390+ Irrigation Engineering Solved MCQs

These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Civil Engineering .

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1.	Which of the following methods of applying water may be used on rolling land ?
A.	boarder flooding
B.	check flooding
C.	furrow flooding
D.	free flooding
Answer» A. boarder flooding

discuss

2.	The value of Sodium Absorption Ratio for high sodium water lies between
A.	0 to 10
B.	10 to 18
C.	18 to 26
D.	26 to 34
Answer» C. 18 to 26

discuss

3.	Optimum depth of kor watering for rice is
A.	135 mm
B.	165 mm
C.	190 mm
D.	215 mm
Answer» C. 190 mm

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4.	Irrigation water having the concentration of Na++ , Ca++ and Mg++ as 20, 3 and 1 Milli equivalent per litre respectively will be classified as
A.	low sodium water
B.	medium sodium water
C.	high sodium water
D.	very high sodium water
Answer» B. medium sodium water

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5.	The duty is largest
A.	at the head of water course
B.	on the field
C.	at the head of a main canal
D.	same at all places
Answer» B. on the field

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6.	The "outlet discharge factor" is the duty at the head of
A.	main canal
B.	branch canal
C.	watercourse
D.	distributory
Answer» C. watercourse

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7.	The kor depth for rice is 190 mm and kor period is 14 days. The outlet factor for this will be
A.	637 hectares/m3/sec
B.	837 hectares/m3/sec
C.	972 hectares/m3/sec
D.	1172 hectares/m3/sec
Answer» A. 637 hectares/m3/sec

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8.	For supplying water to rabi crop, kharif crop and sugarcane, the channel is designed for a capacity equal to the greater of the water requirement of
A.	rabi or kharif
B.	rabi and kharif or sugarcane
C.	rabi and sugarcane or kharif and sugarcane
D.	rabi or kharif or sugarcane
Answer» C. rabi and sugarcane or kharif and sugarcane

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9.	The ratio of the quantity of water stored in the root zone of the crops to the quantity of water actually delivered in the field is known as
A.	water conveyance efficiency
B.	water application efficiency
C.	water use efficiency
D.	none of the above
Answer» B. water application efficiency

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10.	The water utilizable by plants is available in soils mainly in the form of
A.	gravity water
B.	capillary water
C.	hydroscopic water
D.	chemical water
Answer» B. capillary water

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11.	The amount of irrigation water required to meet the evapotranspiration needs of the crop during its full growth is called
A.	effective rainfall
B.	consumptive use
C.	consumptive irrigation requirement
D.	net irrigation requirement
Answer» C. consumptive irrigation requirement

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12.	With the increase in the quantity of water supplied, the yield of most crops
A.	increases continuously
B.	decreases continuously
C.	increases upto a certain limit and then becomes constant
D.	increases upto a certain limit and then decreases
Answer» D. increases upto a certain limit and then decreases

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13.	Hydrograph is the graphical representation of
A.	runoff and time
B.	surface runoff and time
C.	ground waterflow and time
D.	rainfall and time
Answer» A. runoff and time

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14.	Infiltration rate is always
A.	more than the infiltration capacity
B.	less than the infiltration capacity
C.	equal to or less than the infiltration capacity
D.	equal to or more than the infiltration capacity
Answer» C. equal to or less than the infiltration capacity

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15.	The depth of water required to bring the soil moisture content of a given soil upto its field capacity is called
A.	hygroscopic water
B.	equivalent moisture
C.	soil moisture deficiency
D.	pellicular water
Answer» C. soil moisture deficiency

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16.	Infiltration capacity
A.	is a constant factor
B.	changes with time
C.	changes with location
D.	changes with both time and location
Answer» D. changes with both time and location

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17.	Infiltration is the
A.	movement of water through the soil
B.	absorption of water by soil surface
C.	both (a) and (b)
D.	none of the above
Answer» A. movement of water through the soil

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18.	If the intensity of rainfall is more than the infiltration capacity of soil, then the infiltration rate will be
A.	equal to rate of rainfall
B.	equal to infiltration capacity
C.	more than rate of rainfall
D.	more than infiltration capacity
Answer» B. equal to infiltration capacity

