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All questions of Irrigation Engineering for Civil Engineering (CE) Exam
With the increase in supplied irrigation water, the yield of crops- a)increases continuously
- b)decreases continuously
- c)increases up to a certain limit, and then becomes constant
- d)increases up to a certain limit, and then decreases
Correct answer is option 'D'. Can you explain this answer?
With the increase in supplied irrigation water, the yield of crops
a)
increases continuously
b)
decreases continuously
c)
increases up to a certain limit, and then becomes constant
d)
increases up to a certain limit, and then decreases
 | Shounak Saini answered |
Initially, when supply increases plants will get adequate water depth for their growth but ager certain limit water will cause water logging thus, degrading the growth of plants.
The total number of independent equations that form the Lacey's regime theory is- a)6
- b)10
- c)3
- d)4
Correct answer is option 'C'. Can you explain this answer?
The total number of independent equations that form the Lacey's regime theory is
a)
6
b)
10
c)
3
d)
4
 | Manasa Bose answered |
Lacey collected a large number of data of stable channels in Indo-Ganetic plains. Analyzing the data he gave the following equations of regime channel relating regime velocity Vc, silt factor f, hydraulic radius R, area A, sediment size in mm and bed slope S,
These four equations are the Lacey’s basic regime flow equations.
These four equations are the Lacey’s basic regime flow equations.
Permanent wilting point moisture content for a crop represents the- a)hygroscopic water
- b)capillary water
- c)field capacity water
- d)water of adhesion
Correct answer is option 'A'. Can you explain this answer?
Permanent wilting point moisture content for a crop represents the
a)
hygroscopic water
b)
capillary water
c)
field capacity water
d)
water of adhesion
 | Sanvi Kapoor answered |
Permanent wilting point is the point beyond which the roots of plant cannot access water. It is the hygroscopic water.
Useful soil moisture for plant growth is capillary water.
Useful soil moisture for plant growth is capillary water.
The most preferred soil for the central impervious core of a zoned embankment type of an earthen dam, is- a)highly impervious clay
- b)highly pervious gravel
- c)coarse sand
- d)clay mixed with fine sand
Correct answer is option 'D'. Can you explain this answer?
The most preferred soil for the central impervious core of a zoned embankment type of an earthen dam, is
a)
highly impervious clay
b)
highly pervious gravel
c)
coarse sand
d)
clay mixed with fine sand
 | Raksha Nair answered |
Preferred Soil for Central Impervious Core of a Zoned Embankment Earthen Dam
The central impervious core of a zoned embankment type of an earthen dam plays a crucial role in preventing seepage and leakage of water through the dam. The most preferred soil for this core is clay mixed with fine sand. Let's understand why.
Properties of Ideal Soil for Impervious Core
The ideal soil for the central impervious core of a zoned embankment earthen dam should have the following properties:
1. High Plasticity: The soil should have high plasticity to prevent any cracks or fissures from forming in the core.
2. Low Permeability: The soil should have low permeability to prevent water from seeping through the core.
3. High Cohesion: The soil should have high cohesion to provide stability to the core.
4. High Compaction: The soil should be able to achieve high compaction to form a dense and stable core.
Why Clay Mixed with Fine Sand is Preferred?
Clay mixed with fine sand is the most preferred soil for the central impervious core of a zoned embankment earthen dam because it possesses all the above properties. Let's understand how:
1. High Plasticity: Clay has high plasticity, which prevents any cracks or fissures from forming in the core. Fine sand helps in reducing the plasticity index of the clay, making it easier to work with.
2. Low Permeability: Clay has low permeability, which prevents water from seeping through the core. Fine sand helps in reducing the hydraulic gradient of the soil, which further reduces the permeability.
3. High Cohesion: Clay has high cohesion, which provides stability to the core. Fine sand helps in increasing the angle of internal friction of the soil, which further enhances the stability.
4. High Compaction: Clay mixed with fine sand can achieve high compaction to form a dense and stable core. The compaction can be achieved through proper moisture content, compaction energy, and compaction method.
Conclusion
In conclusion, clay mixed with fine sand is the most preferred soil for the central impervious core of a zoned embankment earthen dam because it possesses the required properties of high plasticity, low permeability, high cohesion, and high compaction.
The central impervious core of a zoned embankment type of an earthen dam plays a crucial role in preventing seepage and leakage of water through the dam. The most preferred soil for this core is clay mixed with fine sand. Let's understand why.
Properties of Ideal Soil for Impervious Core
The ideal soil for the central impervious core of a zoned embankment earthen dam should have the following properties:
1. High Plasticity: The soil should have high plasticity to prevent any cracks or fissures from forming in the core.
2. Low Permeability: The soil should have low permeability to prevent water from seeping through the core.
3. High Cohesion: The soil should have high cohesion to provide stability to the core.
4. High Compaction: The soil should be able to achieve high compaction to form a dense and stable core.
Why Clay Mixed with Fine Sand is Preferred?
Clay mixed with fine sand is the most preferred soil for the central impervious core of a zoned embankment earthen dam because it possesses all the above properties. Let's understand how:
1. High Plasticity: Clay has high plasticity, which prevents any cracks or fissures from forming in the core. Fine sand helps in reducing the plasticity index of the clay, making it easier to work with.
2. Low Permeability: Clay has low permeability, which prevents water from seeping through the core. Fine sand helps in reducing the hydraulic gradient of the soil, which further reduces the permeability.
3. High Cohesion: Clay has high cohesion, which provides stability to the core. Fine sand helps in increasing the angle of internal friction of the soil, which further enhances the stability.
4. High Compaction: Clay mixed with fine sand can achieve high compaction to form a dense and stable core. The compaction can be achieved through proper moisture content, compaction energy, and compaction method.
Conclusion
In conclusion, clay mixed with fine sand is the most preferred soil for the central impervious core of a zoned embankment earthen dam because it possesses the required properties of high plasticity, low permeability, high cohesion, and high compaction.
The canal, which can irrigate only on one side, is a- a)watershed canal
- b)contour canal
- c)side slope canal
- d)None of these
Correct answer is option 'B'. Can you explain this answer?
The canal, which can irrigate only on one side, is a
a)
watershed canal
b)
contour canal
c)
side slope canal
d)
None of these
| | Arya Menon answered |
A contour canal irrigates only on one side because the area on the other sides is higher.
Hydraulic depth is the ratio of- a)wetted area to wetted perimeter
- b) Area of flow section and top water surface width.
- c)wetted area to bottom width
- d)wetted perimeter to top width
Correct answer is option 'B'. Can you explain this answer?
Hydraulic depth is the ratio of
a)
wetted area to wetted perimeter
b)
Area of flow section and top water surface width.
c)
wetted area to bottom width
d)
wetted perimeter to top width
 | Engineers Adda answered |
Solution:
Hydraulic depth (D) is defined as the ratio of the cross-sectional area of flow (A) to the top water surface width (T). This parameter is commonly used in open channel flow to describe the average depth of water.
Mathematically, it is given by:
Where:
- A is the area of the flow section.
- T is the top water surface width.
Therefore, the correct answer is Option B: Area of flow section and top water surface width.
