Dams and Hydraulic Structures MCQs 2026

Morning glory spillway is

1. AHighway rotary design✓
2. BRailway turntable✓
3. CVertical shaft spillway dropping through dam✓
4. DAirport radar✓

Safety inspection of dam includes checking

1. AOnly office furniture✓
2. BOnly vehicle polish✓
3. CSeepage cracks instrumentation and spillway✓
4. DOnly uniform buttons✓

Small dam or pond for community irrigation in Punjab often

1. AAircraft carrier deck✓
2. BEarthen bund with pipe outlet✓
3. CRailway terminal✓
4. DHarbour container crane✓

Central Asia and Himalayan dams face challenge of

1. AHigh sediment load and seismicity✓
2. BZero rainfall always✓
3. CNo foundation rock ever✓
4. DNo irrigation demand✓

Earthquake induced hydrodynamic pressure on dam face computed using

1. AOnly manual thumb rule zero✓
2. BOnly traffic formula✓
3. COnly wind formula only✓
4. DWestergaard or finite element methods✓

Flip bucket on spillway throws jet

1. AAway from toe to reduce scour✓
2. BInto powerhouse always✓
3. CInto intake always✓
4. DInto penstock always✓

Labyrinth weir increases

1. ARailway curve radius✓
2. BEffective crest length for discharge✓
3. CRunway width only✓
4. DBuilding floor area✓

Joint in concrete dam accommodates

1. AOnly aircraft movement✓
2. BOnly train movement✓
3. COnly ship movement✓
4. DTemperature and shrinkage movement✓

Wave height on reservoir fetch depends on

1. ARail axle load✓
2. BWind speed duration and fetch length✓
3. CHighway camber✓
4. DBuilding setback✓

Dam safety review in Pakistan considers

1. AOnly paint colour✓
2. BOnly staff uniform✓
3. CSeismic hydrologic and structural adequacy✓
4. DOnly canteen menu✓

Sediment flushing through low level outlets helps

1. AMaintain live storage capacity✓
2. BIncrease harbour depth always✓
3. CWiden railway gauge✓
4. DExtend runway only✓

Tailwater rating curve relates

1. AWind speed to runway length✓
2. BESAL to CBR✓
3. CTide to berth rent✓
4. DDischarge to downstream water level✓

Dam break analysis provides

1. AOnly runway wind rose✓
2. BOnly pavement design chart✓
3. CInundation mapping downstream✓
4. DOnly BOQ format✓

Underground powerhouse advantage is

1. AReduced surface environmental impact✓
2. BAlways cheaper without geology check✓
3. CNo ventilation needed ever✓
4. DNo access tunnel needed✓

Barrage on river like Sukkur Barrage primarily

1. AStores multi-year flood only✓
2. BDiverts irrigation water with gates✓
3. CServes as airport runway✓
4. DActs as railway bridge only✓

Regulator dam or weir differs from storage dam by

1. AAircraft hangar function✓
2. BRailway station function✓
3. CHarbour breakwater only ocean✓
4. DLimited storage raising river level✓

Air entrainment on spillway face reduces

1. ADam height requirement always to zero✓
2. BReservoir capacity to zero✓
3. CCavitation damage potential✓
4. DNeed for any stilling basin always✓

Earthquake load on dam analysed using

1. AOnly manual guess✓
2. BPseudo-static or dynamic analysis per guidelines✓
3. COnly traffic count✓
4. DOnly rainfall colour✓

Ice load on dam in cold regions adds to

1. AHorizontal pressure on structure✓
2. BOnly runway friction✓
3. COnly harbour tide✓
4. DOnly traffic signal✓

Factor of safety against sliding on gravity dam considers

1. AOnly paint thickness✓
2. BOnly wind on sign✓
3. COnly toll revenue✓
4. DResisting friction and cohesion versus driving force✓

