MCQ
26381.
The average out-turn of first class bricks in kiln burning is-
50 to 60%
60 to 70%
70 to 80%
80 to 90%
26382.
Lime occurs in a free state in nature.
True
False
26383.
For one cubic metre of brick masonry, the number of bricks required is-
400
450
500
550
ব্যাখ্যা: [Note: মেট্রিক ইট 500টি লাগে।
26384.
The compressive strength of paving bricks should not be less than-
20 MN/m²
30 MN/m²
40 MN/m²
50 MN/m²
26385.
The fuel generally used for burning limestone is
coalur
firewood
charcoal
any one of these
26386.
The average out-turn of first class bricks in clamp burning is about-
50%
60%
70%
80%
26387.
The main constituent of Portland cement is-
lime
iron oxide
alumina
alkalies
26388.
The compressive strength of ordinary cement is less than its tensile strength
right
wrong
26389.
The compressive strength of perforated bricks should not be less than-
4 MN/m²
5 MN/m²
6 MN/m²
7 MN/m²
26390.
The burning of bricks in kilns is completed within-----hours.
12
24
48
96
26391.
The frog of a brick is normally made on its-
longer face
bottom face
shorter face
top face
ব্যাখ্যা: ব্যাখ্যা: ইটের যে-কোনো একপাশে খোদাইকৃত বা কোম্পানির নাম সংবলিত অংশকে ফ্রগ বলে।
26392.
The natural drying of bricks is also called back drying.
true
false
26393.
The initial setting time of rapid hardening cement should not be less than--
30 min
4 hours
1 hour
10 hours
26394.
The commonly used lime in white washing is---
quick lime
fat lime
lean lime
hydraulic lime
26395.
The silica in Portland cement should be
10 to 20%
20 to 25%
25 to 40%
40 to 60%
ব্যাখ্যা: ব্যাখ্যা: ১। ক্যালসিয়াম অক্সাইড (CaO)..........63%
২। ম্যাগনেশিয়াম অক্সাইড (MgO)..........2%
৩। সিলিকা (SiO₂)..........22%
৪। অ্যালুমিনা (Al2O3)..........7%
৫। আয়রন অক্সাইড (Fe2O3)..........3%
৬। সালফার ট্রাই-অক্সাইড (SO3).........2%
৭। ক্ষারকীয় পদার্থ...........1%
........ মোট 100%
26396.
The final setting time of ordinary cement should not be more than-
2 hours,
4 hours
4 hours
10 hours
26397.
The percentage of the slag component of Portland-slag cement varies from-
10 to 40%
70 to 80%
40 to 70%
80 to 90%
26398.
The cementing property in cement is mainly due to---
lime
silica
iron oxide
alumina
26399.
The amount of gypsum usually added in the manufacture of cement is-
0.5 to 1%
3 to 5%
1 to 3%
0.1 to 0.5%
26400.
The normal consistency of Portland cement is about-
10%
15%
20%
25%