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Civil Engineering : Irrigation - Quiz(MCQ)
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.

A)
ridge line
B)
valley line
C)
contour line
D)
straight line

Correct Answer :   ridge line

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.

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.

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

A)
degrading type
B)
aggrading type
C)
meandering type
D)
sub-critical type

Correct Answer :   degrading type

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

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.

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

A)
1/50 (B+d)â…”
B)
1/100 (B+d)â…”
C)
1/150 (B+d)â…”
D)
1/200 (B+d)â…”

Correct Answer :   1/200 (B+d)â…”

A)
trough stage
B)
delta stage
C)
rocky stage
D)
boulder stage

Correct Answer :   trough stage

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.

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

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

A)
berm
B)
free board
C)
height of bank
D)
None of the above

Correct Answer :   free board

A)
15 cm lower
B)
15 cm higher
C)
at the same level
D)
None of the above

Correct Answer :   15 cm lower

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

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

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

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.

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.

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.

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.

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.

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)

A)
inclined down stream
B)
inclined up stream
C)
perpendicular to the bank
D)
None of the above

Correct Answer :   inclined down stream

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

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

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

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

A)
(D₂-D₁)³ / D₁D₂
B)
(D₂-D₁)³ / 2D₁D₂
C)
(D₂-D₁)³ / 3D₁D₂
D)
(D₂-D₁)³ / 4D₁D₂

Correct Answer :   (Dâ‚‚-D₁)³ / 4D₁Dâ‚‚

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

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.

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

A)
pipe flow
B)
with critical velocity
C)
under negative pressure
D)
under atmospheric pressure

Correct Answer :   pipe flow

A)
10 cumecs
B)
14 cumecs
C)
20 cumecs
D)
25 cumecs

Correct Answer :   14 cumecs

A)
syphon
B)
super passage
C)
aqueduct
D)
syphon-aqueduct

Correct Answer :   aqueduct

A)
0.25
B)
0.50
C)
0.75
D)
1.00

Correct Answer :   1.00

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.

A)
perennial canals
B)
ridge canals
C)
permanent canals
D)
inundation canals

Correct Answer :   perennial canals

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

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.

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.

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.

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.

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.

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.

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.

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

A)
a level crossing
B)
a syphon
C)
an aqueduct
D)
inlet and outlet

Correct Answer :   a level crossing

A)
120°
B)
110°
C)
90°
D)
80°

Correct Answer :   110°

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

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

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°

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

A)
forest area
B)
fallow land
C)
alkaline area
D)
populated area

Correct Answer :   fallow land

A)
to store water
B)
to control floods
C)
to raise water level
D)
All of the above

Correct Answer :   All of the above

A)
30°
B)
45°
C)
60°
D)
90°

Correct Answer :   45°

A)
defective outlets
B)
inadequate slope
C)
defective head regulator
D)
All of the above

Correct Answer :   All of the above

A)
12.0 cm
B)
13.5 cm
C)
17.5 cm
D)
19.0 cm

Correct Answer :   13.5 cm

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

A)
efficiency
B)
flexibility
C)
sensitivity
D)
modular limit

Correct Answer :   efficiency

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

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.

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.

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.

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.

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.

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.

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.

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.

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

A)
11
B)
10
C)
9
D)
8

Correct Answer :   11

A)
an aqueduct
B)
a super-passage
C)
a syphon aqueduct
D)
None of the above

Correct Answer :   a super-passage

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)

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

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

A)
capillary water
B)
gravity water
C)
chemical water
D)
hygroscopic water

Correct Answer :   capillary water

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

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

A)
m³
B)
m½
C)
mâ…“
D)
mâ…”

Correct Answer :   m½

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.

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.

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.

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.

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.

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.

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.

