390+ Irrigation Engineering Solved MCQs

101.

The main cause of meandering is

A. presence of an excessive bed slope in the river
B. degradation
C. the extra turbulence generated by the excess of river sediment during floods
D. none of the above
Answer» C. the extra turbulence generated by the excess of river sediment during floods
102.

Tortuosity of a meandering river is always

A. equal to 1
B. less than 1
C. greater than 1
D. less than or equal to 1
Answer» C. greater than 1
103.

Select the correct statement.

A. A meander increases the river length but a cut off reduces the river length.
B. A cutoff increases the river length but a meander reduces the river length.
C. Both meander and cutoff increase the river length.
D. Both meander and cutoff decrease the river length.
Answer» A. A meander increases the river length but a cut off reduces the river length.
104.

River training for depth is achieved by

A. groynes
B. construction of dykes or leavees
C. both (a) and (b)
D. groynes and bandalling
Answer» D. groynes and bandalling
105.

Main purpose of mean water training for rivers is

A. flood control
B. to provide sufficient depth of water in navigable channels, during low water periods
C. to preserve the channel in good shape by efficient disposal of suspended and bed load
D. all of the above
Answer» C. to preserve the channel in good shape by efficient disposal of suspended and bed load
106.

If D is the depth of scour below original bed, then the width of launching apron is generally taken as

A. 1.2 D
B. 1.5 D
C. 2.0 D
D. 2.5 D
Answer» B. 1.5 D
107.

Study the following statements.
i) Levees are constructed parallel to river flow,
ii) Spurs are constructed parallel to river flow,
iii) Levees are constructed transverse to river flow,
iv) Spurs are constructed transverse to river flow.
The correct answer is

A. (i) and (ii)
B. (i) and (iv)
C. (ii) and (iii)
D. (iii) and (iv)
Answer» B. (i) and (iv)
108.

A repelling groyne is aligned

A. pointing upstream
B. pointing downstream
C. perpendicular to bank
D. parallel to bank
Answer» A. pointing upstream
109.

A river training work is generally required when the river is

A. aggrading type
B. degrading type
C. meandering type
D. both (a) and (b)
Answer» C. meandering type
110.

A river bend characterized by silting

A. scouring on concave side
B. silting on convex side
C. scouring on convex side and on concave side
D. scouring on concave side and silting on convex side
Answer» D. scouring on concave side and silting on convex side
111.

Select the incorrect statement.

A. Intensive irrigation should be avoided in areas susceptible to water logging.
B. Extensive irrigation should be adopted in areas susceptible to water logging.
C. Lift irrigation increases water logging.
D. all of the above
Answer» C. Lift irrigation increases water logging.
112.

A land is known as waterlogged

A. when the permanent wilting point is reached
B. when gravity drainage has ceased
C. capillary fringe reaches the root zone of plants
D. none of the above
Answer» C. capillary fringe reaches the root zone of plants
113.

Lining of irrigation channels

A. increases the waterlogging area
B. decreases the waterlogging area
C. does not change the water logging area
D. none of the above
Answer» B. decreases the waterlogging area
114.

A runoff river plant is

A. a low head scheme
B. a medium head scheme
C. a high head scheme
D. none of the above
Answer» A. a low head scheme
115.

The net speed under which the turbine reaches its peak efficiency is called

A. design speed
B. rated speed
C. gross speed
D. operating speed
Answer» A. design speed
116.

A runoff river plant

A. is a medium head scheme
B. generates power during peak hours only
C. is suitable only on a perennial river
D. has no pondage at all
Answer» C. is suitable only on a perennial river
117.

The net head under which the turbine reaches its peak efficiency at synchronous speed is called

A. design head
B. rated head
C. gross head
D. operating head
Answer» A. design head
118.

The ratio of the average load to the installed capacity of the plant whose reserve capacity is zero will be equal to

A. load factor
B. plant factor
C. utilisation factor
D. both (a) and (b)
Answer» D. both (a) and (b)
119.

A hydroelectric scheme operating under a head of 80 m will be classified as

A. low head scheme
B. medium head scheme
C. high head scheme
D. none of the above
Answer» C. high head scheme
120.

A hyetograph is a graphical representation of

A. rainfall intensity and time
B. rainfall depth and time
C. discharge and time
D. cumulative rainfall and time
Answer» A. rainfall intensity and time
121.

