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Past Questions — 2010
In the design of rigid boundary canals by method of economic section in a trapezoidal channel, following conditions are fulfilled
A)
hydraulic radius R is one third of depth y
B)
side slope is inclined to the horizontal at 45º to the horizontal
C)
half of top width is equal to one slanting side
D)
none of the above
In the design of a trapezoidal channel, the 'most economical section' (or best hydraulic section) is the one that provides the maximum discharge for a given cross-sectional area, slope, and roughness, which occurs when the wetted perimeter is minimized. For a trapezoidal section, the conditions for the most economical section are:
1. The hydraulic radius (R) must be half of the depth of flow (y), i.e., R = y/2. This contradicts option (a), which states R = y/3.
2. The top width (T) should be such that half of the top width is equal to the length of one of the sloping sides (L). Mathematically: T/2 = L. This matches option (c).
3. The most economical side slope for a trapezoidal section is 60 degrees to the horizontal (forming a half-hexagon), not 45 degrees. This contradicts option (b).
Therefore, the condition that half of the top width is equal to one slanting side is the correct characteristic of an economical trapezoidal section.
Curvature of earth is considered in:
A)
plane surveying
B)
geodetic surveying
C)
compass survey
D)
survey in small area
Surveying is broadly classified into two categories based on whether the curvature of the earth is taken into account:
1. **Plane Surveying**: In this type of surveying, the earth's surface is considered a flat plane. The curvature of the earth is neglected. This is applicable for small areas (typically less than 250 square kilometers) where the error introduced by ignoring curvature is negligible.
2. **Geodetic Surveying**: This type of surveying is used for very large areas or high-precision work. It accounts for the true spherical (or ellipsoidal) shape of the earth. Curvature is considered to ensure accuracy over long distances.
Analyzing the options:
- Option (a) is incorrect because plane surveying ignores curvature.
- Option (b) is correct because geodetic surveying specifically accounts for the earth's curvature.
- Option (c) is incorrect because compass surveying is generally a form of plane surveying used for smaller areas.
- Option (d) is incorrect because in small areas, the earth's surface can be treated as flat without significant error.
The most popular and widely used theory of sediment in channel and stream is
A)
Brahms and Aiery’s theory
B)
Jaffrey’s lift concept theory
C)
White’s theory
D)
Shields’ tractive force theory
In hydrology and fluvial hydraulics, the movement of sediment in a stream is governed by the forces acting on the particles. The most widely accepted and popular theory for determining the onset of sediment motion is Shields' Tractive Force Theory.
1. **Shields' Tractive Force Theory**: This theory introduces the concept of 'critical shear stress' (or tractive force). It posits that a sediment particle will begin to move when the dimensionless shear stress (Shields parameter) exceeds a critical value. This theory is fundamental to calculating the 'critical velocity' and 'critical shear stress' required to initiate the motion of bed load.
2. **Analysis of other options**:
- **Brahms and Aiery’s theory**: These are not recognized standard theories for sediment transport in hydrology.
- **Jaffrey’s lift concept theory**: While lift forces are a component of sediment transport (especially for larger particles), it is not the primary or most widely used general theory for channel sediment.
- **White’s theory**: While Frank White is a renowned authority on fluid mechanics and open channel flow, there is no 'White's theory' that serves as the primary standard for sediment initiation of motion compared to Shields.
In non-uniform steady gradually varied flow
A)
velocity varies gradually
B)
depth changes gradually
C)
discharge changes
D)
pressure changes gradually
In fluid mechanics, specifically open channel flow, flow is classified based on how parameters change with respect to time and space.
1. **Steady Flow**: The flow properties (velocity, depth, etc.) at any point do not change with time. Therefore, discharge (Q) remains constant throughout the reach, making option (c) incorrect.
2. **Non-Uniform Flow**: The flow properties change from one section to another along the length of the channel.
3. **Gradually Varied Flow (GVF)**: This is a specific type of non-uniform flow where the depth (y) and velocity (v) change slowly over a long distance. The defining characteristic of GVF is that the curvature of the water surface is small, meaning the depth changes gradually along the length of the channel.
While velocity also changes (option a), the fundamental definition and the primary parameter used to describe GVF in hydraulic engineering is the gradual change in depth (the water surface profile). Pressure in open channel flow is typically atmospheric at the surface and hydrostatic vertically; the 'gradual' nature of GVF refers specifically to the water surface profile (depth) rather than a pressure gradient (option d).