A)
pond level
B)
F.S.L. of the canal
C)
discharge perimeters
D)
All of the above

Correct Answer :   All of the above

A)
90 cm
B)
80 cm
C)
70 cm
D)
60 cm

Correct Answer :   90 cm

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

A)
hydraulic jump
B)
seepage forces
C)
hydraulic pressure
D)
All of the above

Correct Answer :   All of the above

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

A)
x = r₁ d₁
B)
x = râ‚‚ dâ‚‚
C)
x = d₁ / r₁
D)
x = dâ‚‚ / râ‚‚

Correct Answer :   x = râ‚‚ dâ‚‚

A)
aqueduct
B)
super passage
C)
syphon aqueduct
D)
super-aqueduct

Correct Answer :   syphon aqueduct

A)
13.5 cm
B)
17.5 cm
C)
19.0 cm
D)
23.0 cm

Correct Answer :   19.0 cm

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

A)
left side
B)
right side
C)
both sides
D)
All of the above

Correct Answer :   All of the above

A)
1.20 m
B)
2.20 m
C)
3.20 m
D)
4.90 m

Correct Answer :   1.20 m

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

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

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

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
B)
12 – 15.5
C)
> 15.5
D)
9 – 12.5

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.

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
B)
ii only
C)
ii and iii
D)
i, ii, and iii

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.

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
B)
172.8 hectares/cumec, 194.4 hectares/cumec
C)
182.9 hectares/cumec, 194.4 hectares/cumec
D)
185.6 hectares/cumec, 184.6 hectares/cumec

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
B)
0.77H.P
C)
0.80H.P
D)
0.85H.P

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
B)
184.89hectares/cumec
C)
186.25hectares/cumec
D)
187.45hectares/cumec

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.

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.

A)
degrading
B)
aggrading
C)
meandering
D)
All of the above

Correct Answer :   meandering

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

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

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

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

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

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

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.

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
B)
1.32 cumec
C)
1.33 cumec
D)
1.35 cumec

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
B)
2.08 cumec
C)
2.1 cumec
D)
2.2 cumec

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.

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.

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.

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.

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.

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.

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).

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.

A)
permanent wilting point
B)
maximum saturated point
C)
ultimate utilisation point
D)
None of the above

Correct Answer :   permanent wilting point

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

A)
zero
B)
one
C)
less than one
D)
more than one

Correct Answer :   one

A)
2.053
B)
1.054
C)
1.074
D)
1.084

Correct Answer :   1.084

A)
check method
B)
free flooding
C)
furrow method
D)
sprinkler irrigation

Correct Answer :   sprinkler irrigation

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

A)
Gibb's theory
B)
Lacey's theory
C)
Kennedy's theory
D)
Lindlay theory

Correct Answer :   Kennedy's theory

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

A)
2.5 m/sec
B)
2 m/sec
C)
1.5 m/sec
D)
1 m/sec

Correct Answer :   2 m/sec

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

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

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

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

A)
2.00
B)
1.50
C)
1.00
D)
zero

Correct Answer :   zero

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

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

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.

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.

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 Râ…” x S½
20 = (1/0.015) x y² (2.09) x (0.5y) â…” 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

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.

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.

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.

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.

A)
semi-modular outlet
B)
right modular outlet
C)
non-modular outlet
D)
flexible modular outlet

Correct Answer :   right modular outlet

A)
ridge canals
B)
drains
C)
valley canals
D)
inundation canals

Correct Answer :   drains

A)
30 to 33 cumecs
B)
30 to 60 cumecs
C)
Over 60 cumecs
D)
Over 100 cumecs

Correct Answer :   Over 60 cumecs

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

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

A)
canal
B)
ridge canal
C)
perennial canal
D)
inundation canal

Correct Answer :   inundation canal

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

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
B)
an aqueduct
C)
a super passage
D)
a syphon aqueduct

Correct Answer :   an aqueduct

A)
efficiency
B)
sensitivity
C)
flexibility
D)
modular limit

Correct Answer :   sensitivity

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.

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
B)
2.40 m
C)
2.60 m
D)
2.80 m

Correct Answer :   2.80 m


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

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.