Please keep at least one language enabled. || కనీసం ఒక భాషను ఎంచుకోండి.
Question 1
ప్రశ్న 1
What is the basic purpose of a cross-drainage work on an irrigation canal?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
A canal alignment may intersect natural streams, drains or depressions on its way through the command area. A cross-drainage work provides the hydraulic arrangement needed for the canal and drainage to pass one another. Depending on their relative levels, one flow may pass above the other or the two may meet at nearly the same level. The selected structure must safely accommodate the design discharges, water levels, sediment and foundation conditions. Therefore Option A is correct.
వివరణ:
Question 2
ప్రశ్న 2
Which description correctly defines an aqueduct as a canal cross-drainage work?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
In an aqueduct, the canal is carried above the natural drainage channel. The drainage has sufficient vertical clearance to pass below the canal structure as open-channel or free-surface flow. This usually requires the canal bed or trough to be well above the drainage high-flood level or required drainage water surface. The canal may be carried in an earthen section, between retaining walls or in a structural trough depending on the adopted aqueduct type. Therefore Option B is correct.
వివరణ:
Question 3
ప్రశ్న 3
Which statement correctly describes a siphon aqueduct?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
A siphon aqueduct still carries the canal above the drainage. Unlike an ordinary aqueduct, the available vertical clearance is insufficient for the drainage flood to pass freely beneath the canal trough. The drainage is therefore locally depressed and conveyed through barrels that run full or under pressure during the design condition. Head losses and uplift on the barrel or trough system become important design considerations. Therefore Option A is correct.
వివరణ:
Question 4
ప్రశ్న 4
What is a superpassage in canal engineering?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
A superpassage is essentially the reverse of an aqueduct. The natural drainage is carried in a trough or suitable passage above the canal. The canal passes underneath while maintaining free-surface flow, so its full-supply level remains below the underside of the drainage-carrying structure with adequate clearance. This arrangement is appropriate when drainage levels are substantially higher than canal levels. Therefore Option B is correct.
వివరణ:
Question 5
ప్రశ్న 5
Which description best defines a canal siphon or inverted siphon used as a cross-drainage work?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
A canal siphon is used when the drainage passes above the canal and the canal cannot pass beneath it with a free water surface. The canal is depressed and conveyed through one or more closed barrels. The canal water therefore flows under pressure through the crossing. The available canal head must be sufficient to overcome entrance, friction, bend and exit losses through the siphon. Therefore Option A is correct.
వివరణ:
Question 6
ప్రశ్న 6
When is a level crossing generally considered for a canal and natural drainage?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
A level crossing is used where the canal and drainage meet at approximately the same elevation and grade separation would be difficult or uneconomical. The two waters are allowed to meet in a controlled junction. Regulators are provided so that the required canal supply and drainage discharge can be managed downstream of the crossing. The arrangement is more satisfactory when excessive sediment entry from the drain into the canal is not expected. Therefore Option B is correct.
వివరణ:
Question 7
ప్రశ్న 7
A canal bed is much higher than the design high-flood level of a crossing drain, leaving adequate clearance for the drain to pass below as open-channel flow. Which cross-drainage work is generally most suitable?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
The canal is at the higher elevation in the stated situation. The drain also has enough vertical clearance to pass beneath the canal without becoming pressurized. These are the characteristic hydraulic conditions for an aqueduct. A siphon aqueduct would become relevant if the drain could not pass freely below the canal trough. Therefore Option A is correct.
వివరణ:
Question 8
ప్రశ్న 8
The bed of a natural drain is well above the full-supply level of a canal, so the canal can pass underneath with a free water surface. Which structure is generally appropriate?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
In this case the drainage naturally lies above the canal. The stated clearance permits the canal to continue below the drain without touching the roof of the crossing and without developing pressure flow. This is the defining condition for a superpassage. A canal siphon would instead be required if the canal had to flow full under the drainage. Therefore Option C is correct.
