Irrigation Engineering MCQs Practice Set

1.The irrigation engineering may be defined as

• The process of artificially supplying water to soil for raising crops
• A science of planning and designing an efficient and economic irrigation system
• The engineering of controlling and harnessing the various natural sources of water, by the construction of dams, canals and finally distributing the water to the agricultural fields
• All of the above (Ans)

2.The irrigation is necessary in an area

• Where there is a scanty rainfall
• Where the rainfall is non-uniform
• Where commercial crops require more water
• All of the above (Ans)

3.The irrigation water is said to be unsatisfactory, if it contains

• Chemicals toxic to plants or to persons using plants as food
• Chemicals which react with the soil to produce unsatisfactory moisture characteristics
• Bacteria injurious to persons or animals eating plants irrigated with water
• All of the above (Ans)

4.Sandy soils with good drainage become impermeable after prolonged use, if it is irrigated with a water containing ………………….. sodium.

• 25%
• 50%
• 75%
• 85% (Ans)

5.For irrigation purposes, the p-H value of water should be

• Between 3 and 6
• Between 6 and 8.5 (Ans)
• Between 8.5 and 11
• More than 11

6.Which of the salt present in water is harmful for cultivation purposes?

• Sodium carbonate
• Potassium sulphate
• Calcium sulphate
• None of these (Ans)

7.When an oven-dried sample of soil is kept open in the atmosphere, it absorbs some amount of water. This water is known as

• Capillary water
• Gravitational water
• Hygroscopic water (Ans)
• All of these

8.A part of water which exists in the porous space of the soil by molecular attraction, is known as

• Capillary water (Ans)
• Gravitational water
• Hygroscopic water
• All of these

9.Super-fluous water is also called

• Capillary water
• Gravitational water (Ans)
• Hygroscopic water
• All of these

10.A useful soil moisture for plant growth is

• Capillary water (Ans)
• Gravitational water
• Hygroscopic water
• All of these

11.The amount of water required to fill up the pore spaces in soil particles by replacing all air held in pore spaces, is known as

• Field capacity
• Saturation capacity (Ans)
• Available moisture
• All of these

12.The moisture content of the soil, after free drainage has removed most of the gravity water, is known as

• Field capacity (Ans)
• Saturation capacity
• Wilting co-efficient
• Available moisture

13.The water content at which plants can no-longer extract sufficient water from the soil for its growth, is called

• Field capacity
• Saturation capacity
• Permanent wilting point (Ans)
• Available moisture

14.Available moisture may be defined as the

• Moisture content at permanent wilting point
• Difference in water content of the soil between field capacity and permanent wilting (Ans)
• Maximum moisture holding capacity
• All of these

15.The field capacity of a soil depends upon

• Capillary tension in soil
• Porosity of soil
• Either (a) or (b)
• Both (a) and (b) (Ans)

16.Consumptive use of water by a crop is equal to

• The depth of water consumed by evaporation
• The depth of water consumed by transpiration
• The depth of water consumed by evaporation and transpiration during crop growth, including water consumed by accompanying weed growth (Ans)
• None of the above

17.The consumptive use of water of a crop

• Is measured as the volume of water per unit area
• Is measured as depth of water on irrigated area
• May be supplied partly by precipitation and partly by irrigation
• All of the above (Ans)

18.The ratio between the area of a crop irrigated and the quantity of water required during its entire period of the growth, is known as

• Delta
• Duty (Ans)
• Base period
• Crop period

19.The total depth of water required by a crop during the entire period the crop is in the field, is known as

• Delta (Ans)
• Duty (Ans)
• Base period
• Crop period

20.The duty is largest

• At the head of the main canal
• At the head of the water course
• On the field (Ans)
• At all place

21.The time (in days) that crops takes from the instant of its sowing to that of its harvest,is known as ……………… period.

• Base
• Crop (Ans)
• Kor

22.The whole period of cultivation from the time when irrigation water is first supplied for preparation of the ground to its last watering before harvesting, is called

• Base period (Ans)
• Crop period
• Kor period
• None of these

23.The duty of irrigation water goes on …………….. as the water flows.

