Steam Boilers, Engines, Nozzles And Turbines MCQs

Option A: it has heating value

Option B: it helps in electrostatic precipitation of ash in flue-gases

Option C: it leads to corrosion of air heaters, ducting, etc. if flue gas exit temperature is low

Option D: it erodes furnace walls

Correct Answer: it erodes furnace walls ✔

Option A: inherent moisture and surface mois¬ture are different things

Option B: in some coals moisture may be present upto 40%

Option C: some moisture in coal helps in better burning which is not possible with completely dry coal

Option D: it increases thermal efficiency

Correct Answer: it increases thermal efficiency ✔

Option A: to provide proper conditions for con-tinuous complete combustion

Option B: mix fuel with air and ignite

Option C: separate ash from coal

Option D: maintain heat supply to prepare and ignite the incoming fuel

Correct Answer: separate ash from coal ✔

Option A: high burning rate is possible

Option B: heat release can be easily controlled

Option C: fuel burns economically

Option D: it is the best technique for burning high ash content fuel having low fusion ash

Correct Answer: it is the best technique for burning high ash content fuel having low fusion ash ✔

Option A: high calorific value

Option B: produce minimum smoke and gases

Option C: ease in storing

Option D: high ignition point

Correct Answer: high ignition point ✔

Option A: 15%

Option B: 20%

Option C: 30%

Option D: 45%

Correct Answer: 30% ✔

Option A: one-fourth

Option B: half

Option C: one

Option D: two

Correct Answer: one ✔

Option A: boiler efficiency, turhine efficiecny, generator efficiency

Option B: all the three above plus gas cycle efficiency

Option C: carnot cycle efficiency

Option D: regenerative cycle efficiency

Correct Answer: boiler efficiency, turhine efficiecny, generator efficiency ✔

Option A: heating takes place at bottom and the water supplied at bottom gets converted into the mixture of steam bubbles and hot water which rise to drum

Option B: water is supplied in drum and through down-comers located in atmospheric condition it passes to the water wall and rises to drum in the form of mixture of water and steam

Option C: feed pump is employed to supplement natural circulation in water wall type furnace

Option D: water is converted into steam in one pass without any recirculation

Correct Answer: water is converted into steam in one pass without any recirculation ✔

Option A: heat carried away by flue gases

Option B: heat carried away by ash

Option C: moisture present in fuel and steam formed by combustion of hydrogen in fuel

Option D: radiation

Correct Answer: all of the above ✔

Option A: lancashire boiler

Option B: locomotive boiler

Option C: babcock and wilcox boiler

Option D: cochran boiler

Correct Answer: locomotive boiler ✔

Option A: drooping characteristic

Option B: linear characterisstic

Option C: rising characteristic

Option D: flat characteristic

Correct Answer: rising characteristic ✔

Option A: from a metal wall from one medium to another

Option B: from heating an itermediate material and then heating the air from this material

Option C: by direct mixing ,

Option D: heat is transferred by bleeding some gases from furnace

Correct Answer: from a metal wall from one medium to another ✔

Option A: 100°C

Option B: above dew-point temperature of flue gases

Option C: below dew-point temperature of flue gases

Option D: less than wet bulb temperature of flue gases

Correct Answer: above dew-point temperature of flue gases ✔

Option A: approach temperature should be as low as possible

Option B: handling and maintenance should be easier

Option C: heat transfer area should be optimum

Option D: stack gases should not be cooled to the dew point

Correct Answer: stack gases should not be cooled to the dew point ✔

Option A: create vacuum

Option B: inject chemical solution in feed pump

Option C: pump water, similar to boiler feed pump

Option D: add make up water in the system

Correct Answer: pump water, similar to boiler feed pump ✔

Option A: the draft to be created

Option B: limitation of construction facilities

Option C: control of pollution

Option D: quantity of flue gases to be handled

Correct Answer: control of pollution ✔

Option A: more

Option B: equal

Option C: less

Option D: could be more or less depending on the size of plant

Correct Answer: less ✔

Option A: chimney

Option B: induced draft fan

Option C: both combined A. and B.

