Steam Generators and Power Plants MCQs 2026

Hot well collects

1. A flue ash ✓
2. B combustion air ✓
3. C superheated steam ✓
4. D condensate from condenser for feed pump suction ✓

Condenser effectiveness measures

1. A boiler steam purity only ✓
2. B fuel CV only ✓
3. C chimney height ✓
4. D approach to ideal minimum cooling water exit temperature ✓

Isentropic efficiency of turbine is

1. A boiler efficiency ✓
2. B condenser effectiveness only ✓
3. C pump efficiency ✓
4. D actual work / isentropic work for same inlet and exit pressure ✓

Steam consumption of turbine is

1. A fuel ash content ✓
2. B cooling tower drift only ✓
3. C steam mass flow required for given power output ✓
4. D boiler mountings count ✓

Blow-down loss depends on

1. A turbine blade angle only ✓
2. B quantity and enthalpy of water removed ✓
3. C condenser tube count only ✓
4. D chimney draft only ✓

Radiation loss from boiler surfaces is typically

1. A 50% always ✓
2. B zero for insulated boiler ✓
3. C 1–2% of heat input ✓
4. D equal to turbine output ✓

Stack loss in boiler is

1. A radiation from drum only always ✓
2. B blow-down only always ✓
3. C heat carried away by dry flue gas and moisture ✓
4. D steam to process only ✓

Heat balance sheet of boiler lists

1. A only turbine output ✓
2. B heat supplied and heat losses to flue gas, radiation etc. ✓
3. C only condenser duty ✓
4. D only chimney height ✓

Factor of evaporation converts

1. A actual steam generation to equivalent evaporation ✓
2. B electrical kW to HP only ✓
3. C coal tonnage to ash ✓
4. D condenser vacuum to bar ✓

Equivalent evaporation from and at 100 °C means

1. A actual steam at boiler pressure only without reference ✓
2. B water flow in cooling tower ✓
3. C turbine RPM ✓
4. D steam produced converting feedwater at 100 °C to dry saturated steam at 100 °C ✓

Low pressure boiler generally below

1. A 200 bar ✓
2. B critical pressure always ✓
3. C vacuum operation ✓
4. D 20 bar ✓

High pressure boiler typically exceeds

1. A 1 bar atmospheric only ✓
2. B 10 bar always maximum ✓
3. C 0.1 bar vacuum ✓
4. D 70 bar ✓

Steam separator or cyclone in drum

1. A adds fuel to steam ✓
2. B increases furnace temperature only ✓
3. C removes moisture from steam leaving boiler ✓
4. D pumps condensate to cooling tower ✓

Foaming in boiler water is caused by

1. A pure distilled feedwater only ✓
2. B excess superheat always ✓
3. C high vacuum in condenser ✓
4. D high dissolved solids and oil contamination ✓

Priming in boiler is

1. A carryover of water droplets with steam ✓
2. B normal superheat process ✓
3. C deliberate blow-down ✓
4. D feed pump cavitation only ✓

Boiler water treatment prevents

1. A all steam generation always ✓
2. B scale, corrosion and carryover ✓
3. C need for safety valve ✓
4. D condenser vacuum ✓

Soot blower cleans

1. A furnace and convection tube surfaces of ash deposits ✓
2. B turbine blades with steam always ✓
3. C condenser tubes with fuel ✓
4. D feed pump impeller with oil ✓

Primary air in PF boiler carries

1. A flue gas to chimney ✓
2. B feedwater to economizer ✓
3. C pulverized coal from mill to burners ✓
4. D steam to turbine ✓

Pulverized fuel firing suspends

1. A large coal chunks on grate only always ✓
2. B water slurry without air ✓
3. C natural gas only ✓
4. D fine coal particles in air stream for rapid combustion ✓

Chain grate stoker feeds coal by

1. A pulverized pneumatic injection only always ✓
2. B oil spray only ✓
3. C gas burner only ✓
4. D moving grate through furnace ✓