Variability of rainfall is
i) largest in regions of high rainfall
ii) largest in coastal areas
iii) largest in regions of scanty rainfall
The correct answer is

A. only (i)
B. (i) and (ii)
C. only (iii)
D. (ii) and (iii)
Answer» C. only (iii)
122.

In India, which of the following is adopted as standard recording raingauge ?

A. Symon's raingauge
B. tipping bucket type
C. natural syphon type
D. weighing bucket type
Answer» C. natural syphon type
123.

The maximum average depth due to one day storm over an area of 100 km2 is 100 mm. Depth-Area-Duration (DAD) curves indicate that for the same area of 100 km2 the maximum average depth for a 3 hour storm will be

A. 100 mm
B. more than 100 mm
C. less than 100 mm
D. none of the above
Answer» B. more than 100 mm
124.

The maximum rainfall depth of 300 mm in 24 hours has a return period of 100 years. The probability of 24 hours rainfall equal to or greater than 300 mm occurring at least once in 10 years is given by

A. (0.99)10
B. 1 - (0.99)10
C. (0.9)'00
D. l-(0.9)100
Answer» B. 1 - (0.99)10
125.

The most suitable chemical which can be applied to the water surface for reducing evaporation is

A. methyl alcohol
B. ethyl alcohol
C. cetyl alcohol
D. butyl alcohol
Answer» C. cetyl alcohol
126.

Interception losses are due to
i) evaporation
ii) transpiration
iii) stream flow
The correct answer is

A. only (i)
B. (i)and(ii)
C. (ii) and (iii)
D. (i), (ii) and (iii)
Answer» A. only (i)
127.

A 6 hours storm had 4 cm of rainfall and the resulting runoff was 2 cm. If <j) index remains at the same value, the runoff due to 10 cm of rainfall in 12 hours in the catchment is

A. 4.5 cm
B. 6.0 cm
C. 7.5 cm
D. 9.0 cm
Answer» B. 6.0 cm
128.

Which of the following methods is used to estimate flood discharge based on high water marks left over in the past ?

A. slope-area method
B. area-velocity method
C. moving boat method
D. ultra-sonic method
Answer» A. slope-area method
129.

To determine the discharge at a section in a stream from its rating curve, the required data are
i) slope of water surface at the section
ii) stage at the section
iii) current meter readings at the section The correct answer is

A. (i) and (ii)
B. (ii) and (iii)
C. only (ii)
D. only (iii)
Answer» C. only (ii)
130.

The stage of river carrying a discharge of Q m7sec at a point is 10 m and slope of water surface is (1/4000). The discharge of a flood at the same point and same stage of 10 m with a water surface slope of(l/1000)willbe

A. V2 Q m3/sec
B. 0.5 Q mVsec
C. 2 Q m3/sec
D. 4 Q m3/sec
Answer» C. 2 Q m3/sec
131.

The stream which does not have any base flow contribution is called

A. perennial stream
B. intermittent stream
C. ephemeral stream
D. none of the above
Answer» C. ephemeral stream
132.

The flow-mass curve is graphical representation of

A. cumulative discharge and time
B. discharge and percentage probability of flow being equaled or exceeded
C. cumulative discharge, volume and time in chronological order
D. discharge and time in chronological order
Answer» C. cumulative discharge, volume and time in chronological order
133.

If the demand line drawn from a ridge in a flow mass curve does not intersect the curve again, it indicates that

A. demand cannot be met by inflow
B. reservoir was not full at the beginning
C. both (a) and (b)
D. none of the above
Answer» A. demand cannot be met by inflow
134.

The shape of recession limb of a hydrograph depends upon

A. basin characteristics only
B. storm characteristics only
C. both (a) and (b)
D. none of the above
Answer» A. basin characteristics only
135.