If the uplift pressure is neglected, the base width of an elementary profile of a gravity dam of height H, having relative' density of the dam material = Sc, and coefficient of friction = μ is- a)H/(Sc + 1)
- b)H/(Sc - 1)1/2
- c)larger of
- d)smaller of
Correct answer is option 'C'. Can you explain this answer?
If the uplift pressure is neglected, the base width of an elementary profile of a gravity dam of height H, having relative' density of the dam material = Sc, and coefficient of friction = μ is
a)
H/(Sc + 1)
b)
H/(Sc - 1)1/2
c)
larger of
d)
smaller of
| | Gitanjali Chauhan answered |
Hence, if B is taken equal to or greater than
no tension will be developed at the heel with full reservoir.
When, C = 1
If uplift is not considered,
For the dam to be safe in sliding,
If C = 0, i.e., no uplift is considered then,
The centre of pressure of wave pressure due to wave of height hw acting on a gravity dam will be at a. height above the maximum still water level of- a)hw/2
- b)3hw/&
- c)hw/3
- d)2hw/3
Correct answer is option 'B'. Can you explain this answer?
The centre of pressure of wave pressure due to wave of height hw acting on a gravity dam will be at a. height above the maximum still water level of
a)
hw/2
b)
3hw/&
c)
hw/3
d)
2hw/3
 | Constructing Careers answered |
The wave pressure acting on the dam due to the wave of height h_w can be calculated using the following formula:
p = 1/2 * ρ * g * h_w * (1 + cos(2πx/L))
Where:
- p is the wave pressure
- ρ is the density of water
- g is the acceleration due to gravity
- h_w is the wave height
- x is the horizontal distance from the dam
- L is the wavelength
The center of pressure of this wave pressure distribution is located at a height of 2/3 * h_w above the maximum still water level.
This is because the wave pressure distribution follows a sinusoidal pattern, and the centroid of this pressure distribution is located at 2/3 of the wave height above the still water level.
Therefore, the correct answer is that the center of pressure of the wave pressure due to a wave of height h_w acting on a gravity dam is located at a height of 2/3 * h_w above the maximum still water level.
In modern practice the free board normally provided for gravity dam is- a)3 to 4% of dam height
- b)2 hw (hw = height of wave)
- c)2 to 3% of dam height
- d)3 hw
Correct answer is option 'A'. Can you explain this answer?
In modern practice the free board normally provided for gravity dam is
a)
3 to 4% of dam height
b)
2 hw (hw = height of wave)
c)
2 to 3% of dam height
d)
3 hw
| | Dhruba Jain answered |
Fine board is provided in gravity dam is normally 3/2 hw or 4-5% of the dam material.
The following structure serves the purpose of a ‘safety valve’ for a canal - a)head regulator
- b)cross regulator
- c)canal escape
- d)canal fall
Correct answer is option 'C'. Can you explain this answer?
The following structure serves the purpose of a ‘safety valve’ for a canal
a)
head regulator
b)
cross regulator
c)
canal escape
d)
canal fall
| | Dhruba Jain answered |
Canal escapes are the safety valves of canal and must be provided at regular intervals depending upon the importance of the canal and availability of suitable drainage. Minimum capacity of escape is generally kept as half of the channel capacity at the point of escape.
Irrigation frequency is a function of- a)crop only
- b)soil, crop and climate
- c)soil, crop, climate and fertilizer
- d)soil and climate
Correct answer is option 'B'. Can you explain this answer?
Irrigation frequency is a function of
a)
crop only
b)
soil, crop and climate
c)
soil, crop, climate and fertilizer
d)
soil and climate
| | Madhurima Banerjee answered |
Irrigation frequency is the number of times irrigation is required to be done to maintain the required soil moisture level for a crop to grow and yield optimally. The frequency at which irrigation is required depends on several factors, which are discussed below.
Factors affecting irrigation frequency
Soil characteristics: The texture, structure, and water-holding capacity of the soil determine how much water the soil can retain and how quickly it drains. Sandy soils drain water quickly and require more frequent irrigation, whereas clay soils hold water for a longer time and require less frequent irrigation.
Crop water requirement: Different crops have different water requirements depending on their growth stage. For example, the water requirement of a crop during vegetative growth is higher than during the reproductive phase. The crop water requirement is also influenced by the crop's rooting depth, leaf area, and canopy cover.
Climate: The evapotranspiration rate (ET) of a crop, which is the amount of water lost through evaporation from the soil and transpiration from the plant, is influenced by climate factors such as temperature, humidity, wind speed, and solar radiation. Regions with high temperatures and low humidity require more frequent irrigation.
Fertilizer requirement: The application of fertilizers increases the water requirement of a crop as it increases the crop's growth rate and nutrient uptake. Therefore, the frequency of irrigation should be adjusted to ensure that the soil moisture level is adequate for both crop growth and fertilizer uptake.
Conclusion
In conclusion, irrigation frequency is a function of soil, crop, and climate factors, and should be adjusted based on the specific requirements of each crop. Proper irrigation management can help to optimize crop yield, reduce water use, and increase the sustainability of agricultural practices.
Factors affecting irrigation frequency
Soil characteristics: The texture, structure, and water-holding capacity of the soil determine how much water the soil can retain and how quickly it drains. Sandy soils drain water quickly and require more frequent irrigation, whereas clay soils hold water for a longer time and require less frequent irrigation.
Crop water requirement: Different crops have different water requirements depending on their growth stage. For example, the water requirement of a crop during vegetative growth is higher than during the reproductive phase. The crop water requirement is also influenced by the crop's rooting depth, leaf area, and canopy cover.
Climate: The evapotranspiration rate (ET) of a crop, which is the amount of water lost through evaporation from the soil and transpiration from the plant, is influenced by climate factors such as temperature, humidity, wind speed, and solar radiation. Regions with high temperatures and low humidity require more frequent irrigation.
Fertilizer requirement: The application of fertilizers increases the water requirement of a crop as it increases the crop's growth rate and nutrient uptake. Therefore, the frequency of irrigation should be adjusted to ensure that the soil moisture level is adequate for both crop growth and fertilizer uptake.
Conclusion
In conclusion, irrigation frequency is a function of soil, crop, and climate factors, and should be adjusted based on the specific requirements of each crop. Proper irrigation management can help to optimize crop yield, reduce water use, and increase the sustainability of agricultural practices.
The ‘meander belt’ for an alluvial river is- a)the total river width between embankments
- b)the width between the outer edges of fully developed meander loop, measured perpendicular to river axis
- c)the same as meander width
- d)both (b) and (a)
Correct answer is option 'D'. Can you explain this answer?
The ‘meander belt’ for an alluvial river is
a)
the total river width between embankments
b)
the width between the outer edges of fully developed meander loop, measured perpendicular to river axis
c)
the same as meander width
d)
both (b) and (a)
| | Aarav Chauhan answered |
Meander belt (MB) is the distance between the outer edges of clockwise and anti-clockwise loops of the meander.
The wetted perimeter P of a stable channel is proportional to
where, Q is the discharge- a)Q
- b)√Q
- c)Q2
- d)Q1/3
Correct answer is option 'B'. Can you explain this answer?