• Increasing (Ans)
• Decreasing

24.Crop ratio is the ratio of area irrigated

• In Rabi season to Kharif season
• In Kharif season to Rabi season (Ans)
• Under perennial crop to total crop
• Under perennial crop to non- perennial crop

25.The duty of irrigation water will be less if

• Area irrigated is more
• Water supply required is less
• Water supply required is more (Ans)
• None of these

26.The relation between duty (D) in hectares/cumec, delta ( ) in metres and base period (B) in days is

• Delta =8.64B/D (Ans)
• Delta =86.4B/D
• Delta =864B/D
• Delta =8640B/D

27.The area in which crop is grown at a particular time or crop season, is called

• Gross commanded area
• Culturable commanded area (Ans)
• Culturable uncultivated area
• None of these

28.The first watering before sowing the crop, is known as

• Kor watering
• Paleo (Ans)
• Delta
• None of these

29.The crops require maximum water during

• First watering before sowing the crops
• Last watering before harvesting
• First watering when the crop has grown a few centimetres (Ans)
• All of the above

30.The maximum depth in soil strata, in which the crop spreads its root system, and derives water from the soil, is called

• Kor depth
• Root zone depth (Ans)
• Delta
• Overlap allowance

31.The depth of root zone is 90 cm for

• Wheat
• Sugar cane
• Rice (Ans)
• Cotton

32.The duty of a crop is 432 hectares per cumec when the base period of the crop is 100 days .The dalta for the crop will be

• 100
• 200 (Ans)
• 432
• 864

33.The average delta of rice crop is nearly

• 30 cm
• 60 cm
• 120 cm (Ans)
• 150 cm

34.The average  duty for sugar-cane in hetares/cumec is

• 200
• 400
• 600
• 800 (Ans)

35.The optimum depth of kor watering is 19 cm for

• Wheat
• Sugar-cane
• Rice (Ans)
• Cotton

36.Outlet discharge for a particular crop is given by

• Area/outlet factor (Ans)
• Outlet factor/area
• Area*outlet factor
• None of these

37.The optimum depth of kor watering for wheat in the plains of north India is

• 5 cm (Ans)
• 5 cm
• 19 cm
• 21 cm

38.The kor depth for rice is 19 cm and kor period is 14 days. The outlet factor for the crop in hectares per cumec will be

• 437
• 637 (Ans)
• 837
• 1037

39.Where steep land is available, the method of irrigation adopted is

• Free flooding (Ans)
• Border flooding
• Check flooding
• Basin flooding

40.For closed growing crops (such as wheat), the method of irrigation used is

• Free flooding
• Border flooding (Ans)
• Check flooding
• Basin flooding

41.Check flooding method of irrigation is used for

• Closed growing crops
• Crops which can stand inundation of water for sometime (Ans)
• Tracts with flat gradients
• Crops such as sugarcane, potatoes etc.

42.Sprinklar irrigation is adopted for ……………….. areas.

• Level
• Uneven (Ans)
• Hilly

43.The method of irrigation used for orchards is

• Free flooding
• Border flooding
• Check flooding
• Basin flooding (Ans)

44.The hydrology is a science which deals with the

• Occurrence of water on the earth
• Distribution of water on the earth
• Movement of water on the earth
• All of these (Ans)

45.The knowledge of hydrology is necessary in civil engineering for

• Designing and construction of irrigation structures
• Designing and construction of bridges and culverts
• Flood control works
• All of these (Ans)

46.The hydrology helps in

• Predicting maximum discharge
• Deciding capacity of reservoir
• Fore casting flood
• All of these (Ans)

47.The science which deals with the physical features and conditions of water on the earth surface is called

• Hydrometry
• Hydrography (Ans)
• Hydrosphere
• Hydraulics

48.The earth’s water circulatory system, is known as

• Water cycle
• Hydrologic cycle (Ans)
• Precipitation cycle
• All of these

49.The fall of moisture from the atmosphere to the earth surface in any form, is called

