Dams and Hydraulic Structures MCQs 2026

Zoning in earth dam may include

1. A Only single homogeneous fill always without design ✓
2. B Filter drain shell and core ✓
3. C Only asphalt runway layer ✓
4. D Only rail ballast ✓

Gravity dam resists water pressure mainly by

1. A Its own weight ✓
2. B Tension in thin arch only ✓
3. C Cable stay force ✓
4. D Air pressure in hollow ✓

Arch dam transfers load to

1. A Only reservoir water directly upward ✓
2. B Abutments through arch action ✓
3. C Only downstream air ✓
4. D Only penstock flow ✓

Buttress dam has

1. A Only earth embankment ✓
2. B Only steel truss runway ✓
3. C Only harbour breakwater crown ✓
4. D Sloping deck supported on triangular walls ✓

Earth dam core function is

1. A Decorative surface only ✓
2. B Load from aircraft ✓
3. C Impervious barrier against seepage ✓
4. D Rail vibration damping ✓

Spillway safely passes

1. A Flood flow exceeding reservoir storage ✓
2. B Only sediment always ✓
3. C Only fish migration only ✓
4. D Only penstock maintenance ✓

Ogee spillway profile matches

1. A Upper surface of aircraft wing ✓
2. B Lower nappe of free falling jet ✓
3. C Railway rail head ✓
4. D Harbour quay face ✓

Energy dissipator downstream of spillway prevents

1. A Scour in riverbed ✓
2. B Evaporation in reservoir ✓
3. C Wind on runway ✓
4. D Noise in city only ✓

Stilling basin designed for

1. A Aircraft landing roll ✓
2. B Rail shunting ✓
3. C Building HVAC ✓
4. D Hydraulic jump to dissipate kinetic energy ✓

Gallery inside dam used for

1. A Public shopping mall ✓
2. B Aircraft hangar ✓
3. C Inspection grouting drainage and instrumentation ✓
4. D Railway station ✓

Grout curtain reduces

1. A Wind load on building ✓
2. B Foundation seepage under dam ✓
3. C Traffic ESAL ✓
4. D Harbour wave height ✓

Phreatic line in earth dam should remain

1. A Below downstream toe ✓
2. B Above crest always ✓
3. C At runway level ✓
4. D Inside penstock ✓

Freeboard on dam crest provides

1. A Decorative height only ✓
2. B Margin against wave overtopping ✓
3. C Railway platform width ✓
4. D Harbour berth depth ✓

Uplift pressure on gravity dam reduces

1. A Shear strength of steel rail ✓
2. B Wind on airport ✓
3. C LoS on highway ✓
4. D Effective normal stress on base ✓

Reservoir sedimentation reduces

1. A Concrete strength gain ✓
2. B Rail gauge ✓
3. C Storage capacity over time ✓
4. D Runway length need ✓

Diversion tunnel during dam construction carries

1. A River flow around work site ✓
2. B Only aircraft taxi ✓
3. C Only rail freight ✓
4. D Only municipal sewer ✓

Cofferdam is

1. A Permanent spillway ✓
2. B Temporary enclosure for construction in water ✓
3. C Aircraft shelter ✓
4. D Railway bridge always ✓

Intake structure withdraws

1. A Only sediment for landfill ✓
2. B Only fish without water ✓
3. C Water from reservoir for power or irrigation ✓
4. D Only air for penstock ✓

Penstock conveys

1. A Only wind to generator ✓
2. B Only rail traffic ✓
3. C Only harbour cargo ✓
4. D Pressurized water to turbine ✓

Surge tank on hydropower scheme controls

1. A Aircraft crosswind ✓
2. B Highway superelevation ✓
3. C Pressure transients from load changes ✓
4. D Building live load ✓

Tailrace channel returns

1. A Fuel to aircraft ✓
2. B Turbine discharge to river ✓
3. C Ballast to railway ✓
4. D Silt to harbour only ✓

Tarbela dam on Indus is primarily

1. A Thin arch only ✓
2. B Small weir only ✓
3. C Harbour breakwater ✓
4. D Earth and rockfill dam ✓

Mangla dam primarily serves

1. A Storage and power on Jhelum ✓
2. B Airport runway irrigation ✓
3. C Railway electrification only ✓
4. D Urban metro only ✓

