Free Mechanical Engineering MCQs Mock Test Online with Answers

Q1 : Practical fluids___________________?

A: are viscous B: . possess surface tension C: are compressible D: possess all the above properties

Q2 : Calorific value of coal is of the order of _______________________?

A: 200-400 kcal/kg B: 800-1200 kcal/kg C: 2000-4000 kcal/kg D: 5000-8000 kcal/kg

Q3 : The safety valve at superheater as compared to drum safety valve setting is set at___________________?

A: higher value B: ower value C: same value D: any value

Q4 : For a body floating in a liquid the normal pressure exerted by the liquid acts at ____________________?

A: bottom surface of the body B: e.g. of the body C: metacentre D: all points on the surface of the body

Q5 : Size of boiler tubes is specified by___________________?

A: mean diameter and thickness B: inside diameter and thickness C: outside diameter and thickness D: outside diameter and inside diameter

Q6 : Which type of boiler can meet rapid changes of load____________________?

A: vertical fire tube type B: horizontal fire tube type C: horizontal water tube type D: forced circulation type

Q7 : The pressure of reheat steam after passing through reheater compared to inlet condition is _________________?

A: more B: less C: equal D: . may be more or less depending on capacity of reheater

Q8 : At critical point, i.e. p=225.65 kg/cm2, the latent enthalpy of vaporisation is______________?

A: maximum B: minimum C: zero D: depends on temperature also

Q9 : The depth of the center of pressure on a vertical rectangular gate 8 m wide and 6 m high, when the water surface coincides with the top of the gate, is____________________?

A: 2.4 m B: 3.0 m C: 4.0 m D: ”2.5 m

Q10 : Efficiency of rankine cycle can be increased by_________________?

A: decreasing initial steam pressure and temperature B: increasing exhaust pressure C: decreasing exhaust pressure D: increasing the expansion ratio

Q11 : Total pressure on a lmxlm gate immersed vertically at a depth of 2 m below the free water surface will be_______________?

A: 1000 kg B: 4000 kg C: 2000 kg D: 8000 kg

Q12 : The efficiency of the ideal diesel cycle is ________ than that of Otto cycle, for the same compression ratio

A: Higher B: Lower C: Equal D: None of these

Q13 : Spontaneous combustion is a phenomenon in which____________________?

A: all the fuel burns instantaneously producing high energy release B: fuel burns with less air 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 D: explosion in furnace

Q14 : Falling drops of water become spheres due to the property of ____________________?

A: adhesion B: cohesion C: surface tension D: compressibility

Q15 : The radius of a dished head is taken approximately as______________________?

A: one-fourth B: half C: one D: two

Q16 : Vacuum for reciprocating steam engines compared to steam turbines is__________________?

A: more B: equal C: less D: could be more or less depending on the size of plant

Q17 : Center of pressure compared to e.g. is___________________?

A: above it B: below it C: at same point D: above or below depending on area of body

Q18 : The total pressure on the surface of a vertical sluice gate 2 m x 1 m with its top 2 m surface being 0.5 m below the water level will be ________________?

A: 500 kg B: 1000 kg C: 1500 kg D: 2000 kg

Q19 : Alcohol is used in manometer, because____________________?

A: its vapour pressure is low B: it provides suitable meniscus for the inclined tube C: its density is less D: it provides longer length for a given pressure difference

Q20 : Water tube boilers are those in which________________?

A: flue gases pass through tubes and water around it B: water passes through the tubes and flue gases around it C: work is done during adiabatic expansion D: change in enthalpy

Q21 : Boiler parameters are expressed by ___________________?

A: tonnes/hr. of steam B: pressure of steam in kg/cm2 C: temperature of steam in °C D: all of the above

Q22 : The relative heat absorption for successively added equal areas of boiler convection heating surfaces____________________?

A: increases B: decreases C: remains unaffected D: first increases and then decreases

Q23 : Fire tube boilers are limited to a maximum design working pressure of ____________________?

A: 1 kg/cm B: 6 kg/cm C: 17 kg/cm2 D: 100 kg/cm2

Q24 : Newton’s law of viscosity is a relationship between____________________?

A: shear stress anctthejiate of angular distortion B: shear stress and viscosity C: shear stress, velocity and viscosity D: shear stress, pressure and rate of angular distortion

Q25 : Which of the following boilers is best suited to meet fluctuating demands___________________?

A: babcock and wilcox B: locomotive C: lancashire D: cochran

Q26 : In a throttling process________________?

A: steam temperature remaisn constant B: steam pressure remains constant C: steam enthalpy remains constant D: steam entropy remains constant

Q27 : Alcohol is used in manometers because___________________?

A: it has low vapour pressure B: it is clearly visible C: it has low surface tension D: it can provide longer column due to low density

Q28 : Sulphur content of fuels is very important to the plant operators because it____________________?

