Free Mechanical Engineering MCQs Mock Test Online with Answers

Q1 : A ship whose hull length is 100 m is to travel at 10 m/sec. For dynamic similarity, at what velocity should a 1:25 model be towed through water ?

A: 10 m/sec B: 25 m/sec C: 2 m/sec D: 50 m/sec

Q2 : 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

Q3 : 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

Q4 : Which of the following substance will have same percentage in both proximate and ultimate analysis___________________?

A: ash B: volatile matter C: moisture D: . hydrogen

Q5 : 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

Q6 : The continuity equation is connected with__________________?

A: viscous/unviscous fluids B: compressibility of fluids C: conservation of mass D: steady/unsteady flow

Q7 : The number of flue tubes in Lancashire boiler is_________________?

A: zero B: one C: two D: four

Q8 : 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

Q9 : 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

Q10 : While steam expands in turbines, theoretically the entropy________________?

A: remains constant B: increases C: decreases D: behaves unpredictably

Q11 : The capacity of induced draft fan compared to forced draft fan in a boiler is__________________? 0 A. same

A: same B: more C: less D: less or more depending on size of boiler

Q12 : Gusset stays in a boiler are provided to____________________?

A: prevent the bulging of flat surfaces B: avoid explosion in furnace C: prevent leakage of hot flue gases D: . support furnace freely from top

Q13 : 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

Q14 : A boiler in India should conform to safety regulations of__________________?

A: DIN B: BS C: ASTM D: IBR

Q15 : Heating of dry steam above saturation temperature is known as_____________________?

A: enthalpy B: superheating C: supersaturation D: latent heat

Q16 : Mechanical equivalent of heat for 1 kcal or Joule’s equivalent is equal to_________________?

A: 421 kgm B: 421 kgm C: 539 kgm D: 102 kgm

Q17 : Water boils when its vapour pressure ___________________?

A: equals that of the surroundings B: equals 760 mm of mercury C: equals to atmospheric pressure D: equals the pressure of water in the container

Q18 : Which of the following solid fuel has high caloric value : ___________?

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

Q19 : An object having 10 kg mass weighs 9.81kg on a spring balance. The value of ‘g’ at this place is _________________?

A: 10m/sec2 B: 9.81 m/sec2 C: 10.2/m sec D: 9.75 m/sec2

Q20 : The speed of sound in a ideal gas varies directly as its__________________?

A: pressure B: temperature C: density D: absolute temperature

Q21 : Evaporative capacity of boiler is expressed as____________________?

A: kg of steam produced B: steam pressure produced C: kg of fuel fired D: kg of steam produced per kg of fuel fifed

Q22 : The diameters of fire tubes and superheaer tubes in locomotive boiler are_________________?

A: 47.5 mm, 130 mm B: 32.5 mm, 180 mm C: 65.5 mm, 210 mm D: 24.5 mm, 65 mm

Q23 : The fire tubes in, a Coarran and Scotish marine boiler are_________________?

A: horizontal B: vertical C: . inclined D: both horizontal and vertical

Q24 : 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

Q25 : At very low temperature, the melting and boiling temperatures become equal. This temperature is____________________?

A: 373°K B: 273.16°K C: 303°K D: 0°K.

Q26 : 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

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 : A safety valve in a locomotive starts leaking. The leaking medium will be_________________?

A: water B: dry steam C: wet steam D: super heated steam

Q29 : Center of pressure on an inclined plane is___________________?

A: at the centroid B: above the centroid C: below the centroid D: at metacentre

Q30 : The evaporation of 15.653 kg of water per hour from and at 100°C is called_________________?

A: evaporative capacity B: factor of evaporation C: equivalent evaporation D: one boiler h.p.

Q31 : Pick up the correct statement as regards Cornish boiler and Lancashire boiler _______________?

A: cornish is fire tube and lancashire is water tube B: cornish is water tube and lancashire is fire tube C: cornish has two fire tubes and lancashire has one D: lancashire has two fire tubes and cornish has one

Q32 : Bernoulli equation deals with the law of conservation of__________________?

A: mass B: momentum C: energy D: work

Q33 : The balanced draft furnace is one using _________________________?

A: induced draft fan and chimney B: induced draft fan and forced draft fan C: forced draft fan and chimney D: any one of the above

Q34 : 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

Q35 : 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

Q36 : Hydrometer is used to determine____________________?