• Evaporation
• Transpiration
• Precipitation (Ans)
• None of these

50.Liquid Precipitation consists of

• Snow
• Hail
• Sleet
• Rainfall (Ans)
• 51.The hydrology cycle is expressed by the equation
  • P = E-R
  • P = E+R (Ans)
  • P = E*R
  • P = E/R
  Where            P = Precipitation, E = Evaporation, and R = Run-off.52.Cyclonic Precipitation results from
  • Lifting of air masses converging into low pressure area (Ans)
  • Natural rising of warmer, lighter air in colder and denser surroundings
  • Lifting of warm moisture-laden air masses due to topographic barriers
  • All of the above
  53.The Precipitation caused by natural rising of warmer lighter air in colder and denser surroundings, is called
  • Convective Precipitation (Ans)
  • Orographic Precipitation
  • Cyclonic Precipitation
  • None of these
  54. The Precipitation caused by lifting of warm moisture laden air masses due to topographic barriers, is called
  • Convective Precipitation (Ans)
  • Orographic Precipitation (Ans)
  • Cyclonic Precipitation
  • None of these
  55.The process of loosing water from the leaves of plants, is termed as
  • Surface evaporation
  • Water Surface evaporation
  • Transpiration (Ans)
  • Precipitation
  56.The amount of Precipitation is measured by
  • Rain gauge (Ans)
  • Osmoscope
  • Turbidimeter
  • All of these
  57.The commonly used Rain gauge is
  • Weighing bucket type
  • Tipping bucket type
  • Float type (Ans)
  • None of these
  58.The standard height of a standard Rain gauge is
  • 10 cm
  • 20 cm
  • 30 cm (Ans)
  • 40 cm
  59.According to Dicken’s formula, the flood discharge (Q) in cumecs is given by
  • Q = CA^2/3
  • Q = CA^3/4 (Ans)
  • Q = CA^5/6
  • Q = CA^7/8
  Where                 C = Flood coefficient, and A = Area of basin in sq km.60.For Madras catchments, the flood discharge is estimated from Q = CA^2/3 . This formula is known as
  • Dicken’s formula
  • Ryve’s formula (Ans)
  • Nawab jang Bahadur formula
  • Inglis formula
  61.According to Fanning’s formula, the flood discharge (Q) in cumecs is given by
  • Q = CA^2/3
  • Q = CA^3/4
  • Q = CA^5/6 (Ans)
  • Q = CA^7/8
  62. Dicken’s formula for high flood discharge is useful for catchments in
  • Southern India
  • Northern India (Ans)
  • Eastern India
  • Western India
  63.In order to estimate the high flood discharge in fan-shaped catchment, the formula used is
  • Dicken’s formula
  • Ryve’s formula
  • Inglis formula (Ans)
  • Fanning’s formula
  64.The estimate of flood can be made
  • By physical indication of past floods
  • By flood discharge formulae
  • By unit hydrograph
  • All of these (Ans)
  65.Which of the following method is useful for obtaining values of flood discharges for a high recurrence interval?
  • California method
  • Hazen’s method
  • Gumbel’s method (Ans)
  • All of these
  66.A graph showing variations of discharge with time, at a particular point of a stream is known as
  • Mass inflow curve
  • Logistic curve
  • Hydrograph (Ans)
  • None of these
  67.The graphical representation of average rainfall and rainfall excess (i.e. rainfall minus infiltration) rates over specified areas diring successive unit time intervals during a storm is known as
  • Hydrograph
  • Flood hydrograph
  • Unit hydrograph (Ans)
  • S- hydrograph
  68.A hydrograph representing one cm of run off from a rainfall of some unit duration and specific area distribution is known as
  • Hyetograph
  • Flood hydrograph
  • Unit hydrograph (Ans)
  • S- hydrograph
  69.Run-off is measured in
  • M³/s (Ans)
  • M³/min
  • M³/h
  • None of these
  70.A canal aligned nearly parallel to the contours of a country, is known as
  • Side slope canal
  • Contour canal (Ans)
  • Water shed canal
  • Ridge canal
  71.A canal aligned approximately parallel to the natural drainage of a country is called
  • Side slope canal (Ans)
  • Contour canal
  • Water shed canal
  • Ridge canal
  72.The water shed canal is also called
  • Side slope canal
  • Contour canal
  • Ridge canal (Ans)
  • All of these
  73.Irrigation canals are generally aligned along
  • Contour line
  • Water shed (Ans)
  • Straight line
  • Valley line
  74.A canal aligned at right angles to the contour of a country, is known as
  • Side slope canal (Ans)
  • Contour canal
  • Water shed canal
  • Branch canal
  75.The alignment of a canal
  • Should be such, so as to ensure minimum number of cross drainage works
  • On a water shed is the most economical
  • Should avoid valuable properties
  • All of the above (Ans)
