SSC JE MECHANICAL 2021 Paper 1

                                                           SSC JE MECHANICAL 2021

1. The density of fluid does not affect the working of  ?

• AA rotameter
• BAn orifice meter
• CA nozzle meter
• DAn electro-magnetic flow meter

2. Uniform flow is the type of flow wherein velocity at any given time ___ with respect to space. ?

• AIncreases
• BDecreases
• CDoes not change
• DChanges

3 .The value of quality or dryness fraction of a substance in saturated liquid-vapour mixture is ?.

• A0
• BBetween 0 and 1
• C2
• D1

4. If there is no change in pressure at any point of the system with time, then the system is said to be in:?

• APhase equilibrium
• BThermal equilibrium
• CChemical equilibrium
• DMechanical equilibrium

5. The maximum temperature in case of internal combustion engines is obtained at ?.

• AStart of the expansion process
• BStart of the compression process
• CEnd of the expansion process
• DEnd of the compression process

6. Those pumps employed for mud related work have ____ type of impeller ?

• AA one-side shrouded
• BAn open
• CA two-side shrouded
• DA double-suction

7. A two-stroke engine consists of __ port(s) ?.

• AOne
• BThree
• CFour
• DTwo

8. A capillary tube is employed in a refrigeration cycle to ?.

• AProduce a cooling effect
• BControl temperature of the refrigerated space
• CReduce pressure of the refrigerant
• DControl flow of the refrigerant

9. The Babcock—Wilcox boiler is classified as a water tube boiler because ?

• AWater passes through the tube and hot gases around
• BIt has a large reservoir of water at the bottom
• CWater heater is mounted on the boiler itself
• DWater passes around the tubes having hot gases

10. The modern francis turbine is a flow turbine ?

• ARadial
• BTangential
• CMixed
• DAxial

11. Which of the following is not an intensive property?

• ATemperature
• BDensity
• CTotal volume
• DPressure

12.    ____ Cannot be classified as inversion(s) of a single-slider crank mechanism ?

• AOscillating cylinder engine
• BCrank and slotted-lever mechanism
• CWhitworth quick-return mechanism
• DElliptical trammel

13. For a refrigerating machine, capacity is expressed as __ ?

• AInside volume of the cabinet
• BGross weight of the machine
• CThe lowest temperature attained
• DRate of heat extraction from the space being cooled

14. The moisture content of steam at the turbine exit of a steam power plant operating on the Rankine cycle can be decreased by ?

• ADecreasing boiler pressure
• BReheating steam
• CIncreasing boiler pressure
• DSuper cooling steam

15.Air cooling is mostly preferred for ?

• AMulti-utility vehicles
• BMotorcycles
• CBuses
• DHeavy trucks

16. In the context of laminar flow, which of the following statements is the most appropriate?

• AFlow is always through small tanks.
• BThere will be an exchange of momentum from fluid particles of one layer to another layer.
• CLaminar flow is observed in high viscous fluids at low velocity.
• DParticles move in a turbulent order.

17.Fusible plug in a steam boiler is placed __ ?.

• AAt the fire grate of the boiler
• BNear the manhole
• CAt the crown of the furnace
• DBelow the water level indicator

18.Compounding of a steam turbine is done to ?

• AReduce the blade friction
• BBalance the rotor
• CReduce the rotor speed
• DConnect the shaft

20. In the Rankine cycle, the fluid which enters the boiler is ?:

• ASteam
• BMercury
• COxygen
• DWater

21.  _____ is not a water tube boiler ?.

• AScotch marine boiler
• BBenson boiler
• CStirling boiler
• DBabcock-Wilcox boiler

22.  ____ is used for pumping water into a boiler ?

• ADuplex pump
• BRotor
• CFeed pump
• DEconomiser

23 Pitot tube measures ____.?

• AGauge pressure
• BDynamic pressure of a moving stream
• CTemperature of moving water
• DPressure difference between two fluids

24.The tendency of material to fracture without appreciable deformation is called _____ ?.

• APlasticity
• BStiffness
• CToughness
• DBrittleness

25.For a steady flow, the values of all fluid properties at any fixed point ?

• ADo not change with time
• BChange with time
• CChange with location
• DDo not change with location

26. The splash system is not used to lubricate ____. ?

• APiston rings
• BTappets
• CCamshafts
• DGear teeth and roller bearings

27.Which of the following assumptions is the most relevant in air-standard cycle analysis?

• ASpecific heat of air changes during the cycle
• BCycle is assumed to be an open cycle
• CWorking fluid is a fixed mass
• DAll the processes within the cycle are irreversible

28.Which of the following is the most widely used fuel in boilers?

• AAnthracite coal
• BWood
• COil
• DPulverized coal

29.The efficiency of an ideal diesel engine does not directly depend on .?

• AThe compression ratio
• BThe isentropic index
• CThe cut-off ratio
• DThe fluid pressure

30. Which of the following is not a part of refrigeration systems?

• ACompressor
• BEvaporator
• CTurbine
• DCondenser

31 .Lancashire boiler has ___ flue tube(s), whereas cornish boiler has__ flue tube(s).?

• A2:3
• B1:2
• C2:1
• D3:2

32. Which of the following is not a unit of pressure?

• AN/m²
• BPa
• CJoule
• DBar

33. Two stroke engines consist of a combined process of ______ in a single stroke.?

• ACompression and expansion
• BSuction and compression
• CSuction and exhaust
• DSuction and expansion

34 .To the context of roto-dynamic machines, which of the following statements is correct?

• ALinear momentum is normal to the stator.
• BThere will be a relative motion between the rotor vanes and the fluid.
• CLinear momentum is the direction normal to the rotor.
• DWhile flowing through the stator, linear momentum changes.