A: has high heating value B: retards electric precipitation C: promotes complete combustion D: has highly corrosive effect

Q29 : If no resistance is encountered by displacement, such a substance is known as ___________________?

A: fluid B: water C: gas D: ideal fluid

Q30 : Which of the following are used in diesel engines and oil fired boilers :

A: Paraffin B: Gasoline C: Heavy fuel oils D: Patrol

Q31 : Free surface of a liquid behaves like a sheet and tends to contract to smallest possible area due to the_________________?

A: force of adhesion B: force of cohesion C: force of friction D: force of diffusion

Q32 : Lancashire ‘boiler is a__________________?

A: stationary fire tube boiler B: stationary water tube boiler C: water tube boiler with natural/forced circulation D: mobile fire tube boiler

Q33 : The diameter of fire tubes in Cochran boiler is of the order of___________________?

A: 2 cm B: 6 Cm C: 8 cm D: 12 cm

Q34 : The biggest size of thermal power unit operating in India is ________________?

A: 30 MW B: 60 MW C: 100 MW D: 500 MW

Q35 : With increase in load, radiant super heater has____________________?

A: drooping characteristic B: lihear characterisstic C: rising characteristic D: flat characteristic

Q36 : True one-dimensional flow occurs when_________________?

A: the direction and magnitude of the veiocity at all points are identical B: the velocity of successive fluid par-ticles, at any point, is the same at suc-cessive periods of time C: the magnitude and direction of the velocity do not change from point to point in the fluid D: the fluid particles move in plane or parallel planes and the streamline pat-terns are identical in each plane

Q37 : The stress developed in a material at breaking point in extension is called__________?

A: Breaking stress B: Fracture stress C: Fracture stress D: Fracture stress

Q38 : The flow in which the particles of a fluid attain such velocities that vary from point to point in magnitude and direction as well as from instant to instant, is known as__________________?

A: one dimensional flow B: uniform flow C: steady flow D: turbulent flow

Q39 : The patrol is distilled at a temperature from :

A: 6° to 20° B: 220° to 345° C: 65° to 220° D: 15° to 120°

Q40 : Which of the following solid fuel has high carbon content?

A: Coke B: Coal C: Peat D: None of these

Q41 : Diesel Cycle is also known as : __________?

A: Constant temperature cycle B: Constant Volume cycle C: Constant Pressure Cycle D: All of above

Q42 : The normal stress in a fluid will be constant in all directions at a point only if__________________________?

A: it is incompressible B: it has uniform viscosity C: it has zero viscosity D: it is at rest

Q43 : Which of the following instrument can be used for measuring speed of a submarine moving in deep sea__________________?

A: Venturimeter B: Orifice plate C: hot wire anemometer D: pitot tube

Q44 : Free surface of a liquid tends to contract to the smallest possible area due to force of_______________?

A: surface tension B: viscosity C: friction D: cohesion

Q45 : Ultimate analysis of fuel is determination of percentage of____________________?

A: carbon, hydrogen, nitrogen, sulphur, moisture B: . fixed carbon, ash, volatile matter, moisture C: higher calorific value D: best analysis

Q46 : Which of the following is mostly used used as blast furnace fuel for extracting pig iron from iron ores?

A: Brown coal B: Anthracite coal C: Hard coke D: Woodchar coal

Q47 : Choose the wrong statement ?

A: any weight, floating or immersed in a liquid, is acted upon by a buoyant force B: Buoyant force is equal to the weight of the liquid displaced C: The point through which buoyant force acts, is called the center of buoyancy D: Center of buoyancy is located above the center of gravity of the displaced liquid v

Q48 : A supercritical boiler is one that operates above the pressure and temperature of following values_____________________?

A: 100 kg/cm2 and 540°C B: 1 kg/cm2 and 100°C C: 218 kg/cm2 abs and 373°C D: 100 kg/cm2 abs and 373°C

Q49 : Rotameter is a device used to measure______________?

A: absolute pressure B: velocity of fluid C: flow D: rotation

Q50 : Which of the following solid fuel has high caloric value : ___________?

A: Wood B: Peat C: Bituminous coal D: Anthracite coal

Q51 : Which tool is used to measure gap size in a rough alignment?

A: Inside caliper B: . Dial indicator C: Feeler gage D: Measuring tape

Q52 : In designing air preheater, the important design consideration is that_________________?

A: approach temperature should be as low as possible B: handling and maintenance should be easier C: heat transfer area should be optimum D: heat transfer area should be optimum

Q53 : Density of water is maximum at__________________?

A: 0°C B: 0°K C: 4°C D: 4°C

Q54 : Viscosity of water in comparison to mercury is_________________?