Option D: steam jet draught

Correct Answer: steam jet draught ✔

Option A: infinitely long

Option B: around 200 meters

Option C: equal to the height of the hot gas column producing draught

Option D: outside temperature is very low

Correct Answer: equal to the height of the hot gas column producing draught ✔

Option A: induced draft fan

Option B: smoke meter

Option C: chimney

Option D: precipitator

Correct Answer: precipitator ✔

Option A: carbon, hydrogen, nitrogen, sulphur, moisture

Option B: fixed carbon, ash, volatile matter, moisture

Option C: higher calorific value

Option D: lower calorific value

Correct Answer: carbon, hydrogen, nitrogen, sulphur, moisture ✔

Option A: all the fuel burns instantaneously producing high energy release

Option B: fuel burns with less air

Option C: coal bursts into flame without any external ignition source but by itself due to gradual increase in temperature as a result of heat released by combination of oxygen with coal

Option D: explosion in furnace

Correct Answer: coal bursts into flame without any external ignition source but by itself due to gradual increase in temperature as a result of heat released by combination of oxygen with coal ✔

Option A: increases steam pressure

Option B: increases steam flow

Option C: decreases fuel consumption

Option D: decreases steam pressure

Correct Answer: decreases fuel consumption ✔

Option A: has high heating value

Option B: retards electric precipitation

Option C: promotes complete combustion

Option D: has highly corrosive effect

Correct Answer: has highly corrosive effect ✔

Option A: prevent the bulging of flat surfaces

Option B: avoid explosion in furnace

Option C: prevent leakage of hot flue gases

Option D: support furnace freely from top

Correct Answer: prevent the bulging of flat surfaces ✔

Option A: lowest temperature at which oil will flow under set condition

Option B: storage temperature

Option C: temperature at which fuel is pumped through burners

Option D: temperature at which oil is transported

Correct Answer: lowest temperature at which oil will flow under set condition ✔

Option A: the content of sulphur

Option B: the content of ash and heating value

Option C: the proximate analysis

Option D: the exact analysis

Correct Answer: the proximate analysis ✔

Option A: causing clinkering and slagging

Option B: corroding air heaters

Option C: spontaneous combustion during coal storage

Option D: facilitating ash precipitation

Correct Answer: all of the above ✔

Option A: heated sufficiently

Option B: burnt in excess air

Option C: heated to its ignition point

Option D: burnt as powder

Correct Answer: heated to its ignition point ✔

Option A: various chemical constituents, carbon, hydrogen, oxygen etc, plus ash as per-cents by volume

Option B: various chemical constituents, carbon, hydrogen, oxygen, etc, plus ash as per-cents by weight

Option C: fuel constituents as percents by volume of moisture, volatile, fixed carbon and ash

Option D: fuel constituents as percents by weight of moisture, volatile, fixed carbon and ash

Correct Answer: fuel constituents as percents by weight of moisture, volatile, fixed carbon and ash ✔

Option A: same value

Option B: higher value

Option C: lower value

Option D: lower/higher depending on steam flow

Correct Answer: higher value ✔

Option A: temperature, time, and turbulance

Option B: total air, true fuel, and turbulance

Option C: thorough mixing, total air, and temperature

Option D: total air, time, and temperature

Correct Answer: temperature, time, and turbulance ✔

Option A: higher effectiveness of boiler

Option B: high calorific value coal being burnt

Option C: fouling of heat transfer surfaces

Option D: raising of steam temperature

Correct Answer: fouling of heat transfer surfaces ✔

Option A: same

Option B: more

Option C: less

Option D: less or more depending on size of boiler

Correct Answer: more ✔

Option A: reduce hardness and for removal of solids

Option B: increase efficiency-of thermal power plant

Option C: increase *heat transfer rate

Option D: increase steam parameters

Correct Answer: ✔

Option A: tonnes/hr. of steam

Option B: pressure of steam in kg/cm2

Option C: temperature of steam in °C

Option D: all of the above

Correct Answer: all of the above ✔

Option A: 200-400 kcal/kg

Option B: 800-1200 kcal/kg

Option C: 2000-4000 kcal/kg

Option D: 5000-8000 kcal/kg

Correct Answer: 2000-4000 kcal/kg ✔

Option A: dry

Option B: wet

Option C: saturated

Option D: supersaturated

Correct Answer: wet ✔

Option A: remain unaffected

Option B: improve C. worsen

Option C: may improve/worsen depending on size

Option D: unpredictable

Correct Answer: may improve/worsen depending on size ✔

Option A: supply of excess, air

Option B: supply of excess coal

Option C: burning CO and unburnts in upper zone of furnace by supplying more air

Option D: fuel bed firing

Correct Answer: burning CO and unburnts in upper zone of furnace by supplying more air ✔