Diamer Basha dam planned as

1. A Small farm pond ✓
2. B Highway culvert ✓
3. C Large roller compacted concrete dam ✓
4. D Building basement ✓

Factor of safety against sliding on gravity dam considers

1. A Only paint thickness ✓
2. B Only wind on sign ✓
3. C Only toll revenue ✓
4. D Resisting friction and cohesion versus driving force ✓

Ice load on dam in cold regions adds to

1. A Horizontal pressure on structure ✓
2. B Only runway friction ✓
3. C Only harbour tide ✓
4. D Only traffic signal ✓

Earthquake load on dam analysed using

1. A Only manual guess ✓
2. B Pseudo-static or dynamic analysis per guidelines ✓
3. C Only traffic count ✓
4. D Only rainfall colour ✓

Piping failure in earth dam occurs when

1. A Only concrete cures ✓
2. B Only paint dries ✓
3. C Seepage erodes fine particles along concentrated path ✓
4. D Only rail expands ✓

Horizontal drain on downstream toe of earth dam

1. A Increases uplift always ✓
2. B Lowers phreatic line and controls seepage exit ✓
3. C Blocks all drainage ✓
4. D Heats concrete ✓

Riprap on upstream slope protects against

1. A Rail creep ✓
2. B Aircraft jet blast ✓
3. C Building fire ✓
4. D Wave erosion ✓

RCC dam construction places concrete in

1. A Thin layers compacted by vibratory rollers ✓
2. B Only single pour 100 m high at once always ✓
3. C Only asphalt paver ✓
4. D Only rail tamping ✓

Arch dam suitable when

1. A Wide alluvial valley only ✓
2. B Flat desert plain only ✓
3. C Soft clay infinite width ✓
4. D Narrow canyon with strong rock abutments ✓

Buttress dam economic when

1. A Foundation rock good and wide valley moderate ✓
2. B Only marsh without foundation ✓
3. C Only sand dune ✓
4. D Only landfill gas ✓

Spillway design flood often based on

1. A Average daily flow only ✓
2. B Probable maximum flood PMF or standard project flood ✓
3. C Zero flood assumption ✓
4. D Only garden hose flow ✓

Afflux upstream of dam raises

1. A Runway elevation ✓
2. B Rail level always down ✓
3. C Water surface elevation during flood ✓
4. D Building floor always ✓

Dead storage in reservoir holds

1. A Sediment below intake level ✓
2. B Only aviation fuel ✓
3. C Only railway coal ✓
4. D Only fresh air ✓

Live storage used for

1. A Only permanent sediment trap ✓
2. B Only fish pond without use ✓
3. C Irrigation power and supply ✓
4. D Only decoration ✓

Rule curve for reservoir operation guides

1. A Only paint schedule ✓
2. B Release versus storage through season ✓
3. C Only staff roster colour ✓
4. D Only cricket fixture ✓

Low level outlet provides

1. A Only aircraft refueling ✓
2. B Only harbour dredging ✓
3. C Only highway lighting ✓
4. D Drawdown and emergency release at depth ✓

Fish ladder at dam allows

1. A Only sediment passage always ✓
2. B Migration past obstruction ✓
3. C Only boats only without water ✓
4. D Only rail wagons ✓

Instrumentation on dam includes

1. A Piezometers extensometers and seismographs ✓
2. B Only decorative lights ✓
3. C Only billboard ✓
4. D Only café meter ✓

Piezometer measures

1. A Wind speed ✓
2. B Air traffic ✓
3. C Pore water pressure in dam or foundation ✓
4. D Bitumen penetration ✓

Drawdown curve during rapid reservoir lowering can cause

1. A Improved rail alignment ✓
2. B Longer runway always ✓
3. C Higher harbour tide ✓
4. D Slope instability in upstream embankment ✓

Gallery drainage holes relieve

1. A Traffic congestion ✓
2. B Aircraft delay ✓
3. C Uplift and seepage in concrete dam ✓
4. D Building HVAC only ✓

Spillway chute blocks or dentated sill enhance

1. A Energy dissipation in stilling basin ✓
2. B Vehicle speed on highway ✓
3. C Train acceleration ✓
4. D Ship berthing speed ✓

Emergency spillway or fuse plug used when

1. A Never needed on any dam ✓
2. B Only for buildings ✓
3. C Only for highways ✓
4. D Auxiliary capacity needed beyond main spillway ✓

Homogeneous earth dam relies on

1. A Zero thickness core always impossible ✓
2. B Only steel plate face always ✓
3. C Low permeability fill and controlled seepage ✓
4. D Only open mesh ✓