The values or signs of latitude and departure of a line are both negative, Reduced bearing θ of the line is
A)
N θ W
B)
S θ E
C)
S θ W
D)
N θ W
In surveying, Latitude and Departure are the projections of a line on the North-South (meridian) and East-West axes, respectively.
1. **Latitude (L)**: This is the projection of a line on the North-South axis.
- If the line is directed towards the North, Latitude is positive (+).
- If the line is directed towards the South, Latitude is negative (-).
2. **Departure (D)**: This is the projection of a line on the East-West axis.
- If the line is directed towards the East, Departure is positive (+).
- If the line is directed towards the West, Departure is negative (-).
Given in the question:
- Latitude is negative (-) $\rightarrow$ The direction is South (S).
- Departure is negative (-) $\rightarrow$ The direction is West (W).
Therefore, the line lies in the third quadrant (South-West quadrant). The Reduced Bearing (RB) of a line in this quadrant is expressed as S $\theta$ W.
The scour depth of a river during flood may be calculated from the Lacey’s equation with usual notations, is
A)
D = 0.47(Q/f)^(1/2)
B)
D = 0.47(Q/f)^(1/3)
C)
D = 0.47(Q/f)^(2/3)
D)
D = 0.47(Q/f)^(1/4)
According to Lacey's theory on river regimes, the regime depth (R) is given by the formula R = 0.47 (Q/f)^(1/3), where Q is the discharge and f is the silt factor. When considering the scour depth (D) of a river during a flood, the depth of scour is typically related to the regime depth. Specifically, the maximum depth of scour (R) is calculated using this specific power of 1/3.
Step-by-step analysis:
1. Lacey's regime depth formula is R = 0.47 (Q/f)^(1/3).
2. In the context of river engineering and scour calculations for bridge piers or abutments, the basic regime depth serves as the foundation for calculating the total scour depth.
3. Comparing this to the options provided:
- Option (a) uses a power of 1/2, which is incorrect.
- Option (b) uses a power of 1/3, which matches Lacey's regime depth formula.
- Option (c) uses a power of 2/3, which is incorrect.
- Option (d) uses a power of 1/4, which is incorrect.
Therefore, the correct expression for the depth based on Lacey's equation is D = 0.47(Q/f)^(1/3).
Extensively used levelling instrument is
A)
tilting level
B)
wye level
C)
dumpy level
D)
bubble tube
In surveying, levelling is the process of determining the relative heights of points. Among the options provided:
1. **Dumpy Level (Option c):** This is the most extensively used levelling instrument in general engineering and construction projects. It consists of a telescope rigidly fixed to its support, which is mounted on a tripod. Its simplicity, stability, and ease of use make it the standard choice for most field levelling tasks.
2. **Tilting Level (Option a):** While more precise than a dumpy level because the telescope can be tilted slightly to establish a perfectly horizontal line of sight, it is more complex to operate and is used for high-precision work rather than extensive general use.
3. **Wye Level (Option b):** This is an older type of level where the telescope can be rotated in a vertical plane about a transverse axis. It has largely been superseded by the dumpy level and automatic levels.
4. **Bubble Tube (Option d):** This is not a levelling instrument itself, but rather a component (a leveling accessory) used within instruments like the dumpy level to ensure the line of sight is horizontal.
Therefore, the dumpy level is the most extensively used instrument for general levelling operations.
Synthetic unit hydrographs of Synder based on parameters
A)
Base time T
B)
Peak discharge Qp
C)
basin lag time tp
D)
all the above
Snyder's Synthetic Unit Hydrograph (SUH) method is used to derive a unit hydrograph for ungauged basins. The method relies on several key parameters derived from basin characteristics (like area, length, and slope).
1. **Basin Lag Time (tp):** This is the primary parameter in Snyder's method. It is the time from the centroid of rainfall excess to the peak of the hydrograph. It is calculated using the formula: tp = Ct(L)^m, where L is the basin length and Ct and m are constants.
2. **Peak Discharge (Qp):** Once the lag time is determined, the peak discharge of the unit hydrograph is calculated using the formula: Qp = (2.78 * CA * qp), where CA is the basin area and qp is a coefficient related to the lag time.
3. **Base Time (T):** The base time (the total duration of the hydrograph) is also a critical parameter used to define the recession limb of the hydrograph, typically calculated as T = 5.8 * tp.
Since the construction of a Snyder's Synthetic Unit Hydrograph requires the determination of the lag time to find the peak discharge and the base time to define the overall shape, all three parameters are essential components of the method.