The wetted perimeter P of a stable channel is proportional to
where, Q is the discharge
where, Q is the discharge
a)
Q
b)
√Q
c)
Q2
d)
Q1/3
| | Abhay Banerjee answered |
The wetted perimeter P of a channel is given by,
Consider the following statements: An aqueduct is a cross drainage work in which
1. a canal is carried over the drainage channel.
2. a drainage channel is carried over the canal.
3. both drainage channel and canal are at the same level.
Which of these statements is/are correct?- a)1 only
- b)1 and 2 only
- c)2 and 3 only
- d)1,2 and 3
Correct answer is option 'A'. Can you explain this answer?
Consider the following statements: An aqueduct is a cross drainage work in which
1. a canal is carried over the drainage channel.
2. a drainage channel is carried over the canal.
3. both drainage channel and canal are at the same level.
Which of these statements is/are correct?
1. a canal is carried over the drainage channel.
2. a drainage channel is carried over the canal.
3. both drainage channel and canal are at the same level.
Which of these statements is/are correct?
a)
1 only
b)
1 and 2 only
c)
2 and 3 only
d)
1,2 and 3
| | Siddharth Bajaj answered |
An aqueduct and syphon aqueduct are cross drainage works in which the canal is taken over the natural drain, such that the drainage water runs below the canal either freely or under syphoning pressure. Super passage and syphon are cross drainage works in which the drain is taken over the canal such that the canal water runs below the drain either freely or under syphoning pressure. Level crossing is a cross drainage work in which the canal water and drain water are allowed to intermingle with each other. A level crossing is generally provided when a large canal and a huge drainage (such as a stream or a river) approach each other practically at the same level.
The spillway which can be adopted with ease on gravity as well as earthen dams, is- a)ogee spillway
- b)chute spillway
- c)both ogee as well as chute spillway
- d)Noneofthese
Correct answer is option 'B'. Can you explain this answer?
The spillway which can be adopted with ease on gravity as well as earthen dams, is
a)
ogee spillway
b)
chute spillway
c)
both ogee as well as chute spillway
d)
Noneofthese
| | Gauri Roy answered |
An ogee spillway is mostly suitable for concrete gravity dams especially when the spillway is located within the dam body in the same valley. The trough spillway or chute spillway is the simplest type of a spillway which can be easily provided independently and at low costs. It is lighter and adaptable to any type of foundations and hence provided easily on earth and rockfill dams.
Under-drainage arrangements in canals are- necessarily required in- a)unlined canals
- b)Both (a) and (c)
- c)Lined canal
- d)lined canals constructed on sandy soils alone
Correct answer is option 'B'. Can you explain this answer?
Under-drainage arrangements in canals are- necessarily required in
a)
unlined canals
b)
Both (a) and (c)
c)
Lined canal
d)
lined canals constructed on sandy soils alone
| | Poulomi Patel answered |
Under-Drainage Arrangements in Canals
Introduction:
Canals are constructed to transport water from one place to another for irrigation, industrial use, or other purposes. It is essential to design an efficient drainage system to maintain the structural stability of the canal. Under-drainage arrangements are necessary to ensure the proper functioning of the canal.
Lined Canals:
Lined canals are constructed with a lining material such as concrete, asphalt, or clay to prevent seepage of water from the canal. However, under-drainage arrangements are still required in lined canals to remove the seepage water that penetrates through the lining material. The under-drainage system consists of perforated pipes laid beneath the canal bed, which collects the seepage water and discharges it into a sump or a nearby water body.
Unlined Canals:
Unlined canals are constructed without any lining material, and the water flows through the soil. Under-drainage arrangements are necessary in unlined canals to reduce the seepage losses. The under-drainage system in unlined canals is similar to that of lined canals.
Conclusion:
Under-drainage arrangements are necessary in both lined and unlined canals to maintain the stability of the canal and reduce the seepage losses. Proper design and construction of the under-drainage system are essential for the efficient functioning of the canal.
Introduction:
Canals are constructed to transport water from one place to another for irrigation, industrial use, or other purposes. It is essential to design an efficient drainage system to maintain the structural stability of the canal. Under-drainage arrangements are necessary to ensure the proper functioning of the canal.
Lined Canals:
Lined canals are constructed with a lining material such as concrete, asphalt, or clay to prevent seepage of water from the canal. However, under-drainage arrangements are still required in lined canals to remove the seepage water that penetrates through the lining material. The under-drainage system consists of perforated pipes laid beneath the canal bed, which collects the seepage water and discharges it into a sump or a nearby water body.
Unlined Canals:
Unlined canals are constructed without any lining material, and the water flows through the soil. Under-drainage arrangements are necessary in unlined canals to reduce the seepage losses. The under-drainage system in unlined canals is similar to that of lined canals.
Conclusion:
Under-drainage arrangements are necessary in both lined and unlined canals to maintain the stability of the canal and reduce the seepage losses. Proper design and construction of the under-drainage system are essential for the efficient functioning of the canal.
Which of the following are the purpose of a groyne as a river training structure?
1. It contracts a river channel to improve its depth.
2. It protects the river bank.
3. It does not allow silt to deposit in the vicinity.
4. It trains the flow along a certain course.Select the correct answer using the codes given below:- a)1 and 2
- b)1, 2 and 4
- c)1 and 3
- d)2, 3 and 4
Correct answer is option 'B'. Can you explain this answer?
Which of the following are the purpose of a groyne as a river training structure?
1. It contracts a river channel to improve its depth.
2. It protects the river bank.
3. It does not allow silt to deposit in the vicinity.
4. It trains the flow along a certain course.
1. It contracts a river channel to improve its depth.
2. It protects the river bank.
3. It does not allow silt to deposit in the vicinity.
4. It trains the flow along a certain course.
Select the correct answer using the codes given below:
a)
1 and 2
b)
1, 2 and 4
c)
1 and 3
d)
2, 3 and 4
| | Anand Kumar answered |
Groynes are embankment type structures, constructed transverse to the river flow, extending from the bank into the river. They are constructed to protect the bank from which they are extended,' by deflecting the current away from the bank. These are called repelling groynes. On the upstream side of a repelling groyne, a still water pocket is formed, where the suspended sediments carried by the river, gets deposited. For low water training or training for depth groynes can be used; Herein they contract the width of the channel to provide sufficient depth for navigation during low water periods.
In order to train the flow along a certain course guide banks are most commonly used. However groynes can also be used to deflect the flow or attract the flow.
In order to train the flow along a certain course guide banks are most commonly used. However groynes can also be used to deflect the flow or attract the flow.
A free pipe outlet is a- a)rigid module
- b)flexible module
- c)non-modular module
- d)all of the above
Correct answer is option 'B'. Can you explain this answer?
A free pipe outlet is a
a)
rigid module
b)
flexible module
c)
non-modular module
d)
all of the above
| | Divya Kulkarni answered |
Pipe outlet discharging freely into the atmosphere is the simplest and the oldest type of a flexible outlet. The discharge through such an outlet will depend only upon the water level of the distributary, and will be independent of the water level of the watercourse.
