SSC JE MECHANICAL PAPER

1 Define pure substance ?

  • ASubstance which is available in the purest form in nature
  • BSubstance with non-uniform composition
  • CA single substance without any mixture
  • DSubstance with fixed chemical composition throughout

2 The specific gravity of water at standard atmospheric conditions is ?

  • A1
  • Bgreater than 1
  • C0
  • Dless than 0

3 Which of the following statements is more relevant?

  • AIn the Eulerian method, control volume approach is not used.
  • BIn the Lagrangian approach, a fluid particle of fixed mass is considered.
  • CIn kinematics of fluid flow, pressure is a vector field.
  • DFluid kinematics deals with the action of the forces in producing or changing motion of fluid.

 4 In a triple fluid vapour absorption refrigeration system, hydrogen gas is used to ?

  • Aimprove system performance
  • Bcirculate the refrigerant
  • Creduce partial pressure of refrigerant in evaporator
  • Dprovide vapour seal

5 In the context of aircraft refrigeration cycle, what is temperature of air at the exit

of cooling turbine in the absence of moisture condensation?

  • ADry air temperature (DAT)
  • BSuper-saturated temperature
  • CDry air rated temperature (DART)
  • DSaturated temperature

6 Which of the following statements is INCORRECT in the context of static fluid pressure?

  • AIt exerts force normal to the walls of the container.
  • BIt is independent of shape or area of the container.
  • CIt is directly proportional to depth of fluid.
  • DAt any particular depth. it changes with direction.

7 The fourth stage of the compression ignition process is ?

  • Aignition delay period
  • Bburning on the expansion stroke
  • Cperiod of rapid or uncontrolled combustion
  • Dperiod of controlled combustion

8 The refrigerant used in the VCR based refrigerant cycle rejects heat in _____ ?

  • Athe expansion valve
  • Bthe condenser
  • Cthe compressor
  • Dthe evaporator

9 For a Kaplan turbine, the value of speed ratio is _____ ?

  • A0.9
  • B0.5
  • C0.1
  • D2

10 While loading, _______ material undergoes fracture after large amount of deformation ?

  • Aisotropic
  • Bplastic
  • Cbrittle
  • Dductile

11 With respect to the first law of thermodynamics, which of the following statements is the most relevant?

  • AEnergy can be created or destroyed depending on the source of input
  • BEnergy is always conserved
  • CA process that involves transfer of heat energy is irreversible
  • DThere is a natural tendency for any system to degenerate into a disordered state

12 Which of the following helps to increase efficiency of the Rankine cycle?

  • AIncreasing the condenser pressure
  • BIncreasing average temperature at which heat is rejected from the working fluid
  • CIncreasing average temperature at which heat is transferred to the working fluid
  • DOperating at constant temperature

13 In Lancashire boilers, the feed water tube is ?

  • Athin conduit
  • Bopen channel type
  • Csolid
  • Dperforated

14 A fusible plug must be used primarily for safety purposes in which of the following types of boilers ?

  • AOil-fired boiler
  • BHigh-pressure boiler
  • CMarine type boiler
  • DFire-tube boiler

15 Which refrigeration system is driven by low-grade energy?

  • ASteam jet refrigeration
  • BVortex tube systems
  • CGas cycle refrigeration
  • DThermo-electric refrigeration

16 In the context of fluid mechanics, which of the following statements is INCORRECT?

  • AFluid cannot sustain any shear stress when at rest.
  • BFluid continues in motion under the application of shear stress.
  • CFluid does not deform continuously under shear stress.
  • DFluid deforms under very small shear stress.

17 For a static fluid, the increase of pressure at any point inside the fluid, in a vertically downward direction, must be equal to the product of the of the fluid and depth from the free surface ?

  • Aspecific gravity
  • Bdensity
  • Cviscosity
  • Dspecific weight

18 Which of the following is the working fluid in an air-cycle refrigeration system?

  • ASaturated air
  • BCompressed air
  • CAir at high Mach number
  • DGas

19 The benchmark pressure above which a boiler is considered to be a high- pressure boiler is ?

  • A70 bar
  • B60 bar
  • C80 bar
  • D50 bar

20 Which of the following is NOT considered as external loads?

  • AThose arising from fluid pressure
  • BThose arising from service conditions
  • CThose arising from cohesion of material
  • DThose arising from environment

21 ______ is also called spheroidal graphite cast iron ?

