Looks Fam Flashcards
- Liquids:
B do not occupy definite shape.
- Specific weight of liquid:
Does not vary on any other planet
- The specific weight of water is 1000 kg/m³
D all the above.
- Specific weight of sea water is more than that of pure water because of:
all of the above
- Water belongs to:
A Newtonian fluids.
- Fluids change the volume under external pressure due to:
C compressibility.
- Molecules of fluids get attracted due to:
D adhesion.
- Falling drops of water become spheres due to:
C surface tension.
- In an open tube
free surface of mercury remains:
- If cohesion between the molecules of a fluid is more than adhesion between the fluid and glass
the free level of fluid in a dipped glass tube will be:
- A rise or fall of liquid in a glass tube of a very small diameter when dipped is:
Directly proportional to the diameter of the glass tube.
- Hydrostatic pressure on a dam depends upon its:
D both (b) and (c).
- Barometers are used to measure:
C atmospheric pressure.
- Piezometers are used to measure:
very low pressure
- Manometers are used to measure:
Pressure in water channels
- Differential manometers are used to measure:
B difference in pressure at two points.
- The pressure less than atmospheric pressure
is known:
- Atmospheric pressure varies with:
none of these
- Mercury is generally used in barometers because:
D both (a) and (b) above.
- The total pressure force on a plane area is equal to the area multiplied by the intensity of pressure at its centroid
if:
- The center of pressure of a vertical plane immersed in a liquid is at:
none of these
- On an inclined plane
center of pressure is located:
- When a body is totally or partially immersed in a fluid
it is buoyed up by a force equal to:
- A floating body attains stable equilibrium if its metacenter is:
B above the centroid.
- Center of buoyancy is:
B centroid of the fluid displaced.
- The rise of the liquid along the walls of a revolving cylinder above the initial level
is:
- When a liquid rotates at constant angular velocity about a vertical axis of a rigid body
the pressure:
- The imaginary line drawn such that the tangents at its all points indicate the direction of the velocity of the fluid particles at each point
is called:
- In fluids
steady flow occurs when:
- Uniform flow is said to occur when:
A size and shape of the crosssection in a particular length remain constant.
- If velocities of fluid particles vary from point to point in magnitude and direction
as well as from instant to instant
- A steady uniform flow is through:
D a long pipe at constant rate.
- A nonuniform steady flow is through:
A an expanding tube at constant rate.
- The continuity equation:
B relates mass rate of flow along a streamline.
- Equation of continuity of fluids is applicable only if:
D all the above.
- The flow in which each liquid particle has a definite path
and the paths of adjacent particles do not cross each other
- Total head of a liquid particle in motion is the sum of:
D potential head
- The main assumption of Bernoulli’s equation is:
D All the above.
- Reynold number is the ratio of initial force and:
D viscosity.
- The velocity of the fluid particle at the center of the pipe section
is:
- An independent mass of a fluid does not possess:
Pressure Energy
- Frictional loss of head includes the loss of energy due to:
none of these
- Energy equation is usually applicable to:
A steady flow.
- The line joining the points to which the liquid rises in vertical piezometer tubes fitted at different crosssections of a conduit
is known as:
- Hydraulic grade line:
A may be above or below the center line of conduit.
- A pitot tube is used to measure:
A velocity of flow.
- The ratio of the inertia and viscous forces acting in any flow
ignoring other forces
- The ratio of the inertia and gravitational force acting in any flow
ignoring other forces
- Mach number is the ratio of inertia force to:
Elasticity
- Weber number is the ratio of inertia force to:
C surface tension.
- A piezometer opening in pipes measures:
B static pressure.
- Manning’s formula is used for:
C head loss due to friction in open channels.
- For a long pipe
the head loss:
- Hydraulic radius is equal to:
C area divided by wetted perimeter.
- The magnitude of water hammer in a pipe depends upon:
D all the above.