Conjunctive use of water in a basin means- a)combined use of water for irrigation and for hydropower generation
- b)combined use of surface and ground water resources
- c)use of irrigation water by cooperation of farmers
- d)use of irrigation water for both rabi and kharif crops
Correct answer is option 'B'. Can you explain this answer?
Conjunctive use of water in a basin means
a)
combined use of water for irrigation and for hydropower generation
b)
combined use of surface and ground water resources
c)
use of irrigation water by cooperation of farmers
d)
use of irrigation water for both rabi and kharif crops
| | Prasad Desai answered |
Conjunctive use of water in a basin refers to the coordinated use of both surface water and groundwater resources. It involves managing the two sources of water in a way that optimizes their combined use and minimizes the negative impacts of their overuse.
Explanation:
Conjunctive use of water is an important strategy for managing water resources in areas where surface water and groundwater are both available. It involves using both sources of water in a coordinated manner to meet the water needs of different users while also maintaining the long-term sustainability of the water resources.
The following are some of the key aspects of conjunctive use of water in a basin:
1. Combined use of surface and groundwater resources: Conjunctive use involves using both surface water and groundwater resources in a coordinated and integrated manner. This can involve diverting surface water to recharge aquifers, pumping groundwater to supplement surface water supplies during dry periods, or using surface water to offset the overuse of groundwater.
2. Optimization of water use: Conjunctive use aims to optimize the use of water resources by balancing the demand for water with the available supply. This can involve allocating water resources based on the needs of different users, such as farmers, households, or industries, and managing the water resources to ensure that they are used efficiently and sustainably.
3. Minimization of negative impacts: Conjunctive use also aims to minimize the negative impacts of water use on the environment, including the depletion of aquifers, the degradation of water quality, and the loss of biodiversity. This can involve managing water resources to ensure that they are used in a way that minimizes their impact on the environment, while also meeting the needs of different users.
4. Collaboration among stakeholders: Conjunctive use requires collaboration among different stakeholders, including water users, government agencies, and civil society organizations. This can involve developing policies and regulations that promote the sustainable use of water resources, as well as engaging in dialogue and consultation with different stakeholders to ensure that their needs and concerns are taken into account.
In conclusion, conjunctive use of water in a basin involves managing both surface water and groundwater resources in a way that optimizes their combined use and minimizes the negative impacts of their overuse. It is an important strategy for ensuring the long-term sustainability of water resources in areas where both sources of water are available.
Explanation:
Conjunctive use of water is an important strategy for managing water resources in areas where surface water and groundwater are both available. It involves using both sources of water in a coordinated manner to meet the water needs of different users while also maintaining the long-term sustainability of the water resources.
The following are some of the key aspects of conjunctive use of water in a basin:
1. Combined use of surface and groundwater resources: Conjunctive use involves using both surface water and groundwater resources in a coordinated and integrated manner. This can involve diverting surface water to recharge aquifers, pumping groundwater to supplement surface water supplies during dry periods, or using surface water to offset the overuse of groundwater.
2. Optimization of water use: Conjunctive use aims to optimize the use of water resources by balancing the demand for water with the available supply. This can involve allocating water resources based on the needs of different users, such as farmers, households, or industries, and managing the water resources to ensure that they are used efficiently and sustainably.
3. Minimization of negative impacts: Conjunctive use also aims to minimize the negative impacts of water use on the environment, including the depletion of aquifers, the degradation of water quality, and the loss of biodiversity. This can involve managing water resources to ensure that they are used in a way that minimizes their impact on the environment, while also meeting the needs of different users.
4. Collaboration among stakeholders: Conjunctive use requires collaboration among different stakeholders, including water users, government agencies, and civil society organizations. This can involve developing policies and regulations that promote the sustainable use of water resources, as well as engaging in dialogue and consultation with different stakeholders to ensure that their needs and concerns are taken into account.
In conclusion, conjunctive use of water in a basin involves managing both surface water and groundwater resources in a way that optimizes their combined use and minimizes the negative impacts of their overuse. It is an important strategy for ensuring the long-term sustainability of water resources in areas where both sources of water are available.
Commonly adopted moisture tension, in atmosphere, of a soil at permanent wilting point is- a)15
- b)7
- c)45
- d)150
Correct answer is option 'A'. Can you explain this answer?
Commonly adopted moisture tension, in atmosphere, of a soil at permanent wilting point is
a)
15
b)
7
c)
45
d)
150
| | Sravya Tiwari answered |
The soil moisture tension at the permanent wilting point is usually around 15 atmospheres or -15 bars. This is the point at which plants can no longer extract enough water to meet their needs and remain wilted until water is added to the soil.
The ‘meander length’ for an alluvial river is- a)the total channel length along its looped course
- b)the total channel length minus the direct straight length
- c)the axial length of one meander
- d)the looped length of one meander
Correct answer is option 'C'. Can you explain this answer?
The ‘meander length’ for an alluvial river is
a)
the total channel length along its looped course
b)
the total channel length minus the direct straight length
c)
the axial length of one meander
d)
the looped length of one meander
| | Sreemoyee Chauhan answered |
Meander length (ML) is the axial length of one meander, i.e., the tangential distance between the corresponding points of a meander.
Water-logging of cropped land leads to reduced crop yields, due to- a)ill-aeration of root zone, causing lack of oxygen to plants
- b)growth of water-loving plants interfering with the sown crop
- c)surrounding of the root zone by the resultant saline water, which extracts the good water from plant roots by osmosis
- d)all of the above
Correct answer is option 'D'. Can you explain this answer?
Water-logging of cropped land leads to reduced crop yields, due to
a)
ill-aeration of root zone, causing lack of oxygen to plants
b)
growth of water-loving plants interfering with the sown crop
c)
surrounding of the root zone by the resultant saline water, which extracts the good water from plant roots by osmosis
d)
all of the above
| | Ameya Sen answered |
The life of a plant depends upon the nutrients like nitrates and the form in which the nitrates are consumed by the plants is produced by the bacteria, under a process called nitrification.
These bacteria need oxygen for their survival. The supply of oxygen gets cutoff when the land becomes ill aerated, resulting in death of these bacteria, and fall in production of plant’s food and consequent reduction in the plant’s growth, which reduces the crop yield.
These bacteria need oxygen for their survival. The supply of oxygen gets cutoff when the land becomes ill aerated, resulting in death of these bacteria, and fall in production of plant’s food and consequent reduction in the plant’s growth, which reduces the crop yield.
In the alignment of an - irrigation channel wherefrom offtakes have to be provided at regular intervals, changes in the given channel parameters are made use of. The correct sequence of the decreasing order of preference of these parameters is- a)width, slope, depth
- b)width, depth, slope
- c)depth, slope, width
- d)depth, width, slope
Correct answer is option 'C'. Can you explain this answer?
In the alignment of an - irrigation channel wherefrom offtakes have to be provided at regular intervals, changes in the given channel parameters are made use of. The correct sequence of the decreasing order of preference of these parameters is
a)
width, slope, depth
b)
width, depth, slope
c)
depth, slope, width
d)
depth, width, slope
| | Garima Basak answered |
The best alignment of off-taking channel is that in which the off-taking channel makes zero angle with the parent channel initially and then separates out in transition. The depth of water should always be such that off take channel runs full. The transitions should be properly designed, so as to avoid accumulation of silt. The transition can also be used as metering flume. Thus depth, slope and width will be the correct order of preference of parameters.
