HGE Flashcards

Question 1

Q

A pressure gage at elevation 12 m at the side of the tank containing a liquid reads 100 kPa. Another gauge at elevation 7m reads 140 Kpa. Determine the following:
1. Compute the Specific Weight of the liquid
a. 5 KN/m^3
b. 6 KN/m^3
c. 7 KN/m^3
d. 8 KN/m^3
2. Compute the density of the liquid
a. 515.5 kg/m^3
b. 815.5
c. 615.5
d. 415.5
3. Compute the specific gravity of the liquid
a. 0.703
b. 0.796
c. 0.862
d.0.815

Question 2

Q

An open tank contains 5.7 m of water covered with 2.8 m of kerosene having a unit weight of 8kN/m3. If the diameter of the tank is 1m.
1. Find the pressure at the interface of the water and kerosene (kpa)
a. 22.4
b. 78.32
c. 61.51
d. 56.68
2. Find the pressure at the bottom of the tank(kPa)
a. 22.4
b. 78.32
c. 61.51
d. 56.68
3. Find the total force at the bottom of the tank
a. 22.4
b. 78.32
c. 61.51
d. 56.68

Question 3

Q

A 150 cc sample of wet soil has a mass of 250 g when 100% saturated. When oven dried, the mass is 162g. Calculate the following soil properties.
1. Moisture Content in %
a. 32.67
b. 54.32
c. 24.78
d. 67.32
2. Void Ratio
a. 0.42
b. 1.42
c. 2.42
d. 0.24
3. Specific gravity of solid soils
a. 2.61
b. 2.53
c. 2.89
d. 2.69

Question 4

Q

A dry sample of sand is placed in a container having a volume of 0.3 ft3. The dry weight of the sample is 31 lb. Water is carefully added to the container so not to disturb the condition of the sand. When the container is filled, the combined weight of soil plus water is 38.2 lbs. From this data, compute the following soil properties.
1. Void Ratio
a. 0.6252
b. 0.5343
c. 0.7868
d. 0.9282
2. Specific gravity of solid soils
a. 2.61
b. 2.53
c. 2.89
d. 2.69
3. Dry unit weight in pcf
a. 203.33
b. 103.33
c. 254.54
d. 154.54

Question 5

Q

A pressure in a given tank reads 277mm of Hg
1. Determine the equivalent height of column of water in meters.
a. 4.59
b. 1.28
c. 2.52
d. 3.77
2. Determine the equivalent height of column of kerosene having a specific gravity of 0.82.
a. 4.59
b. 1.28
c. 2.52
d. 3.77
3. Determine the equivalent height of column of nectar having a specific gravity of 2.94
a. 4.59
b. 1.28
c. 2.52
d. 3.77

Question 6

Q

The reading of an automobile fuel gage is proportional to the gage pressure found at the bottom of the tank. The tank is 32cm deep, the air had (h)deep (vented), gasoline at (d) deep, while water at the bottom is 3cm deep. Unit weight of gasoline is 6670N/m^3, and that of air is 11.8N/m^3. The unit weight of water is 9790N/m^3.

How many centimeters of air remains at the top (h deep) when the gage indicates full if the tank is 32cm deep and is contaminated with 3cm of water?
a. 1.41
b. 0.335
c. 33.5
d. 0.00156
Determine the pressure at the interface of gasoline and water when the gage indicates full (kpa)
a. 1840.42
b. 2134.4
c. 3706.61
d. 4003.24
Determine the gage reading (Pgage) when the tank is full of gasoline.
a. 1840.42
b. 2134.4
c. 3706.61
d. 4003.24

Question 7

Q

The moist unit weight and degree of saturation of a soil are given in the following table.
16.61 KN/m^3 - 50%
17.73 KN/m^3 - 75%
Determine the following properties
1. Saturated unit weight in KN/m^3
a. 16.60
b. 17.7
c. 18.8
d. 19.9
2. Specific gravity of soil
a. 2.65
b. 2.53
c. 2.89
d. 2.73
3. Void ratio
a. 0.80
b. 0.60
c. 0.72
d. 0.54

