MCQ
26341. The main constituent of Portland cement is-
lime
iron oxide
alumina
alkalies
26342. A first class brick when immersed in cold water for 24 hours should not absorb water more than- [BPSC-22]
ব্যাখ্যা: A first class brick when immersed in cold 11 water for 24 hours, it absorb 1/5 to 1/7 (15% to 20%).
It should not absorb water more than 20%.
10%
20%
15%
25%
26343. যদি বালুর FM ৩.০ হয় তবে উক্ত বালুকে বলা হয়-
very fine sand
fine sand
medium sand
flaky
26344. The final setting time of ordinary cement should not be more than-
2 hours,
4 hours
4 hours
10 hours
26345. A good quality of stone absorbs water less than------[BPSC-22]
ব্যাখ্যা: A good building stone should be less porous. It should not absorb more than 5% of water. Any stone absorbing 10% of water should be rejected.
5%
10%
15%
20%
26346. The moisture content in timber for framework should not exceed-
5%
10%
15%
20%
26347. 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%
26348. ইটের Herring-bone bond গাঁথুনি কোন কাজে ব্যবহৃত হয়?
Brick paving
Very thick wall
Partition walls
Footing foundation
26349. The normal consistency of Portland cement is about-
10%
15%
20%
25%
26350. 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
26351. The main purpose of timber seasoning is-[BPSC-22]
ব্যাখ্যা: Seasoning of timber is the process by which moisture content in the timber is reduced to required level. By reducing moisture content, the strength, elasticity and durability properties are developed.
to make timber cocter
to made timber fire resistant
to remove moisture at uniform rate
None of the above
26352. The commonly used lime in white washing is---
quick lime
fat lime
lean lime
hydraulic lime
26353. The cementing property in cement is mainly due to---
lime
silica
iron oxide
alumina
26354. The initial setting time of rapid hardening cement should not be less than--
30 min
4 hours
1 hour
10 hours
26355. The percentage of the slag component of Portland-slag cement varies from-
10 to 40%
70 to 80%
40 to 70%
80 to 90%
26356. The compressive strength of ordinary cement is less than its tensile strength
right
wrong
26357. The fuel generally used for burning limestone is
coalur
firewood
charcoal
any one of these
26358. In brick field, pugmill is used for- [BPSC-22]
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.
preparation of clay
drying of bricks
burning of bricks
moulding of bricks
26359. Initial setting time (minimum) of ordinary port land cement is- [BPSC-22]
ব্যাখ্যা: Initial setting time (minimum) of ordinary portland cement is 30 minutes and final setting time 10 hours.
60 minutes
45 minutes
30 minutes
20 minutes
26360. The silica in Portland cement should be
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%
10 to 20%
20 to 25%
25 to 40%
40 to 60%