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19.	Cyclonic precipitation is caused by lifting of an air mass due to
A.	pressure difference
B.	temperature difference
C.	natural topographical barriers
D.	all of the above
Answer» A. pressure difference

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20.	Which of the following is a non-recording raingauge ?
A.	tipping bucket type raingauge
B.	Simon's raingauge
C.	Steven's weighing type raingauge
D.	floating type raingauge
Answer» B. Simon's raingauge

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21.	A raingauge should preferably be fixed
A.	near the building
B.	under the tree
C.	in an open space
D.	in a closed space
Answer» C. in an open space

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22.	Which of the following types of rain gauges is used for measuring rain in remote hilly inaccessible areas ?
A.	tipping bucket type
B.	weighing type
C.	floating type
D.	Simon's raingauge
Answer» A. tipping bucket type

discuss

23.	Rate of evaporation from a water surface increases if i) difference of vapour pressure between water and air is increased ii) velocity of wind is decreased iii) concentration of soluble solids in water is decreased The correct answer is
A.	(i) and (ii)
B.	(i) and (iii)
C.	(ii) and (iii)
D.	(i). (ii) and (iii)
Answer» B. (i) and (iii)

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24.	A 70% index of wetness means
A.	rain excess of 30%
B.	rain deficiency of 30%
C.	rain deficiency of 70%
D.	none of the above
Answer» B. rain deficiency of 30%

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25.	Under the same conditions, which of the following shapes of water surface will give the highest rate of evaporation ?
A.	flat water surface
B.	convex water surface
C.	concave water surface
D.	independent of shape of water surface
Answer» B. convex water surface

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26.	Assertion A : To estimate the rainfall over a catchment, the number of raingauges required per unit area is large for hilly areas. Reason R : Rainfall gradient is steep. Select your correct answer according to the coding system given below :
A.	Both A and R are true and R is the correct explanation of A
B.	Both A and R are true but R is not the correct explanation of A
C.	A is true but R is false
D.	A is false but R is true
Answer» A. Both A and R are true and R is the correct explanation of A

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27.	When surface of transpiration is submerged under water, then potential evapotranspiration is
A.	much more than evapotranspiration
B.	much less than evapotranspiration
C.	equal to evapotranspiration
D.	equal to or less than evapotr
Answer» A. much more than evapotranspiration

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28.	Unit of runoff in M.K.S. system is
A.	cubic metre/sec
B.	metre/sec
C.	cubic metre
D.	square metre
Answer» A. cubic metre/sec

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29.	The runoff increases with
A.	increase in intensity of rain
B.	increase in infiltration capacity
C.	increase in permeability of soil
D.	all of the above
Answer» A. increase in intensity of rain

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30.	The area between the isohyets 45 cm and 55 cm is 100 square km and between 55 cm and 65cm is 150 square km. The average depth of annua! precipitation over the above basin of 250 square km will be
A.	50 cm
B.	55 cm
C.	56 cm
D.	60 cm
Answer» C. 56 cm

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31.	A current meter is used to measure the
A.	velocity of flow of water
B.	depth of flow of water
C.	discharge
D.	none of the above
Answer» A. velocity of flow of water

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32.	If it rains between 2 P.M. and 3 P.M. and the entire basin area just starts contributing water at 3 P.M. to the outlet, then time of concentration will be
A.	15 minutes
B.	20 minutes
C.	30 minutes
D.	60 minutes
Answer» D. 60 minutes

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33.	The rainfall on five successive days were measured as 100 mm, 80 mm, 60 mm, 40 mm and 20 mm respectively. If the infiltration index or the storm loss rate for the catchment area is earlier estimated as 50 mm/day, the total surface run off will be
A.	50 mm
B.	60 mm
C.	90 mm
D.	140 mm
Answer» C. 90 mm

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34.	The normal annual precipitation at stations X, A, B and C are 700 mm, 1000 mm, 900 mm and 800 mm respectively. If the storm precipitation at three station A, B and C were 100 mm, 90 mm and 80 mm respectively, then the storm precipitation for station X will be
A.	70mm
B.	80mm
C.	90 mm
D.	105 mm
Answer» A. 70mm

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35.	The best unit duration of storm for a unit hydrograph is
A.	1 hour
B.	one-fourth of basin lag
C.	one-half of basin lag
D.	equal to basin lag
Answer» B. one-fourth of basin lag

