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Question 1
ప్రశ్న 1
Kennedy developed his theory of stable alluvial canals primarily from observations of which type of channel?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
Kennedy's theory was empirical and arose from observations of stable alluvial irrigation canals. His principal data came from reaches of the Upper Bari Doab Canal system that had remained reasonably free from serious silting and scouring. He related the observed stable mean velocity mainly to the depth of flow. The resulting relationship was therefore not derived from a complete theoretical sediment-transport model. Its observational origin is one of the main reasons the theory must be applied cautiously outside conditions similar to those from which it was developed. Therefore Option B is correct.
వివరణ:
Question 2
ప్రశ్న 2
In Kennedy's theory, what is meant by the critical velocity of an alluvial canal?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
Kennedy used the term critical velocity in a sediment-stability sense rather than in the Froude-number sense of critical flow. It represents the mean canal velocity associated with a non-silting and non-scouring condition for the sediment and channel conditions being considered. A lower velocity may provide insufficient sediment-supporting capacity and can encourage deposition. A substantially higher velocity may promote erosion or scour of an erodible boundary. The expression therefore concerns alluvial-channel stability, not the hydraulic condition Fr = 1. Therefore Option C is correct.
వివరణ:
Question 3
ప్రశ్న 3
Which is the standard SI form of Kennedy's basic critical-velocity relationship for the reference sediment condition?
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Explanation:
Kennedy correlated the stable mean velocity with the depth of flow D. The original fitted coefficient is often quoted close to 0.546 in SI units and is conventionally rounded to 0.55 in irrigation-engineering calculations. The corresponding exponent on depth is approximately 0.64. Thus the standard simplified relationship is Vc = 0.55 D^0.64, with Vc in m/s and D in metres. Hydraulic radius does not replace D in Kennedy's critical-velocity equation. Therefore Option A is correct.
వివరణ:
Question 4
ప్రశ్న 4
How is Kennedy's critical-velocity equation commonly modified to account approximately for a sediment grade different from that of the reference canal system?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
Kennedy's original depth-velocity relationship reflected the sediment conditions of the canals from which it was obtained. A critical velocity ratio, conventionally denoted by m, was introduced to adjust the required stable velocity for other sediment grades. The commonly used modified expression is Vc = 0.55 m D^0.64. For the reference sediment condition, m is approximately unity. The factor is an empirical adjustment and does not convert Kennedy's theory into a complete sediment-transport theory. Therefore Option D is correct.
వివరణ:
Question 5
ప్రశ్న 5
At the same flow depth, what does a critical velocity ratio m greater than 1 generally indicate in Kennedy's modified relationship?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
The factor m adjusts Kennedy's reference critical velocity for differences in sediment grade. Coarser sediment generally requires a higher velocity to maintain the corresponding stable transporting condition, so m is commonly greater than unity. Finer sediment is associated with values below unity relative to the reference condition. An m value greater than one should not by itself be interpreted as proof that an existing channel is actively scouring. Scour or deposition depends on how the actual hydraulic velocity compares with the appropriate stable velocity for the sediment and boundary conditions. Therefore Option B is correct.
వివరణ:
Question 6
ప్రశ్న 6
What physical mechanism did Kennedy emphasize as providing the principal silt-supporting action in an alluvial canal?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
Kennedy associated sediment suspension with turbulent eddies generated by the moving water near the channel bed. The upward components of these eddies were considered capable of supporting sediment particles against their tendency to settle. On this basis he emphasized the contribution of the bed width to the silt-supporting process. Later understanding recognizes that turbulence and sediment transport are more complex and that the sides of a channel can also contribute. This simplified physical picture is therefore useful historically but is also one of the limitations of the theory. Therefore Option A is correct.
వివరణ:
Question 7
ప్రశ్న 7
According to Kennedy's basic relationship Vc = 0.55 D^0.64, what happens to the critical velocity as the flow depth increases?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
Kennedy's equation contains depth raised to the power 0.64. Because this exponent is positive, an increase in D increases the critical velocity. Because 0.64 is less than one, the increase is sublinear rather than directly proportional. Doubling the depth therefore increases the critical velocity by less than a factor of two. This depth dependence was obtained empirically from the observed stable canal reaches. Therefore Option C is correct.
వివరణ:
Question 8
ప్రశ్న 8
Using Kennedy's relation Vc = 0.55 m D^0.64, what is the critical velocity for D = 2.0 m and m = 1.0?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
The formula is Vc = 0.55 m D^0.64. With m = 1.0 and D = 2.0 m, the depth term is 2^0.64. Its value is approximately 1.558. Multiplication by 0.55 gives Vc ≈ 0.857 m/s. Thus the appropriate rounded value is about 0.86 m/s. Therefore Option D is correct.