In order to have a continuous flow through a siphon, no portion of the pipe be higher than
A)
10 m
B)
10.33 m
C)
5.5 m
D)
7.6 m
A siphon works on the principle of atmospheric pressure pushing the liquid up into the pipe. For a continuous flow to occur, the pressure at the highest point (the summit) of the siphon must not drop below the vapor pressure of the liquid. If the pressure drops too low, the liquid will boil (cavitation), creating a vapor lock that breaks the continuous column of liquid and stops the flow.
For water at standard atmospheric pressure (1 atm = 101.325 kPa) and standard temperature, the maximum theoretical height (vacuum lift) that water can be raised is approximately 10.33 meters. This is because the atmospheric pressure acting on the surface of the reservoir can support a column of water roughly 10.33 meters high. In practical applications, the height is always less than this due to friction losses and the vapor pressure of the water, but the theoretical limit used in competitive exams is 10.33 m.
Triaxial shear test is preferred to direct shear test because
A)
stress distribution on the failure plane is not uniform
B)
it can be performed under all three drainage conditions with complete control
C)
precise measurement of the pore pressure and change in volume during test, is not possible
D)
none of the above
The Triaxial Shear Test is considered superior to the Direct Shear Test for several fundamental reasons in soil mechanics:
1. **Drainage Control (Option b):** This is the primary advantage. In a triaxial test, the drainage valves can be opened or closed to simulate specific field conditions: Unconsolidated Undrained (UU), Consolidated Undrained (CU), and Consolidated Drained (CD). In a direct shear test, drainage cannot be strictly controlled.
2. **Pore Pressure Measurement:** Triaxial tests allow for the measurement of pore water pressure during the test, which is essential for determining effective stress parameters. Direct shear tests cannot measure pore pressure.
3. **Failure Plane:** In a direct shear test, the failure plane is forced (predetermined) horizontally. In a triaxial test, the soil fails along its weakest plane, which is more representative of actual field behavior.
4. **Stress Distribution:** In a direct shear test, the stress distribution is non-uniform. In a triaxial test, the confining pressure ensures a more uniform stress state.
Evaluating the options:
- Option (a) describes a disadvantage of the Direct Shear Test, not a reason why the Triaxial test is preferred (the phrasing suggests it's a characteristic of the triaxial test, which is incorrect).
- Option (b) is correct as it highlights the versatility of drainage control.
- Option (c) is incorrect because precise measurement of pore pressure and volume change IS possible in a triaxial test, whereas the option claims it is 'not possible'.
When the density ρ of the fluid flow changes from point to point, flow is called
A)
rotational
B)
irrotational
C)
compressible
D)
incompressible
In fluid mechanics, the classification of flow based on density changes is as follows:
1. **Compressible Flow**: A flow is called compressible if the density ($
ho$) of the fluid changes from point to point within the flow field or changes with time. This is typical of gases, where changes in pressure or temperature significantly affect the density.
2. **Incompressible Flow**: A flow is called incompressible if the density remains constant throughout the flow field ($
ho = ext{constant}$). Most liquids are treated as incompressible for practical engineering purposes.
3. **Rotational Flow**: This refers to the vorticity of the fluid. If the fluid particles rotate about their own axis while moving along a streamline, the flow is rotational.
4. **Irrotational Flow**: If the fluid particles do not rotate about their own axis, the flow is irrotational.
Since the question specifically asks about the change in density ($
ho$) from point to point, the correct term is 'compressible'.
The father of soil mechanics is
A)
Karl Terzaghi
B)
Fellenius
C)
Kray
D)
Henkel
Karl Terzaghi is universally recognized as the 'Father of Soil Mechanics'. He revolutionized the field of geotechnical engineering by publishing his seminal work, 'Erdbaumechanik' (Theoretical Soil Mechanics), in 1925. His most significant contribution was the development of the 'Principle of Effective Stress', which explains how the load is shared between the soil skeleton and the pore water, providing the theoretical foundation for calculating settlement and shear strength in soils.
Regarding the other options:
- Fellenius is known for his contributions to slope stability analysis (the Fellenius method).
- Henkel (likely referring to Skempton or similar researchers in the field of consolidated undrained tests) and Kray are not credited with founding the discipline of soil mechanics.