Fluidized bed combustion boiler achieves

1. A zero heat transfer to tubes ✓
2. B only gas turbine cycle ✓
3. C vacuum furnace operation ✓
4. D efficient burning of low-grade fuel with sulfur capture ✓

Benson boiler operates

1. A only subcritical with large drum always ✓
2. B once-through supercritical without drum ✓
3. C as fire tube Lancashire only ✓
4. D at atmospheric pressure only ✓

Drum type boiler maintains

1. A circulation between drum, downcomers and risers ✓
2. B once-through flow without recirculation always ✓
3. C only supercritical pressure always ✓
4. D no steam separation ✓

Boiler feed pump handles

1. A exhaust steam from turbine always ✓
2. B flue gas to chimney ✓
3. C condenser air only ✓
4. D high pressure water to economizer or drum ✓

Make-up water in power cycle compensates for

1. A turbine power increase only ✓
2. B losses from blow-down, leaks and cooling tower drift ✓
3. C superheat rise only ✓
4. D vacuum improvement only ✓

Steam turbine governing by throttle control

1. A admits steam to intermediate stages only always ✓
2. B reduces inlet steam pressure at partial load ✓
3. C increases condenser pressure always ✓
4. D shuts boiler always ✓

Parsons turbine is primarily

1. A impulse only with one nozzle ✓
2. B reaction type with gradual expansion ✓
3. C hydraulic turbine ✓
4. D gas turbine combustor ✓

Curtis stage is

1. A single reaction stage only ✓
2. B condenser tube bundle ✓
3. C velocity compounded impulse stage with multiple blade rows ✓
4. D feed pump impeller ✓

De Laval turbine uses

1. A pure reaction blading only ✓
2. B hydraulic pelton buckets ✓
3. C reciprocating piston ✓
4. D single velocity compounded impulse stage with one nozzle ring ✓

Degree of reaction of 50% means

1. A equal enthalpy drop in stator and rotor ✓
2. B all drop in nozzle ✓
3. C all drop in condenser ✓
4. D zero expansion ✓

Reaction steam turbine stage has

1. A pressure drop only in nozzles ✓
2. B pressure drop in both fixed and moving blades ✓
3. C zero velocity change ✓
4. D no steam expansion ✓

Impulse steam turbine stage has

1. A pressure drop only in moving blades ✓
2. B equal drop in fixed and moving always ✓
3. C no pressure drop in moving blades — drop in fixed nozzles ✓
4. D no nozzles ✓

Draught in boiler furnace may be produced by

1. A chimney (natural) or forced/induced fans ✓
2. B condenser vacuum only ✓
3. C feed pump only ✓
4. D steam trap only ✓

Air preheater improves boiler efficiency by

1. A heating combustion air with flue gas ✓
2. B cooling steam in turbine ✓
3. C condensing feedwater ✓
4. D bypassing economizer always ✓

Superheater raises

1. A steam temperature at constant pressure ✓
2. B feedwater temperature before economizer only ✓
3. C condensate subcooling only ✓
4. D flue gas velocity only ✓

Economizer in boiler preheats

1. A combustion air only always ✓
2. B steam after turbine ✓
3. C condensate after cooling tower only ✓
4. D feedwater using flue gas heat ✓

Fire tube boiler has

1. A water in tubes and fire outside only always ✓
2. B hot combustion gases passing through tubes immersed in water ✓
3. C no furnace ✓
4. D only supercritical operation ✓

Water tube boiler differs from fire tube in that

1. A water flows in tubes heated externally by hot gases ✓
2. B hot gases flow inside large tubes surrounded by water shell only ✓
3. C no steam drum exists ever ✓
4. D only low pressure steam possible ✓

Cochran boiler is

1. A horizontal water tube only ✓
2. B vertical multi-tubular fire tube boiler ✓
3. C once-through Benson boiler ✓
4. D fluidized bed only ✓

Lancashire boiler is

1. A vertical water tube only ✓
2. B horizontal fire tube boiler with two large flue tubes ✓
3. C package watertube with superheater only ✓
4. D recovery boiler for chemical pulping only ✓