వివరణ:
Question 9
ప్రశ్న 9
A canal must pass above a drain, but the drain high-flood level is higher than the underside of the proposed canal trough. Which type of cross-drainage work is indicated?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
The canal is required to remain above the drainage, so the crossing belongs to the aqueduct family. However, the drainage high-flood level is too high for a free water surface to pass below the trough with adequate clearance. The drain must therefore be locally depressed and passed through full-running barrels. This condition identifies a siphon aqueduct rather than an ordinary aqueduct. Therefore Option B is correct.
వివరణ:
Question 10
ప్రశ్న 10
A natural drain is to pass above a canal, but the canal full-supply level is too high to provide free-surface clearance beneath the drainage trough. Which structure is generally required?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
The drainage is at the higher level in the stated arrangement. The canal cannot remain as free-surface flow beneath the drain because adequate clearance is unavailable. The canal is therefore depressed into closed barrels and passes the crossing under pressure. This configuration is called a canal siphon or inverted siphon. Therefore Option C is correct.
వివరణ:
Question 11
ప్రశ్న 11
What is the main hydraulic function of regulators in a level crossing?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
At a level crossing, canal and drainage water meet because grade separation is not provided. The combined flow must subsequently be directed into the required downstream canal and drainage paths. Regulators permit these discharges and water levels to be controlled. They also help protect canal operation during large drainage flows. Therefore Option A is correct.
వివరణ:
Question 12
ప్రశ్న 12
Which factor is most fundamental in the preliminary selection among aqueduct, siphon aqueduct, superpassage, canal siphon and level crossing?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
The relative elevations determine whether either waterway can pass above or below the other with free-surface clearance. Their design discharges and water levels determine the size of the required passages and the consequences of contraction or pressure flow. Foundation conditions, allowable head loss, sediment and economy then refine the selection. A structure should therefore not be chosen from its name or appearance alone. Therefore Option B is correct.
వివరణ:
Question 13
ప్రశ్న 13
What is the primary hydraulic requirement when fixing the drainage waterway beneath an aqueduct?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
The opening beneath an aqueduct belongs hydraulically to the natural drainage system. It must therefore accommodate the design drainage discharge at acceptable upstream water level and velocity. Excessive contraction can create afflux and high local velocities that increase scour and protection requirements. The waterway must also be coordinated with piers, foundations, training works and the natural channel geometry. Therefore Option A is correct.
వివరణ:
Question 14
ప్రశ్న 14
A drainage channel must pass a design flood of 120 m³/s beneath an aqueduct. If an adopted average discharge intensity of 6 m³/s per metre of effective waterway is used for a preliminary objective calculation, what effective waterway is required?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
For the stated preliminary calculation, discharge intensity is Q divided by effective waterway. The required width is therefore 120/6. This gives an effective waterway of 20 m. The result is only a preliminary hydraulic sizing value and must later be checked for afflux, scour, contractions and actual drainage geometry. Therefore Option B is correct.
వివరణ:
Question 15
ప్రశ్న 15
In a Type III aqueduct arrangement, why may the canal be flumed into a masonry or RCC trough across a comparatively large drain?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
A Type III aqueduct replaces the normal wide earthen canal section across the drain with a narrower structural trough. This reduces the length of the drainage barrels or supporting crossing measured along the canal direction. The saving in the drainage structure can be significant for a large stream, although the flumed trough itself becomes more substantial. Smooth upstream and downstream transitions are required because the canal width changes. Therefore Option A is correct.
వివరణ:
Question 16
ప్రశ్న 16
What is the principal purpose of transitions on the approaches to and exits from a flumed aqueduct trough?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
A flumed trough is commonly narrower than the normal canal section. An abrupt contraction can create flow separation, cross-waves and poor velocity distribution. An abrupt expansion can similarly create eddies and excessive energy loss at the outlet. Properly shaped transitions guide the flow progressively between the normal canal and the trough. Therefore Option A is correct.
వివరణ:
Question 17
ప్రశ్న 17
A rectangular aqueduct trough carries 24 m³/s with a clear waterway width of 6 m and flow depth of 1.5 m. What is the average canal velocity in the trough?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
The trough flow area is width multiplied by depth. Thus A = 6 × 1.5 = 9 m². Continuity gives V = Q/A = 24/9. The average velocity is therefore approximately 2.67 m/s. This velocity would need to be checked against lining, head-loss and transition requirements in a real design.