The earthen embankments constructed parallel to the river banks at suitable distance for flood control are called
A)
flood walls
B)
dikes
C)
levees
D)
both (b) and (c)
In hydrology and hydraulic engineering, structures built parallel to a river bank to prevent flooding of the adjacent land are known as levees or dikes.
1. **Levees**: These are earthen embankments constructed parallel to the river channel to increase the effective depth of the channel and prevent the river from overflowing its banks into the floodplain.
2. **Dikes**: While often used interchangeably with levees, dikes are specifically embankments constructed to prevent flooding from the sea or to reclaim land from the sea, but in general civil engineering terminology, they are also used to describe embankments that contain water within a channel.
3. **Flood walls**: These are vertical structures usually made of reinforced concrete or masonry. Since the question specifically mentions 'earthen embankments', flood walls are incorrect.
Because both 'levees' and 'dikes' refer to earthen embankments used for flood control and water containment, option (d) is the most comprehensive and correct answer.
In open channel flow, when specific energy is minimum, flow condition is
A)
super critical
B)
sub critical
C)
transitional
D)
critical
In open channel flow, the specific energy (E) is defined as the energy per unit weight of water at any section with respect to the channel bottom. It is given by the formula: E = y + V²/2g, where 'y' is the depth of flow and 'V' is the average velocity. For a given discharge (Q), the specific energy varies with the depth of flow. There is a unique depth called the 'critical depth' (yc) at which the specific energy is at its minimum value. When the flow occurs at this minimum specific energy, the flow condition is defined as 'critical flow'.
- If the depth is greater than critical depth (y > yc), the velocity is low and the flow is 'subcritical'.
- If the depth is less than critical depth (y < yc), the velocity is high and the flow is 'supercritical'.
- Therefore, the condition where specific energy is minimum is exactly the 'critical' state.
In open channel flow
A)
Hydraulic grade line (HGL) is above the free surface
B)
Hydraulic grade line (HGL) coincides with free surface
C)
Hydraulic grade line (HGL) and total energy line (TEL) are same
D)
Total energy line (TEL) is below hydraulic energy line (HGL)
In fluid mechanics, the Hydraulic Grade Line (HGL) represents the sum of the pressure head (P/γ) and the datum head (z). For an open channel flow, the liquid surface is exposed to the atmosphere, meaning the gauge pressure at the free surface is zero (P = 0). Therefore, at the free surface, the HGL consists only of the elevation head (z), which is exactly the height of the water surface above the datum. Consequently, the HGL coincides with the free surface of the liquid.
Analyzing the other options:
- Option (a) is incorrect because the HGL cannot be above the free surface in an open channel; it is defined by the surface.
- Option (c) is incorrect because the Total Energy Line (TEL) is the sum of the HGL and the velocity head (v²/2g). Since velocity is generally non-zero, TEL is always higher than HGL.
- Option (d) is incorrect because the TEL is always above the HGL by the magnitude of the velocity head.
For determination of average precipitation in a catchment, best method is
A)
arithmetical method
B)
isohytel mean method
C)
Theissen polygon method
D)
none of the above
To determine the average precipitation over a catchment area, three primary methods are commonly used in hydrology:
1. **Arithmetical Mean Method**: This is the simplest method, calculating the simple average of rainfall at all stations. It is only accurate if the stations are uniformly distributed and the terrain is flat (no significant topographic variation).
2. **Thiessen Polygon Method**: This method assigns a weight to each station based on the area it represents. It is more accurate than the arithmetical mean because it accounts for non-uniform distribution of gauges, but it does not account for changes in precipitation due to topography (elevation).
3. **Isohyetal Method**: This method involves drawing lines of equal precipitation (isohyets) on a map. It accounts for both the non-uniform distribution of rain gauges and the effects of topography (orographic effects). Because it integrates the spatial variation of rainfall across the entire basin, it is widely considered the most accurate and 'best' method for determining average precipitation.
Therefore, the Isohyetal mean method is the most precise of the three options provided.
Ground water occurs in different zones below ground level (GL). The zone just below the GL is
A)
zone of aeration
B)
capillary fringe
C)
unconfined aquifer
D)
pressure or confined aquifer
In hydrology, the subsurface is divided into distinct zones based on the saturation of the soil/rock pores.
1. **Zone of Aeration (Unsaturated Zone):** This is the layer immediately below the ground level (GL) and extending down to the water table. In this zone, the pore spaces contain both air and water. Because it is the topmost layer below the surface, it is the correct answer.