Diamer Basha dam planned as

1. ASmall farm pond✓
2. BHighway culvert✓
3. CLarge roller compacted concrete dam✓
4. DBuilding basement✓

Mangla dam primarily serves

1. AStorage and power on Jhelum✓
2. BAirport runway irrigation✓
3. CRailway electrification only✓
4. DUrban metro only✓

Tarbela dam on Indus is primarily

1. AThin arch only✓
2. BSmall weir only✓
3. CHarbour breakwater✓
4. DEarth and rockfill dam✓

Tailrace channel returns

1. AFuel to aircraft✓
2. BTurbine discharge to river✓
3. CBallast to railway✓
4. DSilt to harbour only✓

Surge tank on hydropower scheme controls

1. AAircraft crosswind✓
2. BHighway superelevation✓
3. CPressure transients from load changes✓
4. DBuilding live load✓

Penstock conveys

1. AOnly wind to generator✓
2. BOnly rail traffic✓
3. COnly harbour cargo✓
4. DPressurized water to turbine✓

Intake structure withdraws

1. AOnly sediment for landfill✓
2. BOnly fish without water✓
3. CWater from reservoir for power or irrigation✓
4. DOnly air for penstock✓

Cofferdam is

1. APermanent spillway✓
2. BTemporary enclosure for construction in water✓
3. CAircraft shelter✓
4. DRailway bridge always✓

Diversion tunnel during dam construction carries

1. ARiver flow around work site✓
2. BOnly aircraft taxi✓
3. COnly rail freight✓
4. DOnly municipal sewer✓

Reservoir sedimentation reduces

1. AConcrete strength gain✓
2. BRail gauge✓
3. CStorage capacity over time✓
4. DRunway length need✓

Uplift pressure on gravity dam reduces

1. AShear strength of steel rail✓
2. BWind on airport✓
3. CLoS on highway✓
4. DEffective normal stress on base✓

Freeboard on dam crest provides

1. ADecorative height only✓
2. BMargin against wave overtopping✓
3. CRailway platform width✓
4. DHarbour berth depth✓

Phreatic line in earth dam should remain

1. ABelow downstream toe✓
2. BAbove crest always✓
3. CAt runway level✓
4. DInside penstock✓

Grout curtain reduces

1. AWind load on building✓
2. BFoundation seepage under dam✓
3. CTraffic ESAL✓
4. DHarbour wave height✓

Gallery inside dam used for

1. APublic shopping mall✓
2. BAircraft hangar✓
3. CInspection grouting drainage and instrumentation✓
4. DRailway station✓

Stilling basin designed for

1. AAircraft landing roll✓
2. BRail shunting✓
3. CBuilding HVAC✓
4. DHydraulic jump to dissipate kinetic energy✓

Energy dissipator downstream of spillway prevents

1. AScour in riverbed✓
2. BEvaporation in reservoir✓
3. CWind on runway✓
4. DNoise in city only✓

Ogee spillway profile matches

1. AUpper surface of aircraft wing✓
2. BLower nappe of free falling jet✓
3. CRailway rail head✓
4. DHarbour quay face✓

Spillway safely passes

1. AFlood flow exceeding reservoir storage✓
2. BOnly sediment always✓
3. COnly fish migration only✓
4. DOnly penstock maintenance✓

Earth dam core function is

1. ADecorative surface only✓
2. BLoad from aircraft✓
3. CImpervious barrier against seepage✓
4. DRail vibration damping✓

Buttress dam has

1. AOnly earth embankment✓
2. BOnly steel truss runway✓
3. COnly harbour breakwater crown✓
4. DSloping deck supported on triangular walls✓

Arch dam transfers load to

1. AOnly reservoir water directly upward✓
2. BAbutments through arch action✓
3. COnly downstream air✓
4. DOnly penstock flow✓

Gravity dam resists water pressure mainly by

1. AIts own weight✓
2. BTension in thin arch only✓
3. CCable stay force✓
4. DAir pressure in hollow✓

Piping failure in earth dam occurs when

1. AOnly concrete cures✓
2. BOnly paint dries✓
3. CSeepage erodes fine particles along concentrated path✓
4. DOnly rail expands✓

Horizontal drain on downstream toe of earth dam

1. AIncreases uplift always✓
2. BLowers phreatic line and controls seepage exit✓
3. CBlocks all drainage✓
4. DHeats concrete✓

Riprap on upstream slope protects against

1. ARail creep✓
2. BAircraft jet blast✓
3. CBuilding fire✓
4. DWave erosion✓

RCC dam construction places concrete in

1. AThin layers compacted by vibratory rollers✓
2. BOnly single pour 100 m high at once always✓
3. COnly asphalt paver✓
4. DOnly rail tamping✓