Question 8

Q

A clay soil is found to have a liquid limit of 75%, a plastic limit of 45% and a shrinkage limit of 25%. If a sample of this soil has a total volume of 30 cm at the liquid limit and a volume of 16.7 cm at the shrinkage limit, determine the following soil properties:
1. Mass of soil at the shrinkage limit
a. 35.5g
b. 26.6g
c. 47.7g
d. 51.1g
2. Shrinkage ratio
a. 1.2
b. 1.4
c. 1.6
d. 1.8
3. Specific gravity of solid soils
a. 2.61
b. 2.53
c. 2.89
d. 2.67

Question 9

Q

A hemispherical tank (4m diameter) w/ open monometer as shown deflects by 25 cm when half filled with water. Find the difference in mercury levels when the tank is full?
a. 0.103m
b. 0.203m
c. 0.303m
d. 0.403m

Question 10

Q

A square frame 3m by 3m in dimension is submerged in water vertically with its top 4m from the surface. If oil (s = 0.80) occupies the top meter. Compute the horizontal pressure(kN) acting on the frame.
a. 179.65
b. 279.65
c. 379.65
d. 476.65

Question 11

Q

The results are taken from the Sieve Analysis.
US Sieve # - % Passing
4 - 100
10 - 93.20
40 - 81
200 - 55
LL - 45
PL - 17
Find the group index according to AASHTO Specifications
a. 10
b. 12
c. 15
d. 8

Question 12

Q

Compute the height of the water for which the gate AB will start to fail if it has a length of 16 feet and 8 feet wide. The gate supports a load of 11,000lbs attached on a rope wrapped around a frictionless pulley (negligible weight) with other end of rope attached to point A of the other end of the gate. The gate is inclined at an angle of 60 degrees from the horizontal and is hinged at point B.
a. 11.71’
b. 4.51’
c. 8.61’
d. 21.41’

Question 13

Q

A vertical rectangular gate is 2m wide and 6m high is hinged at the top, has oil having a specific gravity of 0.84 standing 7m deep on one side. The liquid surface being under a vacuum pressure of 18.46kpa.
1. Compute the hydrostatic force acting on the gate in kN.
a. 174
b. 136
c. 206
d. 268
2. How far is the force acting below the hinged.
a. 1.705m
b. 2.705m
c. 3.705m
d. 4.705m
3. How much horizontal force applied at the bottom is needed to open the gate.
a. 174
b. 136
c. 206
d. 268

Question 14

Q

A loose, uncompacted sand fill 1.8m depth has a relative density of 40%. Laboratory test indicated that the minimum and maximum void ratios of the sand are 0.46 and 0.90, respectively. Specific gravity of the solids of the sand is 2.65.
1. Determine the void ratio of the sand having a relative density of 40%.
a. 0.724
b. 0.834
c. 0.644
d. 0.564
2. What is the dry unit weight of the sand in Kn/m^3.
a. 12.08
b. 13.08
c. 14.08
d. 15.08
3. If the sand is compacted to a relative density of 75%, what is the decrease in the thickness of the 1.8m fill?
a. 120mm
b. 151mm
c. 161mm
d. 170mm

Question 15

Q

From the figure shown, the gate is 1m wide and hinged at the bottom of the gate. Considering the effect of hydrostatic force and buoyancy. Assume unit weight of concrete to be 23.6KN/m^3
1. Compute the hydrostatic force acting on the gate.
a. 18.5kN
b. 14.14kN
c. 16.79kN
d. 19.62kN
2. Compute the location of the center of pressure of the gate from the hinge support.
a. 0.665m
b. 0.96m
c. 0.273m
d. 1.078m
3. Compute the minimum volume of concrete needed to keep the gate in a closed position.
a. 0.379cu.m
b. 0.296cu.m
c. 0.873cu.m
d. 1.178cu.m