- For the most economical rectangular section of a channel
the depth is kept:
- For the most economical trapezoidal section of a channel with regards to discharge
the required condition is:
- Most economical section of a triangular channel is:
right angled triangle with equal sides
- Most economical section of a circular channel for maximum discharge:
all of the above
- The most efficient channel section is:
semi-circular
- The phenomenon occurring in an open channel when a rapidly flowing stream abruptly changes to a slowly flowing stream causing a distinct rise of liquid surface is:
B hydraulic jump.
- An open container filled with water is moved vertically downward with a uniform linear acceleration. The pressure at its bottom will be:
lesser than static pressure.
- The metacentric height of a body equals the distance between:
A the metacenter and center of gravity.
- In steady flow
which one of the following changes with time:
- For a most economical rectangular channel
the width of the channel must be:
- For a most economical rectangular channel
the hydraulic mean depth is equal to:
- For a most economical trapezoidal open channel
the half of the top width must be equal to:
- For the most economical trapezoidal open channel:
D all of these.
- The best side slope for the most economical trapezoidal section is:
60°
- For critical depth of flow of water in open channels
the specific energy must be:
- Find the swell of a soil that weighs 1661 kg/m³ in its natural state and 1186 kg/m³ after excavation.
0.4
- Find the shrinkage of a soil that weighs 1661 kg/m³ in its natural state and 2077 kg/m³ after compaction.
B 20%
- A soil weighs 1163 kg/LCM
1661 kg/BCM
- A soil weighs 1163 kg/LCM
1661 kg/BCM
- Find the base width and height of a triangular spoil bank containing 76.5 BCM if the pile length is 9.14 m
the soil’s angle of repose is 37°
- Find the base diameter and height of a conical spoil pile that will contain 76.5 BCM of excavation if the soil’s angle of repose is 32° and its swell is 12%.
B D = 10.16m H = 3.17m
- Find the volume (bank measure) of excavation required for a trench 0.92 m wide
1.83 m deep
- Estimate the actual bucket load in bank cubic meters for a loader bucket whose heaped capacity is 3.82 m³. The soil’s bucket fill factor is 0.90 and its load factor is 0.80.
B 2.75 BCM
- Find the expected production in loose cubic meters (LCM) per hour of a small hydraulic excavator.
C 113 LCM/h
- Find the expected production in loose cubic meters (LCM) per hour of a 2.3m³ hydraulic shovel.
290 LCM/h
- Determine the expected dragline production in loose cubic meters (LCM) per hour based on the provided information.
A 165 LCM/h
- Estimate the production in loose cubic meters per hour for a mediumweight clamshell excavating loose earth.
A 53 LCM/h
- A wheel tractorscraper weighing 91 t is being operated on a haul road with a tire penetration of 5 cm. What is the total resistance (kg) and effective grade when ascending a slope of 5%?
A Total Resistance = 9100 kg; Effective Grade = 10%
- A wheel tractorscraper weighing 91 t is being operated on a haul road with a tire penetration of 5 cm. What is the total resistance (kg) and effective grade when descending a slope of 5%?
C Total Resistance = 0 kg; Effective Grade = 0%
- A crawler tractor weighing 36 t is towing a rubbertired scraper weighing 45.5 t up a grade of 4%. What is the total resistance (kg)?
A 5535 kg
A fourwheeldrive tractor weighs 20,000 kg and produces a maximum rimpull of 18,160 kg. Can the tractor perform under these conditions?
Because the maximum pull as limited by traction is LESS than the required. The tractor CANNOT perform in these conditions
- A powershift crawler tractor has a rated blade capacity of 7.65 LCM. Estimate the production of the dozer.
C 271 LCM/h
- Estimate the hourly production in loose volume (LCM) of a 2.68m³ wheel loader.
B 168 LCM/h
- Estimate the production of a singleengine twoaxle tractor scraper.
B 192 BCM/h
- The estimated cycle time for a wheel scraper is 6.5 min. Calculate the number of pushers required to serve a fleet of nine scrapers.
A backtrack = 3; chain = 2
- Find the expected production of the scraper fleet if only one pusher is available and the chainloading method is used.
