Civil Engineering Irrigation Quiz (or) MCQ

1 .

What is the other name for Flood Irrigation?

A) Lift Irrigation

B) Flow Irrigation

C) Surface Irrigation

D) Uncontrolled irrigation

Correct Answer : Uncontrolled irrigation

Explanation : Normally this of irrigation is practiced in alluvial and deltaic regions where river water level is available in hot seasons, with this the soil is kept submerged and thoroughly flooded with water to thorough saturation of land. The water can be supplied to the land by flow, or partly by flow and partly by lift.

2 .

Irrigation canals are generally aligned along_______.

A) ridge line

B) valley line

C) contour line

D) straight line

Correct Answer : ridge line

3 .

In which of the following types of irrigation water is supplied to the crops throughout their crop period?

A) Flood Irrigation

B) Perennial Irrigation

C) Direct Irrigation

D) Storage Irrigation

Correct Answer : Perennial Irrigation

Explanation : In perennial irrigation, system water is supplied at a constant and continuous rate from perennial water sources, which get their supplies from melting snow, in accordance with the requirements of crop. Water is supplied by canal distribution system using a weir or reservoir.

4 .

Which of the following type of irrigation system is practised on small scale in India?

A) Lift Irrigation

B) Flood Irrigation

C) Artificial sub-irrigation

D) Natural sub-irrigation

Correct Answer : Artificial sub-irrigation

Explanation : It is a system in which open joint drains is artificially laid below the soil, to supply water to the soil by capillarity. So, therefore it is very costly and can only be practiced in special cases, like favorable soil conditions and for cash crops of good return.

5 .

Borrow pits should preferably be located in_________.

A) fields on both sides of the canal

B) field on the left side of the canal

C) field on the right side of the canal

D) central half width of the section of the canal

Correct Answer : central half width of the section of the canal

6 .

A deficit of sediments in flowing water may cause a river_____.

A) degrading type

B) aggrading type

C) meandering type

D) sub-critical type

Correct Answer : degrading type

7 .

If the straight sides of a triangular section of a lined canal with circular bottom of radius D, make an angle θ with horizontal, the hydraulic mean depth is________.

A) D

B) D/2

C) D/3

D) D/4

Correct Answer : D/2

8 .

If water table is comparatively high, the irrigation canal becomes useless, due to______.

A) large amount of seepage

B) spread of malaria

C) uncertain water demand

D) All of the above

Correct Answer : All of the above

Explanation : * large amount of seepage
* spread of malaria
* uncertain water demand
* water logging of the cultivated areas

9 .

Which of the following type of irrigation method is also called as trickle irrigation?

A) Check Flooding

B) Furrow Irrigation Method

C) Drip Irrigation Method

D) Sprinkler Irrigation Method

Correct Answer : Drip Irrigation Method

Explanation : In this type of method, it involves laying a system of the head, mains, sub-mains, laterals, and drip nozzles. From these nozzles, water oozes or trickles out at a small rate into the plant roots area. Hence the name trickle irrigation method.

10 .

The length of a meander is the distance along the river between the tangent point of one curve to the tangent point of_________.

A) reverse curve

B) next curve of the same order

C) reverse curve plus the width of the river

D) None of the above

Correct Answer : next curve of the same order

11 .

If B and d are the bed width and depth of a channel in metres, the combined losses due to evaporation and seepage in cumecs per kilometre length of the channel, is_______.

A) 1/50 (B+d)⅔

B) 1/100 (B+d)⅔

C) 1/150 (B+d)⅔

D) 1/200 (B+d)⅔

Correct Answer : 1/200 (B+d)⅔

12 .

Meandering of a river generally occurs, in_____.

A) trough stage

B) delta stage

C) rocky stage

D) boulder stage

Correct Answer : trough stage

13 .

Which of the following type of irrigation methods uses supply ditch, borders, ridges?

A) Basin Flooding

B) Check Flooding

C) Border Flooding

D) Drip Irrigation Method

Correct Answer : Border Flooding

Explanation : This type of method uses borders to divide the land into strips of with 10 to 20 meters, 100 to 400 meters in length each. Ridges are provided between borders so as to prevent overtopping during irrigation. Supply ditches run perpendicular to borders either on one side of the field to provide water for irrigation.

14 .

Pick up the incorrect statement from the following :

A) Side walls of a venturi head flume are splayed out from the end of the throat at 1 : 10 for a length of 4.5 m

B) Length of side walls should be such that the width of the flume is made equal to 2/3rd the bed width of the distributary

C) Once the width of the flume becomes 2/3rd of the width of the distributary, the splayed walls are increased to 1 in 3 to get full bed width

D) All of the above

Correct Answer : All of the above

15 .

The consumptive use of water for a crop _______.

A) is measured as depth of water on irrigated area

B) is measured as the volume of water per unit area

C) may be supplied partly by precipitation and partly by irrigation

D) All of the above

Correct Answer : All of the above

16 .

The difference in level between the top of a bank and supply level in a canal, is called_______.

A) berm

B) free board

C) height of bank

D) None of the above

Correct Answer : free board

17 .

F.S.L. of a canal at its head with respect to parent channel is kept_______.

A) 15 cm lower

B) 15 cm higher

C) at the same level

D) None of the above

Correct Answer : 15 cm lower

18 .

The velocity of drainage water in the barrels of a syphon-aqueduct, is normally limited to

A) 4 to 5 m per second

B) 3 to 4 m per second

C) 2 to 3 m per second

D) 1 to 2 m per second

Correct Answer : 2 to 3 m per second

19 .

A river is said to be of_______.

A) meandering type if it flows in sinuous curve

B) degrading type if it cuts its bed to a certain slope

C) aggrading type if it builds up its bed to a certain slope

D) All of the above

Correct Answer : All of the above

20 .

A land is said to be water-logged if its soil pores within_____.

A) a depth of 40 cm are saturated

B) a depth of 50 cm are saturated

C) root zone of the crops are saturated

D) All of the above

Correct Answer : All of the above

21 .

Which of the following type of irrigation methods uses artificial rain to irrigate the land?

A) Furrow Method

B) Drip Irrigation Method

C) Sprinkler Irrigation Method

D) Border Irrigation Method

Correct Answer : Sprinkler Irrigation Method

Explanation : In this method, water is applied to the field through a network of pipes connected to sprinklers of different types, and through these sprinklers, water comes out as artificial rain and waters the crops in the field.

22 .

Which of the following is the quality of a good irrigation method?

A) Increased Yield

B) Soil Erosion

C) Drainage Troubles

D) Leached Fertilizers

Correct Answer : Increased Yield

Explanation : Because good irrigation has uniform water distribution for both light irrigation and heavy irrigation. It also reduces conveyance and labor losses. It also facilitates mechanized farming. So, these advantages lead to increased yield.

23 .

Which of the following type of irrigation method can be used for both flat lands and relatively steep lands?

A) Furrow Method

B) Free Flooding

C) Basin Flooding

D) Drip Irrigation Method

Correct Answer : Free Flooding

Explanation : Irrigation by this type of method is done, by dividing the entire land to be irrigated into a number strips called laterals. These laterals may be perpendicular to the sides of the field or perpendicular to the contour lines. So, as this method uses contour lines of field it is suitable for both flat lands and steep lands.

24 .

What is the other name of perennial irrigation system?

A) Flood Irrigation

B) Controlled Irrigation

C) Direct Irrigation

D) Storage Irrigation

Correct Answer : Controlled Irrigation

Explanation : As perennial irrigation system works on perennial water sources, the flow of water in those sources can be controlled by the construction of canals, weirs, check dams, dams etc. So in this way there is no sudden rush of water during irrigation unlike in uncontrolled irrigation.