Question 16

Q

There were 6 undisturbed soil samples from borings in a proposed cut area for a highways construction. The average dry unit weight achieved in the field is 16.90 kN/m^3 and the average moisture content is 9.1% A proctor compaction test produces a max. dry unit weight of 19.5 kN/m3 and an optimum moisture content of 12.8%. The estimated plan calls for a 9100 cu.m. of cut and 8800 cu. m. of fill and the DPWH requires a relative compaction of 93%.
1. Compute the required quantity of import or export soils based on the unit weight of cut.
a. 300m^3
b. 342m^3
c. 452m^3
d. 400m^3
2. Compute the required quantity of water in liters to bring the soils to the optimum moisture content
a. 602040Li
b. 502040Li
c. 302040Li
d. 402040Li

Question 17

Q

For a sandy soil, the following are given.
Max. Void Ratio = 0.70
Min. Void Ratio = 0.46
Hydraulic conductivity of sand at a relative density of 90% is 0.006cm/sec
1. Compute the void ratio at a relative density of 80%
a. 0.308
b. 0.58
c. 0.38
d. 0.508
2. Compute the void ratio at a relative density of 50%
a. 0.308
b. 0.58
c. 0.38
d. 0.508
3. Determine the hydraulic conductivity of the sand at a relative density of 50%
a. 0.00852cm/sec
b. 0.00569cm/sec
c. 0.001345cm/sec
d. 0.0006752cm/sec

Question 18

Q

A 12-m x12-m gate is installed at the end water reservoir, as shown, and is hinged at the top. The gate hinge is 6 m below the water surface. The gate is connected to a rectangular tank of water which is 12 m wide (into the paper) and filled with 6 m of weights of the tank and gate are negligible.
1. Determine the hydrostatic force acting on the gate.
a. 16952kN
b. 16852kN
c. 16752kN
d. 16652kN
2. Determine the location of the center of pressure from the hinge.
a. 3m
b. 4m
c. 7m
d. 6m
3. How long “L” would the tank have to be able to open the gate?
a. L = 18.03m
b. L = 18.53m
c. L = 18.83m
d. L = 18.33m

Question 19

Q

A cubical box, 1.6 m on each edge, has its base horizontal and is half-filled with water. The remainder of the box is filled with air under a gage pressure of 85 kPa. One of the vertical sides is hinged at the top and is free to swing inward. To what depth can the top of this box be submerged in an open body of fresh water without allowing any water to enter?
a. 4.31m
b. 5.31m
c. 6.31m
d. 7.31m

Question 20

Q

A proctor compaction test has been performed on a soil that has G = 2.70. The test results were as follows:
Mass of empty mold = 1.970kgs
Volume of mold = 0.00094m^3
1. Compute the maximum dry unit weight (kN/m^3)
a. 16.5
b. 17.3
c. 18.4
d. 15.2
2. Compute the degree of saturation at the optimum moisture content.
a. 51%
b. 61%
c. 71%
d. 81%

Question 21

Q

A group of civil engineering students visited Angat Dam during their field trip in Bulacan. One of the students, Jovanie, noticed that the concrete dam has a trapezoidal cross section and the
top of the dam where they are standing is 3m wide. Jovanie asked the guide engineer and was told that the base of the dam is 15m in length with a height of 40m. Given that sg=2.4 for concrete and the water level at the vertical face of the dam is 32m, estimate:
1. The total hydrostatic force acting on the upstream side of the dam.
A. 5023 kN C. 5650 kN
B. 2825 kN D. 8475 kN
2. The factor of safety against overturning assuming that there is no leakage under the foundation.
A. 1.56 C. 1.50
B. 1.65 D. 1.60
3. The factor of safety against sliding if the
coefficient of friction between the dam and its foundation is 0.64.
A. 0.91 C. 0.89
B. 1.25 D. 1.08

Question 22

Q

A consolidated drained triaxial shear
stress conducted on a consolidated clay has the following results:
Chamber confining pressure = 250 kPa
Deviator stress = 450 kPa
Evaluate the following:
1. The angle of friction in degrees
A. 28.94° C. 28.27°
B. 22.70° D. 27.48°
2. The shear stress at the plane of failure in kPa.
A. 198.16 kPa C. 207.57 kPa
B. 195.17 kPa D. 199.61 kPa
3. The normal stress at the plane of maximum shear in kPa.
A. 455 kPa C. 465 kPa
B. 475 kPa D. 485 kPa