Option A: cavitation of .boiler feed pumps

Option B: corrosion caused by oxygen

Option C: heat transfer coefficient

Option D: pH value of water

Correct Answer: corrosion caused by oxygen ✔

Option A: increases

Option B: decreases

Option C: remains unaffected

Option D: first increases and then decreases

Correct Answer: decreases ✔

Option A: increases

Option B: decreases

Option C: remains constant

Option D: may increase or decrease depending upon the method of storage

Correct Answer: decreases ✔

Option A: very low pressure

Option B: atmospheric pressures

Option C: medium pressures

Option D: very high pressures

Correct Answer: very high pressures ✔

Option A: more heating surface

Option B: less heating surface

Option C: equal heating surface

Option D: heating surface depends on other parameters

Correct Answer: more heating surface ✔

Option A: increases

Option B: decreases

Option C: remains unchanged

Option D: increases/decreases depending on steam temperature requirements

Correct Answer: decreases ✔

Option A: corrosion

Option B: scale

Option C: carryover

Option D: embrittlement

Correct Answer: all of the above ✔

Option A: regulate flow of boiler water

Option B: check level of water in boiler drum

Option C: recirculate unwanted feed water

Option D: allow high pressure feed water to flow to drum and not allow reverse flow to take place

Correct Answer: allow high pressure feed water to flow to drum and not allow reverse flow to take place ✔

Option A: convection

Option B: radiation

Option C: conduction

Option D: radiation and conducton

Correct Answer: radiation ✔

Option A: 1 kg/cm

Option B: 6 kg/cm

Option C: 17 kg/cm2

Option D: 100 kg/cm2

Correct Answer: 17 kg/cm2 ✔

Option A: increases

Option B: decreases

Option C: remains unaffected

Option D: first increases and then decreases

Correct Answer: decreases ✔

Option A: increases

Option B: decreases

Option C: remains unaffected

Option D: first increases and then decreases

Correct Answer: decreases ✔

Option A: 100 kg/cm2 and 540°C

Option B: 1 kg/cm2 and 100°C

Option C: 218 kg/cm2 abs and 373°C

Option D: 218 kg/cm2 abs and 540°C

Correct Answer: 218 kg/cm2 abs and 373°C ✔

Option A: unburnt carbon in ash

Option B: incomplete combustion

Option C: ash content

Option D: flue gases

Correct Answer: flue gases ✔

Option A: induced draft fan and chimney

Option B: induced draft fan and forced draft fan

Option C: forced draft fan and chimney

Option D: any one of the above

Correct Answer: induced draft fan and forced draft fan ✔

Option A: kg of steam produced

Option B: steam pressure produced

Option C: kg of fuel fired

Option D: kg of steam produced per kg of fuel fifed

Correct Answer: kg of steam produced ✔

Option A: better burning

Option B: more calorific value

Option C: less radiation loss

Option D: medium sized units

Correct Answer: better burning ✔

Option A: smoky chimney exit

Option B: excess air in flue gases

Option C: measuring carbon mono-oxide in flue gases

Option D: measuring temperature of flue gases at exit of furnace

Correct Answer: measuring carbon mono-oxide in flue gases ✔

Option A: (1- moisture content)

Option B: (1 + moisture content)

Option C: 1 + moisture content

Option D: 1 – moisture content

Correct Answer: (1- moisture content) ✔

Option A: provide air around burners for obtaining optimum combustion

Option B: transport and dry the coal

Option C: cool the scanners

Option D: supply air for ignitors

Correct Answer: convert CO (formed in lower zone of furnace) into C02 at higher zone ✔