A: specific gravity of liquids B: specific gravity of solids C: specific gravity of gases D: relative humidity

Q37 : Specific weight of sea water is more that of pure water because it contains_________________?

A: dissolved air B: dissolved salt C: suspended matter D: all of the above

Q38 : The steam temperature with increase in load in case of a boiler fitted with radiation super heater________________?

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

Q39 : The latent heat of steam with increase of pressure__________________?

A: remains same B: increases C: decreases D: behaves unpredictably

Q40 : 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

Q41 : At which pressure the properties of water and steam become identical_________________?

A: 0.1 kg/cm2 B: 1 kg/cm2 C: 100 kg/cm2 D: 225.6 kg/cm2

Q42 : 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: unpredictable

Q43 : The total pressure force on a plane area is equal to the area multiplied by the intensity of pressure at the centriod, if___________________?

A: the area is horizontal B: the area is vertical C: the area is inclined D: all of the above

Q44 : Which of the following is a fire tube boiler________________?

A: locomotive boiler B: Babcock and Wilcox boiler C: Stirling boiler. D: all of the above

Q45 : 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

Q46 : For manometer, a better liquid combination is one having ___________________?

A: higher surface tension B: lower surface tension C: surface tension is no criterion D: high density and viscosity

Q47 : For burning 1 kg of carbon to CO as per chemically correct combusiton, amount of air required is___________________?

A: 1 kg B: 4/3kg C: 8/3kg D: 16/3 kg

Q48 : 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

Q49 : The average calorific value of wood is about : __________?

A: 33500 kj/kg B: 25000 kj/kg C: 23000 kj/kg D: 19700 kj/kg

Q50 : The bulk modulus of elasticity___________________?

A: has the dimensions of 1/pressure B: increases with pressure C: is large when fluid is more compressible D: is independent of pressure and viscosity

Q51 : Ball valves are commonly used to_________?

A: throttle flow B: check flow C: change flow direction D: start/stop flow

Q52 : The difference of pressure between the inside and outside of a liquid drop is _______________?

A: p = Txr B: p = T/r C: p = T/2r D: p = 2T/r

Q53 : Gradually varied flow is__________________?

A: steady uniform B: non-steady non-uniform C: non-steady uniform D: steady non-uniform

Q54 : Secondary air is the used to_________________?

A: provide air around burners for obtaining optimum combustion B: transport and dry the coal C: convert CO (formed in lower zone of furnace) into C02 at higher zone D: air delivered by induced draft fan

Q55 : The ratio of absolute viscosity to mass density is known as_________________?

A: specific viscosity B: viscosity index C: kinematic viscosity D: coefficient of viscosity

Q56 : The hydraulic turbines are also known as : ___________?

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

Q57 : For very great pressures, viscosity of moss gases and liquids__________________?

A: remains same B: increases C: decreases D: shows erratic behavior

Q58 : According to Bernoulli’s equation for steady ideal fluid flow____________________?

A: principle of conservation of mass holds B: velocity and pressure are inversely proportional C: total energy is constant throughout D: the energy is constant along a stream-line but may vary across streamlines

Q59 : 100% efficiency of a thermal cycle cannot be achieved because of __________________?

A: frictional losses B: it is not possible to achieve 0°K temperature C: leakage D: non-availability of ideal substance

Q60 : If a steam sample is nearly in dry condition, then its dryness fraction can be most accurately determined by___________________?

A: throttling calorimeter B: separating calorimeter C: combined separating and throttling calorimeter D: bucket calorimeter

Q61 : Pulverized fuel is used for___________________?

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

Q62 : 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

Q63 : 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

Q64 : The number of drums in Benson steam generator is_________________?

A: one B: two C: one steam drum and one water drum D: no drum

Q65 : The safety valve on boiler drum compared to safety valve on super heater is set at ________________?

A: same value B: higher value C: lower value D: lower/higher depending on steam flow

Q66 : 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

Q67 : 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

Q68 : According to the principle of buoyancy a body totally or partially immersed in a fluid will be lifted up by a force equal to_________________?

A: the weight of the body B: more than the weight of the body C: less than the weight of the body D: weight of the fluid displaced by the body

Q69 : It is required to produce large amount of steam at low pressure. Which boiler should be used ?

A: pulverised fuel fired boiler B: cochran boiler C: lancashire boiler D: lancashire boiler

Q70 : The part of the coupling that actually transmits power and rotation from one shaft to the other shaft is_________?