25 .

In India most irrigation schemes fall under which category of irrigation?

A) Lift Irrigation

B) Combined System

C) River Canal Irrigation

D) Tank Irrigation

Correct Answer : Tank Irrigation

Explanation : In this system solid barrier, such as a dam or a storage weir is constructed across the river and water is stored. Volume of storage required depends upon requirements of crops, or hydroelectric power generation and flow of water in the river, unlike the other type of irrigation systems.

26 .

The measure to remove water logging of land, is________.

A) to reduce percolation from canals and water courses

B) to increase outflow from the ground water reservoir

C) Both (A) and (B)

D) Neither (A) nor (B)

Correct Answer : Both (A) and (B)

27 .

Attracting groynes are built_________.

A) inclined down stream

B) inclined up stream

C) perpendicular to the bank

D) None of the above

Correct Answer : inclined down stream

28 .

Retrogression of the bed level of a river downstream a weir, occurs due to_________.

A) less percentage of silt

B) heavy impact of water

C) soft soil strata

D) increase of the bed level

Correct Answer : less percentage of silt

29 .

Retrogression of the bed level of a river downstream a weir, occurs due to_________.

A) less percentage of silt

B) heavy impact of water

C) soft soil strata

D) increase of the bed level

Correct Answer : less percentage of silt

30 .

A fall in a canal bed is generally provided, if____.

A) designed bed slope exceeds the ground slope

B) ground slope is practically the same as the designed bed slope

C) ground slope exceeds the designed bed slope

D) None of the above

Correct Answer : ground slope exceeds the designed bed slope

31 .

According to Khosla, the exist gradient of surface flow_________.

A) is independent of the b/d ratio

B) depends upon the b/d ratio

C) is independent of the depths of d/s cut off walls

D) None of the above

Correct Answer : depends upon the b/d ratio

32 .

If D1 and D2 are depths of water upstream and down stream of a hydraulic jump, the loss of head at the jump, is______.

A) (D₂-D₁)³ / D₁D₂

B) (D₂-D₁)³ / 2D₁D₂

C) (D₂-D₁)³ / 3D₁D₂

D) (D₂-D₁)³ / 4D₁D₂

Correct Answer : (D₂-D₁)³ / 4D₁D₂

33 .

The uplift pressure on the roof of an inverted syphon, is maximum when______.

A) canal is running dry

B) drain in running dry

C) drain is running with H.F.L

D) canal is running with F.S.L

Correct Answer : drain is running with H.F.L

34 .

Which of the following type of method is adopted for research studies on crops?

A) Lysimeter Method

B) Phytometer Method

C) Drip Irrigation Method

D) Furrow Irrigation Method

Correct Answer : Lysimeter Method

Explanation : Actually lysimeter method is used to determine the AET. This method consists of a tight tanker filled with a block of soil and is installed in a field of growing plants. The conditions to maintain this tanker on par with conditions of the field and the measurement of water added to the tanker to maintain moisture content are time-consuming and costlier field studies.

35 .

According to G.W. Pickles the effect of confining the flood water of a river between levee, is to increase______.

A) maximum discharge

B) velocity and scouring action

C) water surface elevation during floods

D) surface slope of streams above the leveed portion

Correct Answer : surface slope of streams above the leveed portion

36 .

In a canal syphon, the flow is_______.

A) pipe flow

B) with critical velocity

C) under negative pressure

D) under atmospheric pressure

Correct Answer : pipe flow

37 .

If L is total length of a canal in kilometres, P is total perimeter of its lining in metres and C is the cost of lining per square metre, the additional expenditure involved on lining, is_____.

A) 1000 PLC

B) PLC / 1000

C) PL / 1000C

D) PC / 100L

Correct Answer : 1000 PLC

38 .

In a Sarda type fall, the rectangular crest, may be used for discharge upto___.

A) 10 cumecs

B) 14 cumecs

C) 20 cumecs

D) 25 cumecs

Correct Answer : 14 cumecs

39 .

When a canal is carried over a natural drainage, the structure provided, is known as______.

A) syphon

B) super passage

C) aqueduct

D) syphon-aqueduct

Correct Answer : aqueduct

40 .

For the stability of a structure against seepage pressure according to Khosla's creep theory, the critical gradient is____.

A) 0.25

B) 0.50

C) 0.75

D) 1.00

Correct Answer : 1.00

41 .

If the irrigation efficiency is 80%, conveyance losses are 20% and the actual depth of watering is 16 cm, the depth of water required at the canal outlet, is_______.

A) 10 cm

B) 15 cm

C) 20 cm

D) 25 cm

Correct Answer : 25 cm

42 .

The useful moisture of soil, is equal to its_______.

A) field capacity

B) saturation capacity

C) moisture content at permanent wilting point

D) difference between filed capacity and permanent wilting point within the root zone of plants.

Correct Answer : difference between filed capacity and permanent wilting point within the root zone of plants.

43 .

Canals taken off from ice-fed perennial rivers, are known______.

A) perennial canals

B) ridge canals

C) permanent canals

D) inundation canals

Correct Answer : perennial canals

44 .

In rigid module, the discharge______.

A) depends upon the water level in distributary

B) depends upon the water level in the water course

C) is independent of water levels in the distributary and water course

D) depends upon the water levels of both, i.e. distributary and water course

Correct Answer : is independent of water levels in the distributary and water course

45 .

The ratio of the rate of change of discharge of an outlet and parent channel, is known as________.

A) efficiency

B) flexibility

C) sensitivity

D) modular limit

Correct Answer : flexibility

Explanation : It provides a criteria for judging the behaviour of modules and semi-modules. It is generally denoted by letter 'F'. It is the ratio of the rate of change of outlet discharge to the rate of change of discharge of the parent channel.

46 .

What is the field irrigation requirement (FIR)?

A) The water required to meet the evaporation needs of a crop

B) Amount of water required to delivered at the field to meet evapotranspiration and leaching needs

C) Amount of water required to meet the field irrigation requirements plus water lost in conveyance through the canal system

D) Amount of water required to meet the net irrigation requirements plus water lost due to surface runoff and percolation

Correct Answer : Amount of water required to meet the net irrigation requirements plus water lost due to surface runoff and percolation

Explanation : FIR can be defined as the water required meeting the net irrigation requirements plus the amount of water lost as surface runoff and through deep percolation.
Mathematically, FIR = NIR / Na where Na = application efficiency and NIR = Net irrigation requirement.

47 .

Which of the following is the correct formula for Gross irrigation requirement?

A) NIR/Na

B) FIR/Nc

C) Cu – Re

D) CIR + leaching losses

Correct Answer : FIR/Nc

Explanation : It is defined as the amount of water required to meet the field irrigation requirements plus the amount of irrigation water lost in conveyance through the canal system by evaporation and seepage.

Mathematically, GIR = FIR/Nc.

48 .

Canal irrigation is generally preferred in ________

A) alluvial canal

B) feeder canal

C) non-alluvial canal

D) non-perennial canal

Correct Answer : alluvial canal

Explanation : Direct irrigation using a weir or barrage (canal irrigation) is generally preferred in alluvial soil as compared to storage irrigation. Alluvial soil is a fine-grained fertile soil and due to its porosity and texture provides good drainage making it highly productive and suitable for agriculture.

49 .

Which of the following canal acts as an irrigation canal as well as a feeder canal?

A) Feeder canal

B) Permanent canal

C) Carrier canal

D) Inundation canal

Correct Answer : Carrier canal

Explanation : A carrier canal is a canal used for both direct irrigation and for feeding water to another canal. Thus, it acts as an irrigation canal as well as a feeder canal. Upper Chenab Canal is an example of this type of canal.