A: higher B: lower C: same D: higher/lower depending on temperature

Q55 : Choose the wrong statement ?

A: The center of buoyancy is located at the center of gravity of the displaced liquid B. For stability of a submerged body, the center of gravity of body must lie directly below the center of buoyancy B: If e.g. and center of buoyancy coincide, the submerged body must lie at neutral equilibrium for all positions C: For stability of floating cylinders or spheres, the e.g. of body must lie below the center of buoyancy D: All floating bodies are stable

Q56 : Pulverized fuel is used for___________________?

A: better burning B: more calorific value C: less radiation loss D: medium sized units

Q57 : The dry saturated steam at very high pressure (150-200 kg/cm2) when throttled to atmosphere will become_______________?

A: wet B: superheated C: remain dry saturated D: none of the above

Q58 : With increase in load, convection superheater has_______________________?

A: drooping characteristic B: linear characterisstic C: rising characteristic D: flat characteristic

Q59 : The specific heat of superheated steam in kcal/kg is generally of the order of___________________?

A: 0.1 B: 0.3 C: 0.5 D: 1.0

Q60 : Incomplete combustion can be best judged by__________________?

A: smoky chimney exit B: excess air in flue gases C: measuring carbon mono-oxide in flue gases D: measuring temperature of flue gases at exit of furnace

Q61 : Fire tube boilers are those in which__________________?

A: flue gases pass through tubes and water around it B: water passes through the tubes and flue gases around it C: forced circulation takes place D: tubes are laid vertically

Q62 : Heating value of fuel used is as on fired basis. If it is reported for dry or moisture free fuel, then latter should be multiplied by the following factor to correct for as fired value ___________________?

A: (1- moisture content) B: (1 + moisture content) C: 1 + moisture content D: 1 – moisture content

Q63 : Caking coals are those which __________________________?

A: . form lumps or masses of coke B: burn freely C: show little or no fusing action D: burn completely

Q64 : The value of the coefficient of compressibility for water at ordinary pressure and temperature in kg/cm is equal to_________________?

A: 1000 B: 2100 C: 2700 D: 21,000

Q65 : The high pressure boiler is oiie producing steam at a pressure more than_________________?

A: atmospheric pressure B: 5 kg/cm2 C: 10 kg/cm2 D: 75-80 kg/cm2

Q66 : The diameter of tubes for natural circulation boiler as compared to controlled circulation boilers is___________________?

A: more B: less C: same D: could be more or less depending on other factors

Q67 : The difference between cornish boiler and lancashire boiler is that_________________?

A: former is fire tube type and latter is water tube type boiler B: former is water tube type and latter is fire tube type C: former contains one fire tube and latter contains two fire tubes D: none/of the above

Q68 : In natural circulation type boiler _______________?

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 B: water is supplied in durm and through down-comers located in atmospheric conditon it passes to the water wall and rises to drum in the form of mixture of water and steam C: feed pump is employed to supplement natural circulation in water wall type furnace D: water is converted into steam in one . pass without any recirculation

Q69 : The hydraulic turbines are also known as : ___________?

A: steam turbines B: water turbines C: combustion turbines D: Gas turbines

Q70 : Sulphur in coal results in___________________?

A: causing clinkering and slagging B: corroding air heaters C: spontaneous combustion during coal storage D: all of the above

Q71 : Overfire burning is the phenomenon of _____________________?

A: supply of excess, air B: supply of excess coal C: burning CO and unburnts in upper zone of furnace by supplying more air D: fuel bed firing

Q72 : A packaged boiler is one in which various parts like firing equipment, fans, feed pumps and automatic controls are________________?

A: supplied by same manufacturer loose and assembled at site B: supplied mounted on a single base C: purchased from several parties and packed together at site D: packaged boiler does not exist

Q73 : The feed check valve is used in order to ______________________?

A: regulate flow of boiler water B: check level of water in boiler drum C: recirculate unwanted feed water D: allow high pressure feed water to flow to drum and not allow reverse flow to take place

Q74 : Working principle of dead weight pressure gauge tester is based on_______________?

A: Pascal’s law B: Dalton’s law of partial pressure C: Newton’s law of viscosity . D: Avogadro’s hypothesis

Q75 : The resultant upward pressure of the fluid on an immersed body due to its tendency to uplift the sub-merged body is called_______________?

A: upthrust B: reaction C: buoyancy D: metacentre

Q76 : The state of vapour under saturation condition is described by_______________?

A: pressure alone B: temperature alone C: pressure and temperature D: pressure and dryness fraction

Q77 : 02 content in atmospheric air on volume basis is___________________?

A: 21% B: 23%% C: 30% D: 70%

Q78 : For a floating body to be in stable equilibrium, its metacentre should be___________________?

