MCQ
741. For increasing setting time of concreate, what type of admixture is used?
রিটার্ডার: এডমিক্সার, যা কংক্রিটের সেটিং রেটকে ধীর করে দেয়, কংক্রিটের সেটিংয়ে গরম আবহাওয়ার ত্বরিত প্রভাবকে প্রতিরোধ করতে ব্যবহৃত হয়। বেশিরভাগ রিটার্ভারগুলি পানি হ্রাসকারী হিসাবেও কাজ করে।
উত্তর সহ কয়েকটি অনুরুপ গুরুত্বপূর্ণ প্রশ্ন
1. Admixtures which cause early setting and hardening of concrete are called - Accelerators
2. Pick up the incorrect statement from the following: - Admixtures accelerate hydration
3. The admixture of coarser particles like sand or silt to clay causes - Decrease in both liquid limit and plasticity index
4. The admixture of coarser particles like sand or silt to clay causes-Decrease in both liquid limit and plasticity index
accelerator
retarder
water reducing
air entraining
742. Izzard formula for the time of concentration in minutes for the plots having no channels, is (where Lo is the length of overland flow in metres and Kp rainfall intensity in cm/hour)
T= 111 b. L0 1/3/(Kp)2/3
Т= 222 bL10 1/2/(Kp)1/3
T= 333 b. LO/Kp
T= 111 b. LO 1/3/(Kp)2/5
743. Pick up the correct statement from the following:
If ground water enters the channel, the channel is known as effluent channel
If water goes out of channel to meet ground water, the channel is said to be influent stream
If the water table is at higher level than the water level in channel, ground water flows to the stream
All the above
744. Pick up the correct statement from the following:
Yield of a drainage basin is the run off at any time
Yield of a drainage basin is the run off over long periods
Yield of a drainage basin is expressed as surface run off per year
Run off is expressed as total volume per day
745. Workability of concrete is measured by (.. যারা কংক্রিটের কার্যক্ষমতা পরিমাণ করা হয়।)
Cylinder test, cube test-কংক্রিটের কম্প্রেসিভ স্ট্রেই নির্ণয়ের জন্য করা হয়। setting time test-সিমেন্টের ইনিশিয়াল ও ফাইনাল সেটিং টাইম নির্ণয়ের জন্য করা হয়। slump test-যারা কংক্রিটের ঘনত্ব এবং কার্যক্ষমতা পরিমাপ করা হয়।
উত্তর সহ কয়েকটি অনুরুপ গুরুত্বপূর্ণ প্রশ্ন
1. In slump test, each layer of concrete is compacted by a steel rod 60 cm long and of 16 mm diameter for - 25 times
2. Workability of concrete mix with low water cement ratio is determined by -Compaction factor test
3. Workability of concrete is measured by - Slump test
4. Slump test is done for – Concrete
cylinder
cube test
Slump test
setting time test
746. Precipitation caused due to striking of air masses with a topographical feature, is called
Orographic precipitation
Convective precipitation
Cyclonic precipitation
None of these
747. Pick up the correct statement from the following:
The unit hydrograph of a specified unit duration obtained from the past data can be used to obtain the hydrograph of future storms of like duration
To obtain the ordinates of storm hydrograph, the ordinates of unit hydrograph are multiplied by the multiplying factor
The multiplying factor for storm hydrograph may be obtained by dividing the run off in mm by 25 mm
All the above
748. For efficient working of a control meter, its throat length is approximately kept
Equal to the critical depth
Twice the critical depth
Three times the critical depth
Four times the critical depth
749. The net head under which the turbine reaches its peak efficiency at synchronous speed is called
Design head
Rated head
Gross head
Operating head
750. For the upstream face of an earthen dam, the most adverse condition for stability of slope is
Sudden drawdown
Steady seepage
During construction
Sloughing of slope
751. Vertical drop fall is satisfactory for a height upto
0.5 m
1.5 m
3.5 m
5.0 m
752. When the reservoir is full, the maximum compressive force in a gravity dam is produced
At the toe
At the heel
Within the middle third of base
At centre of base
753. Lining of irrigation channels
Increases the water-logging area
Decreases the water-logging area
Does not change the water logging ares
None of the above
754. Efflorescence in cement plaster is due to excess of. (কিসের আধিক্যের কারণে সিমেন্ট প্লাস্টারে Efflorescence হয়?)
সিমেন্টের গ্রহনযোগ্য ক্ষায়কীয় পদার্থ (Alkalies) ১% এর বেশি নয়। ক্ষায়কীয় পদার্থ ১% এর বেশি হলে সিমেন্ট পুষ্পায়ন দেখা দেয়।
উত্তর সহ কয়েকটি অনুরুপ শুরুত্বপূর্ণ প্রশ্ন
1. Efflorescence in cement is caused due to an excess of- Alkalis
2. For 12 mm thick cement plastering 1: 6 on 100 sq.m new brick work, the quantity of cement required, is - 0.274 m3
Alumine
Silica
Lime
Alkali
755. In the estimate of design flood, Dickens assumes that high flood in cumecs, is proportional to catchment area raised to the power
1/4
1/2
3/4
2/3
756. If ID is the depth of scour below original bed, then the width of launching apron is generally taken as
1.2 D
1.5 D
2.0 D
2.5 D
757. The equation V (1000 ID10/60)×(1.8T+42) which is used for determining the velocity of ground water flow in metres per day is known as
Meinzer's formula
Slichter's formula
Darcy's formala
Hazen formula
758. The stage of river carrying a discharge of Q m/sec at a point is 10 m and slope of water surface is (1/4000). The discharge of a flood same point and same stage of 10 m with a water surface slope of (1/1000) will be
3/sec
0.5 Q m3/sec
2 Q m3/sec
4 Q m3 sec
759. A unit hydro graph has one unit of
Rainfall duration
Rainfall excess
Time base of direct runoff
Discharge
760. When a constant discharge 2.91 litres/sec. was obtained in a pumping test, the draw downs in the test wells at 3 m and 6.184 m were 2.6 m and 0.3 m respectively. If over-all depth of the pumping well was 16 m, the permeability of the soil, is
0.0005 cm/sec
0.001 cm/sec
0.002 cm/sec
0.01 cm/sec