వివరణ:
Question 9
ప్రశ్న 9
For a canal depth of 2.0 m and critical velocity ratio m = 1.20, what critical velocity is obtained from Vc = 0.55 m D^0.64?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
At D = 2.0 m, the reference Kennedy velocity is approximately 0.857 m/s. The critical velocity ratio m = 1.20 raises the required value by 20 percent relative to that reference velocity. Thus Vc = 1.20 × 0.857 ≈ 1.029 m/s. The same result follows directly from 0.55 × 1.20 × 2^0.64. The value should not be interpreted independently of the sediment condition represented by m. Therefore Option B is correct.
వివరణ:
Question 10
ప్రశ్న 10
A stable canal 2.0 m deep is observed to require a mean velocity of 0.95 m/s. Using Kennedy's modified equation Vc = 0.55 m D^0.64, what critical velocity ratio is implied?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
At D = 2.0 m, Kennedy's reference critical velocity for m = 1 is approximately 0.857 m/s. The modified relation gives m = Vc/[0.55D^0.64]. Substitution gives m = 0.95/0.857. This is approximately 1.108, which rounds to about 1.11. The value indicates a stable velocity requirement somewhat higher than the reference-sediment value at the same depth. Therefore Option C is correct.
వివరణ:
Question 11
ప్రశ్న 11
A canal must carry 18 m³/s at a Kennedy-compatible mean velocity of 0.90 m/s. What flow area is required from the continuity equation?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
The continuity equation is Q = AV. Rearranging gives A = Q/V. With Q = 18 m³/s and V = 0.90 m/s, A = 18/0.90. The required flow area is therefore 20 m². Kennedy's equation supplies a stable-velocity criterion, while continuity links that velocity to the required canal area. Therefore Option A is correct.
వివరణ:
Question 12
ప్రశ్న 12
A trapezoidal canal has flow area 20 m², depth D = 2.0 m, and side slopes z = 0.5 horizontal to 1 vertical on each side. Using A = D(B + zD), what bed width B is required?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
For the stated symmetrical trapezoid, A = D(B + zD). Substitution gives 20 = 2[B + 0.5(2)]. Thus 20 = 2(B + 1), or B + 1 = 10. The resulting bed width is B = 9 m. This illustrates how the section dimensions are obtained from continuity and geometry after a trial depth and stable velocity have been selected. Therefore Option D is correct.
వివరణ:
Question 13
ప్రశ్న 13
For the trapezoidal section with B = 9.0 m, D = 2.0 m and side slope z = 0.5H:1V, the area is 20 m². What is the hydraulic radius R = A/P, where P = B + 2D sqrt(1 + z²)?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
The wetted perimeter is P = 9 + 2(2)sqrt(1 + 0.5²). The square-root term is approximately 1.118, giving P ≈ 13.472 m. The hydraulic radius is therefore R = 20/13.472. This gives R ≈ 1.485 m, or about 1.48 m. Hydraulic radius is useful in the separate resistance equation used to test the hydraulic velocity and slope, even though Kennedy's critical-velocity expression itself uses depth D. Therefore Option B is correct.
వివరణ:
Question 14
ప్రశ్న 14
In a trial design by Kennedy's method, what condition indicates that the assumed section is hydraulically compatible with the stable-channel criterion?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
Kennedy's equation provides the velocity considered appropriate for sediment stability at the assumed depth and sediment grade. A separate hydraulic resistance relation is used to determine the velocity that the proposed section and slope would actually produce. The trial section is satisfactory when these two velocities are reasonably consistent. If they do not agree, the depth or other section dimensions are adjusted and the calculations are repeated. This is why Kennedy canal design is normally a trial-and-adjustment procedure rather than a single direct equation. Therefore Option C is correct.
వివరణ:
Question 15
ప్రశ్న 15
If the actual mean velocity in an erodible alluvial canal is appreciably below the appropriate Kennedy critical velocity for its sediment and depth, what tendency is expected in the simplified theory?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
Kennedy's critical velocity represents the approximate mean velocity associated with a stable sediment condition. If the actual velocity is appreciably lower, the turbulent transporting and supporting action is reduced. Suspended material is then more likely to settle within the canal. Progressive deposition reduces the effective flow area and can impair canal capacity and operation. This is the simplified silting tendency represented by Kennedy's theory. Therefore Option A is correct.
వివరణ:
Question 16
ప్రశ్న 16
If the actual mean velocity in an erodible alluvial canal is appreciably greater than the appropriate stable Kennedy velocity, what tendency does the simplified theory indicate?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
A stable alluvial channel requires the hydraulic action to remain compatible with the resistance of its boundary material. If actual velocity becomes substantially greater than the velocity associated with the stable condition, erosion can be encouraged. Bed or bank material may then be detached and transported downstream. The precise onset of scour depends on more than mean velocity alone, which is one reason modern sediment mechanics uses more detailed criteria. Within Kennedy's simplified framework, however, excessive velocity indicates a scouring tendency. Therefore Option D is correct.