1112 BCM/h
Given the shovel/truck operation, calculate the number of trucks required and the production of this combination.
No. of trucks required = 11; Expected production = 212 BCM/h
Given the shovel/truck operation, calculate the expected production if two trucks are removed.
186 BCM/h
- Calculate the grader hours required for reshaping and leveling the gravel road.
C 23.1 h
- Determine the rock volume produced per meter of drilling.
B 6.8 m³/m
- Find the minimum size of the 38mm screen to be used.
2.9m²
- Calculate the maximum hourly production of an asphalt plant.
B 123 ton/h
- Calculate the volume of plastic concrete produced by the mix design.
B 0.51 m³
- Determine the actual weight of each component to be added considering excessnmoisture.
A Water = 63 kg; Sand = 447 kg; Gravel = 560 kg
- Refer to the previous problem. Determine the weight of each component required to make a threebag mix.
B Cement = 127.8 kg; Sand = 370 kg; Gravel = 464k; Water= 52 kg; Mix Volume= 0.42 cu.m
- Find the required feed rate (ton/h) for each mix component to achieve this production.
C 115.6
Using the equation and the driving data below, determine the safe load capacity of a 6in.square concrete pile 60 ft long. Assume that the unit weight of the pile is 150 lb/cu ft. Pile driver energy = 14,000 ftlb Ram weight = 4000 lb Weight of driving appurtenances = 1000 lb Average penetration last six blows = 1/5 in./blow K = 0.2
59,862 lb
- Calculate the safe load capacity of a bulb pile based on the following driving data. Hammer weight = 3 tons Height of drop = 20 ft Volume in last batch driven = 5 cu ft Number of blows to drive last batch = 40 Volume of base and plug = 25 cu ft Selected K value = 25
B 164 t
Determine the design lateral force for the slab form 152 mm thick, 6.1 m wide, and 30.5 m long. The slab is to be poured in one pour. Assume concrete density is 2403 kg/m3 and that the formwork weighs 0.72 kPa.
1.46 kN/m
- Calculate the number of bricks 95 x 57 x 203 mm laid in running bond required for a double wythe wall 2.44 x 4.27 m having one opening 1.22 x 1.83 m and one opening 0.81 x 1.22 m. Mortar joints are 13 mm. Allow 3% for brick waste.
B 981
- Estimate the quantity of mortar required for the previous problem. The joint thickness between wythes is 13 mm. Assume a 25% waste factor.
C 0.53 m³
- Find the maximum safe unsupported height in feet and meters for a 20cm heavyweight concrete block wall if the maximum expected wind velocity is 80 km/h.
A 1.9m
Using the straightline method of depreciation, find the annual depreciation and book value at the end of each year for a track loader having an initial cost of $50,000, a salvage value of $5000, and an expected life of 5 years.
$9000
Estimate the hourly repair cost for the first year of operation of a crawler tractor costing $136,000 and having a 5year life. Assume average operating conditions and 2000 h of operation during the year.
$4.08
Calculate the expected hourly owning and operating cost for the second year of operation of the twinengine scraper described below. Cost delivered = $152,000 Tire cost = $12,000 Estimated life = 5 years Salvage value = $16,000 Depreciation method = sumoftheyears’ digits Investment (interest) rate = 10% Tax, insurance, and storage rate = 8% Operating conditions = average Rated power = 465 hp Fuel price = $1.30/gal Operator’s wage = $32.00/h
$97.34/h
- To compress 2.8 m³ of free air per minute from atmospheric (0.101 N/mm²) to (0.7 N/mm² indicated on the gauge (i.e. 8.01 bar absolute) requires a compressor with a theoretical power value Theoretical power = 103 × 0.101 x log P2 9e 0.101
C 9.7 kW or 13.1 hp
The density of air decreases with increasing altitude and thus for a compressor operated above sea level, k should be reduced. For example, to compress 2.8 m³ of air per minute from 0.05 N/mm² (atmospheric pressure) to 0.801 N/mm² (absolute pressure) requires a compressor with a power value
6.47kW
Calculate the pressure loss for a 200 m length of 50 mm diameter pipe, resulting from delivering 10 m³/min (free air) compressed to 7 bar, i.e. 8 bar absolute. Use f=82×10³ for steel pipes.