A: below the center of gravity B: below the center of buoyancy C: above the center of buoyancy D: above the center of gravity

Q79 : In an experiment to determine dryness fraction of steam, the mass of water separated was 1.2 kg in 15 mts and the mass of steam passed out in same time was 4.8 kg. Dryness fraction is__________________?

A: 40% B: 25% C: 50% D: 80%

Q80 : The buoyancy depends on___________________?

A: mass of liquid displaced B: viscosity of the liquid C: pressure of the liquid displaced D: depth of immersion

Q81 : Piezometer is used to measure_____________________?

A: pressure in pipe, channels etc. B: atmospheric pressure C: very low pressures D: difference of pressure between two points

Q82 : In accelerated circulation type boiler________________?

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 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 C: 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 D: water is fed under high pressure and high velocity

Q83 : Pick up the wrong statement?

A: aluminium in steel results in excessive grain growth B: manganese in steel induces hardness C: nickel and chromium in steel help in raising the elastic limit and improve the resilience and ductility D: tungsten in steels improves magnetic properties and hardenability

Q84 : On Mollier chart, free expansion, or throttling process from high pressure to atmosphere is represented by_______________?

A: horizontal straight line B: vertical straight line C: straight inclined line D: none of the above

Q85 : Bomb calorimeter is used to determine ___________________?

A: Higher calorific value at constant volume B: Lower calorific value at constant volume , C: Higher calorific value at constant pressure D: Lower calorific value at constant pressure

Q86 : Pressure of the order of 10″‘ torr can be measured by__________________?

A: Bourdon tube B: Pirani Gauge C: micro-manometer D: ionisastion gauge

Q87 : A wet vapour can be completely specified by__________________?

A: pressure only B: temperature only C: dryness fraction only D: pressure and dryness fraction

Q88 : The coal requirement per kW hour generation in the thermal power plant is of the order of__________________?

A: 0.1 to 0.2 kg B: 0.2 to 0.4 kg C: 0.6 to 0.8 kg D: 1.0 to 1.5 kg

Q89 : 1 kg.m is equal to_________________?

A: 9.81 Joules B: All Joules C: D: 427 Joules

Q90 : Equivalent evaporation is the amount of water evaporated in a boiler from and at ____________________?

A: 0°C B: 100°C C: saturation temperature at given pressure D: room temperature

Q91 : The overall efficiency of thermal power plant is________________?

A: boiler efficiency, turhine efficiecny, generator efficiency B: all the three above plus gas cycle efficiency C: carnot cycle efficiency D: regenerative cycle efficiency

Q92 : Uniform flow occurs when_____________________?

A: the direction and magnitude of the velocity at all points are identical B: the velocity of successive fluid paiticles, at any point, is the same at successive periods of time C: the magnitude and direction of the velocity do not change from point to point in the fluid D: the fluid particles move in plane or parallel planes and the streamline pat-terns are identical in each pleasure

Q93 : The property of fluid by virtue of which it offers resistance to shear is called________________?

A: surface tension B: adhesion C: cohesion D: viscosity

Q94 : The critical pressure at which latent heat of vaporisation is zero is________________?

A: 225.65 kgf/cm2 B: 273 kgf/cm2 C: 100 kgf/cm2 D: 1 kgf/cm2

Q95 : In forced circulation type boiler__________________?

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 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 C: feed pump is employed to supplement natural circulation in water wall type furnace D: water is converted into steam in one pass without any recirculation

Q96 : In ordetjo obtain superheated steam, a superheater is added in an existing boiler. As as result, furnace vacuum will _________________?

A: remain unaffected B: improve C. worsen C: may improve/worsen depending on size D: unpredictable

Q97 : Select the correct statement?

A: Local atmospheric pressure depends upon elevation of locality only B: Standard atmospheric pressure is the mean local atmospheric pressure a* sea level C: Local atmospheric pressure is always below standard atmospheric pressure D: A barometer reads the difference be-tween local and standard atmospheric pressure

Q98 : Units of surface tension are____________________?

A: energy/unit area B: distance C: both of the above D: it has no units

Q99 : In a recuperative air preheater, the heat is transferred____________________?

A: from a metal wall from one medium to another B: from heating an itermediate material and then heating the air from this material C: by direct mixing , D: heat is transferred by bleeding some gases from furnace

Q100 : The economizer is used in boilers to _______________________?

A: increase thermal efficiency of boiler B: economise on fuel C: extract heat from the exhaust flue gases D: increase flue gas temperature

Free Mechanical Engineering MCQs Mock Test Online with Answers

Time to prove what you know!

LAT Test

GAT Test

Contact Info

Free Mechanical Engineering MCQs Mock Test Online with Answers

Subscribe our Newsletter

LAT Test

GAT Test

Contact Info