Arch dam suitable when

1. AWide alluvial valley only✓
2. BFlat desert plain only✓
3. CSoft clay infinite width✓
4. DNarrow canyon with strong rock abutments✓

Buttress dam economic when

1. AFoundation rock good and wide valley moderate✓
2. BOnly marsh without foundation✓
3. COnly sand dune✓
4. DOnly landfill gas✓

Spillway design flood often based on

1. AAverage daily flow only✓
2. BProbable maximum flood PMF or standard project flood✓
3. CZero flood assumption✓
4. DOnly garden hose flow✓

Afflux upstream of dam raises

1. ARunway elevation✓
2. BRail level always down✓
3. CWater surface elevation during flood✓
4. DBuilding floor always✓

Dead storage in reservoir holds

1. ASediment below intake level✓
2. BOnly aviation fuel✓
3. COnly railway coal✓
4. DOnly fresh air✓

Live storage used for

1. AOnly permanent sediment trap✓
2. BOnly fish pond without use✓
3. CIrrigation power and supply✓
4. DOnly decoration✓

Rule curve for reservoir operation guides

1. AOnly paint schedule✓
2. BRelease versus storage through season✓
3. COnly staff roster colour✓
4. DOnly cricket fixture✓

Low level outlet provides

1. AOnly aircraft refueling✓
2. BOnly harbour dredging✓
3. COnly highway lighting✓
4. DDrawdown and emergency release at depth✓

Fish ladder at dam allows

1. AOnly sediment passage always✓
2. BMigration past obstruction✓
3. COnly boats only without water✓
4. DOnly rail wagons✓

Instrumentation on dam includes

1. APiezometers extensometers and seismographs✓
2. BOnly decorative lights✓
3. COnly billboard✓
4. DOnly café meter✓

Piezometer measures

1. AWind speed✓
2. BAir traffic✓
3. CPore water pressure in dam or foundation✓
4. DBitumen penetration✓

Drawdown curve during rapid reservoir lowering can cause

1. AImproved rail alignment✓
2. BLonger runway always✓
3. CHigher harbour tide✓
4. DSlope instability in upstream embankment✓

Gallery drainage holes relieve

1. ATraffic congestion✓
2. BAircraft delay✓
3. CUplift and seepage in concrete dam✓
4. DBuilding HVAC only✓

Spillway chute blocks or dentated sill enhance

1. AEnergy dissipation in stilling basin✓
2. BVehicle speed on highway✓
3. CTrain acceleration✓
4. DShip berthing speed✓

Emergency spillway or fuse plug used when

1. ANever needed on any dam✓
2. BOnly for buildings✓
3. COnly for highways✓
4. DAuxiliary capacity needed beyond main spillway✓

Zoning in earth dam may include

1. AOnly single homogeneous fill always without design✓
2. BFilter drain shell and core✓
3. COnly asphalt runway layer✓
4. DOnly rail ballast✓

Homogeneous earth dam relies on

1. AZero thickness core always impossible✓
2. BOnly steel plate face always✓
3. CLow permeability fill and controlled seepage✓
4. DOnly open mesh✓

Hydraulic height of dam is

1. ARunway length✓
2. BDifference between max pool and downstream toe elevation✓
3. CRail gauge✓
4. DBuilding height limit city✓

Probable maximum precipitation used to estimate

1. ADaily office rainfall average only✓
2. BZero rain forever✓
3. COnly fog✓
4. DExtreme inflow to reservoir✓

Routing flood through reservoir uses

1. AStorage and outflow relationship✓
2. BOnly paint viscosity✓
3. COnly soil colour✓
4. DOnly signal cycle✓

Penstock bifurcation near powerhouse splits flow to

1. AHighway lanes✓
2. BMultiple turbine units✓
3. CRail tracks✓
4. DHarbour berths✓

Trash rack at intake stops

1. AAll dissolved salts✓
2. BAll fish always without exception✓
3. CAll water✓
4. DLarge debris entering penstock✓

Cavitation in spillway or turbine occurs when

1. ALocal pressure drops below vapor pressure✓
2. BConcrete always gains strength✓
3. CWater becomes solid ice instantly always✓
4. DAir becomes liquid✓