Option A: various chemical constituents, carbon, hydrogen, oxygen etc, plus ash as per-cents by volume

Option B: various chemical constituents, carbon, hydrogen, oxygen, etc, plus ash as per-cents by weight

Option C: fuel constituents as percents by volume of moisture, volatile, fixed carbon and ash

Option D: fuel constituents as percents by weight of moisture, volatile, fixed carbon and ash

Correct Answer: various chemical constituents, carbon, hydrogen, oxygen, etc, plus ash as per-cents by weight ✔

Option A: form lumps or masses of coke

Option B: burn freely

Option C: show little or no fusing action

Option D: burn completely

Correct Answer: form lumps or masses of coke ✔

Option A: provide air around burners for obtaining optimum combustion

Option B: transport and dry the coal

Option C: convert CO (formed in lower zone of furnace) into C02 at higher zone

Option D: air delivered by induced draft fan

Correct Answer: provide air around burners for obtaining optimum combustion ✔

Option A: heating the oil in the settling tanks

Option B: cooling the oil in the settling tanks

Option C: burning the oil

Option D: suspension

Correct Answer: heating the oil in the settling tanks ✔

Option A: keep the burner tips cool

Option B: aid in proper combustion

Option C: cause sputtering, possibly extinguish¬ing flame

Option D: clean the nozzles

Correct Answer: cause sputtering, possibly extinguish¬ing flame ✔

Option A: provide air around burners for obtaining optimum combustion

Option B: transport and dry the coal

Option C: convert CO (formed in lower zone of furnace) into C02 at higher zone

Option D: air-delivered by forced draft fan

Correct Answer: transport and dry the coal ✔

Option A: 21%

Option B: 23%

Option C: 30%

Option D: 40%

Correct Answer: 21% ✔

Option A: increase thermal efficiency of boiler

Option B: economise on fuel

Option C: extract heat from the exhaust flue gases

Option D: increase flue gas temperature

Correct Answer: increase thermal efficiency of boiler ✔

Option A: correct fuel air ratio

Option B: proper ignition temperature

Option C: 02 to support combustion

Option D: all the three above

Correct Answer: all the three above ✔

Option A: Higher calorific value at constant volume

Option B: Lower calorific value at constant volume ,

Option C: Higher calorific value at constant pressure

Option D: Lower calorific value at constant pressure

Correct Answer: Higher calorific value at constant volume ✔

Option A: carbon, hydrogen, nitrogen, sulphur, moisture

Option B: fixed carbon, ash, volatile matter, moisture

Option C: higher calorific value

Option D: lower calorific value

Correct Answer: fixed carbon, ash, volatile matter, moisture ✔

Option A: entropy

Option B: enthaply

Option C: pressure

Option D: temperature

Correct Answer: temperature ✔

Option A: desirable

Option B: economical

Option C: essential

Option D: optional

Correct Answer: economical ✔

Option A: boiler drum

Option B: superheater tubes

Option C: economiser

Option D: a separate coil

Correct Answer: a separate coil ✔

Option A: higher value

Option B: lower value

Option C: same value

Option D: any value

Correct Answer: lower value ✔

Option A: more

Option B: less

Option C: equal

Option D: may be more or less depending on capacity of reheater

Correct Answer: less ✔

Option A: from a metal wall from one medium to another

Option B: from heating an intermediateanaterial and then heating the air from this material

Option C: by direct mixing

Option D: heat is transferred by bleeding some gas from furnace

Correct Answer: from heating an intermediateanaterial and then heating the air from this material ✔

