Irrigation Engineering MCQs 2026

Kennedy critical velocity V0 depends on

1. A depth of flow and silt factor ✓
2. B only canal slope ✓
3. C only lining thickness ✓
4. D only gate opening ✓

Lacey theory defines

1. A regime perimeter and hydraulic radius for stable alluvial channels ✓
2. B rigid boundary Manning n only ✓
3. C pipe Darcy friction ✓
4. D weir discharge ✓

Lacey silt factor f is related to average grain size by

1. A f = d_mm only ✓
2. B f = 1/d_mm ✓
3. C f = 1.76 √d_mm ✓
4. D f = d_mm² ✓

According to Lacey, wetted perimeter P equals

1. A 2.67 √Q only always ✓
2. B 4.75 √Q ✓
3. C Q/V only ✓
4. D Manning AR^(2/3) ✓

Freeboard in canals is provided to accommodate

1. A only boat traffic ✓
2. B sediment deposition always ✓
3. C wave action, wind setup and unexpected rises ✓
4. D zero safety margin ✓

Canal section is said to be in regime when

1. A velocity is maximum possible ✓
2. B depth is always critical ✓
3. C sediment inflow equals sediment outflow without net scour or fill ✓
4. D flow is always laminar ✓

Side slopes in earthen canals in cutting are typically

1. A steeper than in filling sections ✓
2. B always vertical ✓
3. C always 1:1 in fill and cut ✓
4. D zero in all cases ✓

Banks in canal design provide

1. A freeboard storage and structural stability ✓
2. B only decoration ✓
3. C zero seepage control alone ✓
4. D only measurement structures ✓

Bed width in regime canal increases with

1. A decreases with discharge always ✓
2. B is independent of Q ✓
3. C discharge ✓
4. D equals depth only ✓

Kennedy-Lacey design is most applicable to

1. A rocky mountain torrents only ✓
2. B alluvial tracts of Punjab and Sindh type soils ✓
3. C lined pressure pipelines ✓
4. D sewer force mains ✓

Canal lining primarily reduces

1. A seepage losses and improves water conveyance efficiency ✓
2. B canal capacity to zero ✓
3. C need for outlets ✓
4. D crop water requirement ✓

Cement concrete lining is preferred when

1. A high durability and low roughness are required ✓
2. B only temporary diversion needed ✓
3. C soil is highly erodible without subgrade prep ✓
4. D no maintenance access exists ✓

Brick lining in canals is

1. A unsuitable for any canal ✓
2. B always superior to concrete in all cases ✓
3. C only for pipes ✓
4. D economical for moderate heads and good craftsmanship ✓

Plastic membrane lining reduces seepage when protected by

1. A direct exposure to flow only without cover ✓
2. B cover layer against puncture and UV damage ✓
3. C no side protection ✓
4. D open air only ✓

Lining may increase conveyance capacity because

1. A n always increases ✓
2. B Manning n decreases for smoother boundary ✓
3. C slope becomes zero ✓
4. D depth must decrease always ✓

Cross regulator on a canal is provided to

1. A measure rainfall ✓
2. B raise water level upstream to divert flow into off-taking channels ✓
3. C treat sewage ✓
4. D pump groundwater ✓

Head regulator is located at

1. A field outlet only ✓
2. B dam spillway crest ✓
3. C tube well head ✓
4. D offtake from parent canal ✓

Cross regulator gates are commonly

1. A vertical lift or radial gates ✓
2. B only butterfly valves in homes ✓
3. C only sprinkler heads ✓
4. D only drip emitters ✓

Tail channel level downstream of regulator affects

1. A only air temperature ✓
2. B crop variety only ✓
3. C soil pH only ✓
4. D submergence of off-taking structures and discharge ✓

Canal outlet delivers water from

1. A reservoir to ocean ✓
2. B distributary or minor to watercourse or field channel ✓
3. C sewer to treatment plant ✓
4. D rain gauge to lab ✓

Kennedy gauge outlet is

1. A a modular outlet maintaining constant discharge over varying head ✓
2. B only siphon tube ✓
3. C only sprinkler nozzle ✓
4. D only trickling filter ✓

Modular outlet means discharge is

1. A always zero ✓
2. B always proportional to tail level only ✓
3. C equal to rainfall ✓
4. D independent of tail water level within modular range ✓

Non-modular outlet discharge depends on

1. A upstream only always ✓
2. B neither level ✓
3. C wind speed only ✓
4. D both upstream and downstream water levels ✓

Orifice type outlet is suited for

1. A low discharge turnouts from minors ✓
2. B main river spillway only ✓
3. C dam foundation ✓
4. D highway drainage only ✓

Pipe outlet with semi-module uses

1. A rising pipe to break submergence effect partially ✓
2. B no pipe at all ✓
3. C only open channel weir at dam ✓
4. D sewer vent ✓

Outlet capacity is fixed considering

1. A culturable command area and crop water duty ✓
2. B only canal colour ✓
3. C bridge width only ✓
4. D wind direction ✓