50 .

What type of irrigation scheme uses pick-up weir?

A) Direct Irrigation

B) Storage Irrigation

C) Combined System

D) Perennial Irrigation

Correct Answer : Combined System

Explanation : In this system water is first stored at upstream side of the dam for power generation and then discharged back into the river at the downstream side of the dam. Thus, sufficient quantity of flow is again available in the river. At a suitable place in downstream pick-up weir is constructed to divert water to canals.

51 .

Diversion scheme, comes under which type of irrigation system?

A) Flow Irrigation

B) Storage Irrigation

C) Inundation Irrigation

D) Direct Irrigation

Correct Answer : Direct Irrigation

Explanation : In direct irrigation system water is directly diverted to the canal without storing water. For this system low diversion weir or diversion barrage is constructed across the river. So, this gives the diversion scheme for direct irrigation system over the other systems of irrigation.

52 .

A water-logged land is found suitable for cultivation due to

A) ease of tillage for preparation of the field for optimum condition of germination

B) absence of aeration of soil from root zone of the plant

C) regular supply of water to plants from the water table by capillary action

D) None of the above

Correct Answer : None of the above

53 .

When a canal and a drainage approach each other at the same level, the structure so provided, is_______.

A) a level crossing

B) a syphon

C) an aqueduct

D) inlet and outlet

Correct Answer : a level crossing

54 .

For smooth entry of water in a canal, the angle between head regulator and water is generally kept______.

A) 120°

B) 110°

C) 90°

D) 80°

Correct Answer : 110°

55 .

For the design of major hydraulic structures on the canals, the method generally preferred to, is based on

A) Bligh's theory

B) The relaxation method

C) Electrical analogy method

D) Khosla's method of independent variables

Correct Answer : Khosla's method of independent variables

56 .

For designing the venturi head,________.

A) width of the throat should not be less than one-third of the bed width of main canal

B) minimum throat width should not be less than 60 cm

C) length of the throat should be 2.5 times the depth measured to F.S.L. in the main canal

D) All of the above

Correct Answer : All of the above

57 .

Groynes are generally built_______.

A) perpendicular to the bank

B) inclined down stream upto 30°

C) inclined up stream up to 30°

D) All of the above

Correct Answer : inclined up stream up to 30°

58 .

The top of the capillary zone________.

A) lies above the water table at every point

B) coincides the water table at every point

C) lies below the water table at every point

D) None of the above

Correct Answer : lies above the water table at every point

59 .

Pick up the incorrect statement from the following. Culturable commanded area is the gross area of an irrigation canal system less______.

A) forest area

B) fallow land

C) alkaline area

D) populated area

Correct Answer : fallow land

60 .

The main function of a diversion head works of a canal from a river, is______.

A) to store water

B) to control floods

C) to raise water level

D) All of the above

Correct Answer : All of the above

61 .

The down stream expansion head of a guide bank is extended to subtend an angle at the centre, equal to_____.

A) 30°

B) 45°

C) 60°

D) 90°

Correct Answer : 45°

62 .

The main cause of silting up a channel,_______.

A) defective outlets

B) inadequate slope

C) defective head regulator

D) All of the above

Correct Answer : All of the above

63 .

In north Indian Plains, optimum depth of kor watering for wheat, is_______.

A) 12.0 cm

B) 13.5 cm

C) 17.5 cm

D) 19.0 cm

Correct Answer : 13.5 cm

64 .

Cross regulators in main canals are provided______.

A) to overflow excessive flow water

B) to regulate water supply in the distributaries

C) to increase water head upstream when a main canal is running with low supplies

D) None of the above

Correct Answer : to increase water head upstream when a main canal is running with low supplies

65 .

The ratio of the head recovered to the head put in, is known as_______.

A) efficiency

B) flexibility

C) sensitivity

D) modular limit

Correct Answer : efficiency

66 .

A fall which maintains its depth, is________.

A) a low weir fall

B) a trapezoidal notch fall

C) a rectangular notch fall

D) All of the above

Correct Answer : All of the above

67 .

What is the Annual Intensity of irrigation (AII)?

A) Gross Irrigated Area/Cultivable Command Area

B) Net Irrigated Area/Cultivable Command Area

C) Cultivable Command Area/Gross Irrigated Area

D) Cultivable Command Area/Net Irrigated Area

Correct Answer : Gross Irrigated Area/Cultivable Command Area

Explanation : The AII is the sum total of intensities of irrigation of all the seasons of the year. IT can also be defined as the percentage of CCA which may be irrigated annually. It is thus obtained by dividing the gross irrigated area by the CCA.

68 .

Which of the following is a remedial measure for water-logging?

A) Quick disposal of rainwater

B) By lowering the F.S.L of the canals

C) Installation of lift irrigation systems

D) Controlling seepage from the canals

Correct Answer : Installation of lift irrigation systems

Explanation : Installation of lift irrigation system is one of the remedial measures adopted to reclaim the water-logged area and others are preventive measures which keep the land free from water-logging. It is found to be a very effective method of reclaiming water-logged land.

69 .

Due to inadequate drainage which of the following factor causes waterlogging with constant percolation?

A) Flat Topography

B) Inadequate Surface Drainage

C) Impervious Obstruction

D) Over and Intensive Irrigation

Correct Answer : Inadequate Surface Drainage

Explanation : During rains storm water gets mixed with irrigation water. The irrigation water should be removed so as to not mix with storm water as this leads to percolation. Moreover, if proper drainage is not present constant percolation happens and water table rises.

70 .

Which of the following factor causing waterlogging suggests extensive irrigation?

A) Excessive Rains

B) Over and Intensive Irrigation

C) Impervious Obstruction

D) Seepage of Water from High Lands

Correct Answer : Over and Intensive Irrigation

Explanation : When intensive irrigation is practiced, it only irrigates a small portion of the whole irrigable land. Due to this over irrigation it leads to heavy percolation which leads to rising of water table causing waterlogging. So, to prevent waterlogging extensive method of irrigation is recommended.

71 .

What type of irrigation system needs mechanical means to supply water for irrigation?

A) Lift Irrigation

B) Combined System

C) Storage Irrigation

D) Perennial Irrigation

Correct Answer : Lift Irrigation

Explanation : Unlike any other irrigation systems lift irrigation system is used in when water supply is at too low level to run by gravitation on to the land. So, in such cases water is needed to be lifted by mechanical means for irrigation.

72 .

What type of irrigation system is based merely on gravitation?

A) Lift Irrigation

B) Direct Irrigation

C) Flow Irrigation

D) Storage Irrigation

Correct Answer : Flow Irrigation

Explanation : Flow irrigation is the type of irrigation in which supply of irrigation water is merely conveyed onto the land by the gravity flow or gravitation. In other words, water is supplied from higher grounds to lower grounds.

73 .

In which of the following types of irrigation systems hydroelectric power can be generated?

A) Storage Irrigation

B) Lift Irrigation

C) Flood Irrigation

D) Perennial Irrigation

Correct Answer : Storage Irrigation

Explanation : Dams are constructed in this type of irrigation system, which leads to formation of reservoir on the upstream side of the dam. The hydroelectric power is generated when water is released through the dam for irrigation, or any other multipurpose, or when reservoir is full.

74 .

Which of the following CD works carry drainage over the canal?

A) Canal Syphon and Aqueduct

B) Aqueduct and Syphon Aqueduct

C) Level-crossing and inlets outlets

D) Super passage and Syphon

Correct Answer : Super passage and Syphon

Explanation : In Aqueduct and Syphon Aqueduct, the canal is carried over the natural drain. In level crossing and inlet and outlets, the canal water and drainage water are allowed to intermingle with each other.