Question 23

Q

For the stressed soil element shown:
Determine the following:
1. Determine the value of the deviator stress in kPa
A. 72 kPa C. 64 kPa
B. 84 kPa D. 96 kPa
2. Determine the value of maximum shear in kPa.
A. 36 kPa C. 48 kPa
B. 42 kPa D. 32 kPa
3. Determine the value of the major principal stress in kPa.
A. 101 kPa C. 97 kPa
B. 107 kPa D. 113 kPa

Question 24

Q

When the ship’s metacenter and center of gravity coincide at the same point, the vessel is said to be in.
A. equilibrium
B. stable equilibrium
C. unstable equilibrium
D. neutral equilibrium

Question 25

Q

Water contained in an open vessel moving at an acceleration of one half that of gravity. At what angle with the vertical will the water surface be?
A. 26.6° C. 23.4°
B. 63.4° D. 66.6°

Question 26

Q

The velocity head of the flow at one section of a pipeline is 5 m. Evaluate the velocity head, in meter(s), at the next section if the velocity of flow increases by one-half that of the previous section.
A. 20 C. 11.3
B. 15 D. 7.5

Question 27

Q

A turbine is rated at 450 kW when the flow of water through it is 0.609 m3/s. Assuming an efficiency of 87%, what head is acting on the turbine, in meters?
A. 75.3 C. 65.5
B. 90.8 D. 86.6

Question 28

Q

A closed cylindrical tank is 2.4 m in
diameter and 7.5 m long is completely filled with gasoline (sg=0.90). The tank, with its long axis horizontal, is pulled by a truck along a horizontal surface.
1. Determine the pressure difference between the ends (along the long axis of the tank) when the truck undergoes an acceleration of 1.5m/s2.
A. 10.1 kPa C. 9.81 kPa
B. 12.5 kPa D. 11.2 kPa
2. Determine the force on the rear wall.
A. 104.50 kN C. 92.30 kN
B. 93.70 kN D. 98.60 kN

Question 29

Q

An open cylindrical tank 2m in diameter is 6m high and filled with water to a certain depth.
1. If it is rotated at a speed of 100 rpm about the vertical axis, determine the maximum depth of water initially in the tank so that no water will be spilled out
A. 6.4 m C. 1.6 m
B. 3.2 m D. 4.8 m
2. How much water will be spilled out if it is rotated at 120 rpm and it was initially full?
A. 11.82 m3 C. 10.86 m3
B. 12.42 m3 D. 14.72 m3
3. What will be the pressure at the center bottom of the tank if the vessel is rotated at 90 rpm?
A. 7.20 kPa C. 18.32 kPa
B. 9.81 kPa D. 14.45 kPa

Question 30

Q

A 4-m diameter circular footing supports
a column load of 1800 kN. According to Boussinesq theory, the incremental stress at a point below the center of a flexible circular area due to a uniform load is given by the expression:
1. Obtain the bearing pressure exerted by the footing onto the supporting soil.
A. 124.43 kPa C. 134.22 kPa
B. 143.24 kPa D. 144.24 kPa
2. Evaluate the vertical stress at a depth of 6m below the center of the footing in kPa.
A. 14.20 C. 19.40
B. 20.94 D. 22.36
3. Obtain how deep below the footing would the pressure be reduced to 1/10 of the pressure at the base of the footing.
A. 8.52 C. 7.41
B. 6.91 D. 9.24

Question 31

Q

A woman with a glass of water having a height of 300mm is inside the elevator with a downward acceleration of 3m/s2. Determine the pressure at the bottom of the glass.
A. 2.04 kPa C. 3.84 kPa
B. 2.94 kPa D. 3.22 kPa

