Open Channel Flow and Coastal Engineering MCQs 2026

Subcritical flow is

1. ATranquil deeper Fr less than 1✓
2. BAlways shooting flow✓
3. COnly in air✓
4. DOnly pressurized✓

Scour at bridge pier caused by

1. AOnly wind on deck✓
2. BOnly seismic shake only✓
3. CAcceleration and vortices around obstruction✓
4. DOnly paint loss✓

Broad crested weir used to

1. APave highway✓
2. BMeasure or control discharge in channels✓
3. CLay railway track✓
4. DBuild dam only always without weir type✓

Venturi flume measures flow by

1. AConstriction causing head difference✓
2. BMagnetic railway ticket✓
3. CWind pressure on building✓
4. DBitumen softening✓

Afflux upstream of bridge obstruction is

1. ADecrease always✓
2. BOnly wind setup on lake unrelated✓
3. COnly runway elevation✓
4. DIncrease in water surface elevation✓

Riprap at channel bank protects against

1. AOnly wind erosion always only✓
2. BErosion by flowing water✓
3. COnly traffic load✓
4. DOnly building settlement✓

Spur dike angled into stream redirects flow to

1. AIncrease erosion same bank always purpose wrong✓
2. BStop river forever completely always✓
3. COnly increase navigation always harmful✓
4. DReduce bank erosion on opposite side✓

Regime theory in alluvial channels relates

1. AWidth depth slope to discharge and sediment✓
2. BOnly concrete strength✓
3. COnly wind load✓
4. DOnly runway friction✓

Lacey wetted perimeter formula used in

1. AAirport runway length✓
2. BHarbour berth width only✓
3. CAlluvial channel design in Pakistan✓
4. DBuilding column design✓

Critical slope for given Q makes

1. AAlways zero slope✓
2. BAlways infinite slope✓
3. CAlways subcritical only✓
4. DNormal depth equal critical depth✓

Hydraulic jump conjugate depths from

1. AOnly energy equation alone always insufficient✓
2. BMomentum equation across jump✓
3. COnly Manning alone✓
4. DOnly wind chart✓

Energy dissipation block in stilling basin creates

1. AWave reflection at sea wall only unrelated✓
2. BWind turbulence only✓
3. CControlled jump location✓
4. DRail vibration✓

Tidal range is difference between

1. AHigh water and low water elevation✓
2. BWind speed max min✓
3. CTemperature day night✓
4. DTraffic peak off peak✓

Coastal sediment budget balances

1. AOnly concrete production✓
2. BInputs outputs and storage along reach✓
3. COnly steel import✓
4. DOnly labour cost✓

Longshore transport driven by

1. AOnly river discharge alone always perpendicular always wrong✓
2. BOnly gravity dam seepage✓
3. COblique wave approach generating alongshore current✓
4. DOnly building HVAC✓

Breakwater shadow zone may cause

1. AAutomatic beach build always✓
2. BZero waves always beneficial always wrong tradeoff✓
3. COnly increase ship speed✓
4. DDown drift erosion from reduced sediment supply✓

Salinity intrusion in estuary worsens when

1. ARiver flow low and tide high✓
2. BFlood flow maximum always pushes salt out✓
3. COnly wind from desert always primary✓
4. DOnly snow melt in desert none✓

Open channel carriers in Pakistan irrigation include

1. AOnly motorway drainage only always✓
2. BOnly airport taxiway✓
3. CBranch distributaries minors and watercourses✓
4. DOnly railway culvert only✓

Check structure in canal regulates

1. AVehicle speed on highway✓
2. BWater level and discharge downstream✓
3. CAircraft takeoff✓
4. DTrain timetable✓

Cross regulator in canal system

1. AControls water level upstream for rotation✓
2. BStops earthquakes✓
3. CMeasures wind✓
4. DTests bitumen✓

Sediment excluder at canal headworks removes

1. AAll water entirely wrong✓
2. BOnly fish always only✓
3. COnly air✓
4. DBed load entering canal✓

Wave refraction bends wave crests toward

1. AAlways offshore deep always wrong✓
2. BMountain peaks✓
3. CShallower regions parallel to depth contours✓
4. DBuilding roofs✓

Wave diffraction occurs when

1. AWaves pass gap or around structure✓
2. BOnly in pipes✓
3. COnly in concrete curing✓
4. DOnly in soil consolidation✓

Run-up on beach is

1. ATrain speed on upgrade✓
2. BVehicle stopping distance✓
3. CBuilding drift✓
4. DMax vertical swash extent on slope✓

Coastal groin field design considers

1. AOnly bitumen grade✓
2. BSpacing length and sediment transport direction✓
3. COnly rebar diameter✓
4. DOnly zoning FAR✓