Instantaneous unit hydrograph is a hydrograph of
i) unit duration
ii) unit rainfall excess
iii) infinitely small duration
iv) infinitely small rainfall excess
The correct answer is

A. (i) and (ii)
B. (i)and(iv)
C. (ii) and (iii)
D. (iii) and (iv)
Answer» C. (ii) and (iii)
136.

For a catchment area of 120 km2, the equilibrium discharge in m3/hour of an S-curve obtained by the summation of 6 hour unit hydro graph is

A. 0.2 x 106
B. 0.6 x 106
C. 2.4 xlO6
D. 7.2 xlO6
Answer» A. 0.2 x 106
137.

A unit hydro graph has one unit of

A. rainfall duration
B. rainfall excess
C. time base of direct runoff
D. discharge
Answer» B. rainfall excess
138.

The peak of a 4 hour flood hydrograph is 240 m3/sec . If the rainfall excess is 80 mm and base flow which is constant is 40 m3/sec, then the peak of 4-hours unit hydrograph will be

A. 20 3/sec
B. 25 m3/sec
C. 30 m3/sec
D. 35 m3/sec
Answer» B. 25 m3/sec
139.

To estimate the magnitude of a flood with a return period of T years, Gumbel's distribution method requires the following data pertaining to annual flood series
i) mean value
ii) standard deviation
iii) length of record
iv) coefficient of skew
The correct answer is

A. (i) and (ii)
B. (i),(ii) and (iii)
C. (i), (ii) and (iv)
D. (i), (ii), (iii) and (iv)
Answer» B. (i),(ii) and (iii)
140.

For an annual flood series arranged in descending order of magnitude, the return for a magnitude listed at position period m in a total data N is

A. N/(m+l)
B. m/(N+l)
C. m/N
D. (N+l)/m
Answer» D. (N+l)/m
141.

If the risk of a flood occurring in the next 10 years is accepted to 10%, then the return period for design should be

A. 1 + (0.9)010
B. 1 - (0.9)°l0
C. 1/(1-0.9°10)
D. 1/(1+ 0.9010)
Answer» C. 1/(1-0.9°10)
142.

The crest level in a barrage is kept at a

A. low
B. high
C. moderate
Answer» A. low
143.

When the full supply level (F.S.L.) of the canal is much below the bed level of the drainage trough, then the cross drainage provided is called syphon aqueduct.

A. Yes
B. No
Answer» B. No
144.

A spoil bank is formed when the

A. canal has steel bed slope
B. canal section is too large
C. volume of excavation is in excess of the embankment filling
D. canal alignment is meandrous
Answer» C. volume of excavation is in excess of the embankment filling
145.

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

A. aqueduct
B. super-passage
C. canal syphon
D. syphon aqueduct
Answer» B. super-passage
146.

A levee on flood

A. increases the water surface elevation of the river at flood
B. decreases the surface slope of the stream above the leveed portion
C. increases the velocity and scouring action through leveed section
D. all of the above
Answer» D. all of the above
147.

The primary cause of meandering is the excess of total charge during floods, when excess of turbulence is developed.

A. True
B. False
Answer» A. True
148.

In order to estimate the high flood discharge in fan-shaped catchment, the formula used is

A. Dicken's formula
B. Ryve's formula
C. Inglis formula
D. Fanning's formula
Answer» C. Inglis formula
149.

The capacity of escape channel should not be less than

A. 20%
B. 30%
C. 40%
D. 50%
Answer» D. 50%
150.

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

A. base period
B. crop period
C. kor period
D. none of these
Answer» A. base period
151.

A baffle wall is a sort of low weir constructed at the end of the cistern to

A. head up water to its upstream to such a height that hydraulic jump is formed
B. withstand the actual impact of the high velocity jet to dissipate the energy
C. both (a) and (b)
D. none of the above
Answer» C. both (a) and (b)
152.

The function of a barrage is different to that a weir.

A. Correct
B. Incorrect
Answer» B. Incorrect
153.

The irrigation engineering may be defined as

A. the process of artificially supplying water to soil for raising crops
B. a science of planning and designing an efficient and economic irrigation system
C. the engineering of controlling and harnessing the various natural sources of water, by the construction of dams, canals and finally distributing the water to the agricultural fields
D. all of the above
Answer» D. all of the above
154.