Babcock-Wilcox boiler is

1. A water tube boiler with inclined tubes and drum ✓
2. B fire tube horizontal shell only ✓
3. C package boiler with no drums ✓
4. D once-through nuclear steam generator only ✓

Vacuum in condenser is created mainly by

1. A boiler feed pump alone ✓
2. B superheater coils only ✓
3. C condensing steam and air removal equipment ✓
4. D economizer flue gas ✓

Condenser in steam plant maintains

1. A high back pressure always ✓
2. B superheated steam at outlet ✓
3. C positive pressure above atmospheric always ✓
4. D low pressure at turbine exhaust ✓

Regenerative feed heating in Rankine cycle

1. A cools feedwater before boiler always ✓
2. B extracts steam to preheat feedwater improving efficiency ✓
3. C eliminates condenser ✓
4. D injects fuel in condenser ✓

Reheat Rankine cycle purpose is to

1. A eliminate boiler completely ✓
2. B increase condenser vacuum to zero ✓
3. C replace pump with compressor ✓
4. D reduce moisture at turbine exit and improve efficiency ✓

Thermal efficiency of Rankine cycle can be improved by

1. A decreasing boiler pressure always ✓
2. B increasing turbine inlet temperature and pressure ✓
3. C eliminating condenser always ✓
4. D using open feedwater only ✓

Rankine cycle for steam power plant consists of

1. A compressor, combustor, turbine, heat exchanger only ✓
2. B only boiler and turbine without condenser ✓
3. C pump, boiler, turbine and condenser processes ✓
4. D refrigeration evaporator cycle ✓

Nozzle governing admits steam to

1. A condenser tubes ✓
2. B feed heaters only ✓
3. C economizer coils only ✓
4. D selected groups of nozzles at partial load ✓

Bypass governing diverts steam

1. A only to chimney always ✓
2. B back to boiler feed always ✓
3. C around turbine stages to condenser or process ✓
4. D into combustion air always ✓

Wilson line on Mollier chart indicates

1. A constant pressure line only ✓
2. B locus of maximum moisture in expansion ✓
3. C feedwater temperature line ✓
4. D combustion air line ✓

Moisture in last turbine stages causes

1. A increased superheat always ✓
2. B higher vacuum always ✓
3. C blade erosion and reduced efficiency ✓
4. D zero heat loss ✓

Bleeding steam from turbine is used for

1. A increasing condenser load only always ✓
2. B cooling tower makeup only always ✓
3. C raising exhaust pressure always ✓
4. D feedwater heating and process needs ✓

Open feedwater heater is

1. A direct mixing chamber where steam heats feedwater ✓
2. B closed tube bundle only always ✓
3. C condenser air ejector ✓
4. D boiler furnace ✓

Closed feedwater heater transfers heat through

1. A direct steam-water contact only ✓
2. B tube walls without mixing fluids ✓
3. C combustion in feed line ✓
4. D vacuum pump suction only ✓

Deaerator removes

1. A all minerals as scale only ✓
2. B steam superheat ✓
3. C turbine blades ✓
4. D dissolved oxygen and CO2 from feedwater ✓

Boiler mountings include

1. A safety valve, water level indicator and pressure gauge ✓
2. B turbine blades only ✓
3. C condenser tubes only ✓
4. D cooling tower fill only ✓

Safety valve on boiler prevents

1. A low water level only ✓
2. B steam superheat only ✓
3. C pressure exceeding design limit ✓
4. D feed pump cavitation only ✓

Fusible plug in fire tube boiler melts to

1. A warn of low water exposing furnace crown ✓
2. B increase steam pressure ✓
3. C close safety valve ✓
4. D start feed pump automatically always ✓

Blow-down valve removes

1. A steam to turbine ✓
2. B flue gas to chimney ✓
3. C sediment and concentrated boiler water ✓
4. D condensate to hot well only ✓