  76.Inundation canals draw their supplies from rivers whenever there is a ………………… stage in the river.
  • Low
  • High (Ans)
  • Medium
  77.A contour canal
  • Is most suitable in hilly areas
  • Irrigates only on one side
  • Is aligned parallel to the contour of the country
  • All of the above (Ans)
  78.The narrow strip of land left at the ground level between the inner toe of the bank and top edge of the cutting, is known as
  • Free board
  • Dowel
  • Inspection roadway
  • Berm (Ans)
  79.The gap or margin of height, between full supply level (F.S.L) and top of the bank is called
  • Free board (Ans)
  • Dowel
  • Inspection roadway
  • Berm
  80.The free board in a channel is governed by the
  • Size of the canal
  • Location of the canal
  • Water surface fluctuations
  • All of these (Ans)
  81.The saturation gradient in an ordinary loam soil is
  • 1:1
  • 2:1
  • 3:1
  • 4:1 (Ans)
  82.The height of dowel above the road level should not be more than
  • 10 cm
  • 20 cm
  • 30 cm (Ans)
  • 40 cm
  83.The width of dowel is, usually, kept from
  • 1 m to 0.3 m
  • 3 m to 0.6 m (Ans)
  • 6 m to 0.9 m
  • 9 m to 1.2 m
  84.A spoil bank is formed when the
  • Canal has steep bed slope
  • Canal section is too large
  • Volume of excavation is in excess of the embankment filling (Ans)
  • Canal alignment is meandrous
  85.The borrow pits should, preferably, be taken from
  • The field on the right side of canal
  • The field on the left side of the canal
  • The central half width of the section of the canal (Ans)
  • Any one of the above
  86.In case of small channels, the borrow pits should start from a distance not less than ……………. From the toe of the embankment.
  • 2 m
  • 3 m
  • 4 m
  • 5 m (Ans)
  87.When the quantity of the earth is much in excess of the quantity required for filling, it has to be deposited in the from of spoil banks. The spoil banks are made on
  • The right side
  • The left side
  • Both the sides
  • All of these (Ans)
  88.A land is said to be water-logged when
  • The air circulation is stopped in the root zone due to the rise in water table (Ans)
  • It is submerged in flood
  • The soil pores within a depth of 40 cm are saturated
  • All of the above
  89.The infertility of the soil in water-logged areas is due to
  • Inhibiting activity of the soil bacteria
  • Growth od weeds
  • Increasing of harmful salts
  • All of these (Ans)
  90.Water logging is caused due to
  • Inadequate drainage facilities
  • Over irrigation
  • Presence of impermeable strata
  • All of these (Ans)
  91.The soil becomes, practically, infertile if its _p-H value is
  • 0
  • 7
  • 11 (Ans)
  • 14
  92.Intensity of irrigation should be increased in order to prevent the area from water logging.
  • Yes
  • No (Ans)
  93.The measure adopted to reclaim the water-logged area is
  • Installation of lift irrigation schemes (Ans)
  • Lining of canals
  • Lowering the full supply level
  • All of these
  94.The most economical section of a lined canal is
  • Rectangular section with circular bottom for small discharges
  • Triangular section with circular bottom for small discharges (Ans)
  • Trapezoidal section with rounded corners for higher discharges (Ans)
  • None of the above
  95.Lining of a canal is necessary
  • To minimise the seepage losses in canal
  • To prevent erosion of bed and sides due to high velocities
  • To increase the discharge in canal section by increasing the velocity
  • All of the above (Ans)
  96. Lining of a canal ……………. The maintenance of the canal
  • Increases
  • Decreases (Ans)
  • Does not effect
  97. Lining of a canal
  • Assures economical water distribution
  • Reduces possibility of breaching
  • Increases available head for power generation
  • All of the above (Ans)
  98.The sodium carbonate lining consists of at least
  • 6% sodium carbonate and 10% clay (Ans)
  • 10% sodium carbonate and 6% clay
  • 1% sodium carbonate and 6% clay
  • 1% clay and 6% sodium carbonate
  99.For the repairing of an old but sound concrete lining, the lining preferred is
  • Shotcrete lining (Ans)
  • Precast concrete lining
  • Soil cement lining
  • Sodium carbonate lining
  100.The weed growth in a canal leads to
  • Decrease in silting
  • Decrease in discharge (Ans)
  • Increase in discharge
  • Increase in velocity of flow
  101.Garret’s diagram gives the graphical method of designing a channel based on
  • Lacey’s theory
  • Gibb’s theory
  • Kennedy’s theory (Ans)
  • Khosla’s theory
  102.Kennedy, in his silt theory, assumed that the silt is kept in suspension because of eddies generated from the