A good irrigation module is the one, which- a)draws heavy silt from the canal
- b)draws clear water from the canal
- c)draws fair share of silt from the canal
- d)None of the above
Correct answer is option 'C'. Can you explain this answer?
A good irrigation module is the one, which
a)
draws heavy silt from the canal
b)
draws clear water from the canal
c)
draws fair share of silt from the canal
d)
None of the above
| | Raghavendra Goyal answered |
A good irrigation module should fit well to the decided principles of water distribution. It should be simple and cheap. It should draw its fair share of silt.
The factor which is not primarily responsible for meander in an alluvial river, is- a)variation of discharge
- b)excess silt load
- c)deficient silt load
- d)None of these
Correct answer is option 'C'. Can you explain this answer?
The factor which is not primarily responsible for meander in an alluvial river, is
a)
variation of discharge
b)
excess silt load
c)
deficient silt load
d)
None of these
| | Pankaj Kapoor answered |
The widely accepted theory behind meandering is based upon the extra turbulence generated by the excess of river sediment during floods. During floods, the river carries tremendous amount of silt charge. When the silt charge is in excess of the quantity required for stability, the river starts building up its slope by depositing the silt on its bed. This accretion is the primary process, which leads to meandering.
Consider the following statements:
1. In a super-passage, the drain runs over the canal.
2. In a siphon, the drain runs below the canal.
3. In a siphon aqueduct, type-II, the canal banks are made of RCC walls.
Which of these statements are correct?- a) 1 only
- b)1 and 2 only
- c)2 and 3 only
- d)1 and 3 only
Correct answer is option 'D'. Can you explain this answer?
Consider the following statements:
1. In a super-passage, the drain runs over the canal.
2. In a siphon, the drain runs below the canal.
3. In a siphon aqueduct, type-II, the canal banks are made of RCC walls.
Which of these statements are correct?
1. In a super-passage, the drain runs over the canal.
2. In a siphon, the drain runs below the canal.
3. In a siphon aqueduct, type-II, the canal banks are made of RCC walls.
Which of these statements are correct?
a)
1 only
b)
1 and 2 only
c)
2 and 3 only
d)
1 and 3 only
| | Shraddha Datta answered |
A super passage is just like a bridge in which the natural drain is carried over the canal. A super passage is constructed where the bed of the drain is well above the canal F.S.L.
A syphon serves the same purpose as superpassage and is constructed where the F.S.L.
A syphon serves the same purpose as superpassage and is constructed where the F.S.L.
The base width of a rock fill dam, incomparison to that of an earthen dam is:- a)much larger
- b)much smaller
- c)sometimes larger sometimes smaller
- d)almost equal
Correct answer is option 'B'. Can you explain this answer?
The base width of a rock fill dam, incomparison to that of an earthen dam is:
a)
much larger
b)
much smaller
c)
sometimes larger sometimes smaller
d)
almost equal
| | Rounak Banerjee answered |
Rockfill dams have characteristics lying somewhere between the characteristics of gravity dams and those of earthen dams. They are less flexible than earthen dams and more flexible, then gravity dams. Their foundation requirements are not a strict and rigid as are required for gravity dams. But the foundation requirements are more rigid than those for earthen dams which can be constructed almost on any types of foundations.
A shaft spillway is located- a)inside the body of a gravity dam
- b)inside the stream reservoir
- c)inside the downstream reservoir
- d)on side flanks of the main dam
Correct answer is option 'B'. Can you explain this answer?
A shaft spillway is located
a)
inside the body of a gravity dam
b)
inside the stream reservoir
c)
inside the downstream reservoir
d)
on side flanks of the main dam
 | Rajeev Menon answered |
The shape of the shaft spillway is just like a funnel. The lower end of the funnel is turned at right angles and then taken out below the dam horizontally. Water spills over the circular crest and then enters the vertical shaft and comes out of the dam through the horizontal tunnel.
An earthquake acceleration of 0.1 g acting vertically downward causes in a gravity dam- a)an increase in the weight of dam by 10%
- b)a reduction in the unit weight of concrete only by 10%
- c)a decrease in the unit weights of concrete and water by 10%
- d)a decreases in the unit weights of water by 10%
Correct answer is option 'C'. Can you explain this answer?
An earthquake acceleration of 0.1 g acting vertically downward causes in a gravity dam
a)
an increase in the weight of dam by 10%
b)
a reduction in the unit weight of concrete only by 10%
c)
a decrease in the unit weights of concrete and water by 10%
d)
a decreases in the unit weights of water by 10%
| | Jithin Choudhury answered |
Effective unit weight is given by,
so when αv = 0.1 g (downward)
effective unit weight
Net effective weight of Dam
so when αv = 0.1 g (downward)
effective unit weight
Net effective weight of Dam
For the upstream slope of an earth dam the most critical condition is- a)sudden drawdown condition
- b)steady seepage condition
- c)neither sudden drawdown nor steady seepage
- d)during construction when the reservoir is allowed to be filled.
Correct answer is option 'A'. Can you explain this answer?
For the upstream slope of an earth dam the most critical condition is
a)
sudden drawdown condition
b)
steady seepage condition
c)
neither sudden drawdown nor steady seepage
d)
during construction when the reservoir is allowed to be filled.
| | Ashish Chakraborty answered |
Critical Condition for Upstream Slope of an Earth Dam
The upstream slope of an earth dam is subjected to various conditions that can affect its stability. Among these conditions, the most critical one is sudden drawdown condition. Let us discuss this in detail.
Sudden Drawdown Condition
Sudden drawdown condition refers to the rapid drainage of water from the reservoir behind the dam. This can happen due to various reasons such as a sudden failure of an outlet gate or an earthquake. When the water level drops suddenly, the soil particles in the upstream slope of the dam get disturbed and lose their cohesion. This can cause the slope to become unstable and lead to slope failure.
Why Sudden Drawdown is Critical?
Sudden drawdown is critical for the upstream slope of an earth dam because of the following reasons:
1. Loss of Cohesion: The soil particles in the upstream slope of the dam are held together by the cohesive forces between them. When the water level drops suddenly, these forces are disturbed, and the soil loses its cohesion. This can cause the slope to become unstable and lead to slope failure.
2. Pore Water Pressure: The water in the soil pores exerts pressure on the soil particles. When the water level drops suddenly, this pressure decreases rapidly, causing the soil particles to rearrange themselves. This can cause the slope to become unstable and lead to slope failure.
3. Shear Strength: The shear strength of the soil depends on the stress conditions and the soil properties. When the water level drops suddenly, the stress conditions change rapidly, causing the shear strength of the soil to decrease. This can cause the slope to become unstable and lead to slope failure.
