, 3 (b) 5, 1, 3, 2, 4
(c) 1, 5, 2, 4, 3 (d) 5, 1, 4, 2, 3
Answers:- (a) 5, 1, 2, 4, 3
27. In some brick masonry walls, patches of whitish crystals were found on the exposed surfaces, also chipping and spalling of bricks took place from the same walls. Which among the following are the causes of these defects?
1. Settlement of foundation 2. Over-loading of the walls
3. Sulphate attack 4. Efflorescence
Codes :
(a) 1 and 2 (b) 2 and 3
(c) 2 and 4 (d) 3 and 4
1. Settlement of foundation 2. Over-loading of the walls
3. Sulphate attack 4. Efflorescence
Codes :
(a) 1 and 2 (b) 2 and 3
(c) 2 and 4 (d) 3 and 4
Answer:- (d) 3 and 4
28. The efflorescence of bricks is due to
(a) soluble salts present in clay for making bricks
(b) the high porosity of bricks
(c) high silt content in brick earth
(d) excessive burning of bricks
Answer:- (a) soluble salts present in clay for making bricks
29. What is efflorescence?
(a) Formation of white patches on the brick surface due to insoluble salts in the brick clay.
(b) Swelling of brick due to the presence of carbonaceous matter and gas
(c) Deformation of brick due to exposure to rain
(d) Impurities in the brick clay which show after burning
(a) Formation of white patches on the brick surface due to insoluble salts in the brick clay.
(b) Swelling of brick due to the presence of carbonaceous matter and gas
(c) Deformation of brick due to exposure to rain
(d) Impurities in the brick clay which show after burning
Answer:- (a) Formation of white patches on the brick surface due to insoluble salts in the brick clay.
30. Consider the following with regards to burning of clay bricks.
1. The clay loses its plasticity
2. Carbonate minerals are decarbonated
3. Some of the carbonaceous matter is burnt
4. Clay mass is converted into a glass-like substance
5. Ferrous iron is oxidized to ferric form
The changes that occur during dehydration period are :
(a) 1, 3, 5 (b) 1, 2, 4
(c) 1, 2, 3 (d) 2, 4, 5
1. The clay loses its plasticity
2. Carbonate minerals are decarbonated
3. Some of the carbonaceous matter is burnt
4. Clay mass is converted into a glass-like substance
5. Ferrous iron is oxidized to ferric form
The changes that occur during dehydration period are :
(a) 1, 3, 5 (b) 1, 2, 4
(c) 1, 2, 3 (d) 2, 4, 5
Answer:- (c) 1, 2, 3
31. When the deposits of efflorescence are more than 10 per cent but less than 50 per cent of the exposed areas of brick, the presence of efflorescence is classified as
(a) slight (b) moderate
(c) heavy (d) serious
Answer:- (b) moderate
(a) 20% of its dry weight (b) 15 % of its saturated weight
(c) 10% of its saturated weight (d) 20% of its saturated weight
Answer:- (a) 20% of its dry weight
33. Crushed pottery is used in the manufacture of
(a) fire bricks (b) stone bricks
(c) terracotta (d) clay tiles
(a) fire bricks (b) stone bricks
(c) terracotta (d) clay tiles
Answer:- (c) terracotta
34. Match List-I with List-II and select the correct answer used the codes given below the lists:
List-I List-II
A. Acid Brick 1. Made from Quartzite
B. Silica Brick 2. Made from magnesite
C. Basic Brick 3. Made from fire clay
D. Neutral Brick 4. Made from chromite
Codes :
(a) A B C D (b) A B C D
List-I List-II
A. Acid Brick 1. Made from Quartzite
B. Silica Brick 2. Made from magnesite
C. Basic Brick 3. Made from fire clay
D. Neutral Brick 4. Made from chromite
Codes :
(a) A B C D (b) A B C D
3 1 2 4 3 2 1 4
(c) A B C D (b) A B C D
4 1 2 3 1 2 3 4
Answer:- A B C D
3 1 2 4
3 1 2 4
35. The compressive strength of burnt clay bricks as per IS 1077 is
(a) 100 kg/cm2 (b) 150 kg/cm2
(c) 100 – 150 kg/cm2 (d) 35 – 350 kg/cm2
(a) 100 kg/cm2 (b) 150 kg/cm2
(c) 100 – 150 kg/cm2 (d) 35 – 350 kg/cm2
Answer:- (d) 35-350 kg/cm2
36. The deformation of the shape of bricks caused by the rainwater falling on the hot bricks is known as
(a) spots (b) checks
(c) chuffs (d) blisters
(a) spots (b) checks
(c) chuffs (d) blisters
Answer:- (c) chuffs
37. The defect in clay products because of imprisoned air during their moulding is known as
(a) blister (b) lamination
(c) cracks (d) spots
(a) blister (b) lamination
(c) cracks (d) spots
Answer:- (b) lamination
38. Basic refractory bricks consist of
(a) silica bricks (b) ganister bricks
(c) magnesia bricks (d) chromite bricks
Answer:- (c) magnesia bricks
39. In the steel industry, the bricks used for lining furnaces should be
(a) acid refractory (b) basic refractory
(c) neutral refractory (d) heavy-duty
(a) acid refractory (b) basic refractory
(c) neutral refractory (d) heavy-duty
Answer:- (a) acid refractory
40. Terracotta is burned in
(a) pug mill (b) reverberatory furnace
(c) muffle furnace (d) puddling furnace
(a) pug mill (b) reverberatory furnace
(c) muffle furnace (d) puddling furnace
Answer:- (c) muffle furnace
41. Glazing of clay product is achieved by throwing sodium chloride in the kiln at a temperature of
(a) 600 – 800° C (b) 700 – 1000° C
(c) 900 – 1100° C (d) 1200 – 1300° C
(a) 600 – 800° C (b) 700 – 1000° C
(c) 900 – 1100° C (d) 1200 – 1300° C
Answer:- (d) 1200-1300° C
42. The bricks which are extensively used for basic refractories in furnaces are
(a) chrome bricks (b) sillimanite bricks
(c) magnesite bricks (d) forsterite bricks
Answer:- (c) magnesite bricks
43. Which one of the following procedure is applied to determine the soundness of bricks?
(a) Immersing the bricks underwater for 16 hrs and determining the quantity of water absorbed by the brick
(b) Immersing the brick underwater for 24 hrs and determining its expansion using Le Chatelier apparatus
(c) Taking two bricks, hitting one against the other and observing whether they break or not and the type of sound produced while hitting
(d) Scratching the brick by a fingernail and noting whether any impression is made or not
(a) Immersing the bricks underwater for 16 hrs and determining the quantity of water absorbed by the brick
(b) Immersing the brick underwater for 24 hrs and determining its expansion using Le Chatelier apparatus
(c) Taking two bricks, hitting one against the other and observing whether they break or not and the type of sound produced while hitting
(d) Scratching the brick by a fingernail and noting whether any impression is made or not
Answer:- (a) Immersing the bricks underwater for 16 hrs and determining the quantity of water absorbed by the brick
44. The number of bricks required per cubic meter of brick masonry is
(a) 400 (b) 450
(c) 500 (d) 550
(a) 400 (b) 450
(c) 500 (d) 550
Answer:- (d) 550
*Self Typed
*Source- Internet, Books, Self-Analysis