  • Bed only (Ans)
  • Sides only
  • Whole perimeter
  • Any one of these
  103.According to Kennedy, the silt supporting power is ……………….. to the bed width of the stream.
  • Directly proportional to (Ans)
  • Inversely proportional to
  104.Non-silting, non-scouring velocity is called ……………….. velocity of flow.
  • Mean
  • Critical (Ans)
  105.Kennedy gave a relation between
  • Velocity and hydraulic mean depth
  • Area and velocity
  • Critical velocity and the depth of flowing water (Ans)
  • All of the above
  106.The relation given by Kennedy for critical velocity in m/s is
  • V_O = 0.55 m D⁶⁴ (Ans)
  • V_O = 0.64 m D⁵⁵
  • V_O = 0.74 m D⁸⁴
  • V_O = 0.84 m D⁷⁴
  Where              m = Critical velocity ratio, andD = Depth of water over the bed portion of a channel in metres.107.A channel is said to be in scouring when the critical velocity ratio is …………………….. one.
  • Equal to
  • Less than
  • Greater than (Ans)
  108.Kennedy gave his own formula for the determination of mean velocity
  • Correct
  • Incorrect (Ans)
  109. According to Kennedy, the silt transporting power of a channel is proportional to
  • V_O^1/2
  • V_O^3/2
  • V_O^5/2 (Ans)
  • V_O^7/2
  Where V_O = Critical velocity in a channel110.According to Lacey, a channel is said to be in regime, if
  • It flows in incoherent unlimited alluvium of the same character as that transported material
  • Its discharge is constant
  • The silt grade and the silt charge are constant
  • All of the above (Ans)
  111.The main cause of silting in channel is
  • Non-regime section
  • Inadequate slope
  • Defective head regulator
  • All of these (Ans)
  112.Lacey assumed that silt is kept in suspension because of the normal components of eddies generated from the
  • Bed only
  • Side only
  • Whole perimeter (Ans)
  • None of these
  113.Lacey gave a relation between
  • Velocity and hydraulic mean depth
  • Rea and velocity
  • Both (a) and (b) (Ans)
  • None of these
  114.The Lacey’s silt factor(f) is equal to
  • 3V²/2R
  • 5V²/2R (Ans)
  • 7V²/2R
  • 9V²/2R
  • Where V = Mean regime velocity, and
  R = Hydraulic mean depth115.The channel after attaining its section and longitudinal slope, will be said to be in …………………… regime.
  • Initial
  • Final (Ans)
  • Permanent
  116.The general regime flow equation is
  • V = 10.8 R^2/3 S^1/3 (Ans)
  • V = 10.8 R^1/3 S^2/3
  • V = 10.8 R^3/2 S^1/3
  • V = 10.8 R^3/2 S^1/2
  Where                    V = Mean regime velocity, R = Hydraulic mean depth, and              S = slope of water surface.117.If m is the mean particle diameter of the silt in mm, the Lacey’s silt factor(f) is given by
  • F = 1.76 m^1/2 (Ans)
  • F = 1.76 m^3/2
  • F = 1.76 m²
  • F = 1.76 m^5/2
  118.The perimeter discharge (P-Q) relation is given by the equation
  • P = 2.25 Q^1/2
  • P = 2.25 Q^3/2
  • P = 4.75 Q^1/2 (Ans)
  • P = 4.75 Q^3/2
  119.According to Lacey’s equation, the scour depth is equal to
  • 47(Q/f)^1/2
  • 47(Q/f)^1/3 (Ans)
  • 47(Q/f)^1/4
  • 47(Q/f)^1/5
  120.A structure constructed in an irrigation canal for the purpose of wasting some of its water, is known as a
  • Fall
  • Escape (Ans)
  • Regulator
  • None of these
  121.Escapes are also known as …….. for the canals
  • Outlet
  • Safety valves (Ans)
  • Regulators
  122.The capacity of escape channel should not be less than ……………. Of the capacity of the parent channel at that point.
  • 20%
  • 30%
  • 40%
  • 50% (Ans)
  123.A fall, which maintains the depth is a
  • Trapezoidal notch fall
  • Rectangular notch fall
  • Low weir fall
  • All of these (Ans)
  124.The Sarda canal has a
  • Glacis type fall
  • Vertical drop fall (Ans)
  • Ogee fall
  • Rapid fall
  125.In Sarda type fall, the length of the crest id kept ………….. the bed width of the canal
  • More than
  • Equal to (Ans)
  • Less than
  126. In Sarda type fall, the width of the trapezoidal crest(B) is given by
  • B=0.44
  • B=0.55
  • B=0.44 (Ans)
  • B=0.55
  127.For a discharge of 4 m³/s in Sarda type fall, ……………….. crest is used.
  • Rectangular (Ans)
  • Trapezoidal
  128.A parabolic  glacis type fall is commonly known as
  • Montague fall (Ans)
  • Inglis fall
  • Sarda fall
  • Vertical type fall
  129.When the water is thrown into a well over a crest from where it escapes near its bottom, the type of fall is called
  • Rapid fall
  • Cylinder fall (Ans)
  • Pipe fall
  • Glacis fall
  130.A sudden fall of level of ground along the alignment of a canal joined by an inclined bed is called a
  • Rapid fall (Ans)
  • Cylinder fall
  • Sudden fall
  • Hydraulic jump