Question 32

Q

The column of a certain building is supported by a footing of depth 2m into a
cohesionless soil. The angle of internal friction is 20° and unit weight is 18 kN/m3. Assume FS = 2.5 and use bearing factors Nc = 17.69, Nq = 7.44, & Ny = 3.64. Using Terzaghi’s Formula for general shear failure:
1. Evaluate the ultimate bearing capacity (kPa) of a square footing 2m on a side.
A. 330.2 C. 182.1
B. 128.1 D. 320.3
2. Evaluate the ultimate bearing capacity (kPa) for a rectangular footing with a width 1.5m and length 3m.
A. 124.8 C. 142.8
B. 312.1 D. 321.1
3. Evaluate the design load (kN) for a circular footing of 1.5 m diameter.
A. 210.2 C. 297.3
B. 118.9 D. 279.3

Question 33

Q

A 12m thick layer of soft clay has an initial void ratio of 1.5. Under a compressive load applied above it, the void ratio decreased by one-third. Evaluate the reduction in the thickness of the clay layer, in meters.
A. 1.20 C. 3.60
B. 2.40 D. 4.80

Question 34

Q

An 8m thick layer of soft clay has an initial void ratio of 2.4. Under a compressive load applied above it, the void ratio decreased to one-third. Evaluate the reduction in the thickness of the clay layer, in meters.
A. 1.88 C. 2.82
B. 2.64 D. 3.76

Question 35

Q

A 1.25 cm diameter orifice, in a vertical wall of a tank under a constant head of 5.5m discharged 0.45 cubic meter in 9.5 minutes. Find the coefficient of discharge.
A. 0.65 C. 0.68
B. 0.62 D. 0.70

Question 36

Q

A sharp-edged orifice 150mm in diameter
discharges oil under head of 3.35 m. The average velocity at the vena contracta is 7.85 m. What is the head lost in m?
A. 0.2 C. 0.6
B. 0.4 D. 0.8

Question 37

Q

Given the following data for three pipes
in parallel:
Pipe 1 D1 = 450 mm L1 = 800 m
Pipe 2 D2 = 400 mm L2 = 700 m
Pipe 3 D3 = 500 mm L3 = 600 m
The total flow is 0.86 m3/s. Assuming f = 0.02 for all pipes, evaluate the following:
1. The flow in pipe 1 in m3/s
A. 0.261 C. 0.316
B. 0.428 D. 0.242
2. The flow in pipe 2 in m3/s
A. 0.361 C. 0.256
B. 0.188 D. 0.208
3. The flow in pipe 3 in m3/s.
A. 0.442 C. 0.492
B. 0.385 D. 0.392

Question 38

Q

Given the following data for the three reservoir system:
Reservoir A: Elev. = 30 m, L1 = 1220 m, D1 = 300 mm
Reservoir B: Elev. = 24 m, L2 = 900 m, D2 = 200 mm
Reservoir C: Elev. = 15 m, L3 = 1500 m, D3 = 150 mm
Assuming n = 0.011 for all pipes, determine the following:
1. The flow in line 1 in m3/s
A. 0.0319 C. 0.0434
B. 0.0598 D. 0.1595
2. The flow in line 2 in m3/s.
A. 0.0366 C. 0.0195
B. 0.0266 D. 0.0975
3. The flow in line 3 in m3/s.
A. 0.0620 C. 0.0233
B. 0.0168 D. 0.0124

Question 39

Q

A vertical tank, 6 m in diameter and 6 m
high, has an orifice at the bottom for its outlet. The diameter of the orifice is 100 mm and has a coefficient of discharge of 0.60. The tank is full of water at the start.
1. Find the time, in minutes, to drain 100 m3 of water.
A. 25.7 C. 110.6
B. 20.3 D. 39.7
2. Find the time, in minutes, to lower the water to a depth of 4 m.
A. 25.7 C. 110.6
B. 20.3 D. 39.7
3. Find the time, in minutes, to empty the tank
A. 25.7 C. 110.6
B. 20.3 D. 39.7