Emitter discharge in drip system is typically

1. A 1000 litres per second ✓
2. B zero flow always ✓
3. C equal to canal cumec ✓
4. D 2–8 litres per hour per emitter ✓

Filtration in drip irrigation is essential to prevent

1. A increasing evaporation only ✓
2. B raising delta always ✓
3. C canal siltation upstream ✓
4. D emitter clogging from suspended particles ✓

Sprinkler uniformity coefficient measures

1. A evenness of water application over field ✓
2. B only wind speed ✓
3. C only soil pH ✓
4. D only crop height ✓

Operating pressure in drip laterals must be within range to

1. A maximize canal seepage ✓
2. B maintain design emitter discharge ✓
3. C stop all flow ✓
4. D eliminate filtration ✓

Chemigation through drip lines allows

1. A only sediment removal from canals ✓
2. B only canal lining ✓
3. C fertigation and controlled pesticide application ✓
4. D only flood routing ✓

Lift irrigation scheme uses pumps when

1. A source level is below field elevation ✓
2. B gravity canal suffices ✓
3. C rainfall meets all demand ✓
4. D no power available ever ✓

Pump house in lift irrigation is sited considering

1. A only aesthetic view ✓
2. B only downstream sewer ✓
3. C only highway curve ✓
4. D suction lift, flood level and power supply ✓

Delivery pipeline in lift scheme is designed for

1. A pressure head, surge and friction losses ✓
2. B open channel Manning only ✓
3. C zero velocity ✓
4. D atmospheric pressure only ✓

Stage pumping in lift irrigation is adopted for

1. A zero head systems ✓
2. B only siphon flows ✓
3. C only gravity canals ✓
4. D high lifts dividing total head among pumps in series ✓

Energy cost in lift irrigation makes

1. A efficiency irrelevant ✓
2. B water scheduling and high efficiency methods important ✓
3. C duty infinite always ✓
4. D delta zero ✓

Surface drainage removes

1. A only salt from soil ✓
2. B excess water from land surface via channels ✓
3. C only air pollution ✓
4. D only groundwater always ✓

Sub-surface drainage uses

1. A only overhead sprinklers ✓
2. B only canal lining ✓
3. C buried perforated pipes or tile drains ✓
4. D only dam spillway ✓

Drainage coefficient is defined as

1. A canal duty only ✓
2. B depth of water removed in 24 hours from submerged area ✓
3. C crop delta only ✓
4. D Manning n ✓

Salinity control in irrigated lands often requires

1. A only increased flooding without drainage ✓
2. B zero irrigation ✓
3. C removal of all canals ✓
4. D leaching and adequate drainage ✓

Interceptor drain is placed to

1. A increase water logging ✓
2. B block irrigation supply ✓
3. C cut seepage flow from canal or aquifer before field ✓
4. D raise water table ✓

Drainage of rice fields may use

1. A only pressurized pipe mains ✓
2. B only trickling filters ✓
3. C only air lift pumps ✓
4. D shallow surface drains between bunds ✓

Water logging is caused primarily by

1. A only wind erosion ✓
2. B only canal lining ✓
3. C only drip irrigation ✓
4. D high water table and inadequate drainage ✓

Canal seepage contributes to water logging by

1. A lowering water table always ✓
2. B raising local groundwater table ✓
3. C removing salts always ✓
4. D increasing soil strength ✓

Waterlogged soils show symptoms of

1. A reduced crop yield, salinity and poor aeration ✓
2. B increased fertility always ✓
3. C zero evaporation ✓
4. D higher soil strength for all crops ✓

Reclamation of waterlogged land includes

1. A increasing seepage ✓
2. B abandoning all irrigation forever ✓
3. C drainage, land shaping and leaching ✓
4. D removing topsoil only ✓

Shallow water table within root zone is harmful when it is within

1. A 50 m always safe ✓
2. B only during floods never otherwise ✓
3. C 1–2 m of surface for most crops depending on species ✓
4. D zero depth required always ✓

Ponding on surface after irrigation indicates

1. A perfect soil health always ✓
2. B excessive drainage always ✓
3. C low delta only ✓
4. D poor infiltration or inadequate surface drainage ✓

Gross command area (GCA) is

1. A total area served by irrigation scheme including unculturable land ✓
2. B only cropped area ✓
3. C only forest reserve always excluded ✓
4. D only urban area ✓

Culturable command area (CCA) is

1. A total dam catchment ✓
2. B ocean area ✓
3. C area that can practically be irrigated and cultivated ✓
4. D only building footprint ✓

Intensity of irrigation is ratio of

1. A irrigated area to CCA for a given season or year ✓
2. B canal length to width ✓
3. C pump power to head only ✓
4. D rainfall to evaporation only ✓