వివరణ:
Question 17
ప్రశ్న 17
Which important canal-design quantity is not determined directly by Kennedy's critical-velocity equation?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
Kennedy's basic relation connects stable mean velocity primarily with depth and, in the modified form, with the critical velocity ratio. It does not contain the longitudinal bed slope as an explicit design result. A separate resistance relation such as Kutter, Chezy, or Manning must therefore be used to relate velocity, hydraulic radius, roughness, and slope. This need for another hydraulic equation is a well-known limitation of Kennedy's method. The canal design consequently requires iterative coordination between sediment stability and ordinary uniform-flow hydraulics. Therefore Option B is correct.
వివరణ:
Question 18
ప్రశ్న 18
Why is the canal bed width not fixed directly by Kennedy's equation Vc = 0.55 m D^0.64?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
The modified Kennedy equation contains only the depth D and empirical sediment factor m in addition to the numerical coefficient. It therefore does not provide a direct independent equation for bed width B. Once the trial critical velocity is known, continuity gives the required flow area A = Q/V. The assumed cross-sectional form and side slopes can then be used to compute the corresponding bed width. The absence of a direct width relation is another reason the method requires trial design rather than a unique closed-form channel section. Therefore Option C is correct.
వివరణ:
Question 19
ప్రశ్న 19
Which is a fundamental limitation arising from the empirical origin of Kennedy's theory?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
Kennedy's relationship was developed from field observations on stable reaches of a particular alluvial canal system. The coefficient and exponent therefore reflect the hydraulic and sediment conditions represented in those data. The critical velocity ratio was later used as an empirical adjustment for differences in sediment grade. That adjustment does not guarantee accurate prediction under every type of sediment concentration, grading, channel geometry, or flow condition. The method should therefore be understood as an empirical design approach with a restricted observational foundation. Therefore Option A is correct.
వివరణ:
Question 20
ప్రశ్న 20
Which statement identifies another important limitation of Kennedy's physical model of sediment support?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
Kennedy's explanation focused strongly on vertical eddies generated by resistance at the channel bed. Real open-channel turbulence is generated and modified by the bed, side slopes, secondary circulation, bends, and other geometric effects. Sediment transport also depends on grain size distribution, concentration, settling velocity, boundary shear, and interactions between suspended and bed material. Kennedy's compact depth-velocity relation does not explicitly represent these effects. This simplification is useful for traditional canal-design calculations but limits the theory's general physical completeness. Therefore Option D is correct.
వివరణ:
Question 21
ప్రశ్న 21
According to the classical reasoning associated with Kennedy's theory, the sediment-supporting capacity was taken approximately proportional to which expression?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
Kennedy related the amount of sediment held in suspension to the intensity of vertical eddies produced by the flow. In the classical derivation, the silt-supporting quantity is represented as proportional to bed width B multiplied by a power of the critical velocity. Combining this concept with the empirical depth-velocity exponent gives the velocity power approximately equal to 2.5. Thus the traditional result is proportional to B Vc^(5/2). The relation illustrates Kennedy's emphasis on bed-generated turbulence but should not be mistaken for a modern universal sediment-transport equation. Therefore Option B is correct.
వివరణ:
Question 22
ప్రశ్న 22
Using the classical Kennedy proportionality of sediment-supporting capacity to V^(5/2), by what factor would that capacity change if velocity increased by 20 percent while bed width remained unchanged?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
With bed width unchanged, the stated capacity ratio is (V2/V1)^(5/2). A 20 percent velocity increase gives V2/V1 = 1.20. Therefore the ratio is 1.20^2.5. Its value is approximately 1.577, which rounds to about 1.58. This numerical result also shows the strong velocity sensitivity inherent in the classical Kennedy supporting-capacity concept. Therefore Option C is correct.
వివరణ:
Question 23
ప్రశ్న 23
For the reference sediment condition m = 1, what flow depth approximately corresponds to a Kennedy critical velocity of 1.00 m/s, using Vc = 0.55 D^0.64?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
The equation is 1.00 = 0.55 D^0.64. Rearranging gives D^0.64 = 1/0.55. Raising both sides to the power 1/0.64 gives D = (1/0.55)^(1/0.64). The result is approximately 2.545 m, which rounds to about 2.55 m. This inverse calculation is useful when a required stable velocity is specified and a trial depth is being selected. Therefore Option A is correct.