131.The relation for discharge (Q) over a rectangular crest of a Sarda fall is

• Q = 1.835 LH^3/2 (H/B)^1/6 (Ans)
• Q = 1.835 LH^3/2 (H/B)^1/3
• Q = 1.99 LH^3/2 (H/B)^1/6
• Q = 1.99 LH^3/2 (H/B)^1/3

Where                L = Length of crest in metres

B = Top width of the crest in metres and

H = Depth of water in metres

132.The cylinder or well fall is quite suitable and economical for

• Low discharges and low drops
• Low discharges and high drops (Ans)
• High discharges and low drops
• High discharges and high drops

133.According to Blench formula, the depth of cistern below the down stream bed (x) in metres is given by

• X = D_c + ¼ (H_L – 3/8 D_c) – D
• X =2D_c + ¼ (H_L – 3/8 D_c) – D
• X =2D_c + ¼ (H_L – 1/3 D_c) – D
• X =2D_c + ¼ (H_L – 1/3 D_c) – 2D

134.The discharge (Q) over trapezoidal crest of Sarda fall is …………. As compared to rectangular crest of identical parameters.

• Same
• Less
• More (Ans)

135.The Inglis type fall makes use of …………………….. impact for energy dissipation.

• Straight
• Horizontal (Ans)
• Vertical

136.The fall which can be used as a meter fall, is

• Vertical drop fall (Ans)
• Flumed glacis fall
• Unflumed glacis fall
• None of these

137.A canal outlet should

• Be so designed that the farmer cannot temper with its functioning.
• Be simple so that it can be constructed or fabricated by local masons
• Draw its fare share to silt carried by the distributing channel
• All of the above (Ans)

138.A device which ensures a constant discharge of water passing from one channel to another irrespective of water level in each within certain specified limits, is called

• Flume
• Module (Ans)
• Meter
• None of these

139.An outlet in which the discharge depends upon the difference in level between the water levels in distributing channel and the water course, is known as

• Non-modular outlet (Ans)
• Semi-module outlet
• Modular outlet
• Rigid module

140.In a flexible outlet, the discharge depends upon the

• Water level in distributary (Ans)
• Water level in water course
• Difference of water levels between distributary and water course
• None of the above

141.When discharge of an outlet is independent of the water levels in the water course and the distributary, the outlet is termed as a

• Flexible outlet
• Non-modular outlet
• Semi-module outlet
• Rigid module (Ans)

142.Gibb’s module is a type of

• Non-modular outlet
• Semi-modular outlet
• Rigid modular outlet (Ans)
• Open flume outlet

143.The ratio of the rate of change of discharge of an outlet to the rate of change of the discharge of the distributing channel, is termed as

• Proportionality
• Flexibility (Ans)
• Sensitivity
• Efficiency

144.In a proportional outlet, the rate of change of its discharge is ………………… the rate of change of the discharge of the distributing channel

• Equal to (Ans)
• More than
• Less than

145.The ratio of the head recovered to the head put in an outlet, is called

• Proportionality
• Flexibility
• Sensitivity
• Efficiency (Ans)

146.An outlet is said to be proportional, if its flexibility is

• Equal to zero
• Less than unity
• Equal to unity (Ans)
• More than unity

147.The sensitivity of a rigid module is

• Equal to zero (Ans)
• Less than unity
• Equal to unity
• More than unity

148.The flexibility of a hyper-proportional outlet is …………… one.

• Greater than (Ans)
• Equal to
• Less than

149.The setting of an outlet is defined as the ratio of the

• Rate of change of discharge of an outlet to the rate of change of discharge of the distributing channel
• Rate of change of discharge of an outlet to the rate of change in level of the distributing surface, referred to the normal depth of the channel
• Depth of the sill or the crest level of the module below the full supply of the distributing channel to the full supply depth of the distributing channel (Ans)
• Head recovered to the head put in an outlet

150.For the pipe outlet to be proportional, the outlet is set at ……………. The depth below the water surface.