Conclusion
In conclusion, sudden drawdown condition is the most critical condition for the upstream slope of an earth dam. It can cause the soil particles to lose their cohesion, decrease the pore water pressure, and decrease the shear strength of the soil. This can lead to slope failure and pose a significant risk to the safety of the dam. Therefore, it is essential to consider this condition while designing and constructing an earth dam.
The upstream slope of an earth dam is subjected to various conditions that can affect its stability. Among these conditions, the most critical one is sudden drawdown condition. Let us discuss this in detail.
Sudden Drawdown Condition
Sudden drawdown condition refers to the rapid drainage of water from the reservoir behind the dam. This can happen due to various reasons such as a sudden failure of an outlet gate or an earthquake. When the water level drops suddenly, the soil particles in the upstream slope of the dam get disturbed and lose their cohesion. This can cause the slope to become unstable and lead to slope failure.
Why Sudden Drawdown is Critical?
Sudden drawdown is critical for the upstream slope of an earth dam because of the following reasons:
1. Loss of Cohesion: The soil particles in the upstream slope of the dam are held together by the cohesive forces between them. When the water level drops suddenly, these forces are disturbed, and the soil loses its cohesion. This can cause the slope to become unstable and lead to slope failure.
2. Pore Water Pressure: The water in the soil pores exerts pressure on the soil particles. When the water level drops suddenly, this pressure decreases rapidly, causing the soil particles to rearrange themselves. This can cause the slope to become unstable and lead to slope failure.
3. Shear Strength: The shear strength of the soil depends on the stress conditions and the soil properties. When the water level drops suddenly, the stress conditions change rapidly, causing the shear strength of the soil to decrease. This can cause the slope to become unstable and lead to slope failure.
Conclusion
In conclusion, sudden drawdown condition is the most critical condition for the upstream slope of an earth dam. It can cause the soil particles to lose their cohesion, decrease the pore water pressure, and decrease the shear strength of the soil. This can lead to slope failure and pose a significant risk to the safety of the dam. Therefore, it is essential to consider this condition while designing and constructing an earth dam.
What type of cross drainage work is provided when the canal runs below the drain, with FSL of canal well below the bed of the drain?- a)Aqueduct
- b)Super passage
- c)Level crossing
- d)Siphon aqueduct
Correct answer is option 'B'. Can you explain this answer?
What type of cross drainage work is provided when the canal runs below the drain, with FSL of canal well below the bed of the drain?
a)
Aqueduct
b)
Super passage
c)
Level crossing
d)
Siphon aqueduct
| | Akanksha Tiwari answered |
If bed level of canal is sufficiently above the HFL of the drain, an aqueduct is the right choice. Sometimes bed level of canal may be little below the HFL of drain so that water flows under syphonic action. This structure is known as aqueduct syphon.If bed level of the drain is sufficiently above the canal FSL, a super passage may be constructed. If the canal FSL is little above bed level of drain to allow syphonic action, the structure is called Canal Syphon. Aqueduct or superpassage type of drainage works are used when high flood discharge is large and continues for a sufficient time.
A level crossing is used when the canal water and drain water are allowed to intermingle with each other. This is adopted when high flood drainage discharge is short lived.
A level crossing is used when the canal water and drain water are allowed to intermingle with each other. This is adopted when high flood drainage discharge is short lived.
Consider the following statements:
1. High water training is undertaken to protect against damage due to floods.
2. Low water training is undertaken to provide sufficient depth for navigation.
3. Mean water training is undertaken to provide efficient disposal of sediment load.Which of these statements is/are correct?- a)1 and 2 only
- b)1, 2 and 3
- c)2 and 3 only
- d)2 only
Correct answer is option 'B'. Can you explain this answer?
Consider the following statements:
1. High water training is undertaken to protect against damage due to floods.
2. Low water training is undertaken to provide sufficient depth for navigation.
3. Mean water training is undertaken to provide efficient disposal of sediment load.
1. High water training is undertaken to protect against damage due to floods.
2. Low water training is undertaken to provide sufficient depth for navigation.
3. Mean water training is undertaken to provide efficient disposal of sediment load.
Which of these statements is/are correct?
a)
1 and 2 only
b)
1, 2 and 3
c)
2 and 3 only
d)
2 only
 | Lavanya Menon answered |
1) High water training works ( training for discharge )
High water training works are constructed for the purpose of quick disposal of maximum flood and to protect adjoining land against damage due to floods. It aims to provide sufficient river cross-section for stage passage of maximum flood.
High water training works are constructed for the purpose of quick disposal of maximum flood and to protect adjoining land against damage due to floods. It aims to provide sufficient river cross-section for stage passage of maximum flood.
2) Low water training works (training for depth)
It is undertaken with the primary purpose of providing sufficient water depth for navigation during a low flow period. Generally, spurs are constructed to contract the width of the channel and hence to increase the depth.
It is undertaken with the primary purpose of providing sufficient water depth for navigation during a low flow period. Generally, spurs are constructed to contract the width of the channel and hence to increase the depth.
3) Mean water training works ( training for sediments )
It is undertaken with the primary purpose of providing efficient disposal of sediment load and bedload thus preserving the channel in good shape. It is the most important training of the three types.
It is undertaken with the primary purpose of providing efficient disposal of sediment load and bedload thus preserving the channel in good shape. It is the most important training of the three types.
Net irrigation requirement of a crop is equal to- a)consumptive use
- b)consumptive use - effective rainfall
- c)consumptive use - effective rainfall + leaching and other requirements
- d)percolation loss + effective rainfall
Correct answer is option 'C'. Can you explain this answer?
Net irrigation requirement of a crop is equal to
a)
consumptive use
b)
consumptive use - effective rainfall
c)
consumptive use - effective rainfall + leaching and other requirements
d)
percolation loss + effective rainfall
| | Tanishq Menon answered |
Net Irrigation Requirement (N!R) is the amount of irrigation water required in order to meet the evapotranspiration need of the crop as well another, needs such as leaching. Therefore, NIR = Cu - Re + Water lost as percolation in satisfying other needs such as teaching.
In an irrigation system, water was delivered to the field in ditches spaced about 30 m apart, and was allowed to seep into the ground to maintain the water table at such a height that the water is available to the crops through the capillary fringe. This method of irrigation is called.- a)trickle irrigation
- b)furrow irrigation
- c)border irrigation
- d)sub irrigation
Correct answer is option 'D'. Can you explain this answer?
In an irrigation system, water was delivered to the field in ditches spaced about 30 m apart, and was allowed to seep into the ground to maintain the water table at such a height that the water is available to the crops through the capillary fringe. This method of irrigation is called.
a)
trickle irrigation
b)
furrow irrigation
c)
border irrigation
d)
sub irrigation
| | Diya Sarkar answered |
When a system of open jointed drains is artificially laid below the soil, so as to supply water to the crops by capillarity, then it is known as artificial sub-irrigation. It may be recommended only in some special cases with favourable soil conditions and for cash crops of high return.
With the increase in its capacity-inflow ratio, the trap efficiency of a reservoir:- a)increases
- b)decreases
- c)remains unchanged
- d)may increase or decrease depending on the reservoir characteristics
Correct answer is option 'A'. Can you explain this answer?
