MCQ
4221. The main constituent of Portland cement is-
lime
iron oxide
alumina
alkalies
4222. 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%
4223. The fuel generally used for burning limestone is
coalur
firewood
charcoal
any one of these
4224. The normal consistency of Portland cement is about-
10%
15%
20%
25%
4225. The cementing property in cement is mainly due to---
lime
silica
iron oxide
alumina
4226. 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%
4227. The commonly used lime in white washing is---
quick lime
fat lime
lean lime
hydraulic lime
4228. The percentage of the slag component of Portland-slag cement varies from-
10 to 40%
70 to 80%
40 to 70%
80 to 90%
4229. The compressive strength of perforated bricks should not be less than-
4 MN/m²
5 MN/m²
6 MN/m²
7 MN/m²
4230. The compressive strength of paving bricks should not be less than-
20 MN/m²
30 MN/m²
40 MN/m²
50 MN/m²
4231. The initial setting time of rapid hardening cement should not be less than--
30 min
4 hours
1 hour
10 hours
4232. For one cubic metre of brick masonry, the number of bricks required is-
400
450
500
550
ব্যাখ্যা: [Note: মেট্রিক ইট 500টি লাগে।
4233. Lime occurs in a free state in nature.
True
False
4234. The moisture content in timber for framework should not exceed-
5%
10%
15%
20%
4235. যদি বালুর FM ৩.০ হয় তবে উক্ত বালুকে বলা হয়-
very fine sand
fine sand
medium sand
flaky
4236. ইটের Herring-bone bond গাঁথুনি কোন কাজে ব্যবহৃত হয়?
Brick paving
Very thick wall
Partition walls
Footing foundation
4237. The compressive strength of ordinary cement is less than its tensile strength
right
wrong
4238. In brick field, pugmill is used for- [BPSC-22]
preparation of clay
drying of bricks
burning of bricks
moulding of bricks
ব্যাখ্যা: ব্যাখ্যা: A pugmill or pug mill is a machine in which clay or other materials are mixed into a plastic state. A pugmill
may be a fast continous mixer.
4239. The time required for seasoning of timber in kiln seasoning is-
2 to 5 days
5 to 10 days
10 to 20 days
20 to 40 days
4240. The final setting time of ordinary cement should not be more than-
2 hours,
4 hours
4 hours
10 hours