• 3 times (Ans)
• 5 times
• 8 times

151.The setting for a hyper-proportional outlet is ……………. as compared to a proportional outlet.

• More (Ans)
• Less
• Same

152. The setting for a sub-proportional outlet is ……………. as compared to a proportional outlet.

• More
• Less (Ans)
• Same

153.The ratio between the depths of water levels over crest on the downstream and upstream of the module, is known as

• Flexibility
• Sensitivity
• Drowning ratio (Ans)
• Module ratio

154.Which of the following is a type of non-modular outlet?

• Submerged pipe outlet (Ans)
• Open-flume outlet
• Kennedy’s gauge outlet
• All of these

155. Which of the following is a type of semi-modular outlet?

• Submerged pipe outlet
• Open-flume outlet
• Kennedy’s gauge outlet (Ans)
• All of these

156.The slope of a canal, for a discharge of 300 cumecs, should be

• 1 in 4000
• 1 in 6000
• 1 in 8000 (Ans)
• 1 in 10000

157.A diversion head work is constructed to

• Raise water level at the head of the canal
• Regulate the intake of water into the canal
• Reduce fluctuations in the supply level of the river
• All of the above (Ans)

158.A weir is generally aligned at right angle to the direction of the main river flow because

• It is economical
• Less length of weir is required
• It gives better discharge capacity
• All of these (Ans)

159.A weir fails due to

• Rupture of floor due to uplift
• Rupture of floor due to suction caused by standing wave
• Scour on the upstream and downstream of the weir
• All of the above (Ans)

160.A solid construction put across the river to raise its water level and divert the water into the canal, is known as

• Marginal bund
• Weir (Ans)
• Barrage
• Dam

161.When the difference in weir crest and downstream river bed is limited into 3 metres, the weir generally used is

• Vertical drop weir
• Drystone slope weir
• Concrete slope weir (Ans)
• Parabolic weir

162.Okhla weir on Yamuna river, in Delhi, is an example of

• Vertical drop weir
• Drystone slope weir (Ans)
• Concrete slope weir
• Parabolic weir

163.In Bligh’s creep theory, it is assumed that the percolation water creep

• Along contact of the base profile of the apron with the sub-soil (Ans)
• In a straight path under the floor
• In a straight path under the foundation work
• None of the above

164.In Lane’s weighted creep theory, he proposed a weight of

• Three for vertical creep and one for horizontal creep (Ans)
• Three for vertical creep and one for vertical creep
• Two for vertical and two for horizontal creep
• Any one of the above

165.In Bligh’s creep theory

• There is no distinction between horizontal and vertical creep
• Loss of head does not take place in the same proportion as creep length
• The uplift pressure distribution is not linear, but follows a sine curve
• All of the above (Ans)

166.In a barrage, crest level is kept

• Low with large gates (Ans)
• High with large gates
• High with small gates
• Low with small gates

167.The loss of head per unit length of creep is called

• Coefficient of creep
• Percolation coefficient (Ans)
• Lane’s coefficient
• None of these

168.According to Khosla’s theory, the undermining of the floor starts from the

• Starting end
• Tail end (Ans)
• Intermediate point
• Foundation bed

169.According to Khosla’s theory, the critical hydraulic gradient for alluvial soils is approximately equal to

• 1 (Ans)
• 5
• 2
• 5

170.According to Khosla’s theory, the exit gradient in the absence of a downstream cut-off is

• Zero
• Unity
• Infinity (Ans)
• None of these

171.Foe low navigation dams, the type of gate used is

• Rolling gate
• Bear trap gate (Ans)
• Vertical lift gate
• Drum gate

172.A canal head work in rocky stage of a river is not suitable because

• More cross drainage works are required
• A costly head regulator is required
• More falls are necessary to dissipate the energy
• All of the above (Ans)

173.The crest level in a barrage is kept at a ………… level.

• Low (Ans)
• High
• Moderate

174.The  crest of the under-sluices should be lower than the crest of the head regulator (if silt excluder is provided) by at least

• 1 to 1.2 m
• 8 to 2 m (Ans)
• 2 to 2.5 m
• 4 to 5 m

175.The function of a scouring sluice is

• To control the silt entry into the canal
• To scour the silt deposited in the river bed above the approach channel
• To pass the low floods without dropping the shutters of the main weir
• All of the above (Ans)

176.For smooth entry, the regulators are aligned at an angle of ……………….. to the water.