Question 40

Q

Water flows at a rate of 0.020 m3/s from
reservoir A to reservoir B through three concrete pipes connected in series, as shown in the figure. Neglect minor losses. Use friction factor f = 0.02 for all pipes.
From Reservoir A to B:
Pipe 1: L1 = 1000m, D1 = 160 mm
Pipe 2: L2 = 1600 m, D2 = 200 mm
Pipe 3: L3 = 850 m, D3 = 180 mm
1. Find the difference in water-surface elevations in the reservoirs.
A. 10.24 m C. 12.58 m
B. 11.36 m D. 15.72 m
2. Find the velocity of flow in the pipe 1.
A. 1.11 m/s C. 0.64 m/s
B. 0.99 m/s D. 0.79 m/s
3. Find the difference in water-surface elevations in the reservoirs if C = 120.
A. 12.28 m C. 11.48
B. 16.58 m D. 13.88

Question 41

Q

For a normally consolidated clay layer in the field, the following values are given:
Thickness = 3 m
Natural Void Ratio = 1.30
Compression index = 0.30
Average effective pressure in the layer is 125 kPa. Estimate the primary consolidation settlement of the layer caused by an increase of pressure of 55 kPa.
A. 68 mm C. 73 mm
B. 62 mm D. 74 mm

Question 42

Q

A square footing 4 m on a side and 1.2
below the ground surface has a bulk unit weight of 20 kN/m3. The cohesion of the soil is 10 kPa and the angle of internal friction is 20°. Consider the condition of general shear failure and evaluate the
contribution of the following in soil bearing capacity (kPa), using Terzaghi’s equation for square footing. Nc = 17.69, Nq = 7.44, Ny = 3.64
1. Cohesion strength.
A. 287 C. 259
B. 235 D. 230
2. Footing dimension.
A. 102 C. 116
B. 128 D. 98

Question 43

Q

A footing 2m x 3m in plan and 0.6 m thick,
is designed to support a 0.50 m square column. Due to architectural requirement, the column is so located that its external face is flush with the shorter edge of the footing. The column, however, is located
along the minor principal axis of the footing. The column load, including the weight of the column itself, is 50 kN. Assume the concrete to weigh 24 kN/m3.
1. Evaluate the total downward load acting on the supporting ground, in kN.
A. 124.5 C. 178.5
B. 156.9 D. 136.4
2. Evaluate the overturning moment on the footing,
in kN-m.
A. 62.5 C. 54.2
B. 76.5 D. 86.3
3. Evaluate the maximum pressure induced on the
supporting soil, in kPa.
A. 63.25 C. 43.57
B. 72.89 D. 54.87

Question 44

Q

A 6 m wide braced excavation shown in the figure is carried out in clay having the
following properties: c = 20 kPa, γsat = 18.5 kN/m3.The struts are spaced 5m center to center in plan.
1. Determine the strut load at A.
A. 413 kN C. 496 kN
B. 660 kN D. 557 kN
2. Determine the strut load at B.
A. 663 kN C. 742 kN
B. 546 kN D. 915 kN
3. Determine the strut load at C.
A. 413 kN C. 668 kN
B. 557 kN D. 546 kN

Question 45

Q

: A 9m cut slope has a unit weight of soil
17 kN/m3. Friction angle and cohesion along the rock surface are 20 degrees and 24 kPa respectively. The slope makes an angle of 30° from horizontal and the failure plane is at 15°
1. Determine the force tending to cause sliding in kN.
A. 356.39 C. 834.56
B. 484.11 D. 614.78
2. Determine the frictional strength along the failure plane in kN.
A. 356.39 C. 834.56
B. 484.11 D. 614.78
3. Determine the cohesive strength in kN.
A. 356.39 C. 834.56
B. 484.11 D. 614.78

Question 46

Q

A retaining wall 5.8 m high supports
soil that has the following properties:
Unit weight= 17.3 KN/m3
Angle of internal friction = 26°
Cohesion= 14.5 kPa
Determine the following:
1. Normal pressure acting at the back of the wall assuming no tensile crack occurs in the soil.
A. 4.48 kN C. 8.44 kN
B. 10.52 kN D. 15.66 kN
2. Location of tensile crack measured from the base of horizontal backfill.
A. 2.68 m C. 3.12 m
B. 3.86 m D. 2.21 m
3. Active force acting on the wall if tensile crack occurs in the soil.
A. 41.36 kN C. 72.50 kN
B. 32.79 kN D. 59.34 kN