  • ADuctile cast iron
  • BMalleable cast iron
  • CWhite cast iron
  • DGray cast iron


For a carburising flame, the flow of ______ is kept higher ?

  • Aargon
  • Bnitrogen
  • Coxygen
  • Dacetylene

23 Under what condition of fluid flow does shear stress NOT exist?

  • ARelative motion exists between fluid layers
  • BFluid in low velocity motion
  • CNegligible viscosity
  • DFluid in high velocity motion

24 Another name for the Bell-Coleman cycle is ?

  • ACarnot cycle
  • Breversed Carnot cycle
  • Cideal reverse Brayton cycle
  • DRankme cycle

25 With respect to reaction turbines, which of the following statements is relevant?

  • AGoverning of reaction turbines is done by altering position of the guide vanes.
  • BFlow rate cannot be controlled by changing the gate openings to the runner.
  • CWater does not flow through a scroll casing.
  • DGuide blades are not connected to the regulating ring.

26 Which of the following is the best example of a thixotropic fluid?

  • AToothpaste
  • BMinerals in suspension
  • CFly ash
  • DPrinting ink

27 What happens when a fluid is at rest?

  • AFrictional force is present
  • BInternal deformation is considerable
  • CFluid element will not be subjected to normal and shear component
  • DThere is no shear component

28 Nominal volume generated by the working piston when travelling from one dead centre to the next is called ?

  • Aclearance volume
  • Bswept volume
  • Ctotal volume
  • Dstroke volume

29 What is the unit of surface tension?

  • AN/m
  • Bkg/m
  • CN
  • DN-m

30. Aircraft engines use ________ for cooling engines ?

  • Aan air-cooled system
  • Ba thermo-syphon cooling system
  • Ca water-cooled system
  • Da forced cooling system

31 Which of the following characteristics of a centrifugal pump is vital?

  • ASlip will decrease with the increase in flow rate
  • BThere will be no whirl component of velocity at the entry to impeller
  • CFluid is considered to have friction while flowing inside the pump
  • DFluid moves normal to the blade

32 What is radiant heating in the context of boilers?

  • AHeating process carried out using radiation effect
  • BSaturated steam is re-circulated and super-heated
  • CHeating done on external walls only by reflecting radiant energy
  • DHeating done on radial tubes

33 An appurtenance whose length generally does NOT exceed three times of its diameter is called ?

  • Aan orifice
  • Ba diffuser
  • Ca non-return valve
  • Da mouthpiece

34. In actual compressors, there is a clearance between the cylinder head and piston to take care of thermal expansion. Identify the correct expression from the given options, where C is the clearance (in mm) and L is the stoke length (in mm) ?

  • AC = (0.005L + 0.5)
  • BC = (0.05L + 0.05)
  • CC = (0.005 + 0.5L)
  • DC = (0.05L + 0.5)

35. The major function of a steam nozzle is to ?

  • Aproduce low viscosity steam
  • Bproduce low velocity jet of steam
  • Cproduce high viscosity steam
  • Dproduce high velocity jet of steam

36. A member of length 200 mm and diameter 25 mm is subjected to a tensile load of 20 kN. The final length of the member is found to be 220 mm. The percentage increase in the length of the member is ?

  • A1%
  • B10%
  • C5%
  • D20%

37. At sea level, under normal conditions, what is the atmospheric pressure?

  • A104.013 kPa
  • B100.043 kPa
  • C101.32 kPa
  • D100.1 kPa

38. How is a high-pressure boiler classified?

  • AWhen it operates, high amount of steam is required for the operation of the cycle
  • BWhen pressure > 50 bar
  • CWhen velocity of water is very low
  • DWhen pressure > 80 bar

39 Which of the following does NOT result in poor performance of boilers?

  • APoor combustion
  • BSurface fouling
  • CPoor water quality
  • DBoiler mounting

40. Which is the most practical fluid for the Rankine cycle?

  • AFuel
  • BAir
  • CAir-fuel mixture
  • DWater

41. What is a dilatant?

  • AIt is a shear thickening fluid.
  • BIt is a fluid with suspended colour pigments.
  • CIt is a fluid that sustains shear stress without ally deformation.
  • DIt is a shear thinning fluid

42. According to Kelvin-Planck’s statement of the second law of thermodynamics, which of the following statements is correct?

