.png)
41. A first class brick when immersed in cold water for 24 hours should not absorb water more than
a) 15%
b) 20%
c) 22%
d) 25%
Ans: b
42. Crushing strength of a first class brick should not be less than
a) 3.5 N/mm2
b) 7.0 N/mm2
c) 10.5 N/mm2
d) 14.0 N/mm2
Ans: c
43. The main function of alumina in brick earth is
a) to impart plasticity
b) to make the brick durable
c) to prevent shrinkage
d) to make the brick impermeable
Ans: a
44. The percentage of alumina in a good brick earth lies between
a) 5 to 10%
b) 20 to 30%
c) 50 to 60%
d) 70 to 80%
Ans: b
45. Excess of alumina in brick earth makes the brick
a) impermeable
b) brittle and weak
c) to lose cohesion
d) to crack and warp on drying
Ans: d
46. The nominal size of the modular brick is
a) 190 mm x 90mmx 80 mm
b) 190 mm x 190 mm x 90 mm
c) 200 mm x 100 mm x 100 mm
d) 200 mm x 200 mm x 100 mm
Ans: c
47. Percentage of silica in a good brick earth lies between
a) 5 to 10%
b) 20 to 30%
c) 50 to 60%
d) 70 to 80%
Ans: c
48. Excess of silica in brick earth results in
a) cracking and warping of bricks
b) loss of cohesion
c) enhancing the impermeability of bricks
d) none of the above
Ans: b
49. Which of the following ingredients of the brick earth enables the brick to retain its shape ?
a) alumina
b) silica
c) iron
d) magnesia
Ans: b
50. Which of the following pairs gives a correct combination of the useful and harmful constituents respectively of a
good brick earth ?
a) lime stone and alumina
b) silica and alkalies
c) alumina and iron
d) alkalies and magnesium
Ans: b
51. The process of mixing clay, water and other ingredients to make brick is known as
a) kneading
b) moulding
c) pugging
d) drying
Ans: a
52. Advantage of a clamp compared to a kiln for burning bricks is that
a) it takes less time for burning
b) it gives more output of first class bricks
c) it has less initial cost
d) it is suitable when bricks are required in large numbers
Ans: c
53. The internal size of mould used in brick preparation is
a) equal to the size of a fully burnt brick
b) smaller than the size of a fully burnt brick
c) greater than the size of a fully burnt brick
d) none of the above
Ans: c
54. Pug mill is used for
a) preparation of clay
b) moulding of clay
c) drying of bricks
d) burning of bricks
Ans: a
55. Which of the following bricks are used for lining of furnaces ?
a) overburnt bricks
b) underburnt bricks
c) refractory bricks
d) first class bricks
Ans: c
56. The frog of the brick in a brick masonry is generally kept on
a) bottom face
b) top face
c) shorter side
d) longer side
Ans: b
57. Number of bricks required for one cubic metre of brick masonry is
a) 400
b) 450
c) 500
d) 550
Ans: c
58. Glazing is used to make earthenware
a) hard
b) soft
c) porous
d) impervious
Ans: d
59. Quick lime is
a) calcium carbonate
b) calcium oxide
c) calcium hydroxide
d) none of the above
Ans: b
60. Quick lime is
i) slow in setting
ii) rapid in slacking
iii) good in strength The correct answer is
a) only (i)
b) only (ii)
c) both (i) and (ii)
d) both (ii) and (iii)
Ans: c