వివరణ:
Question 18
ప్రశ్న 18
A canal carries 24 m³/s. Its normal-flow area before an aqueduct is 18 m², while a flumed trough has flow area 12 m². By what factor does the mean velocity increase in the trough relative to the normal canal section?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
The normal canal velocity is 24/18 = 1.333 m/s. The trough velocity is 24/12 = 2.00 m/s. Their ratio is 2.00/1.333, which is approximately 1.50. The calculation illustrates why excessive fluming can increase velocity and head-loss requirements. Therefore Option C is correct.
వివరణ:
Question 19
ప్రశ్న 19
Which statement correctly distinguishes a drainage barrel in an ordinary aqueduct from one in a siphon aqueduct?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
Both structures carry the canal above the natural drainage. The hydraulic distinction lies mainly in how the drainage passes beneath the canal. In an ordinary aqueduct, adequate clearance permits free-surface drainage flow. In a siphon aqueduct, the drainage is depressed into barrels that can run full under the design flood. Therefore Option B is correct.
వివరణ:
Question 20
ప్రశ్న 20
Which load-transfer description is most appropriate for an RCC aqueduct trough supported on piers or abutments?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
The structural trough directly contains the canal water and therefore carries its hydrostatic and gravity loads. The trough also contributes its own dead weight and may carry additional applicable loads from appurtenances or access provisions. These actions are transmitted through the trough system to piers, abutments or other supports. The supports then transfer the forces safely into the foundation. Therefore Option A is correct.
వివరణ:
Question 21
ప్రశ్న 21
An aqueduct trough contains water to a depth of 2.0 m. Taking the unit weight of water as 9.81 kN/m³, what is the hydrostatic pressure intensity at the bottom of a vertical trough wall due to the canal water?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
Hydrostatic pressure at depth h is p = γw h. With h = 2.0 m and γw = 9.81 kN/m³, the pressure is 9.81 × 2.0. This equals 19.62 kN/m², or 19.62 kPa. The pressure varies from approximately zero at the water surface to this maximum value at the bottom. Therefore Option B is correct.
వివరణ:
Question 22
ప్రశ్న 22
A rectangular aqueduct trough is 5 m wide and carries canal water 1.5 m deep. What vertical water load acts on the trough bottom per metre length along the canal, taking γw = 9.81 kN/m³?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
For one metre length of trough, the water volume is 5 × 1.5 × 1 = 7.5 m³. Multiplying by the unit weight of water gives 7.5 × 9.81 kN. The resulting vertical water load is 73.575 kN per metre length. Rounded suitably, this is approximately 73.58 kN/m. Therefore Option B is correct.
వివరణ:
Question 23
ప్రశ్న 23
Why must scour and foundation conditions be considered in the design of an aqueduct even though the canal itself is carried in a structural trough?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
The natural drainage still passes through or beneath the aqueduct structure during flood conditions. Contraction and obstruction by piers or abutments can increase local velocity and scour. If scour reaches the supporting foundations, structural stability of the entire canal crossing can be threatened. Foundation depth, protection works and drainage waterway must therefore be coordinated with the expected scour condition. Therefore Option A is correct.
వివరణ:
Question 24
ప్రశ్న 24
Which group of factors should be considered before finally selecting a cross-drainage work at a canal-drain crossing?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
Relative levels first determine which grade-separated arrangements are hydraulically feasible. The discharges then control the size of canal and drainage passages and the likely need for pressure flow. Allowable head loss is especially important when a canal siphon or strong fluming is considered. Foundation conditions, dewatering, sediment, scour, construction and maintenance can materially change the preferred alternative. Therefore Option A is correct.