  • AIt restricts the thermal efficiency of the heat engine to be lesser than unity.
  • BHeat from a source should be rejected to a high temperature sink.
  • CIt restricts the mechanical efficiency of the heat engine to be lesser than unity.
  • DThermal efficiency of the heat engine will be unity.

43. Fans and blowers of turbo machines ?

  • Aa higher static pressure will prevail
  • Bdeliver air at a higher desired velocity
  • Cdeliver air at a lower mass flow rate
  • Dspiral casing decreases the static pressure

44. What is the function of a fly wheel in IC engines?

  • ATo absorb energy during suction stroke
  • BTo maintain constant speed
  • CTo increase the speed
  • DTo circulate air in the engine for cooling

45. What is a gauge pressure?

  • AIt is pressure measured relative to local atmospheric pressure.
  • BIt is an alternate name of datum pressure.
  • CIt is the same as local atmospheric pressure.
  • DIt is pressure measured relative to a perfect vacuum.

46. Which of the following is an inferential type of flow meter?

  • ARotameter
  • BMagnetic flowmeter
  • CLaser doppler
  • DPurge flow regulator

47. A single stage impulse turbine is also known as ?

  • Ade Laval turbine
  • BCurtis stage turbine
  • Creaction turbine
  • DRateau turbine

48. _______ is the ability of steel to resist stresses that are reversal in nature ?

  • AImpact strength
  • BToughness
  • CHardness
  • DFatigue strength

49. Which of the following statements is correct with reference to perpetual motion machines of the first kind?

  • AIt violates the second law of thermodynamics.
  • BIt produces heat without receiving work input.
  • CIt produces work without receiving heat.
  • DIt is a reversible process.

50. In a flow-measuring device, what is velocity head?

  • AFree rise of liquid column in an open-ended rube
  • BDifference in elevation in the flow direction
  • CVertical distance through which a column of the flowing liquid would rise in an open-ended tube
  • DFree fall of liquid column to attain a given velocity freely

51 For a single cylinder four-stroke oil engine, indicated power is 15 kW. calorific value of fuel is 40000 kJ/kg and fuel consumed is 0.001 kg/s. What will be the indicated thermal efficiency?

  • A62.5%
  • B40%
  • C75%
  • D37.5%

52 Identify the requirement of a good boiler from the following options ?

  • AIt should have more flexible joints.
  • BIt should be light in weight and compact.
  • CIt should be able to produce steam at minimum pressure.
  • DIt should use maximum refractory material.

53 Which of the following statements is INCORRECT with reference to the first law of thermodynamics?

  • AEnergy transfer to a system from its surroundings is a positive quantity
  • BWork done by a system on its surroundings is a positive quantity
  • CHeat interaction is a path function
  • DEnergy transfer is a point function

54 In air standard cycle analysis of IC engines, which of the following statements is correct?

  • ASpecific heats (Cp, Cv) of air vary with temperature.
  • BThere will be a sudden change in chemical equilibrium of the working fluid.
  • CThere are no intake or exhaust processes.
  • DCompression and expansion processes are considered as irreversible

55 When water is about to vapourise it is called?

  • Asub-cooled liquid
  • Bsuper-heated vapour
  • Csaturated vapour
  • Dsaturated liquid

56 Which of the following statements is more relevant in the context of IC engines?

  • ACompression Ignition (CI) engines have lesser weight than SI engines.
  • BCompression ratio for air is in the range of 16 to 20 for SI engines.
  • CWalls of the engine cylinder of SI engines need to be thicker than CI engines.
  • DCompression ratio of the fuel-air mixture is in the range of 6 to 10 in Spark Ignition (SI) engines.

57 The COP (coefficient of performance) of a heat pump is always _______ the COP of a refrigerator ?

  • Aless than or equal to
  • Bgreater than
  • Cless than
  • Dequal to

58 A thermoelectric refrigeration system requires ?

  • Alow voltage AC
  • Blow voltage DC input
  • Chigh voltage AC input
  • Dhigh voltage DC input

59 In a compressor, work is done by ?

  • Athe rotor on the fluid element
  • Ba static component known as impeller
  • Cthe fluid on the rotor
  • Dthe rotating part called stator

60 Under what condition is an inclined manometer used?

  • AWhen u-tube manometer is not available
  • BWhen surface of measurement is inclined
  • CIn high pressure range
  • DIn small pressure changes

61 With respect to head loss of flowing fluid, select the most appropriate statement ?

  • AIncrease in velocity in a flow induces large-scale turbulence
  • BEnergy loss is nor caused by change in velocity
  • CEnergy loss is not due to formation of eddies
  • DPortion of energy loss will not be dissipated as heat

62 Which of the following pairs is NOT an example of a lower pair?

  • APrismatic pair
  • BHelical and cylindrical pair
  • CRevolute pair
  • DRolling ball on a flat surface

63 In the context of the Reynolds transport theorem, which of the following statements is the most appropriate?

  • AIt uses deforming control volume.
  • BIt links system and control volume approaches.
  • CIt uses fixed control volume.
  • DIt does not use control volume approach.