0.46 bars
A drill hole of diameter d (mm), with the bottom charge extending 1.3B from the base, contains explosive of unit weight P kg/m³, thus P/(10^6)(πα²)/4×1.3B=Q_b^” Q_b^”=fx0.8/wxS/B (1.4a_2 B²+1.4a_3 B³)+(a_4+b_4) B⁴ When f = 1 S / B = 1 w = 1 P = 1000 alpha 2 = 0.07 , alpha 3 = 0.4 , and terms with B⁴ are ignored. When d = 50mm then B is
1.5 m
- Wells are founded in a circular pattern around an excavation 30 m long and 25 m wide. The height of the water table above an impermeable stratum is 9 m. The depth of the excavation is 5 m and the water table lies 1 m below ground level. The coefficient of permeability of the soil k = 0.002 m/s. Determine the required number of wells.
C 15 wells
Determine the hourly production of 0.57 m³ capacity backhoe, excavating a foundation 3 m deep in common earth.
44 m³/h
- Trucks are loaded by a 1 m³ capacity tracked loader machine at the rate of 30 m³/h bulked material. The truck transports the material to a tip 3 km away. Select the size and number of trucks required.
B Three 5 m³ capacity
Trucks arrive at an excavator from distribution points on a large earthmoving project. The arrival time intervals of the trucks are observed and yield the following results. The time taken to load the trucks, which are either 6 or 12 m³ capacity, are fairly constant at 3 and 5 min, respectively, and both types are equally represented in the fleet. If the excavator loads each of the trucks immediately it arrives, in the order that it arrives, calculate the total time that the excavator and trucks will be waiting in any one period of two hours selected at random. Arrival time interval (min) Frequency (%)
Waiting time of excavator = 12 min; of trucks = 16 min
- Quarry rocks of 350 mm size are delivered to a crushing plant at a rate of 50 t/h. The sizes required are 38 mm to 19 mm and 19 mm to fines. Select appropriate crushers and screens.
A 438 mm
A large number of test results produce a standard deviation (s) of 1.5 N/mm², and average strength 10 N/mm². If 5% of results are permitted to fail, what should be the minimum design strength of the mix?
7.06
Calculate the maximum pressure produced when placing 75 mm slump concrete at a rate of 2m/h, shuttering 2.5 m high and 250 mm wide. Assume the temperature of the concrete in the formwork is initially 15°C and vibration is continuous.
55 kN/m²
- A copper wire has a nominal breaking strength of 300 MPa and a reduction of area of 77%. Calculate the true tensile strength.
C 1300 MPa
- A copper wire has a nominal breaking strength of 300 MPa and a reduction of area of 77%. Calculate the true strain ɛ_tr at the point of fracture.
B 174%
- An aluminum wire is stressed in tension. What temperature increase is required to change its length by the same amount?
A 22°C
A stainless steel plate 0.4 cm thick has a circulating hot water on one side and a rapid flow of air on the other side, so that the two metal surfaces are 90°C and 20°C, respectively. How many joules are conducted through the plate per minute?
1575
The true density of a concrete block is 2400 kg/m³ and the volume of open and closed pores are 7.9% and 5.9% respectively. What percentage of total volume of the concrete is made up of these pores?
open pores = 7.9% and closed pores = 5.9%
A concrete block has a bulk density of 2.41 and an apparent density of 2.62. Calculate the bulk density of the concrete block in kg/m³.
bulk density = 2.41 and apparent density = 2.6
- Calculate the cement required in unit mixes for building a low retaining wall 20 m long
1.2 m high
Although paving machines are capable of travelling at 20 m/min or more, the logistical problems of supplying large quantities of concrete commonly result in no more than about 1000 m of pavement being laid during a typical day of production. Thus for a 9 m wide road 200 mm deep and a 50% efficiency factor, what is the production output in m³/h?
112.5