వివరణ:
Question 25
ప్రశ్న 25
Consider the following statements about cross-drainage works: I. In an aqueduct, the canal passes over the drain and the drain normally flows freely. II. In a siphon aqueduct, the canal remains above the drain but the drainage barrels may run under pressure. III. In a superpassage, the drain passes above the canal while the canal remains free surface. IV. In a canal siphon, the canal passes below the drain under pressure. Which option is correct?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
Statement I correctly describes the ordinary aqueduct arrangement. Statement II correctly identifies the pressurized drainage flow that distinguishes a siphon aqueduct. Statement III correctly describes a superpassage, where the canal remains free surface below the drainage structure. Statement IV correctly describes a canal siphon or inverted siphon. Therefore all four statements are correct and Option D is the valid answer.
వివరణ:
Answer Key సమాధానాల పట్టిక
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Question 1 ప్రశ్న 1Answer: A. To permit a canal and a natural drainage channel to cross each other safely without unacceptable interference with either flow సమాధానం: A.
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Question 2 ప్రశ్న 2Answer: B. The canal passes over the drainage, and the drainage passes below with a free water surface సమాధానం: B.
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Question 3 ప్రశ్న 3Answer: A. The canal passes above the drain, but the drain passes through closed or submerged barrels under pressure సమాధానం: A.
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Question 4 ప్రశ్న 4Answer: B. A structure in which the drainage passes above the canal while the canal continues as free-surface flow below సమాధానం: B.
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Question 5 ప్రశ్న 5Answer: A. The canal passes below the drainage and flows through barrels under pressure సమాధానం: A.
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Question 6 ప్రశ్న 6Answer: B. When they meet at nearly the same level and both may carry considerable discharges సమాధానం: B.
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Question 7 ప్రశ్న 7Answer: A. Aqueduct సమాధానం: A.
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Question 8 ప్రశ్న 8Answer: C. Superpassage సమాధానం: C.
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Question 9 ప్రశ్న 9Answer: B. Siphon aqueduct సమాధానం: B.
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Question 10 ప్రశ్న 10Answer: C. Canal siphon సమాధానం: C.
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Question 11 ప్రశ్న 11Answer: A. To control how the combined waters are apportioned back into the canal and drainage downstream of the junction సమాధానం: A.
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Question 12 ప్రశ్న 12Answer: B. The relative canal and drainage bed levels, full-supply or flood levels, and their design discharges సమాధానం: B.
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Question 13 ప్రశ్న 13Answer: A. It should safely pass the design drainage flood without unacceptable afflux, velocity or scour సమాధానం: A.
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Question 14 ప్రశ్న 14Answer: B. 20 m సమాధానం: B.
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Question 15 ప్రశ్న 15Answer: A. To reduce the structural width of the canal crossing and thereby shorten the required drainage barrels or spans, while using transitions to connect back to the normal canal సమాధానం: A.
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Question 16 ప్రశ్న 16Answer: A. To change the canal width gradually and limit separation, cross-waves, local losses and nonuniform velocity సమాధానం: A.
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Question 17 ప్రశ్న 17Answer: C. 2.67 m/s సమాధానం: C.
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Question 18 ప్రశ్న 18Answer: C. 1.50 సమాధానం: C.
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Question 19 ప్రశ్న 19Answer: B. In an ordinary aqueduct the drainage passage normally carries free-surface flow, whereas in a siphon aqueduct the drainage barrel is designed to run full or under pressure during the relevant flood condition సమాధానం: B.
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Question 20 ప్రశ్న 20Answer: A. The trough slab and walls resist the canal-water and self-weight loads and transfer the resulting actions through the supports to the foundations సమాధానం: A.
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Question 21 ప్రశ్న 21Answer: B. 19.62 kPa సమాధానం: B.
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Question 22 ప్రశ్న 22Answer: B. 73.58 kN/m సమాధానం: B.
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Question 23 ప్రశ్న 23Answer: A. Because the drainage flood can scour around piers, abutments and foundations and thereby endanger the supports of the canal trough సమాధానం: A.
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Question 24 ప్రశ్న 24Answer: A. Relative canal and drainage levels, their discharges, allowable canal head loss, foundation and groundwater conditions, sediment characteristics, construction constraints and overall economy సమాధానం: A.
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Question 25 ప్రశ్న 25Answer: D. I, II, III and IV సమాధానం: D.