64 If compression is achieved by trapping a refrigerant vapour in an enclosed space and then reducing its volume, then it is called ?

  • Aradial-flow type compressor
  • Bpositive-displacement type compressor
  • Copen type compressor
  • Droto-dynamic type compressor

65 Which of following is NOT a phase in steel?

  • AAustenite
  • BMartensite
  • CLimonite
  • DPearlite

66 Which of the following is NOT a projectile motion?

  • AA bullet fire d from a gun
  • BA stone thrown in any direction
  • CA stone thrown horizontally from a building
  • DA car moving in a straight line

67 In isentropic compression, similar to aircraft refrigeration cycle, what is ram efficiency?

  • ARatio of input to output ram pressure
  • BIt is proportional to mass flow rate
  • CRatio of actual pressure rise to isentropic pressure
  • DRatio of aircraft velocity to sonic velocity

68 Define a machine in terms of its basic objective ?

  • AA device to transform force.
  • BA device to transfer load to source.
  • CA device used to transfer force.
  • DA device to transfer and transform motion and force from source to load.

69 What is the unit of absolute viscosity?

  • ACentipoise
  • BSaybolt universal unit
  • CCentistoke
  • DViscosity index

70 Identify the method by which steel is NOT classified ?

  • AManufacturing method
  • BBased on notch toughness
  • CBased on heat treatment
  • DBased on chemical composition

71 Which of the following is NOT a water-tube boiler?

  • ALaMont boiler
  • BLoeffler boiler
  • CStirling boiler
  • DCornish boiler

72 What is a diffuser?

  • AIt is a type of nozzle
  • BIt is voltage regulator
  • CIt is a type of valve that decreases pressure
  • DIt is a duct which decreases the velocity and increases pressure.

73 What is the flow called if the velocity at a given instant is the same in both magnitude and direction throughout the flow domain?

  • ALaminar flow
  • BSteady flow
  • CTurbulent flow
  • DUniform flow

74 An ideal constant pressure gas turbine works on the ________ cycle ?

  • AStirling
  • BLenoir
  • CBrayton
  • DAtkinson

75 The air fuel ratios used in a compression ignition engine lie in the range of ?

  • A18 to 25
  • B6 to 14
  • C40 to 48
  • D28 to 36

76 Which of the following statements is INCORRECT with respect to water rube boilers?

  • AThey are smaller and lesser in weight
  • BThey are suitable for high steam pressure
  • CThey cannot handle high steam pressure
  • DThey are suitable for large gas flows

77 In the context of moving control volume, which of the following statements is more relevant?

  • AAbsolute velocity of fluid carries fluid a cross the control volume
  • BDifference between absolute and relative velocities of fluid is the velocity across moving control volume
  • CControl volume is considered as a fixed volume in space
  • DRelative velocity of fluid carries fluid across the control surface of moving control volume

78  _______ states that “pressure of a gas mixture is equal to the sum of the pressures each gas would exert if it existed alone at the mixture temperature and volume” ?

  • ADalton’s law of additive pressures
  • BIdeal gas law
  • CHooke’s law
  • DAmagat’s law of additive volumes

79 Lithium bromide is used as an absorbent in _______ ?

  • AElectrolux refrigerators
  • Bsteam jet refrigeration
  • Cvapour absorption refrigeration
  • Dvapou compression refrigeration

80 A continuity equation for two dimensional compressible flow is given by ?

  • ADescription:
  • BDescription:
  • CDescription:
  • DDescription:

81 Which of the following links does NOT undergo any deformation while transmitting motion?

  • AResistance link
  • BFlexible link
  • CRigid link
  • DFluid link

82 Identify the complete and correct statement of the first law of thermodynamics ?

  • AWhen a closed system executes a complete cycle, the sum of heat interactions is equal to the sum of work interactions.
  • BWhen a system undergoes a cycle, the integral of heat is equal to the integral of work.
  • CDifference between the heat and work interactions during a process, which is property of the system.
  • DDuring a process, extracting work without supplying heat, while sacrificing the energy of the system.