75 .

The sinuosity of a meander is the ratio of________.

A) meander length and the width of meander

B) curved length and the straight distance

C) meander length and half width of the river

D) None of the above

Correct Answer : curved length and the straight distance

76 .

The top soil of a water logged field becomes more alkaline and infertile if its pH value is____.

A) 11

B) 10

C) 9

D) 8

Correct Answer : 11

77 .

When a canal flowing under pressure is carried below a natural drainage such that its F.S.L. does not touch the underside of the supporting structure, the structure so provided, is called____.

A) syphon

B) aqueduct

C) super passage

D) syphon-aqueduct

Correct Answer : super passage

78 .

For the conditions enumerated to provide a crossing at C1 You will probably provide_______.

A) an aqueduct

B) a super-passage

C) a syphon aqueduct

D) None of the above

Correct Answer : a super-passage

79 .

If the straight sides of a triangular section of a lined canal with circular bottom of radius R, make an angle θ with horizontal, the perimeter of the canal is________.

A) R(θ + cos θ)

B) R(θ + tan θ)

C) 2R(θ + tan θ)

D) 2R(θ + cos θ)

Correct Answer : 2R(θ + cos θ)

80 .

Bed bars in a canal are provided______.

A) to measure the discharge

B) to control the silting

C) to watch the general behaviour of canal

D) to raise the supply level

Correct Answer : to watch the general behaviour of canal

81 .

The most suitable location of a canal head work, is______.

A) trough stage of the river

B) rock stage of the river

C) delta stage of the river

D) boulders stage of the river

Correct Answer : trough stage of the river

82 .

Useful soil moisture for plant growth, is________.

A) capillary water

B) gravity water

C) chemical water

D) hygroscopic water

Correct Answer : capillary water

83 .

The water face of the guide banks, is protected by_________.

A) four man stone pitching

B) three man stone pitching

C) two man stone pitching

D) one men stone pitching

Correct Answer : one men stone pitching

84 .

Effective precipitation for a crop may be defined as_______.

A) total precipitation during the crop period

B) total precipitation minus the loss due to evaporation

C) available water stored in soil within root zone of the crop

D) total precipitation minus the loss due to infiltration

Correct Answer : available water stored in soil within root zone of the crop

85 .

If average particle size of the silt in millimetres is m, the Lacey's silt factor f is proportional to____.

A) m³

B) m½

C) m⅓

D) m⅔

Correct Answer : m½

86 .

If the salt concentration of the irrigation water ranges from 0.5 – 2 g/L, then what is the restriction on its use?

A) No restriction on its use

B) No dependency on the salt concentration

C) It should be used with appropriate water management practices

D) It is not generally advised for use unless consulted with specialists

Correct Answer : It should be used with appropriate water management practices

Explanation : If the salt concentration is less than 0.5 g/L, then there is no salinization risk and no restriction on the use of irrigation water. If the concentration is more than 2 g/L, there is high risk and is not generally advised for use. If the concentration is in between there is slight to moderate risk and it should be used with appropriate water management practices.

87 .

On which of the following factor does the pricing of irrigation water is done at a flat rate?

A) Per Hectare

B) Type of Crops Sown

C) For the Whole Field Sown

D) Amount of Irrigation Water Used

Correct Answer : Per Hectare

Explanation : When the pricing of irrigation water is done on the flat rate or crop rate basis, then these rates are specified per hectare of each sown crop, cultivated by the cultivators.

88 .

Which of the following policy was framed in India to reduce the losses?

A) Water Law

B) Policy of Water

C) Irrigation Water Policy

D) National Water Policy

Correct Answer : National Water Policy

Explanation : In order to reduce the huge losses and subsidies, given by the government in operations of irrigation water systems and the urgent need to increase the water rates a new policy was framed in India in 1987.

89 .

What is the main agenda of the National Water Policy?

A) Quality Check of Irrigation Water

B) Recommendations to States

C) Maintenance of the Irrigation Structures

D) Recover Charges

Correct Answer : Recover Charges

Explanation : The main aim or agenda of the National Water Policy is that to recover the revenue rates to adequate the annual operation and maintenance charges and a part of the fixed capital. In this way, we can also convey the scarcity value of natural resources to the consumers.

90 .

Which of the following best is the Hirakud reservoir?

A) Reservoir for irrigation and power

B) Reservoir for flood control, power, and irrigation

C) The purpose is Recreation and fishery

D) Reservoir for irrigation and water supply

Correct Answer : Reservoir for flood control, power, and irrigation

Explanation : It is one of the first major multipurpose river valley projects and is built across the Mahanadi River in Orissa. The dam was constructed to regulate the flow of the river and produce hydroelectricity through several plants. It irrigates almost 75,000 km² of land.

91 .

The canal water flows freely under gravity in which of the following Cross Drainage (CD) works?

A) Super passage and Syphon

B) Canal Syphon and Aqueduct

C) Aqueduct and Super passage

D) Level-crossing and inlets outlets

Correct Answer : Aqueduct and Super passage

Explanation : In canal syphon and syphon aqueduct, canal water flows under symphonic action. The canal and the drainage system approach each other practically at the same level in CD works like Level crossing and inlets and outlets.

92 .

A Super passage is the reverse of ________

A) aqueduct

B) syphon

C) syphon Aqueduct

D) inlets and outlets

Correct Answer : aqueduct

Explanation : In Aqueduct, the drainage water runs below the canal either freely or under symphonic action. In Super passage, the drain is taken over the canal such that the canal water runs below the drain. Similarly, a syphon is also a reverse of aqueduct syphon.

93 .

The crest level of a canal diversion head work, depends upon______.

A) pond level

B) F.S.L. of the canal

C) discharge perimeters

D) All of the above

Correct Answer : All of the above

94 .

The depth of rice root zone, is_____.

A) 90 cm

B) 80 cm

C) 70 cm

D) 60 cm

Correct Answer : 90 cm

95 .

The intensity of irrigation means__________.

A) percentage of gross commanded area to be irrigated annually

B) percentage of culturable commanded area to be irrigated annually

C) total depth of water supplied by the number of waterings

D) percentage of the mean of culturable commanded area and the gross commanded area to be irrigated annually

Correct Answer : percentage of culturable commanded area to be irrigated annually

96 .

The saturation line is the line up to which banks get saturated after the canal runs for some time. The saturation gradient in ordinary loam soil, is generally______.

A) 2 : 1

B) 3 : 1

C) 4 : 1

D) 5 : 1

Correct Answer : 4 : 1

97 .

A hydraulic structure is designed to withstand______.

A) hydraulic jump

B) seepage forces

C) hydraulic pressure

D) All of the above

Correct Answer : All of the above

98 .

In gravity canals, F.S.L. is____.

A) only a few cm above the ground level

B) always at the ground level

C) always below the ground level

D) generally 4 to 5 metres above the ground level

Correct Answer : only a few cm above the ground level

99 .

If d₁ is the depth of cutting, d₂ is the height of the bank from bed level r₂ : 1 and r₁ : 1 are the slopes in filling and cutting respectively, the horizontal distance n between the bed and bank, is_____.

A) x = r₁ d₁

B) x = r₂ d₂

C) x = d₁ / r₁

D) x = d₂ / r₂

Correct Answer : x = r₂ d₂

100 .

The structure constructed to allow drainage water to flow under pressure through an inverted syphon below a canal, is called_____.

A) aqueduct

B) super passage

C) syphon aqueduct

D) super-aqueduct

Correct Answer : syphon aqueduct

101 .