Hydraulic height of dam is

1. A Runway length ✓
2. B Difference between max pool and downstream toe elevation ✓
3. C Rail gauge ✓
4. D Building height limit city ✓

Probable maximum precipitation used to estimate

1. A Daily office rainfall average only ✓
2. B Zero rain forever ✓
3. C Only fog ✓
4. D Extreme inflow to reservoir ✓

Routing flood through reservoir uses

1. A Storage and outflow relationship ✓
2. B Only paint viscosity ✓
3. C Only soil colour ✓
4. D Only signal cycle ✓

Penstock bifurcation near powerhouse splits flow to

1. A Highway lanes ✓
2. B Multiple turbine units ✓
3. C Rail tracks ✓
4. D Harbour berths ✓

Trash rack at intake stops

1. A All dissolved salts ✓
2. B All fish always without exception ✓
3. C All water ✓
4. D Large debris entering penstock ✓

Cavitation in spillway or turbine occurs when

1. A Local pressure drops below vapor pressure ✓
2. B Concrete always gains strength ✓
3. C Water becomes solid ice instantly always ✓
4. D Air becomes liquid ✓

Air entrainment on spillway face reduces

1. A Dam height requirement always to zero ✓
2. B Reservoir capacity to zero ✓
3. C Cavitation damage potential ✓
4. D Need for any stilling basin always ✓

Regulator dam or weir differs from storage dam by

1. A Aircraft hangar function ✓
2. B Railway station function ✓
3. C Harbour breakwater only ocean ✓
4. D Limited storage raising river level ✓

Barrage on river like Sukkur Barrage primarily

1. A Stores multi-year flood only ✓
2. B Diverts irrigation water with gates ✓
3. C Serves as airport runway ✓
4. D Acts as railway bridge only ✓

Underground powerhouse advantage is

1. A Reduced surface environmental impact ✓
2. B Always cheaper without geology check ✓
3. C No ventilation needed ever ✓
4. D No access tunnel needed ✓

Dam break analysis provides

1. A Only runway wind rose ✓
2. B Only pavement design chart ✓
3. C Inundation mapping downstream ✓
4. D Only BOQ format ✓

Tailwater rating curve relates

1. A Wind speed to runway length ✓
2. B ESAL to CBR ✓
3. C Tide to berth rent ✓
4. D Discharge to downstream water level ✓

Sediment flushing through low level outlets helps

1. A Maintain live storage capacity ✓
2. B Increase harbour depth always ✓
3. C Widen railway gauge ✓
4. D Extend runway only ✓

Dam safety review in Pakistan considers

1. A Only paint colour ✓
2. B Only staff uniform ✓
3. C Seismic hydrologic and structural adequacy ✓
4. D Only canteen menu ✓

Wave height on reservoir fetch depends on

1. A Rail axle load ✓
2. B Wind speed duration and fetch length ✓
3. C Highway camber ✓
4. D Building setback ✓

Joint in concrete dam accommodates

1. A Only aircraft movement ✓
2. B Only train movement ✓
3. C Only ship movement ✓
4. D Temperature and shrinkage movement ✓

Labyrinth weir increases

1. A Railway curve radius ✓
2. B Effective crest length for discharge ✓
3. C Runway width only ✓
4. D Building floor area ✓

Flip bucket on spillway throws jet

1. A Away from toe to reduce scour ✓
2. B Into powerhouse always ✓
3. C Into intake always ✓
4. D Into penstock always ✓

Morning glory spillway is

1. A Highway rotary design ✓
2. B Railway turntable ✓
3. C Vertical shaft spillway dropping through dam ✓
4. D Airport radar ✓

Earthquake induced hydrodynamic pressure on dam face computed using

1. A Only manual thumb rule zero ✓
2. B Only traffic formula ✓
3. C Only wind formula only ✓
4. D Westergaard or finite element methods ✓

Central Asia and Himalayan dams face challenge of

1. A High sediment load and seismicity ✓
2. B Zero rainfall always ✓
3. C No foundation rock ever ✓
4. D No irrigation demand ✓

Small dam or pond for community irrigation in Punjab often

1. A Aircraft carrier deck ✓
2. B Earthen bund with pipe outlet ✓
3. C Railway terminal ✓
4. D Harbour container crane ✓

Safety inspection of dam includes checking

1. A Only office furniture ✓
2. B Only vehicle polish ✓
3. C Seepage cracks instrumentation and spillway ✓
4. D Only uniform buttons ✓