Steam trap function is to

1. A discharge condensate without losing live steam ✓
2. B superheat steam always ✓
3. C increase boiler pressure ✓
4. D meter fuel flow ✓

Critical pressure of steam is approximately

1. A 221.2 bar ✓
2. B 1 bar ✓
3. C 100 bar exactly ✓
4. D 500 bar ✓

Dry saturated steam has quality of

1. A 1.0 ✓
2. B 0.0 ✓
3. C 0.5 always at boiler outlet ✓
4. D 2.0 ✓

Wet steam quality 0.85 means

1. A 85% liquid ✓
2. B temperature above saturation ✓
3. C 85% mass is vapor and 15% liquid ✓
4. D superheated always ✓

Boiler efficiency is ratio of

1. A turbine power to coal mass only without heat ✓
2. B condenser vacuum to pressure ✓
3. C heat absorbed by water-steam to heat supplied by fuel ✓
4. D feed pump power to steam flow only ✓

Heat rate of power plant is

1. A electrical output per fuel mass only without time ✓
2. B energy input per unit electrical output ✓
3. C vacuum in condenser ✓
4. D turbine blade pitch ✓

Plant load factor is

1. A peak load only ✓
2. B efficiency at full load only ✓
3. C average load / maximum demand over period ✓
4. D condenser pressure ratio ✓

Capacity factor similar to load factor for

1. A boiler blow-down rate only ✓
2. B steam trap failure only ✓
3. C actual energy output vs maximum possible output ✓
4. D chimney height only ✓

Cooling tower in steam plant rejects

1. A high pressure steam to turbine ✓
2. B low-grade heat from condenser cooling water ✓
3. C flue gas heat to stack only ✓
4. D feedwater enthalpy rise ✓

Natural draft cooling tower relies on

1. A forced fans only always ✓
2. B steam jet ejector only ✓
3. C feed pump head ✓
4. D buoyancy of warm moist air ✓

Surface condenser uses

1. A direct mixing of cooling water and steam always ✓
2. B no heat transfer surface ✓
3. C boiler furnace ✓
4. D tube bundle with cooling water inside tubes ✓

Jet condenser mixes

1. A only closed tubes always ✓
2. B fuel with air ✓
3. C cooling water directly with exhaust steam ✓
4. D feedwater with flue gas ✓

Under-cooling in condenser means

1. A condensate temperature below saturation at exhaust pressure ✓
2. B steam above saturation at exhaust ✓
3. C feedwater at boiling in economizer ✓
4. D flue gas at inlet temperature ✓

Extraction condensing turbine supplies

1. A only mechanical drive with no extraction ✓
2. B process steam at intermediate pressure and exhausts rest to condenser ✓
3. C hydraulic power only ✓
4. D compressed air only ✓

Back pressure turbine exhausts to

1. A process header at constant elevated pressure ✓
2. B high vacuum condenser always ✓
3. C atmospheric chimney only always ✓
4. D boiler feed line directly ✓

Pass-out turbine is another name for

1. A pure condensing only turbine ✓
2. B extraction turbine with controlled bleed steam ✓
3. C hydraulic pelton wheel ✓
4. D gas turbine only ✓

Gland sealing steam on turbine prevents

1. A air ingress at shaft seals ✓
2. B oil leakage into condenser always ✓
3. C feedwater contamination always ✓
4. D superheat loss in boiler only ✓

Turning gear or barring gear rotates turbine slowly during cooldown to

1. A increase speed to rated RPM ✓
2. B generate electricity at startup only ✓
3. C prevent rotor bowing from uneven cooling ✓
4. D pump feedwater at full pressure ✓

Boiler trial purpose includes determining

1. A evaporation rate, efficiency and heat losses ✓
2. B turbine blade material only ✓
3. C cooling tower color only ✓
4. D coal mine location only ✓

Orsat apparatus analyzes

1. A steam purity in turbine ✓
2. B dry flue gas composition for CO2, O2 and CO ✓
3. C feedwater hardness only ✓
4. D cooling water pH only ✓