83 Which of the following is the characteristic of an isochoric process?

  • AProcess during which no mass is transferred
  • BProcess during which specific volume remains constant
  • CProcess applied to impure substances
  • DProcess during which no heat is transferred

84 Which of the following statements is relevant?

  • AFluid deforms under constant shear stress.
  • BFluid can sustain shear stress when at rest.
  • CFluid deforms continuously under the action of shear stress of even very low magnitude.
  • DFluid does not deform continuously under the action of shear stress.

85 Heat and work both are ?

  • Apoint functions
  • Bpoint and path functions both
  • Cpath functions
  • Dstate functions

86 With respect to the term kinematic viscosity, which of the following statements is more relevant?

  • AIt is an indicator of absolute tendency of the fluid.
  • BDenominator represents physical property of the fluid to maintain its momentum.
  • CDenominator represents propagation of disturbance.
  • DNumerator represents property of the fluid to maintain its momentum.

87 What is a degree-of-freedom in the context of kinematics?

  • AMaximum independent coordinates to describe the configuration
  • BMinimum dependent coordinates to describe the configuration
  • CMinimum independent variables specified to fix the configuration
  • DMaximum dependent variables specified to describe the configuration.

88 Which of the following is NOT a maintenance method of a boiler?

  • AShort-term lay-up
  • BChemical lay-up
  • CDry lay-up
  • DWet lay-up

89 Define strain energy ?

  • AIt refers to change in length of a ball.
  • BIt refers to external work done on a bar.
  • CIt is the potential energy stored by an elastic body when deformed
  • DIt is the energy released by a bar during loading process.

90 According to IBR regulations, boilers exceeding _______ need regular inspection and certification ?

  • Acapacity of more than 15 litres
  • Bcapacity of more than 50 gallons
  • Ccapacity of more than 5 gallons
  • Dcapacity lesser than 5 gallons

91 A centrifugal pump ?

  • Aflow is radially outwards in this pump
  • Bworks on the same principle as that of a Francis turbine
  • Cfluid gain is through constant head
  • Dflow is tangential in this pump

92 Intercooling in multistage compression reduces __  ?

  • Athe volume of free air delivered
  • Bthe work input to compressor
  • Cthe pressure of air at delivery
  • Dthe index of compression

93 Boilers in the Rankine cycle are used ?

  • Ato maintain heat in the process
  • Bto store working fluid
  • Cto allow expansion of steam
  • Dfor steam generation

94 The Rankine cycle is an ideal cycle for vapour power plants because?

  • Ait does not allow isentropic expansion
  • Bit includes reversible processes
  • Cwater enters the pump at unsaturated state
  • Dsteam is not condensed in the condenser

95 The compression ratio of a Compression Ignition (CI) engine is ?

  • A< 5
  • B12 to 22
  • C5 to 10
  • D10 to 15

96 Why do engines need to be cooled?

  • ATo regulate mass transfer
  • BTo improve compression volume
  • CTo reduce ignition temperature
  • DTo avoid pre-ignition and knocking

97 Select the most appropriate definition of a turbine from the following statements ?

  • AIt is a device where mechanical energy from moving parts is transferred to a fluid.
  • BIt is device in which kinetic energy held by a fluid is converted to mechanical energy of a rotating member.
  • CIt is a device where potential energy is transferred to a fluid.
  • DTurbine is a fluid machine.

98 One ton of refrigeration is equal to _______ kW ?

  • A1
  • B3.5
  • C2.5
  • D5

99 The Lagrangian description of fluid field is more computational because ?

  • Avelocity field is a continuous function distribution with position and time
  • Bvariation of velocity is expressed in Cartesian coordinates
  • Cit is required to track movement of a large number of fluid particles with time
  • Dvelocity of the fluid particle is the same as the local velocity

100 What is sonic speed?

  • AIt is the speed at which disturbance propagates through a medium.
  • BIt is the speed of air.
  • CIt is the speed at which disturbance propagates at higher velocity.
  • DIt is the speed at which disturbance propagates through an inelastic medium.



SSC JE 2020 : Mechanical Engineering - Previous Years Solved Papers (2008-19)



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