The optimum depth of kor watering for a rice crop, is____.

A) 13.5 cm

B) 17.5 cm

C) 19.0 cm

D) 23.0 cm

Correct Answer : 19.0 cm

102 .

Lane's weighted creep theory assumes_________.

A) equal weightage to horizontal and vertical creeps

B) double weightage to horizontal creep and one weightage to vertical creep

C) triple weightage to horizontal creep and one weightage to vertical creep

D) triple weightage to vertical creep and one weightage to horizontal creep

Correct Answer : triple weightage to vertical creep and one weightage to horizontal creep

103 .

Disposal of extra excavated earth of canals, is utilised to provide a spoil bank on____.

A) left side

B) right side

C) both sides

D) All of the above

Correct Answer : All of the above

104 .

The depth of the crest of a scouring sluice below the crest of a head regulator, is generally kept_______.

A) 1.20 m

B) 2.20 m

C) 3.20 m

D) 4.90 m

Correct Answer : 1.20 m

105 .

Bligh's theory of seepage assumes______.

A) loss of head follows the sine curve

B) equal weightage to the horizontal and vertical creep

C) less weightage to horizontal creep than vertical creep

D) more weightage to horizontal creep than vertical creep

Correct Answer : equal weightage to the horizontal and vertical creep

106 .

The Lacey's regime velocity is proportional to_____.

A) R1/2 S3/4

B) Q3/4 S1/3

C) R3/4 S1/3

D) R2/3 S1/2

Correct Answer : R3/4 S1/3

107 .

V and R are the regime mean velocity and hydraulic mean depth respectively in metres. Lacey's silt factor f is____

A) 2 V² 5 R

B) 3 V² / 4 R

C) 5 V² / 2 R

D) 2 V² / √3 R

Correct Answer : 5 V² / 2 R

108 .

According to Lacey, depth of scour in a river depends upon the straightness of the reach. If D is the depth of scour in regime flow in a right angled bend, it is

A) 1.25 D

B) 1.50 D

C) 1.75 D

D) 2.00 D

Correct Answer : 2.00 D

109 .

An irrigation project is classified as a major project when the CCA involved in the project is more than ________

A) 10000 hectares

B) 5000 hectares

C) 2500 hectares

D) 1500 hectares

Correct Answer : 10000 hectares

Explanation : Culturable Command Area is the basis for the design of watercourse and the basis for the design of an irrigation project. The irrigation schemes in India are classified into three parts viz. Minor, Medium and Major Irrigation schemes depending upon the areas involved. Major irrigation scheme is the one where CCA involved in the project is greater than 10,000 hectares.

110 .

According to the Central Board of Irrigation and Power, the PA ratio for graded aquifer should be ___________

A) < 9

A)

B) 12 – 15.5

B)

C) > 15.5

C)

D) 9 – 12.5

D)

Correct Answer : 12 – 15.5

Explaination : The Central Board of Irrigation and Power suggested the following criteria for PA ratio.

* For uniform aquifers (having Cu < or = 2.0), the PA ratio should be in between 9 – 15.5

* For graded aquifers (having Cu > 2.0), the PA ratio should be in between 12 – 15.5.

111 .

Which of the following strainer is used for shallow irrigation tube wells particularly in deltaic regions of developing countries?

A) Louver type of strainer

B) Coir rope strainers

C) Continuous slot type of strainer

D) Pipe strainer with fine mesh jackets

Correct Answer : Coir rope strainers

Explanation : Coir rope strainers are low-cost strainers and are generally used for shallow irrigation tube wells. The main disadvantage of such a strainer is its short life of 3 to 5 years. The rusting of the iron bars of the supporting frame and the loosening of the coir rope which expands on wetting are the causes of its failure.

112 .

Which of the following is the incorrect statement?

i). Cattle crossings also provide safety to cattle that are swept away by currents besides their usual function of helping the cattle to cross the canal.
ii). A canal escape helps in supplying irrigation water to the downstream watercourses.
iii). Bed bars are constructed in canals at the toe of the canal lining to prevent slippage of the lining.

A) i only

A)

B) ii only

B)

C) ii and iii

C)

D) i, ii, and iii

D)

Correct Answer : i, ii, and iii

Explaination : Canal escape helps in removing surplus water from an irrigation canal into a natural drain. The cattle crossing are not of much use on canals carrying considerable water depths and for the ones who don’t know swimming. Bed bars help in desilting the canal section during its maintenance and indicate the correct alignment and bed levels of the canal.

113 .

Which of the following is a dam reservoir catering to flood control, irrigation, and water supply basically designed for irrigation alone?

A) retarding basins

B) distribution reservoir

C) single-purpose reservoir

D) multipurpose reservoir

Correct Answer : single-purpose reservoir

Explanation : A reservoir planned, designed and constructed for one purpose is called a single purpose reservoir whereas a reservoir planned and constructed to serve various purposes together is a multipurpose reservoir. A small storage reservoir constructed within a city water supply system is called distribution reservoir.

114 .

Let us consider in a given area the plantation of a certain crop takes 20 days, and the total water depth required by this crop is 80 cm on the field. Find the duty of irrigation water required for the crop during this period.

(a) Assuming 20% losses of water in the water courses, find duty at the head of the course.
(b) Find the duty of the water at the head of the distributary, assuming 10% losses from the distributary head.

A) 172.8 hectares/cumec, 185.4 hectares/cumec

A)

B) 172.8 hectares/cumec, 194.4 hectares/cumec

B)

C) 182.9 hectares/cumec, 194.4 hectares/cumec

C)

D) 185.6 hectares/cumec, 184.6 hectares/cumec

D)

Correct Answer : 172.8 hectares/cumec, 194.4 hectares/cumec

Explaination : Total depth of water needed = 80 cm
Period for which water is needed = 20 days
Duty of irrigation water = (864B/d) = (864 x 20 / 80) = 216 hectares/cumec
(a) Given 20% losses in the watercourse
= 216 x 0.8 = 172.8 hectares/cumec
(b) Given 10% losses in the head of the distributary
= 216 x 0.9 = 194.4 hectares/cumec.

115 .

A pump was installed in a field to supply water to the crops. The duty for this crop is 432 hectares/cumec on the field and the efficiency of pump is 50%. The sown area of the field is 5 hectares. Determine the maximum output required (H.P) of the pump, if the highest water level is 4 meters below the highest portion of the field. Assume negligible field channel losses.

A) 0.31H.P

A)

B) 0.77H.P

B)

C) 0.80H.P

C)

D) 0.85H.P

D)

Correct Answer : 0.31H.P

Explaination : Area of field to be irrigated = 5 hectares
Duty of water for crop = 432 hectares/cumec
Discharge required for the crop is = (5 / 432) = 1/86.4 cumec
Volume of water lifted per second = 1 / 86.4 cumec
Therefore, weight of water lifted per second = (1 / 86.4) x 9.81 = 0.1135 KN/sec
(unit wt. of water = 9.81 KN/m3)
Maximum static lift of pump = 4 metres
Work done by the pump in lifting water = 0.1135 x 4 = 0.454 KWatt
The input of the pump = (0.454 / 0.735) = 0.62
(1 metric H.P = 0.735 KWatt)
Output H.P of the pump = (input/η) = (0.62 / 0.5) = 0.31 H.P.

116 .

At a certain place, the transplantation of a crop takes 15 days, and the total depth of water required by the crop is 90 cm on the field. During the plantation rain falls and about 20 cm is utilised to fulfil the demand. Now determine the duty of irrigation water required during the plantation.