Question 47

Q

A pile group consists of 9 piles
arranged in 3 by 3 formation. Each pile is 300 mm in diameter, 15 meters long and spaced 900 mm on centers. Assume cohesion of the soil is 75 kPa, Nc = 9, α = 0.8 and use a factor of safety FS = 3.
1. Determine the ultimate load of individual piles.
A. 896 C. 2688
B. 956 D. 2868
2. Determine the allowable load of the pile group considering individual action.
A. 2868 C. 8064
B. 8604 D. 2688
3. Determine the allowable load of the pile group considering group action.
A. 10537 C. 3512
B. 10735 D. 3215

Question 48

Q

A vertical jet of water thru a nozzle supports a load of 150 N. The velocity and diameter of the jet at the nozzle tip are 17.46 m/s and 3 cm. Find the distance of load from the nozzle tip in meters.
A. 5 C. 7
B. 6 D. 8

Question 49

Q

A trapezoidal canal has a bottom width of 4 m and side slopes of 2 horizontal to 1 vertical. When the depth of flow is 1.2 m, the flow is 30 m3/s. the roughness coefficient n = 0.015. Evaluate the slope of
the channel using Manning’s formula.
A. 0.0040 C. 0.0045
B. 0.0034 D. 0.0056

Question 50

Q

In order to provide water from a nearby spring, a triangular flume of efficient cross-section was provided on a slope of 0.21 percent. Assuming the roughness coefficient of the channel to be n = 0.018.
Obtain the depth of flow in meters of the water in the flume if it is discharging at the rate of 2 m3/s.
A. 1.18 C. 2.25
B. 1.78 D. 2.75

Question 51

Q

For the most economical trapezoidal open
channel,
A. half of the top width must be equal to one of the sloping sides
B. the hydraulic mean depth must be equal to half the depth of flow
C. the semicircle drawn with top width as
diameter must touch the three sides of the
channel
D. all of the above

Question 52

Q

Water flows through an almost level
rectangular channel 3 m wide at 12 m3/s. The depth of the channel gradually increases from 1. 0 m to 1.1 m for a length of 5 m.
1. What is the head loss in meters?
A. 0.02 C. 0.04
B. 0.06 D. 0.08
2 What is the slope of the energy gradient?
A. 0.006 C. 0.004
B. 0.008 D. 0.002
3 Obtain the value of the roughness coefficient.
A. 0.017 C. 0.037
B. 0.027 D. 0.047

Question 53

Q

A jet of water 50 mm in diameter and
having a velocity of 25.4 m/s strikes against a plate at right angles.
1 Determine the force on the plate if the plate is stationary.
A. 1720 N C. 1220 N
B. 1270 N D. 1770 N
2 Determine force on the plate if the plate is moving in the same direction as the jet at a speed of 12 m/s.
A. 445.6 C. 321.5
B. 348.4 D. 412.8
3 Determine force on the plate if the plate is moving towards the nozzle at a velocity of 12m/s.
A. 2300.9 N C. 3600.4 N
B. 3120.6 N D. 2730.2 N

Question 54

Q

A 3 m wide canal with mean velocity of flow 1 m/s is provided with a 1 m high suppressed weir at its end. How high must the canal be if no overflowing must take place? The discharge in the weir is 2m3/s.
A. 1.46 m C. 1.44 m
B. 1.64 m D. 1.66 m

Question 55

Q

A rectangular suppressed weir of length 1 m is constructed or cut at the top of a tall rectangular tank having a horizontal section 20 m x 20 m. If the initial head over the weir is 1 m, compute the time required
to discharge 72 m3 of water. Use Francis formula.
A. 39.69 s C. 33.50 s
B. 45.35 s D. 41.23 s

Question 56

Q

A suppressed weir is 3 m wide and 1 m high. Calculate the flow if its weir constant C = 0.6.
A. 5.13 m3/s C. 5.31 m3/s
B. 3.15 m3/s D. 3.51 m3/s

Question 57

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Question 58

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Question 59

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Question 60

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