• 60^o
• 80^o
• 110^o (Ans)
• 130^o

177.The level of a canal diversion head work depends upon

• Discharge perimeter
• Pond level
• Full supply level of canal
• All of these (Ans)

178.Rivers on alluvial plains may be

• Meandering type
• Aggrading type
• Degrading type
• All of these (Ans)

179.An aggrading river is a ……………. River.

• Scouring
• Silting (Ans)

180.A river meandering through an alluvial plain has a series of consecutive curves of reversed order connected with short straight sketches, is called

• Crossing (Ans)
• Meandering belt
• Meandering length
• None of these

181.The width of meandering belt is the

• Transverse distance between the apex point of one curve and apex point on reverse curve (Ans)
• Axial distance along the river between tangent point of one curve and tangent point of other curve of same order
• Axial distance along the river between the apex point of one curve and apex point on reverse curve
• Transverse distance along the river between tangent point of one curve and tangent point of other curve of same order

182.The degree of sinuosity is the ratio between the

• Meander length and width of meander
• Meander length and the width of river
• Curved length and the straight air distance (Ans)
• None of these

183.Tortuosity of a meandering river is the ratio of

• Meander length to width of meander
• Meander length to width of river
• Curved length along the river to the direct axial length of the river (Ans)
• Direct axial length of the river to the curved length along the river

184.The Tortuosity of a meandering river is always ……………….. one.

• Equal to
• Less than
• Greater than (Ans)

185.The basic factor which controls the process of meandering is

• Discharge
• Valley slope
• Bed and side resistance
• All of these (Ans)

186.When river flows in a plain country, its stage is known as …………….. stage.

• Delta
• Boulder
• Trough (Ans)
• Rocky

187.The width and length of meander as well as width of river, vary approximately with

• Discharge
• Square of discharge
• Square root of discharge (Ans)
• Cube root of discharge

188.The river training works are adopted on a river

• To pass high flood discharge safely and quickly through the breach
• To direct and guide the river flow
• To reduce bank erosion to a minimum
• All of the above (Ans)

189.The method used for training of rivers is

• Guide bank
• Dyke or levee
• Groyne
• All of these (Ans)

190.A river training work is generally required when the river is

• Aggrading type
• Degrading type
• Meandering type (Ans)
• Stable type

191.The repelling groyne is constructed in such a way that it is pointing towards ………………… at an angle of 30^o

• Upstream (Ans)
• Downstream

192.A deflecting groyne has a much ………………… length than a repelling groyne.

• Longer
• Shorter (Ans)

193. A deflecting groyne in a river is

• Inclined towards upstream
• Perpendicular to bank (Ans)
• Inclined towards downstream
• None of these

194.A groyne with a curved head is known as

• Hockey groyne (Ans)
• Burma groyne
• Denehy groyne
• None of these

195.When the bed level of the canal is higher than the highest flood level (H.F.L) of the drainage, then the cross drainage work is said to be

• Aqueduct (Ans)
• Super-passage
• Canal syphon
• Syphon aqueduct

196.When the drain is over the canal, the structure provided is known as

• Aqueduct
• Super-passage (Ans)
• Canal syphon
• Syphon aqueduct

197.When the levels are such that the F.S.L. of the canal is much above the bed level of the drainage trough, so that the canal runs under symphonic action under the trough, the structure provided is known as

• Syphon aqueduct
• Level crossing
• Canal syphon (Ans)
• Super-aqueduct

198.When the irrigation canal and the drain are at the same level, then the cross drainage work is achieved by providing a

• Aqueduct
• Super-passage
• Level crossing (Ans)
• Canal syphon

199.In case of syphon aqueduct, the H.F.L. of the drain is

• Much below the bottom of the canal trough
• Much higher above the canal bed (Ans)
• In level with the canal bed
• None of the above

200.In a Super-passage, the F.S.L. of the canal is

• Lower than the underside of the trough carrying drainage water (Ans)
• Above the bed level of the bed drainage
• In level with the drainage trough
• None of the above

201.In a syphon, the underside of the trough carrying drainage water is ……………….. the F.S.L. of the canal

• Lower than
• Higher than (Ans)
• In level with

202.The bed of a canal is lowered in case of

• Syphon aqueduct
• Level crossing
• Canal syphon (Ans)
• All of these

203.The floor of the aqueduct is subjected to uplift pressure due to

• Seepage of water from the canal to the drainage
• Sub-soil water table in the drainage bed
• Both (a) and (b) (Ans)
• None of the above