A) 185.14hectares/cumec

A)

B) 184.89hectares/cumec

B)

C) 186.25hectares/cumec

C)

D) 187.45hectares/cumec

D)

Correct Answer : 185.14hectares/cumec

Explaination : Total depth of water required = 90 cm
Useful rainfall = 20 cm
Extra water depth needed after useful rainfall = 90 – 20 = 70 cm
Period for which water is needed = 15 days
Duty of irrigated water (∆) = (864B/d) = (864 x 15 / 70) = 185.14 hectares/cumec.

117 .

Which Cross Drainage(CD) work is generally adopted when the drainage discharge is small and the drain crosses the canal with its bed level equal to or slightly higher than the canal FSL?

A) Syphon Aqueduct

B) Aqueduct

C) Inlets and outlets

D) Level crossing

Correct Answer : Level crossing

Explanation : Level crossing is generally adopted when the canal and the drainage are practically at the same level and for high flood drainage discharge but short-lived. Aqueduct or super passage is adopted when high flood drainage discharge is large.

118 .

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

A) degrading

B) aggrading

C) meandering

D) All of the above

Correct Answer : meandering

119 .

Water-shed line is abondened for aligning an irrigation canal if_________.

A) water shed forms a sharp loop

B) canal has to take off from a river

C) towns and villages are located on the water shed line

D) All of the above

Correct Answer : All of the above

120 .

For a given discharge in a channel, Blench curves give the relationship between the loss of head (HL) and________.

A) specific energy down-stream

B) specific energy up-stream

C) depth of water down-stream

D) critical depth of water down-stream

Correct Answer : specific energy down-stream

121 .

A hydraulic jump is generally formed when a stream moving with______.

A) A hyper-critical velocity meets a stream moving with a critical velocity

B) A hyper-critical velocity meets a stream moving with a sub-critical velocity

C) A sub-critical velocity meets a stream moving with a hyper-critical velocity

D) A hyper-critical velocity meets a stream moving with a hyper-critical velocity

Correct Answer : A hyper-critical velocity meets a stream moving with a sub-critical velocity

122 .

For a unique design of a channel by Kennedy's theory_______.

A) its depth must only be known

B) its breadth must only be known

C) its breadth and depth ratio must only be known

D) All of the above

Correct Answer : its breadth and depth ratio must only be known

123 .

In a barrage, the crest level is kept___.

A) low with no gates

B) low with large gates

C) high with no gates

D) high with large gates

Correct Answer : low with large gates

124 .

The width of a dowla is generally kept between 30 to 60 cm and its height above the road level should invariably be more than_______.

A) 10 cm

B) 20 cm

C) 30 cm

D) 40 cm

Correct Answer : 30 cm

125 .

Finally formed berms in canals are provided for______

A) strengthening of banks

B) control of seepage losses

C) protection of banks erosion by the waves

D) All of the above

Correct Answer : All of the above

126 .

By how much percentage canal capacity is increased to meet peak demands?

A) 30 to 35%

B) 20 to 25%

C) 20 to 30%

D) 15 to 20%

Correct Answer : 20 to 25%

Explanation : In order to be more precise, the intervals are kept as small as possible. Monthly water requirements studies are conducted to provide a sufficient quantity of water for irrigation. So, the canal capacity is increased by 20 to 25% to meet the peak demands in a month.

127 .

The field capacity of a soil depends upon______.

A) porosity of soil

B) capillary tension in soil

C) Both (A) and (B)

D) Neither (A) nor (B)

Correct Answer : Both (A) and (B)

128 .

Suppose the culturable commanded for a distributary is 8000 hectares, and the intensity of irrigation for Kharif season is 60% and that of rabi season is 30%. The average duty at the head of a distributary is 4000 hectares/cumec for Kharif season and for Rabi season it is 1800 hectares/cumec, find out discharge required at the head of the distributary?

A) 1.3 cumec

A)

B) 1.32 cumec

B)

C) 1.33 cumec

C)

D) 1.35 cumec

D)

Correct Answer : 1.33 cumec

Explaination : * Area to be irrigated in Kharif season = 8000 x 60/100 = 4800 hectares

* Area to be irrigated in Rabi season = 8000 x 30/100 = 2400 hectares

* Water required at the head of distributary to irrigate Kharif area = 4800 / 4000 = 1.2 cumec

* Water required at the head of distributary to irrigate Rabi area = 2400 / 1800 = 1.33 cumec

* Therefore, the required discharge is maximum of the two = 1.33 cumec.

129 .

Determine the discharge required at the head of the distributary in a canal where Kharif area to be irrigated is 2400 hectares and Rabi area to be irrigated is 1800 hectares, for fulfilling maximum crop requirement. Assume suitable values for kor depth and kor period.

A) 2 cumec

A)

B) 2.08 cumec

B)

C) 2.1 cumec

C)

D) 2.2 cumec

D)

Correct Answer : 2.08 cumec

Explaination : Now let us assume kor period of 4 weeks for Rabi and 3 weeks for Kharif crop. Also, assume kor depth of 12.5 cm for Rabi and 21 cm for Kharif crop.
Outlet factor for rabi = (864B/∆) = 864 x 4 x 7 / 12.5 = 1935.36 hectares/cumec
Outlet factor for kharif = (864B/∆) = 864 x 3 x 7 / 21 = 864 hectares/cumec
Area to be irrigated for Rabi season = 2400 hectares
Area to be irrigated for Kharif season = 1800 hectares
Water required for Kharif season at the distributary = 1800 / 864 = 2.08 cumec
Water required for Rabi season at the distributary = 2400 / 1935.36 = 1.24 cumec
Therefore, the canal capacity at the head of the distributary is the maximum of the two, 2.08 cumec.

130 .

The quantity of water that can be diverted from the river into the main canal has no dependency on which of the following factor?

A) The capacity of the branch canal

B) The capacity of the main canal

C) The water available in the river

D) Water demand of the branch canals

Correct Answer : The capacity of the branch canal

Explanation : This method of distribution of available water into various canals is called canal regulation and the flow from the main canal is followed by the branch canals and then to the distributaries. The flow distribution depends on the demand for water on various canals.

131 .

Which of the following combination is wrong?

A) Chak – Command area of an inlet

B) Head regulator – Regulation of discharge in the canal

C) Roster – Indication of allotted supplies to different channels

D) Flexible regulation – Allocation of supplies with anticipated demand

Correct Answer : Chak – Command area of an inlet

Explanation : Chak is the command area of an outlet. It is a function of operating characteristics of the system, peak design requirement of an outlet and field application rate.

132 .

What are the categories of the entire water conveyance system?

A) The primary distribution system and secondary distribution system

B) The primary distribution system, secondary distribution system, and tertiary distribution system

C) The primary distribution system, the secondary distribution system, and Water allowance

D) The primary distribution system, secondary distribution system, tertiary distribution system, and Water allowance

Correct Answer : The primary distribution system, secondary distribution system, and tertiary distribution system

Explanation : An integral management system designed to deliver a constant flow of water among irrigators along a tertiary canal is called Warabandi. This entire water conveyance system is divided into Primary, Secondary and Tertiary distribution system. Water allowance is just a certain rate of flow which is allocated to each unit of C.C.A in this warabandi system.

133 .

What is the correct formula for Flow Time in an hour for an individual farmer?

A) FT for the unit area + (his bharai – his jharai)

B) FT for the unit area – (his bharai – his jharai)

C) (FT for the unit area) x (area of farmer’s fields) – (his bharai – his jharai)

D) (FT for the unit area) x (area of farmer’s fields) + (his bharai – his jharai)

Correct Answer : (FT for the unit area) x (area of farmer’s fields) + (his bharai – his jharai)

Explanation : The formula for the flow time an hour for an individual farmer after the allowance of Bharai and Jharai timings is –
(FT for the unit area) x (area of farmer’s fields) + (his bharai – his jharai)

Bharai is generally zero in case of the tail (i.e. the last farmer) and Jharai is usually zero for all except for the tail.