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36.	The unit hydrograph due to a storm may be obtained by dividing the ordinates of the direct runoff hydrograph by
A.	direct runoff volume
B.	period of storm
C.	total rainfall
D.	none of the above
Answer» A. direct runoff volume

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37.	The unit hydrograph of a specified duration can be used to evaluate the hydrograph of storms of
A.	same duration only
B.	same and shorter duration
C.	same and longer duration
D.	any duration
Answer» D. any duration

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38.	S-hydrograph is used to obtain unit hydrograph of
A.	shorter duration from longer duration
B.	longer duration from shorter duration
C.	both (a) and (b)
D.	none of the above
Answer» C. both (a) and (b)

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39.	The relation between probability (P) and recurrence interval (T) is given by
A.	PT = 1
B.	PT2 = 1
C.	P/T = 1
D.	P/T2 = 1
Answer» A. PT = 1

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40.	Dimensions of coefficient of transmissibility are
A.	M°L°T°
B.	rvfL'T"1
C.	M° L2 T1
D.	M'LV
Answer» C. M° L2 T1

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41.	If d is the depth of the aquifer through which water is flowing, then the relationship between permeability k and transmissible T is given by
A.	T = kd
B.	T = k/d
C.	T= Vkd
D.	k= VTd
Answer» A. T = kd

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42.	An artesian aquifer is the one where
A.	water surface under the ground is at atmospheric pressure
B.	water is under pressure between two impervious strata
C.	water table serves as upper surface of zone of saturation
D.	none of the above
Answer» B. water is under pressure between two impervious strata

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43.	A deep well
A.	is always deeper than a shallow well
B.	has more discharge than a shallow well
C.	is weaker structurally than a shallow well
D.	both (a) and (b)
Answer» B. has more discharge than a shallow well

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44.	A multipurpose reservoir is the one which is
A.	designed for one purpose but serves more than one purpose
B.	planned and constructed to serve various purposes
C.	both (a) and (b)
D.	none of the above
Answer» B. planned and constructed to serve various purposes

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45.	The useful storage is the volume of water stored in the reservoir between
A.	minimum pool level and maximum pool level
B.	minimum pool level and normal pool level
C.	normal pool level and maximum pool level
D.	river bed and minimum pool level
Answer» B. minimum pool level and normal pool level

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46.	The water stored in the reservoir below the minimum pool level is called
A.	useful storage
B.	dead storage
C.	valley storage
D.	surcharge storage
Answer» B. dead storage

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47.	For a flood control reservoir, the effective storage is equal to
A.	useful storage - valley storage
B.	useful storage + surcharge storage
C.	useful storage + surcharge storage + valley storage
D.	useful storage + surcharge storage -valley storage
Answer» D. useful storage + surcharge storage -valley storage

discuss

48.	Trap efficiency of a reservoir is a function of
A.	capacity/inflow ratio
B.	capacity/outflow ratio
C.	outflow/inflow ratio
D.	none of the above
Answer» A. capacity/inflow ratio

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49.	The total capacity of a reservoir is 25 million cubic metres and dead storage is 5 million cubic metres. If the average volume of sediment deposition is 0.10 million cubic metre per year, then the usefulness of the reservoir will start reducing after
A.	50 years
B.	150 years
C.	200 years
D.	250 years
Answer» A. 50 years

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50.	The forces, which are considered for the analysis of an elementary profile of a gravity dam under empty reservoir condition, are i) Water pressure ii) Self weight iii) Uplift iv) Pressure due to earthquake The correct answer is
A.	Only (ii)
B.	(i), (ii) and (iii)
C.	(i), (ii) and (iv)
D.	(i), (ii), (iii) and (iv)
Answer» A. Only (ii)

discuss

390+ Irrigation Engineering Solved MCQs

Which of the following methods of applying water may be used on rolling land ?