Liquid precipitation consists of

A. snow
B. hail
C. sleet
D. rainfall
Answer» D. rainfall
155.

The main cause of silting in channel is

A. non-regime section
B. inadequate slope
C. defective head regulator
D. all of these
Answer» D. all of these
156.

Lacey's theory as applied to channel design, involves trial and error procedure.

A. Agree
B. Disagree
Answer» B. Disagree
157.

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

A. delta
B. duty
C. base period
D. crop period
Answer» B. duty
158.

The loss of head per unit length of creep is called

A. coefficient of creep
B. percolation coefficient
C. Lane's coefficient
D. none of these
Answer» B. percolation coefficient
159.

The basic factor which controls the process of meandering is

A. discharge
B. valley slope
C. bed and side resistance
D. all of these
Answer» D. all of these
160.

In a flexible outlet, the discharge depends upon the

A. water level in distributary
B. water level in water course
C. difference of water levels between distributary and water course
D. none of the above
Answer» A. water level in distributary
161.

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

A. crossing
B. meandering belt
C. meandering length
D. none of these
Answer» A. crossing
162.

The water shed canal is also called

A. side slope canal
B. contour canal
C. ridge canal
D. all of these
Answer» C. ridge canal
163.

In an Inglis type fall, the baffle holds the jump stable on a horizontal platform.

A. Agree
B. Disagree
Answer» A. Agree
164.

The borrow pits should, preferably, be taken from

A. the field on the right side of canal
B. the field on the left side of the canal
C. the central half width of the section of the canal
D. any one of the above
Answer» C. the central half width of the section of the canal
165.

Rivers on alluvial plains may be

A. meandering type
B. aggrading type
C. degrading type
D. all of these
Answer» D. all of these
166.

A canal sligned nearly parallel to the contours of a country, is known as

A. side slope canal
B. contour canal
C. water shed canal
D. ridge canal
Answer» B. contour canal
167.

The duty at outlet is called capacity factor.

A. Correct
B. Incorrect
Answer» B. Incorrect
168.

The duty is largest

A. at the head of the main canal
B. at the head of the water course
C. on the field
D. at all place
Answer» C. on the field
169.

The knowledge of hydrology is necessary in civil engineering for

A. designing and construction of irrigation structures
B. designing and construction of bridges and culverts
C. flood control works
D. all of these
Answer» D. all of these
170.

Nawab Jang Bahadur formula is used to estimate the flood discharge of American catchments

A. Right
B. Wrong
Answer» B. Wrong
171.

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

A. free flooding
B. border flooding
C. check flooding
D. basin flooding
Answer» B. border flooding
172.

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

A. 1 to 1.2 m
B. 1.8 to 2 m
C. 2 to 2.5 m
D. 4 to 5 m
Answer» B. 1.8 to 2 m
173.

In Bligh's creep theory, it is assumed that the percolation water creep

A. along the contact of the base profile of the apron with the sub-soil
B. in a straight path under the floor
C. in a straight path under the foundation work
D. none of the above
Answer» A. along the contact of the base profile of the apron with the sub-soil
174.

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

A. aqueduct
B. super-passage
C. level crossing
D. canal syphon
Answer» C. level crossing
175.

The amount of precipitation is measured by

A. rain gauge
B. osmoscope
C. turbidimeter
D. all of these
Answer» A. rain gauge
176.

Distributary head regulators are provided

A. to control the supplies to the off-taking channel
B. to control the silt entry in the off-taking canal
C. to stop the supply, when not needed, in the off-taking canal
D. all of the above
Answer» D. all of the above
177.

Which of the following is a type of semi-module outlet?

A. Submerged pipe outlet
B. Open flume outlet
C. Kennedy's gauge outlet
D. all of these
Answer» C. Kennedy's gauge outlet
178.

The opening in the weir wall with a crest at low level on the canal side is known as under sluice or scouring sluice.