134 .

What is the formula for the Flow Time for the unit area in hours?

A) 168 – (total Bharai – total Jharai)

B) 168 + (total Bharai – total Jharai)

C) 168 – (total Bharai – total Jharai) / Total area to be irrigated by the water-course

D) 168 + (total Bharai – total Jharai) / Total area to be irrigated by the water-course

Correct Answer : 168 – (total Bharai – total Jharai) / Total area to be irrigated by the water-course

Explanation : The distribution is done on the basis of seven-day rotation i.e. 24 x 7 = 168 hours.

The bharai time is debited from the common pool time of 168 hours and that value of bharai which is not efficient for field applications, the tail end farmer is compensated and allowed a certain recovery of the bharai time is called jharai.

Hence, the formula for Flow Time for a unit area of a land holding is given as –
FT = 168 – (total Bharai – total Jharai) / Total area to be irrigated by the water-course.

135 .

What is the most important point to be considered while fixing the canal capacity?

A) Demand

B) Keenest Demand

C) Water Demand

D) Average Demand

Correct Answer : Keenest Demand

Explanation : While fixing the capacity of a canal the main important that should be kept in mind is the keenest demand, but not the average demand. For instance, let rice require 160 cm of water during 320 days which gives an outlet factor of 1728 hectares/cumec. (i.e D = 864B/∆ = 864 x 320 / 160 = 1728).

136 .

For a standing crop, the consumptive use of water is equal to the depth of water

A) evaporated by the crop

B) transpired by the crop

C) transpired and evaporated by the crop

D) used by the crop in transpiration, evaporation and also the quantity of water evaporated from adjacent soil.

Correct Answer : used by the crop in transpiration, evaporation and also the quantity of water evaporated from adjacent soil.

137 .

The state of the soil when plants fail to extract sufficient water for their requirements, is_________.

A) permanent wilting point

B) maximum saturated point

C) ultimate utilisation point

D) None of the above

Correct Answer : permanent wilting point

138 .

The field capacity of a soil is 25%, its permanent wilting point is 15% and specific dry unity weight is 1.5. If the depth of root zone of a crop, is 80 cm, the storage capacity of the soil, is______.

A) 12 cm

B) 14 cm

C) 10 cm

D) 16 cm

Correct Answer : 12 cm

139 .

The length and width of a meander and also the width of the river, vary roughly as______.

A) discharge

B) cube of the discharge

C) square root of the discharge

D) square of the discharge

Correct Answer : square root of the discharge

140 .

An outlet is said to be proportional if its flexibility, is_______

A) zero

B) one

C) less than one

D) more than one

Correct Answer : one

141 .

The ratio of the discharge over a trapezoidal crest to a rectangular crest of Sarda falls of identical parameters, is_______.

A) 2.053

B) 1.054

C) 1.074

D) 1.084

Correct Answer : 1.084

142 .

For standing crops in undulating sandy fields, the best method of irrigation, is______.

A) check method

B) free flooding

C) furrow method

D) sprinkler irrigation

Correct Answer : sprinkler irrigation

143 .

In a syphon aqueduct________.

A) canal passes over the drainage and H.F.L. of the drainage is above the bottom of the canal trough

B) drainage passes over the canal and F.S.L. of the canal is above the bottom of the drainage trough

C) canal passes over the drainage and H.F.L. of the drainage is below the bottom of the canal trough

D) drainage passes over the canal and F.S.L. of the canal is below the bottom of the drainage trough

Correct Answer : canal passes over the drainage and H.F.L. of the drainage is above the bottom of the canal trough

144 .

Garnett's diagrams are used for graphical solution of design equations of a canal by________.

A) Gibb's theory

B) Lacey's theory

C) Kennedy's theory

D) Lindlay theory

Correct Answer : Kennedy's theory

145 .

A current meter measures the velocity of flow, if it is held_______.

A) on the surface of water

B) at the bottom of channel

C) at any point within the cross-section

D) None of the above

Correct Answer : at the bottom of channel

146 .

In a concrete canal the approximate permissible velocity of water should not exceed______.

A) 2.5 m/sec

B) 2 m/sec

C) 1.5 m/sec

D) 1 m/sec

Correct Answer : 2 m/sec

147 .

Regime conditions in a channel may occur if_______.

A) discharge is constant

B) silt grade and silt charge are constant

C) channel flows uniformly in incoherent alluvium as that transported in suspension

D) All of the above

Correct Answer : All of the above

148 .

If the optimum depth of kor watering for a crop is 15.12 cm, the outlet factor for the crop for four week period in hectares per cumec, is______.

A) 1600

B) 1400

C) 1200

D) 1000

Correct Answer : 1600

149 .

If H and d are the water depth and drop in the bed level at a Sarda fall, the width B of the trapezoidal crest, is given by_______.

A) B = 0.33 √H + d

B) B = 0.22 √H + d

C) B = 0.55 √H + d

D) B = 0.44 √H + d

Correct Answer : B = 0.55 √H + d

150 .

According to Bligh's creep theory, percolating water flows along_______.

A) straight path under the foundation of the dam

B) the outline of the base of the foundation of the dam

C) circular path under the foundation of the dam

D) None of the above

Correct Answer : the outline of the base of the foundation of the dam

151 .

The width of a meander belt is the transverse distance between_________.

A) apex point and the crossing

B) two banks of meandering river

C) apex point of one curve and apex point of the reserve curve

D) None of the above

Correct Answer : apex point of one curve and apex point of the reserve curve

152 .

The sensitivity of a rigid module, is____.

A) 2.00

B) 1.50

C) 1.00

D) zero

Correct Answer : zero

153 .

Pick up the correct sequence of the part of a canal system from the following_______.

A) Head works-main canal-branch canal-dis-tributary-minor

B) Head work-distributary-branch canal-minor

C) Head works-main canal-branch canal-minor-distributary

D) Heads works-branch canal-main canal distributary, minor

Correct Answer : Head works-main canal-branch canal-dis-tributary-minor

154 .

A counter berm is________.

A) a horizontal benching provided on the inside slope

B) a horizontal benching provided on the outside slope

C) a vertical benching provided on the outer edge of the bank

D) a vertical benching provided on the inner edge of the bank

Correct Answer : a horizontal benching provided on the outside slope

155 .

What type of losses can be mainly avoided by lining the canals?

A) Seepage Losses

B) Evaporation Losses

C) Erosion of Canal Bed

D) Discharge Losses at Branch Canals

Correct Answer : Seepage Losses

Explanation : If lining is not provided in the canal then irrigation water is lost in the form of percolation and absorption as seepage losses. This loss is very significant as it reduces the potential of the irrigation water, which is a costly commodity. So, in order to reduce seepage losses the lining of the canal is needed.

156 .

What is the name given to the land unfit for agriculture due to waterlogging?

A) Tundra

B) Desert

C) Thur

D) Waterlogged Area

Correct Answer : Thur

Explanation : Due to uncontrolled seepage losses the water in the canal gets percolated and the water table level in underground rises. This level rises up to or near the ground level. This renders the land unfit for agriculture as the crop roots bring up the alkali salts to the ground level. This phenomenon is known as waterlogging and the land is called thur.

157 .

Design a lined canal carrying a discharge of 20 cumecs. The slope is 1 in 7000. Assume suitable values for side slopes and lining.