A: gap B: hub C: key D: driver

Q71 : The density of water is 1000 kg/m3 at__________________?

A: 0°C B: 0°K C: 4°C D. 20°C D: all temperature

Q72 : The ratio of heat utilised to produce steam and the heat liberated in furnace is known as___________________?

A: boiler effectiveness B: boiler evaporative capacity C: factor of evaporation D: . boiler efficiency

Q73 : 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

Q74 : Feed water conditioning in thermal power plants in done to__________________?

A: reduce hardness and for removal of solids B: increase efficiency-of thermal power plant C: increase *heat transfer rate D: increase steam parameters

Q75 : 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

Q76 : Locomotive type’ boiler is__________________?

A: horizontal multitubular water tube boiler B: water wall enclosed furnace type C: vertical tubular fire tube type D: horizontal multi-tubular fire tube type

Q77 : The behaviour of coal in a furnace is determained by_______________________?

A: the content of sulphur B: the content of ash and heating value C: the proximate analysis D: the exact analysis

Q78 : The equivalent evaporation of a boiler is a measure to compare _________________?

A: the given boiler with the model B: the two different boilers of the same make C: two different makes of boilers operat¬ing under the same operating conditions D: any type of boilers operating under any conditions

Q79 : 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

Q80 : Choose the wrong statement?

A: Viscosity of a fluid is that property which determines the amount of its resistance to a shearing force B: Viscosity is due primarily to interaction between fluid molecules C: Viscosity of liquids decreases with in-crease in temperature D: Viscosity of liquids is appreciably affected by change in pressure

Q81 : A model of torpedo is tested in a towing tank at a velocity of 25 m/sec. The prototype is expected to attain a velocity of 5 m/sec. What model scale has been used ?

A: 1 : 5 B: 1 : 2.5 C: 1 :25 D: 1:V5″

Q82 : The temperature of flue gases at air heater outlet should be__________________?

A: 100°C B: above dew-point temperature of flue gases C: below dew-point temperature of flue gases D: less than wet bulb temperature of flue gases

Q83 : The property of a fluid which enables it to resist tensile stress is known as___________________?

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

Q84 : The vapour pressure over the concave surface is______________________?

A: less man the vapour pressure over the plane surface B: equal to the vapour pressure over the plane surface C: greater than the vapour pressure over the plane surface D: none of the above

Q85 : Falling drops of water become spheres due to the property of ____________________?

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

Q86 : Expanding steam to a very low pressure (high vacuum) in steam engines is _________________?

A: desirable B: economical C: optional D: uneconomical

Q87 : During the opening of a valve in a pipe line, the flow is_________________?

A: steady B: unsteady C: uniform D: free vortex type

Q88 : One kg of steam sample contains 0.8 kg dry steam; it’s dryness fraction is__________________?

A: 0.2 B: 0.8 C: 1.0 D: 0.6

Q89 : Hard coke is produced by carborisation of coal at_______________?

A: atmospheric temperature B: 500-600°C C: 70O-850°C D: 95O-1100°C

Q90 : Units of surface tension are____________________?

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

Q91 : 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

Q92 : Sublimation region is the region where__________________?

A: solid and vapour phases are in equi-librium B: solid and liquid phases are in equilibrium C: liquid and vapour phases are in equilibrium D: solid, liquid and vapour phases are in equilibrium

Q93 : 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

Q94 : Hard coke is used in________________?

A: cement industry B: thermal power plant C: blast furnace D: domestic use

Q95 : Density of water is maximum at__________________?

A: 0°C B: 0°K C: 4°C D: 4°C

Q96 : 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

Q97 : In forced recirculation 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

Q98 : Pressure of the order of 10″‘ torr can be measured by__________________?

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

Q99 : Mach number is significant in_____________________?

A: supersonics, as with projectiles and jet propulsion B: full immersion or completely enclosed flow, as with pipes, aircraft wings, nozzles etc. C: simultaneous motion through two fluids where there is a surface of dis-continuity, gravity force, and wave making effects, as with ship’s hulls D: all of fhe above

Q100 : The centre of gravity of the volume of the liquid displaced by an immersed body is called ___________________?

A: centre of gravity B: centre of pressure C: metacentre D: centre of buoyancy

Free Mechanical Engineering MCQs Mock Test Online with Answers

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