2. **Capillary Fringe:** This is a thin transition layer located immediately above the water table. Water is drawn upward from the water table by capillary action. While it is part of the unsaturated zone, it is not the zone 'just below the GL' unless the water table is extremely shallow.
3. **Unconfined Aquifer (Phreatic Zone):** This is the zone below the water table where all pore spaces are completely filled with water. It is located below the zone of aeration.
4. **Confined Aquifer (Pressure Aquifer):** This is a saturated zone trapped between two impermeable layers (aquitards/aquicludes), usually located much deeper in the subsurface.
Therefore, the sequence from the surface downwards is: Ground Level $\rightarrow$ Zone of Aeration $\rightarrow$ Capillary Fringe $\rightarrow$ Water Table $\rightarrow$ Saturated Zone (Aquifer).
Different electronic distance measurement (EDM) instruments are
A)
Tellurometer
B)
Geodimeter
C)
Distameter
D)
Electro-optical Distance Meter
E)
all the above
Electronic Distance Measurement (EDM) refers to a variety of instruments used to determine the distance between two points using electromagnetic waves (such as light, infrared, or microwaves).
1. **Tellurometer**: This is a microwave-based EDM instrument that measures distance by calculating the phase difference between transmitted and received waves.
2. **Geodimeter**: This was one of the first EDM instruments; it operates on the principle of measuring the travel time of light pulses (optical EDM).
3. **Distameter**: This is a general term often used for various electronic distance measuring devices, including those using infrared or laser technology.
4. **Electro-optical Distance Meter**: This is a broad category of EDM instruments that use light (visible or infrared) to measure distance, encompassing the technology used in modern Total Stations.
Since all the listed instruments are types of EDM devices, the correct option is 'all the above'.
Contour lines overlap in
A)
vertical cliff
B)
steep slope
C)
hill
D)
all (a), (b) and (c)
Contour lines are imaginary lines joining points of equal elevation. The spacing and behavior of these lines indicate the nature of the terrain:
1. **Vertical Cliff**: In the case of a vertical cliff, multiple points of different elevations occur at the same horizontal position. When projected onto a 2D map, the contour lines for these different elevations appear to coincide or overlap at the same location. Therefore, overlapping contours indicate a vertical cliff.
2. **Steep Slope**: On a steep slope, contour lines are drawn very close to each other, but they remain distinct and do not overlap.
3. **Hill**: A hill is represented by closed contour lines with the highest value in the center. The lines are concentric and do not overlap.
4. **Overhanging Cliff**: It is worth noting that if the cliff overhangs, the contour lines may actually cross each other, but for a standard vertical cliff, they overlap.
The useful soil moisture for plant growth is
A)
chemical water
B)
hygroscopic water
C)
capillary water
D)
gravity water
In soil physics and hydrology, soil water is classified based on how it is held within the soil matrix.
1. **Capillary Water (Correct):** This is the water held in the small pores (capillaries) of the soil by surface tension and adhesive forces. It is held tightly enough to resist the pull of gravity but loosely enough that plant roots can extract it via osmotic pressure. Therefore, it is the primary source of water available for plant growth.
2. **Hygroscopic Water (Incorrect):** This is a very thin film of water that adheres tightly to soil particles. It is held by such strong adhesive forces that plant roots cannot extract it. It is generally considered unavailable to plants.
3. **Gravity Water (Incorrect):** This is water that fills the large macro-pores of the soil and drains away rapidly under the influence of gravity. Because it drains quickly, it is not stored in the root zone for long-term plant use.
4. **Chemical Water (Incorrect):** This refers to water that is chemically combined with the soil minerals (structural water). It is not available for biological use as it is part of the mineral structure itself.
The trapezoidal rule of volume V of an embankment divided into number of sections equidistant L, is given by
A)
V = L( (A1+An)/2 + A2 + A3 + ... + An-1)
B)
V = L/4( A1 + An + 2(A2 + A3 + ... + An-1))
C)
V = L/2( A1 + An + 2(A2 + A3 + ... + An-1))
D)
none of the above
The Trapezoidal Rule for calculating the volume of an embankment (or any earthwork) is based on the principle of calculating the area of a trapezoid formed between two cross-sections.
1. For a single segment between two sections with areas A1 and A2 and distance L, the volume is: V = L * ((A1 + A2) / 2).