వివరణ:
Question 24
ప్రశ్న 24
Which statement correctly distinguishes the roles of flow depth D and hydraulic radius R in a typical Kennedy canal-design calculation?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
Kennedy's empirical critical-velocity expression is written in terms of the depth of flow D. Hydraulic radius R is defined as flow area divided by wetted perimeter and generally differs from D except in special limiting geometries. Uniform-flow equations such as Chezy, Kutter, or Manning use hydraulic radius together with slope and roughness. Kennedy design therefore combines a depth-based sediment-stability relation with a separate hydraulic resistance relation containing R. Confusing D and R would produce an incorrect section or bed-slope calculation. Therefore Option D is correct.
వివరణ:
Question 25
ప్రశ్న 25
A trial trapezoidal canal is required to carry Q = 18 m³/s. Assume D = 2.0 m, m = 1.0 and side slopes z = 0.5H:1V. Using Vc = 0.55mD^0.64, A = Q/Vc and A = D(B + zD), which set of trial values is correct?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
For D = 2.0 m and m = 1.0, Kennedy's equation gives Vc ≈ 0.857 m/s. Continuity then gives A = 18/0.857 ≈ 21.0 m². For side slope z = 0.5, the trapezoidal area equation becomes 21.0 = 2[B + 0.5(2)]. This gives B ≈ 9.50 m. These values form only a trial section, because its hydraulic velocity and required slope must still be checked with an appropriate resistance equation. Therefore Option B is correct.
వివరణ:
Answer Key సమాధానాల పట్టిక
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Question 1 ప్రశ్న 1Answer: B. Stable non-silting and non-scouring reaches of the Upper Bari Doab Canal system సమాధానం: B.
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Question 2 ప్రశ్న 2Answer: C. The mean velocity associated with a stable condition in which objectionable silting and scouring are avoided సమాధానం: C.
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Question 3 ప్రశ్న 3Answer: A. Vc = 0.55 D^0.64 సమాధానం: A.
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Question 4 ప్రశ్న 4Answer: D. Vc = 0.55 m D^0.64 సమాధానం: D.
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Question 5 ప్రశ్న 5Answer: B. A coarser sediment condition for which the required critical velocity is higher than the reference value సమాధానం: B.
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Question 6 ప్రశ్న 6Answer: A. Vertical eddies generated mainly by friction and roughness at the channel bed సమాధానం: A.
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Question 7 ప్రశ్న 7Answer: C. It increases, but less than proportionally because the exponent on depth is less than one సమాధానం: C.
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Question 8 ప్రశ్న 8Answer: D. Approximately 0.857 m/s సమాధానం: D.
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Question 9 ప్రశ్న 9Answer: B. Approximately 1.029 m/s సమాధానం: B.
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Question 10 ప్రశ్న 10Answer: C. Approximately 1.11 సమాధానం: C.
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Question 11 ప్రశ్న 11Answer: A. 20 m² సమాధానం: A.
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Question 12 ప్రశ్న 12Answer: D. 9.0 m సమాధానం: D.
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Question 13 ప్రశ్న 13Answer: B. Approximately 1.48 m సమాధానం: B.
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Question 14 ప్రశ్న 14Answer: C. The mean velocity obtained from the hydraulic resistance relation should approximately equal the Kennedy critical velocity for the chosen depth and sediment సమాధానం: C.
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Question 15 ప్రశ్న 15Answer: A. Silting or deposition because the available sediment-supporting action is inadequate సమాధానం: A.
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Question 16 ప్రశ్న 16Answer: D. Scouring or erosion of the erodible boundary becomes more likely సమాధానం: D.
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Question 17 ప్రశ్న 17Answer: B. Required longitudinal bed slope సమాధానం: B.
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Question 18 ప్రశ్న 18Answer: C. Because the critical-velocity equation contains depth but not width, so width must be obtained from discharge, area, side slopes and the trial geometry సమాధానం: C.
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Question 19 ప్రశ్న 19Answer: A. It was derived from observations of a particular canal system, so extrapolation to very different sediment and channel conditions must be made cautiously సమాధానం: A.
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Question 20 ప్రశ్న 20Answer: D. It emphasizes eddies generated at the bed and does not fully represent side-wall turbulence, sediment concentration and the full complexity of sediment transport సమాధానం: D.
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Question 21 ప్రశ్న 21Answer: B. B Vc^(5/2) సమాధానం: B.
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Question 22 ప్రశ్న 22Answer: C. Approximately 1.58 సమాధానం: C.
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Question 23 ప్రశ్న 23Answer: A. Approximately 2.55 m సమాధానం: A.
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Question 24 ప్రశ్న 24Answer: D. Kennedy's critical-velocity relation uses flow depth D, while hydraulic radius R is normally required in the separate resistance equation used to relate velocity and bed slope సమాధానం: D.
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Question 25 ప్రశ్న 25Answer: B. Vc ≈ 0.857 m/s, A ≈ 21.0 m² and B ≈ 9.50 m సమాధానం: B.