With the increase in its capacity-inflow ratio, the trap efficiency of a reservoir:
a)
increases
b)
decreases
c)
remains unchanged
d)
may increase or decrease depending on the reservoir characteristics
| | Constructing Careers answered |
The trap efficiency of a reservoir is affected by its capacity-inflow ratio. This ratio is the storage capacity of the reservoir divided by the annual inflow volume. Generally, as the capacity-inflow ratio of a reservoir increases, the trap efficiency also increases. This is because a larger or deeper reservoir has more volume to trap sediments before they can be discharged.
Hence, the correct answer is: increases.
‘Bank storage’ in a dam reservoir:- a)increases the computed reservoir capacity
- b)decreases the computed reservoir capacity
- c)sometimes increases and sometimes decreases the computed reservoir capacity
- d)has no effect on computed reservoir capacity
Correct answer is option 'A'. Can you explain this answer?
‘Bank storage’ in a dam reservoir:
a)
increases the computed reservoir capacity
b)
decreases the computed reservoir capacity
c)
sometimes increases and sometimes decreases the computed reservoir capacity
d)
has no effect on computed reservoir capacity
| | Preethi Datta answered |
When the reservoir is filled up, certain amount of water seeps into the permeable reservoir banks. This water comes out as seen as the reservoir gets depleted. This volume of water is known as bank storage. The bank storage efficiently increases the capacity of the reservoir.
A canal fall is a control structure- a)located at a place where the country slope is flatter than the canal bed slope
- b)located most economically where the depth of cutting is less than the balancing depth
- c)the location of which is independent of the command to be served
- d)designed to secure raising of water surface on its upstream
Correct answer is option 'B'. Can you explain this answer?
A canal fall is a control structure
a)
located at a place where the country slope is flatter than the canal bed slope
b)
located most economically where the depth of cutting is less than the balancing depth
c)
the location of which is independent of the command to be served
d)
designed to secure raising of water surface on its upstream
| | Raghavendra Dasgupta answered |
When the available natural ground slope is steeper than the designed bed slope of the channel, the difference is adjusted by constructing canal falls or drops. The location of fall depends upon the topography, command area and the possibility of combining it with a bridge, regulator, or some other masonry work, since such combinations often result in economy and better regulation.
An irrigation outlet is said to be proportional, when its- a)sensitivity = 1
- b)flexibility = 1
- c)setting = 1
- d)all of the above
Correct answer is option 'B'. Can you explain this answer?
An irrigation outlet is said to be proportional, when its
a)
sensitivity = 1
b)
flexibility = 1
c)
setting = 1
d)
all of the above
| | Sahana Dey answered |
Explanation:
An irrigation outlet is said to be proportional when its flexibility is equal to 1. This means that the outlet is able to adjust its flow rate in proportion to changes in pressure or head.
Flexibility:
Flexibility refers to the ability of an irrigation outlet to respond to changes in pressure or head by adjusting its flow rate. When an outlet has a flexibility of 1, it means that it is able to maintain a constant flow rate regardless of changes in pressure or head.
Proportional Outlet:
A proportional irrigation outlet is designed to provide a constant flow rate, regardless of changes in pressure or head. This is important in irrigation systems because it ensures that each section of the field receives an equal amount of water, regardless of variations in pressure.
Benefits of Proportional Outlets:
1. Uniform Water Distribution: Proportional outlets ensure that each section of the field receives the same amount of water, resulting in uniform water distribution. This is important for crop growth and yield.
2. Efficient Water Use: By providing a constant flow rate, proportional outlets help to improve the efficiency of water use in irrigation systems. This reduces wastage and promotes sustainable water management.
3. Improved Crop Performance: Proportional outlets ensure that crops receive a consistent water supply, which is essential for their growth and performance. This can lead to improved crop yields and quality.
4. Reduced Water Stress: Proportional outlets help to minimize water stress on crops by providing a steady water supply. This is particularly important during periods of high water demand or drought.
5. Easy System Design: Proportional outlets simplify system design by eliminating the need for complex pressure regulation devices. This reduces the cost and complexity of irrigation systems.
Conclusion:
In conclusion, a proportional irrigation outlet is one that maintains a constant flow rate regardless of changes in pressure or head. This ensures uniform water distribution, efficient water use, improved crop performance, reduced water stress, and simplified system design. Therefore, the correct answer to the given question is option 'B' (flexibility = 1).
An irrigation outlet is said to be proportional when its flexibility is equal to 1. This means that the outlet is able to adjust its flow rate in proportion to changes in pressure or head.
Flexibility:
Flexibility refers to the ability of an irrigation outlet to respond to changes in pressure or head by adjusting its flow rate. When an outlet has a flexibility of 1, it means that it is able to maintain a constant flow rate regardless of changes in pressure or head.
Proportional Outlet:
A proportional irrigation outlet is designed to provide a constant flow rate, regardless of changes in pressure or head. This is important in irrigation systems because it ensures that each section of the field receives an equal amount of water, regardless of variations in pressure.
Benefits of Proportional Outlets:
1. Uniform Water Distribution: Proportional outlets ensure that each section of the field receives the same amount of water, resulting in uniform water distribution. This is important for crop growth and yield.
2. Efficient Water Use: By providing a constant flow rate, proportional outlets help to improve the efficiency of water use in irrigation systems. This reduces wastage and promotes sustainable water management.
3. Improved Crop Performance: Proportional outlets ensure that crops receive a consistent water supply, which is essential for their growth and performance. This can lead to improved crop yields and quality.
4. Reduced Water Stress: Proportional outlets help to minimize water stress on crops by providing a steady water supply. This is particularly important during periods of high water demand or drought.
5. Easy System Design: Proportional outlets simplify system design by eliminating the need for complex pressure regulation devices. This reduces the cost and complexity of irrigation systems.
Conclusion:
In conclusion, a proportional irrigation outlet is one that maintains a constant flow rate regardless of changes in pressure or head. This ensures uniform water distribution, efficient water use, improved crop performance, reduced water stress, and simplified system design. Therefore, the correct answer to the given question is option 'B' (flexibility = 1).
The Garret’s diagrams are based on- a) Lacey’s theory
- b)Khosla’s theory
- c) Bligh’s theory
- d)Kennedy’s theory
Correct answer is option 'D'. Can you explain this answer?
The Garret’s diagrams are based on
a)
Lacey’s theory
b)
Khosla’s theory
c)
Bligh’s theory
d)
Kennedy’s theory
| | Rithika Reddy answered |
A lot of mathematical calculations are required in designing irrigation channels by the use of Kennedy’s method . To save mathematical calculations, graphical solution of Kennedy’s and Kutter’s equation, was evolved by Garret.
A fully modular canal outlet has its- a)sensitivity = 1, and flexibility = 1
- b)sensitivity = 1, and flexibility = 0
- c)sensitivity = 0, and flexibility = 1
- d)sensitivity = 0, and flexibility = 0
Correct answer is option 'D'. Can you explain this answer?
A fully modular canal outlet has its
a)
sensitivity = 1, and flexibility = 1
b)
sensitivity = 1, and flexibility = 0
c)
sensitivity = 0, and flexibility = 1
d)
sensitivity = 0, and flexibility = 0
| | Navya Saha answered |
Rigid modules or modular outlets are those through which the discharge is constant and fixed within limits irrespective of the fluctuations of the water levels of either the distributary or of the water course or of both .