2. For multiple equidistant sections (A1, A2, ..., An) separated by distance L, the total volume is the sum of the volumes of individual segments:
V = (L/2) * (A1 + A2) + (L/2) * (A2 + A3) + ... + (L/2) * (An-1 + An)
3. Factoring out (L/2), we get:
V = (L/2) * [A1 + 2A2 + 2A3 + ... + 2An-1 + An]
4. This can be rewritten as:
V = L/2 * [A1 + An + 2(A2 + A3 + ... + An-1)]
Comparing this to the options:
- Option (a) is mathematically equivalent to the formula but is written as L((A1+An)/2 + A2 + ...), which simplifies to (L/2)(A1 + An + 2(A2...)). However, standard textbook notation for the Trapezoidal Rule in surveying is typically expressed as shown in option (c).
- Option (b) uses L/4, which is incorrect.
- Option (c) is the standard mathematical representation of the Trapezoidal Rule for volume calculation.
An ideal fluid is one which
A)
obeys Newton’s law of viscosity
B)
is frictionless having shear stress τ=0
C)
is very viscous
D)
none of the above
In fluid mechanics, an 'ideal fluid' is a theoretical construct used to simplify mathematical analysis. It is defined by two primary characteristics: 1) It is incompressible (constant density), and 2) It is inviscid (zero viscosity).
Newton's law of viscosity is given by the formula τ = μ(du/dy), where τ is the shear stress, μ is the dynamic viscosity, and (du/dy) is the velocity gradient. For an ideal fluid, the viscosity (μ) is zero. Consequently, regardless of the velocity gradient, the shear stress (τ) will always be zero. This means there is no internal friction between fluid layers and no friction between the fluid and the walls of the container.
Analysis of options:
- Option (a) is incorrect because while an ideal fluid technically fits the formula τ = 0 * (du/dy), the defining characteristic is the absence of viscosity, whereas 'obeying Newton's law' usually refers to Newtonian fluids which possess a constant, non-zero viscosity.
- Option (b) is correct as it explicitly states the fluid is frictionless and has zero shear stress.
- Option (c) is incorrect because a very viscous fluid is the opposite of an ideal fluid.
A simple manometer may be
A)
piezometer
B)
U-tube manometer
C)
single column manometer
D)
all the above
A manometer is a device used to measure the pressure of a fluid. Simple manometers are those that use a single column of manometric fluid to measure pressure.
1. Piezometer: This is the simplest form of a manometer. It consists of a simple vertical tube open to the atmosphere. It is used to measure moderate pressure in liquids.
2. U-tube Manometer: This consists of a U-shaped tube containing a manometric fluid. It can measure both positive and negative gauge pressures relative to the atmosphere.
3. Single Column Manometer: This is a category of manometers (which includes the U-tube and others like the inverted U-tube) where a single column of liquid is used to determine the pressure difference.
Since all three options (a, b, and c) are types of simple manometers, the correct answer is 'all the above'.
Hydraulic jump occurs when the channel bed slope changes from
A)
subcritical to supercritical
B)
super critical to subcritical
C)
critical to subcritical
D)
none of the above
A hydraulic jump is a phenomenon in open channel flow where a high-velocity, supercritical flow (Froude number Fr > 1) transitions abruptly to a low-velocity, subcritical flow (Froude number Fr < 1). This transition is characterized by a sudden rise in the water surface level and significant energy dissipation through turbulence. This typically occurs when the channel bed slope changes from a steep slope (which promotes supercritical flow) to a mild slope (which promotes subcritical flow), or when the flow encounters an obstruction or a downstream control (like a weir or gate) that forces the flow to slow down.
- Option (a) is incorrect because a transition from subcritical to supercritical flow usually occurs at a drop or a steepening slope and does not result in a jump.
- Option (c) is incorrect because the jump specifically requires a transition from a supercritical state to a subcritical state to dissipate energy.
Manning’s equation is used in open channel to estimate
A)
average velocity
B)
average depth
C)
average slope
D)
average discharge
Manning's equation is an empirical formula used in fluid mechanics and hydraulics to calculate the average flow velocity of water in an open channel. The formula is expressed as: V = (1/n) * R^(2/3) * S^(1/2), where 'V' is the average velocity, 'n' is the Manning roughness coefficient, 'R' is the hydraulic radius (area divided by wetted perimeter), and 'S' is the slope of the energy grade line (usually taken as the bed slope for uniform flow). While the average discharge (Q) can be calculated using this result (Q = A * V), the primary purpose of the Manning's equation itself is to determine the average velocity. Options b and c are parameters used as inputs into the equation, not the values estimated by the equation.