A) Side Slope = 1.4: 1, Depth = 4.1 m

B) Side Slope = 1.2: 1, Depth = 4.4 m

C) Side Slope = 1.5: 1, Depth = 3.77 m

D) Side Slope = 1.3: 1, Depth = 4.5 m

Correct Answer : Side Slope = 1.5: 1, Depth = 3.77 m

Explanation : Let us assume side slope as 1.5 : 1 (1.5H : 1V), the rugosity constant as 0.015.
Now let us design a triangular section.
A = y² (θ + cotθ), P = 2y(θ + cotθ), and R = A/P = y/2
Tanθ = (1/1.5) and cotθ = 1.5 and θ = 0.59
A = y² (0.59 + 1.5) = y² (2.09)
P = 2 y (0.59 + 1.5) = y (4.18)
R = 0.5y
Now Manning’s equation gives
Q = 1/n x A x R⅔ x S½
20 = (1/0.015) x y² (2.09) x (0.5y) ⅔ x (1/7000)½
y= 3.02 m
Freeboard = 0.75 m
Total depth = 3.02 + 0.75 = 3.77 m and side slope = 1.5 : 1

158 .

Depending on what factor does the lining of a canal can increase the capacity of the canal?

A) Side Slope

B) Velocity

C) Type of Flow

D) Width of the Canal

Correct Answer : Velocity

Explanation : The reason is very simple. The lined surface provides a smooth surface for the flow of water with minimum resistance, whereas the unlined canal provides more resistance due to vegetation, undulations, rocks etc. Moreover the velocity of flow in lined canal is high when compared with the velocity in unlined canal, as the capacity of canal is dependent on the velocity directly if velocity increases so does the capacity of the canal.

159 .

Mathematically, depending on what factor we can say velocity increases the capacity of the canal?

A) Coefficient of Viscosity

B) Coefficient of Resistance

C) Coefficient of Capillarity

D) Coefficient of Roughness

Correct Answer : Coefficient of Roughness

Explanation : Coefficient of roughness is indirectly proportional to velocity in any mathematical formula, or condition, or equation. So, therefore the value of this coefficient is more for unlined canals than the lined canals. Hence the velocity is more for lined canals than the unlined canals and therefore capacity for lined canals is more.

160 .

What costs are reduced with the help of lining a canal?

A) A.R and M.O Costs

B) Construction Costs

C) Transportation Costs

D) Irrigation Water Costs

Correct Answer : A.R and M.O Costs

Explanation : The expenditure on Annual repair (A.R) and Maintenance (M.O) costs are reduced with the lining of a canal. The expenditure maybe due to removal of weeds and plants, minor repairs like covering cracks, leakages, and undulations in the bed, removal silt deposited on the bed. So, therefore if lining is done the expenditure (costs) can be reduced.

161 .

The drainage water is sometimes allowed to join the canal water to augment canal supplies through a hydraulic structure is called as ________

A) module

B) canal outlet

C) canal inlet

D) level crossing

Correct Answer : canal inlet

Explanation : The structure allows the drainage water to enter the canal and get mixed with the canal water. It helps in augmenting canal supplies. It is adopted when high flood drainage discharge is small.

162 .

An outlet which maintains a constant discharge irrespective of fluctuation in the water levels of the supplying channel or water course, is known as____.

A) semi-modular outlet

B) right modular outlet

C) non-modular outlet

D) flexible modular outlet

Correct Answer : right modular outlet

163 .

Canals constructed for draining off water from water logged areas, are known____.

A) ridge canals

B) drains

C) valley canals

D) inundation canals

Correct Answer : drains

164 .

A minimum of 90 cm free board is provided if the discharge in the canal is between_________.

A) 30 to 33 cumecs

B) 30 to 60 cumecs

C) Over 60 cumecs

D) Over 100 cumecs

Correct Answer : Over 60 cumecs

165 .

If D is the depth of water upstream of the throat above its sill, B is the width of the throat, to achieve critical flow in an open venturi flume, the theoretical maximum flow Q, is____.

A) Q = 1.71 BD3/2

B) Q = 1.71 BD1/2

C) Q = 1/71 BD2/3

D) Q = 1.71 BD

Correct Answer : Q = 1.71 BD3/2

166 .

In Montague type fall_______.

A) no glacis is provided

B) a circular glacis is provided

C) a straight glacis is provided

D) a parabolic glacis is provided

Correct Answer : a parabolic glacis is provided

167 .

For diversion of flood water of rivers, the type of canal constructed, is_______.

A) canal

B) ridge canal

C) perennial canal

D) inundation canal

Correct Answer : inundation canal

168 .

Process of meandering is due to_______.

A) sediment load of streams

B) relative erodibility of the bed and banks

C) discharge and hydraulic properties of streams

D) All of the above

Correct Answer : All of the above

169 .

For cereal crops the most commonly adopted method of irrigation, is_________.

A) check method

B) furrow method

C) sprinkling method

D) free flowing method

Correct Answer : check method

170 .

While deciding the alignment of a proposed canal taking off from a river at B, three alignments of approximately equal lengths are available. These cross a drainages at C1, C2 and C3 where drainage bed levels C1 > C2 > C3, you will provide at site C3

A) a syphon

A)

B) an aqueduct

B)

C) a super passage

C)

D) a syphon aqueduct

D)

Correct Answer : an aqueduct

171 .

The ratio of the rate of change of discharge of an outlet to the rate of change in level of water surface in a distributary at its normal depth, is known as

A) efficiency

B) sensitivity

C) flexibility

D) modular limit

Correct Answer : sensitivity

172 .

What is the range of value of Manning's coefficient for straight alignment for cast in-situ concrete lining?

A) 0.020 – 0.025

B) 0.018 – 0.020

C) 0.015 – 0.018

D) 0.012 – 0.015

Correct Answer : 0.015 – 0.018

Explanation : In absolutely straight reaches and with relatively higher discharges lower values of Manning’s constant may be attained. For cast in-situ concrete lining, the value of n varies from 0.015–0.018 and for cement plastered masonry the value varies from 0.012-0.015.

173 .

What is the maximum permissible velocity in Cement concrete lining (Unreinforced) as per Indian Standards?

A) 1.2 to 1.8 m/sec

B) 2 to 2.5 m/sec

C) 1.5 to 2 m/sec

D) 1.5 to 2.5 m/sec

Correct Answer : 2 to 2.5 m/sec

Explanation : The maximum permissible velocity for unreinforced cement concrete lining is 2.0 to 2.5 m/sec. For Boulder lining, the maximum permissible velocity is 1.5 m/sec.

174 .

Calculate hydraulic mean depth for concrete-lined channel to carry a discharge of 350 cumecs at a slope of 1 in 5000. The value of manning’s constant for the lining is 0.015. The side slopes of a channel may be taken as 1.5:1. Assume limiting velocity in the channel as 2m/sec.

A) 2.20 m

A)

B) 2.40 m

B)

C) 2.60 m

C)

D) 2.80 m

D)

Correct Answer : 2.80 m

Explaination : Using Manning’s equation: V = 1/n.R2/3.S½
2 = 1/0.015 x R⅔ x 1/5000½
R = 2.80 m.

175 .

Which type of lining is mixed and placed under temperature?

A) Dry Stone Lining

B) Shotcrete Lining

C) Cement Concrete Lining

D) Asphaltic Concrete Lining

Correct Answer : Asphaltic Concrete Lining

Explanation : Asphaltic concrete lining has been under evolution. It is used in very few places. This concrete is a careful mixture of asphalt and graded stone aggregate, and is mixed and applied under elevated temperature. This is a flexible lining and readily confirms to subgrade.

Civil Engineering : Irrigation MCQs with Answers