Option A: water

Option B: dry steam

Option C: wet steam

Option D: super heated steam

Correct Answer: super heated steam ✔

Option A: 2 cm

Option B: 6 Cm ,

Option C: 8 cm

Option D: 12 cm

Correct Answer: 6 Cm , ✔

Option A: drooping characteristic

Option B: lihear characterisstic

Option C: rising characteristic

Option D: flat characteristic

Correct Answer: drooping characteristic ✔

Option A: longitudinally

Option B: circumferentially

Option C: on dished end

Option D: anywhere

Correct Answer: circumferentially ✔

Option A: mean diameter and thickness

Option B: inside diameter and thickness

Option C: outside diameter and thickness

Option D: outside diameter and inside diameter

Correct Answer: outside diameter and thickness ✔

Option A: prevent flat surfaces under pressure from tearing apart

Option B: take care of failure in shear

Option C: take care of failure in compression

Option D: provide support for boiler

Correct Answer: prevent flat surfaces under pressure from tearing apart ✔

Option A: vertical fire tube type

Option B: horizontal fire tube type

Option C: horizontal water tube type

Option D: vertical water tube type

Correct Answer: forced circulation type ✔

Option A: pulverised fuel fired boiler

Option B: cochran boiler

Option C: lancashire boiler

Option D: babcock and wilcox boiler

Correct Answer: lancashire boiler ✔

Option A: can be raised rapidly

Option B: is raisd at slower rate

Option C: is raised at same rate

Option D: could be raised at fast/slow rate depending on design

Correct Answer: can be raised rapidly ✔

Option A: heating takes place at bottom and the water supplied at bottom gets converted into the mixture of stdam bubbles and hot water which rise to durm

Option B: water is supplied in drum and through downcomers” located in atmospheric conditon it passes to the water wall and rises to durm in the from of mixture of water and steam

Option C: feed pump is employed to supplement natural circulation in water wall type furnace

Option D: water is converted into steam in one pass without any recirculation

Correct Answer: water is supplied in drum and through downcomers” located in atmospheric conditon it passes to the water wall and rises to durm in the from of mixture of water and steam ✔

Option A: heating takes place at bottom and the water supplied at bottom gets converted into the mixture of steam bubbles and hot water which rise to drum

Option B: water is supplied in drum and through down-comers located in atmospheric condition it passes to the water wall and rises to drum in the form of mixture of water and steam

Option C: feed pump is employed to supplement natural circulation in water wall type furnace

Option D: water is converted into steam in one pass without any recirculation

Correct Answer: feed pump is employed to supplement natural circulation in water wall type furnace ✔

Option A: bismuth

Option B: copper

Option C: aluminium

Option D: nickel

Correct Answer: bismuth ✔

Option A: former generates steam at high pressure

Option B: former occupies less space for same power

Option C: rate of steam flow is more in former case

Option D: former is used for high installed capacity

Correct Answer: chances of explosion are less in former case ✔

Option A: avoid excessive build up of pressure

Option B: avoid explosion

Option C: extinguish fire if water level in the boiler falls below alarming limit

Option D: control steam dome

Correct Answer: extinguish fire if water level in the boiler falls below alarming limit ✔

Option A: 20%

Option B: 40%

Option C: 50%

Option D: 75%

Correct Answer: 90% ✔

Option A: boiler effectiveness

Option B: boiler evaporative capacity

Option C: factor of evaporation

Option D: equivalent evaporation

Correct Answer: boiler efficiency ✔

Option A: steam evaporation rate per kg of fuel fired

Option B: work done in evaporating 1 kg of steam per hour from and at 100°C into dry saturated steam

Option C: the evaporation of 15.65 kg of water per hour from and at 100°C into dry saturated steam

Option D: work done by 1 kg of steam at saturation condition

Correct Answer: the evaporation of 15.65 kg of water per hour from and at 100°C into dry saturated steam ✔

Option A: in the drum

Option B: in the fire tubes

Option C: above steam dome

Option D: over the combustion chamber

Correct Answer: over the combustion chamber ✔

Option A: one

Option B: two

Option C: one steam drum and one water drum

Option D: no drum

Correct Answer: no drum ✔

Option A: throttling calorimeter

Option B: separating calorimeter

Option C: combined separating and throttling calorimeter

Option D: bucket calorimeter

Correct Answer: throttling calorimeter ✔

Option A: former is fire tube type and latter is water tube type boiler

Option B: former is water tube type and latter is fire tube type

Option C: former contains one fire tube and latter contains two fire tubes

Option D: none/of the above

Correct Answer: former contains one fire tube and latter contains two fire tubes ✔

Option A: horizontal straight line

Option B: vertical straight line

Option C: straight inclined line

Option D: curved line

Correct Answer: vertical straight line ✔