The value of Sodium Absorption Ratio for high sodium water lies between

Optimum depth of kor watering for rice is

Irrigation water having the concentration of Na++ , Ca++ and Mg++ as 20, 3 and 1 Milli equivalent per litre respectively will be classified as

The duty is largest

The "outlet discharge factor" is the duty at the head of

The kor depth for rice is 190 mm and kor period is 14 days. The outlet factor for this will be

For supplying water to rabi crop, kharif crop and sugarcane, the channel is designed for a capacity equal to the greater of the water requirement of

The ratio of the quantity of water stored in the root zone of the crops to the quantity of water actually delivered in the field is known as

The water utilizable by plants is available in soils mainly in the form of

The amount of irrigation water required to meet the evapotranspiration needs of the crop during its full growth is called

With the increase in the quantity of water supplied, the yield of most crops

Hydrograph is the graphical representation of

Infiltration rate is always

The depth of water required to bring the soil moisture content of a given soil upto its field capacity is called

Infiltration capacity

Infiltration is the

If the intensity of rainfall is more than the infiltration capacity of soil, then the infiltration rate will be

Cyclonic precipitation is caused by lifting of an air mass due to

Which of the following is a non-recording raingauge ?

A raingauge should preferably be fixed

Which of the following types of rain gauges is used for measuring rain in remote hilly inaccessible areas ?

Rate of evaporation from a water surface increases if i) difference of vapour pressure between water and air is increased ii) velocity of wind is decreased iii) concentration of soluble solids in water is decreased The correct answer is

A 70% index of wetness means

Under the same conditions, which of the following shapes of water surface will give the highest rate of evaporation ?

Assertion A : To estimate the rainfall over a catchment, the number of raingauges required per unit area is large for hilly areas. Reason R : Rainfall gradient is steep. Select your correct answer according to the coding system given below :

When surface of transpiration is submerged under water, then potential evapotranspiration is

Unit of runoff in M.K.S. system is

The runoff increases with

The area between the isohyets 45 cm and 55 cm is 100 square km and between 55 cm and 65cm is 150 square km. The average depth of annua! precipitation over the above basin of 250 square km will be

A current meter is used to measure the

If it rains between 2 P.M. and 3 P.M. and the entire basin area just starts contributing water at 3 P.M. to the outlet, then time of concentration will be

The rainfall on five successive days were measured as 100 mm, 80 mm, 60 mm, 40 mm and 20 mm respectively. If the infiltration index or the storm loss rate for the catchment area is earlier estimated as 50 mm/day, the total surface run off will be

The normal annual precipitation at stations X, A, B and C are 700 mm, 1000 mm, 900 mm and 800 mm respectively. If the storm precipitation at three station A, B and C were 100 mm, 90 mm and 80 mm respectively, then the storm precipitation for station X will be

The best unit duration of storm for a unit hydrograph is

The unit hydrograph due to a storm may be obtained by dividing the ordinates of the direct runoff hydrograph by

The unit hydrograph of a specified duration can be used to evaluate the hydrograph of storms of

S-hydrograph is used to obtain unit hydrograph of

The relation between probability (P) and recurrence interval (T) is given by

Dimensions of coefficient of transmissibility are

If d is the depth of the aquifer through which water is flowing, then the relationship between permeability k and transmissible T is given by

An artesian aquifer is the one where

A deep well

A multipurpose reservoir is the one which is

The useful storage is the volume of water stored in the reservoir between

The water stored in the reservoir below the minimum pool level is called

For a flood control reservoir, the effective storage is equal to

Trap efficiency of a reservoir is a function of

The total capacity of a reservoir is 25 million cubic metres and dead storage is 5 million cubic metres. If the average volume of sediment deposition is 0.10 million cubic metre per year, then the usefulness of the reservoir will start reducing after

The forces, which are considered for the analysis of an elementary profile of a gravity dam under empty reservoir condition, are i) Water pressure ii) Self weight iii) Uplift iv) Pressure due to earthquake The correct answer is

Rate of evaporation from a water surface increases if
i) difference of vapour pressure between water and air is increased
ii) velocity of wind is decreased
iii) concentration of soluble solids in water is decreased The correct answer is

Assertion A : To estimate the rainfall over a catchment, the number of raingauges required per unit area is large for hilly areas.
Reason R : Rainfall gradient is steep.
Select your correct answer according to the coding system given below :

The forces, which are considered for the analysis of an elementary profile of a gravity dam under empty reservoir condition, are
i) Water pressure
ii) Self weight
iii) Uplift
iv) Pressure due to earthquake
The correct answer is