Increasing irrigation efficiency for same delta will

1. A decrease duty always ✓
2. B increase effective duty ✓
3. C not affect duty ✓
4. D eliminate base period ✓

Higher cropping intensity demands

1. A greater water supply and timely irrigation ✓
2. B less canal capacity ✓
3. C zero storage ✓
4. D no outlets ✓

Crop water requirement for intensity planning uses

1. A only highway traffic ✓
2. B only wind rose ✓
3. C delta and overlap of crop calendars ✓
4. D only concrete grade ✓

Intensity of irrigation for wheat alone of 50% means

1. A all land grows wheat twice ✓
2. B half of CCA receives wheat irrigation that season ✓
3. C no irrigation occurs ✓
4. D delta is zero ✓

Sustainable cropping intensity is limited by

1. A only seed colour ✓
2. B water availability, soil health and drainage capacity ✓
3. C bridge span ✓
4. D canal name ✓

Surface irrigation includes

1. A border, furrow and basin methods ✓
2. B drip and micro-spray only ✓
3. C only sprinkler systems ✓
4. D only sub-surface pipes ✓

Sprinkler irrigation is most suitable for

1. A flat clay fields only with high water table ✓
2. B only rice paddies ✓
3. C undulating terrain and sandy soils ✓
4. D only canal-command flat areas ✓

Drip irrigation primarily saves water by

1. A flooding entire field surface ✓
2. B increasing runoff ✓
3. C applying water directly to root zone with minimal evaporation ✓
4. D raising water table ✓

Well irrigation is extensively used in

1. A high mountains without aquifers ✓
2. B only coastal saline zones ✓
3. C only deserts without aquifers ✓
4. D alluvial plains with favourable groundwater ✓

Canal irrigation systems are classified as

1. A only drip systems ✓
2. B only sprinkler grids ✓
3. C only roof collection ✓
4. D perennial, non-perennial and inundation canals ✓

Lift irrigation is required when

1. A water table is very high ✓
2. B land elevation exceeds command of gravity canals ✓
3. C rainfall exceeds crop need always ✓
4. D canal is always silt-free ✓

Duty of water is defined as

1. A area irrigated per unit discharge over base period ✓
2. B depth of water only ✓
3. C canal velocity only ✓
4. D Manning roughness ✓

Delta Δ is

1. A discharge in cumec ✓
2. B canal bed width ✓
3. C Lacey perimeter ✓
4. D total depth of water applied during base period ✓

Base period B is

1. A time for one irrigation only ✓
2. B total time between first and last irrigation of crop season ✓
3. C canal design life ✓
4. D lining thickness period ✓

Relationship between duty D, delta Δ and base period B is

1. A D = B/Δ only without constant ✓
2. B Δ = D/B without conversion ✓
3. C Δ = 8.64 B/D in metre units with D in ha/cumec and B in days ✓
4. D B = ΔD/100 only ✓

Duty is inversely proportional to

1. A base period always directly ✓
2. B delta for same base period ✓
3. C canal slope ✓
4. D Manning n only ✓

Field duty is always

1. A greater than canal duty ✓
2. B equal to reservoir duty always ✓
3. C independent of losses ✓
4. D less than canal duty due to transit losses ✓

Delta for rice in hot climate may reach

1. A 5–10 cm only always ✓
2. B zero with sprinkler ✓
3. C 100–150 cm or more depending on season ✓
4. D less than wheat always in all regions ✓

If duty is 1000 ha/cumec and base period 120 days, delta is approximately

1. A 50 cm ✓
2. B 200 cm ✓
3. C 10 cm ✓
4. D 103.7 cm ✓

Kennedy theory of canal design assumes

1. A no sediment in water ✓
2. B eddy formation along wetted perimeter causes silting-erosion balance ✓
3. C only concrete lining ✓
4. D uniform velocity at all depths ✓

Culturable area factor accounts for

1. A Manning n variation ✓
2. B unculturable land within GCA when estimating CCA ✓
3. C pipe friction only ✓
4. D wind speed ✓

Command area development includes

1. A only dam construction ✓
2. B only highway paving ✓
3. C only air quality monitoring ✓
4. D field channels, outlets and land leveling ✓

Rotation of supply in command means

1. A simultaneous unlimited withdrawal ✓
2. B zero farmer access ✓
3. C scheduled water delivery to sections in turn ✓
4. D random flooding ✓

Cropping intensity is expressed as

1. A delta per crop only ✓
2. B canal discharge only ✓
3. C percentage of cropped area to CCA in a year ✓
4. D rainfall depth only ✓

If CCA is 10000 ha and area sown in year is 14000 ha, cropping intensity is

1. A 100% ✓
2. B 70% ✓
3. C 200% ✓
4. D 140% ✓

Double cropping means

1. A only one crop ever ✓
2. B zero irrigation ✓
3. C two crops grown on same land within one agricultural year ✓
4. D only forest cover ✓

Rabi season crops in Pakistan include

1. A rice and cotton only in kharif exclusively ✓
2. B only sugarcane in monsoon ✓
3. C wheat, barley and gram ✓
4. D only mango orchard ✓

Kharif season crops include

1. A wheat only ✓
2. B gram only ✓
3. C rice, cotton and maize ✓
4. D only orchard grapes in winter ✓