∴ sensitivity = 0, and flexibility = 0.
∴ sensitivity = 0, and flexibility = 0.
The duty of irrigation water for a given crop is maximum- a)on the field
- b)at the head of the main canal
- c)at the head of the water-course
- d)None of these
Correct answer is option 'A'. Can you explain this answer?
The duty of irrigation water for a given crop is maximum
a)
on the field
b)
at the head of the main canal
c)
at the head of the water-course
d)
None of these
| | Simran Saha answered |
Concept:
Duty:
Duty:
- It is the number of hectares of land irrigated for full growth of a given crop by a supply of 1 cumec of water continuously during the entire base period of that crop.
- Duty is the area that can be irrigated by the discharge of 1 cumec of water.
- At the head of the canal, there are numerous losses to occur later which requires more amount of water to irrigate a particular field. However, if considered on the field, all losses have already occurred and a lesser amount of water is required to irrigate the same considered area.
- Duty of water changes from place to place, it will be maximum at the field and minimum at the head of the canal.
Lacey’s regime theory is not applicable to a channel in- a)true regime
- b)initial regime
- c)final regime
- d)None of these
Correct answer is option 'B'. Can you explain this answer?
Lacey’s regime theory is not applicable to a channel in
a)
true regime
b)
initial regime
c)
final regime
d)
None of these
| | Hiral Sharma answered |
Lacey said that even a channel showing no silting no scouring may actually not be in regime. He differentiated between three regime conditions.
(i) True regime
(ii) Initial regime and
(iii) Final regime
According-to him, a channel which is under ‘initial’ regime is not a channel in regime, as there is no silting or scouring and hence regime theory is not applicable to such channels. His theory is therefore applicable only to; those channels, which are either in true regime or in final regime.
(i) True regime
(ii) Initial regime and
(iii) Final regime
According-to him, a channel which is under ‘initial’ regime is not a channel in regime, as there is no silting or scouring and hence regime theory is not applicable to such channels. His theory is therefore applicable only to; those channels, which are either in true regime or in final regime.
Capacity-inflow ratio for a storage reservoir is defined as- a)
- b)
- c)
- d)None of the above
Correct answer is option 'A'. Can you explain this answer?
Capacity-inflow ratio for a storage reservoir is defined as
a)
b)
c)
d)
None of the above
| | Sanya Agarwal answered |
Capacity-inflow ratio can be defined as the ratio of the reservoir capacity to the total inflow of water. The trap efficient is a function of the capacity-inflow ratio which is represented by a graph between them.
Safety ladders are provided in large irrigation canals, to- a)enable the fish to pass from one place to another
- b)enable the cattle to cross the canal
- c)enable the swimmers to get out of the canal
- d)provide safe exit to avoid accidental drowning
Correct answer is option 'D'. Can you explain this answer?
Safety ladders are provided in large irrigation canals, to
a)
enable the fish to pass from one place to another
b)
enable the cattle to cross the canal
c)
enable the swimmers to get out of the canal
d)
provide safe exit to avoid accidental drowning
| | Rahul Chauhan answered |
In large canals, safety ladders are generally provided on side slopes, at suitable intervals along the canal length. These ladders can be used by persons or cattle, that may be swept away with the flowing water in the canal. Such a person, who may otherwise get drowned, may catch hold of one such ladder and can climb it to get out of the canal easily.
Under which one of the following categories is the river Ganga classified in the reach through UP and Bihar ?- a)Straight river
- b)Meandering river
- c)Braided river
- d)Deltaic river
Correct answer is option 'B'. Can you explain this answer?
Under which one of the following categories is the river Ganga classified in the reach through UP and Bihar ?
a)
Straight river
b)
Meandering river
c)
Braided river
d)
Deltaic river
| | Prerna Menon answered |
Formation of successive bends of reverse order in a river may lead to the formation of a complete S curve called meander. Such a river is called meandering river.
When a river flows in two or more channels around alluvial islands, it is known as a braided river.
Deltaic river is a river which gets divided into branches before joining the sea, thus forming a Δ shaped delta.
When a river flows in two or more channels around alluvial islands, it is known as a braided river.
Deltaic river is a river which gets divided into branches before joining the sea, thus forming a Δ shaped delta.
Trap efficiency of a storage reservoir is defined as- a)Total annual seiment inflow/Reservoir capacity
- b)Total sediment deposited in a given period/Total sediment inflow in that period
- c)Total annual seiment deposited in the reservoir/Dead storage capacity of the reservoir
- d)None of the above
Correct answer is option 'B'. Can you explain this answer?
Trap efficiency of a storage reservoir is defined as
a)
Total annual seiment inflow/Reservoir capacity
b)
Total sediment deposited in a given period/Total sediment inflow in that period
c)
Total annual seiment deposited in the reservoir/Dead storage capacity of the reservoir
d)
None of the above
 | Gate Funda answered |
Trap efficiency of a storage reservoir is the ratio of the total amount of sediment that is trapped or deposited in the reservoir to the total amount of sediment that enters the reservoir. It is a measure of the effectiveness of the reservoir in capturing sediment.
The correct definition of trap efficiency is: Total sediment deposited in a given period / Total sediment inflow in that period
Groynes are adopted for river bank protection works. When it is placed inclined downstream in the direction of flow in the river, it is designated as which one of the following?- a)Repelling groyne
- b)Attracting groyne
- c)Neither repelling nor attracting groyne
- d)Fixed groyne
Correct answer is option 'B'. Can you explain this answer?
Groynes are adopted for river bank protection works. When it is placed inclined downstream in the direction of flow in the river, it is designated as which one of the following?
a)
Repelling groyne
b)
Attracting groyne
c)
Neither repelling nor attracting groyne
d)
Fixed groyne
| | Mehul Choudhury answered |
A groyne pointing downstream has the property of attracting the flow towards it and is called an attracting groyne. In attracting groynes scours holes are developed nearer the bank, as compared to those in a repelling groyne. Since such attracting groynes bring the water current as well as scour holes nearer the bank and make it more susceptible to damage, they are not used generally. The groynes are therefore, generally aligned either perpendicular to the bank or pointing upstream (repelling groyne).
What is the height of wave which is likely to be generated by a wind of 80 km/hr in a reservoir having a fetch of 50 km?- a)0.5 m
- b)1.0 m
- c)2.0 m
- d)3.0 m
Correct answer is option 'C'. Can you explain this answer?
What is the height of wave which is likely to be generated by a wind of 80 km/hr in a reservoir having a fetch of 50 km?
a)
0.5 m
b)
1.0 m
c)
2.0 m
d)
3.0 m
| | Aarav Chauhan answered |
Waves are generated on the surface of reservoir by the blowing winds, which causes a pressure towards the downstream side. Wave pressure depends upon the wave, height. Wave height in metres may be given by the equation.
where V is wind velocity in km/hr and F is fetch in km.
∴
where V is wind velocity in km/hr and F is fetch in km.
∴
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