A. Correct
B. Incorrect
Answer» A. Correct
179.

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

A. 13.5 cm
B. 16.5 cm
C. 19 cm
D. 21 cm
Answer» A. 13.5 cm
180.

The flexibility of a hyper-proportional outlet is

A. greater than
B. equal to
C. less than
Answer» A. greater than
181.

In a proportional outlet, the rate of change of its discharge is

A. equal to
B. more than
C. less than
Answer» A. equal to
182.

A weir fails due to

A. rupture of floor due to uplift
B. rupture of floor due to suction caused by standing wave
C. scour on the upstream and downstream of the weir
D. all of the above
Answer» D. all of the above
183.

The average delta of rice crop is nearly

A. 30 cm
B. 60 cm
C. 120 cm
D. 150 cm
Answer» C. 120 cm
184.

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

A. hydrometry
B. hydrography
C. hydrosphere
D. hydraulics
Answer» B. hydrography
185.

A groyne with a curved head is known as

A. hockey groyne
B. burma groyne
C. denehy groyne
D. none of these
Answer» A. hockey groyne
186.

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

A. 1 in 4000
B. 1 in 6000
C. 1 in 8000
D. 1 in 10000
Answer» C. 1 in 8000
187.

The precipitation caused by natural rising of warmer lighter air in colder and denser surroundings, is called

A. convective precipitation
B. orographic precipitation
C. cyclonic precipitation
D. none of these
Answer» A. convective precipitation
188.

The sensitivity of a rigid module is

A. equal to zero
B. less than unity
C. equal to unity
D. more than unity
Answer» A. equal to zero
189.

The Sarda canal has a

A. glacis type fall
B. vertical drop fall
C. Ogee fall
D. rapid fall
Answer» B. vertical drop fall
190.

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

A. flexible outlet
B. non-modular outlet
C. semi-module outlet
D. rigid module
Answer» D. rigid module
191.

For low navigation dams, the type of gate used is

A. rolling gate
B. bear trap gate
C. vertical lift gate
D. drum gate
Answer» B. bear trap gate
192.

The coefficient of creep is the reciprocal of percolation coefficient.

A. Right
B. Wrong
Answer» A. Right
193.

Cross regulators are provided

A. to raise the water level to its upstream during the periods of low discharges in the parent channel
B. to help in closing the supply to down stream of the parent channel
C. to absorb fluctuation in various sections of the canal system
D. all of the above
Answer» D. all of the above
194.

The commonly used rain gauge is

A. weighing bucket type
B. tipping bucket type
C. float type
D. none of these
Answer» C. float type
195.

Which of the following statement is wrong?

A. In Kennedy's wilt theory, no account was taken of silt concentration and bed load.
B. Kennedy did not gave any slope equation.
C. In Kennedy's theory, silt grade and silt charge were not defined.
D. none of the above
Answer» D. none of the above
196.

The sensitivity of an outlet is defined as the ratio of the

A. rate of change of discharge of an outlet to the rate of change of discharge of the distributing channel
B. rate of change of discharge of an outlet to the rate of change in level of the distributing surface, referred to normal depth of the channel
C. depth of the sill or the crest level of the module below the full supply of the distributing channel to the full supply depth of the distributing channel
D. head recovered to the head put in an outlet
Answer» B. rate of change of discharge of an outlet to the rate of change in level of the distributing surface, referred to normal depth of the channel
197.

Crop ratio is the ratio of area irrigated

A. in Rabi season to Kharif season
B. in Kharif season to Rabi season
C. under perennial crop to total crop
D. under perennial crop to non-perennial crop
Answer» B. in Kharif season to Rabi season
198.

The depth of root zone is 90 cm for

A. wheat
B. sugar cane
C. rice
D. cotton
Answer» C. rice
199.

A parabolic glacis type fall is commonly known as

A. Montague fall
B. Inglis fall
C. Sarda fall
D. vertical type fall
Answer» A. Montague fall
200.

For Madras catchments, the flood discharge is estimated from Q = CA2/3. This formula is known as

A. Dicken's formula
B. Ryve's formula
C. Nawab Jang Bahadur formula
D. Inglis formula
Answer» B. Ryve's formula
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