35. If value of dryness fraction is 0, it indicates that working fluid is at ?

• ASaturated liquid
• BCompressed liquid
• CSaturated vapour
• DSuperheated vapour

36. Nozzles used in steam turbines convert _____.?

• AEnthalpy of steam into work
• BEnthalpy of steam into pressure energy
• CPressure energy into work
• DEnthalpy of steam into kinetic energy

37. A power plant that uses a gas turbine followed by a steam turbine for necessary power generation is known as a ______ cycle power plant. ?

• ACombined
• BBottom
• CGeneration
• DTopping

38.Draught is produced in locomotive boilers by which of the following components?

• ASteam jet
• BLocomotion
• CCentrifugal fan
• DChimney

39 What is ductility in steel?

• AAmount of strain a material can withstand before fracture
• BStress at yield stress
• CRatio of ultimate stress to yield stress
• DRatio of change in length to original length

40.When hot air exhausting from the turbine is used to heat up the compressor exit flow, it is known as ?

• ARe-evaporating
• BIntercooling
• CRegeneration
• DIntercooling

41. If the specific gravity of oil Is 0.7, then its density in kg/m³ will be ____ ?.

• A7000
• B700
• C70
• D7

 42. Chaplets are used in ____ ?.

• AExtrusion
• BCasting
• CWelding
• DForging

43.A ball and socket joint is an example of a ____ pair ?

• ASpherical
• BScrew
• CRolling
• DTurning

44. Fusible plug is generally made up of an alloy (gunmetal) which consists of copper, tin and ___.?

• AAluminium
• BZinc
• CCast iron
• DManganese

45. In flow measurement, a venturi meter is preferred over an orifice plate because _____ ?.

• ASpace is limited
• BIt is cheaper
• CEnergy or head loss is less
• DPressure drop is more

46 .An oil of specific gravity 0.7 is stored in a closed tank up to a height of 2 m. What will be the gauge pressure at the bottom of the tank?

• A0.14 MPa
• B1.4 MPa
• C0.014 MPa
• D14 MPa

47 .Benson boilers have ____ water drum(s). ?

• AThree
• Btwo
• COne
• DZero

48 .A dead weight tester is used widely for ?

• AAccurate measurement of loads
• BProducing high pressures
• CTesting magnitude of the given weight
• DCalibration of other equipment

49 .In a pelton wheel, jet ratio values are ____.?

• AMore than 6
• BLess than or equal to 2
• CBetween 2 and 5
• DLess than 1

50. Variation of stress with strain rate for a newtonian fluid is ____ ?.

• AHyperbolic
• BLinear
• CParabolic
• DElliptical

51.Which of the following is not a property of an ideal fluid.?

• AFlow is irrotational
• BIt is incompressible
• CHas no viscosity
• DIt has viscosity

52. Define thermodynamics ?

• AIt is a science which deals with the relation between work and properties of systems.
• BIt is a science which deals with the relation between heat, work and properties of systems.
• CIt is a science which deals with work done.
• DIt deals with dynamics under thermal conditions.

 53. If the relationship between shear stress of a fluid is not linear to the velocity gradient, then the fluid is ?

• AAn ideal fluid
• BA newtonian fluid
• CA non-newtonian fluid
• DA compressible fluid

54. The function of a carburetor in internal combustion engines is ?

• ATo control air alone
• BTo cool exhaust gases
• CTo maintain air-fuel ratio
• DTo control fuel alone

55. Viscous forces are not available in _____.?

• ATransitional flow
• BLaminar flow
• CRotational flow
• DIrrotational flow

56. Impact load is an example of ?

• ADynamic load
• BUniform load
• CStatic load
• DFatigue load

57. In which of the following types of compressors are the motor and compressor enclosed in the same housing?

• AAxial flow type compressor
• BHermetic compressor
• COpen-type compressor
• DReciprocating compressor

58. Coated electrodes are used in _____ ?.

• AGas tungsten arc welding
• BTungsten inert gas welding
• CShielded metal arc welding
• DSubmerged are welding

59. Foaming is a phenomenon that occurs in the boiler feed water due to ?

• ASodium chloride
• BNitrogen peroxide
• COil
• DManganese

60. Which of the following is not a non-ferrous alloy?

• AAluminium
• BMagnesium
• CStainless steel
• DTitanium

61. Any change in entropy could be achieved by changing _____ ?.

• AVelocity
• BHeat
• CAcceleration
• DMass

62. Define free-body diagram ?.

• AA figure that represents external forces acting on a body.
• BA free-hand sketch representing a body.
• CA diagram that only represents moments acting on a body.
• DA diagram that represents internal forces acting on a body.

63. If the gauge pressure of air in a cylinder is 250 kpa, then it’s absolute pressure will be _____ ?

• A50 kPa
• B150 kPa
• C450 kPa
• D350 kPa

64. What is kinematic viscosity?

• AIt is the rate of change of shear stress.
• BIt is the ratio of dynamic viscosity to mass density.
• CIt is the ratio of dynamic viscosity to relative density.
• DIt is the rate of change of shear strain.

65. Within a refrigeration system, the expansion valve is incorporated between the _____ ?.

• ACompressor and condenser
• BCondenser and evaporator
• CSuper-heater and sub-cooler
• DEvaporator and compressor

66. Which of the following statements is more relevant in the context?

• AMetacentric height is positive in case of unstable equilibrium.
• BIf center of gravity is below the centre of buoyancy, the body is unstable.
• CWhen the body is fully submerged, shape of the displaced fluid alters when the body is tilted.
• DThe centre of buoyancy in a submerged body remains unchanged.

67.Pressure measurement is done by __, by measuring heat loss from a heated wire ?

• AA pirani gauge
• BAn orifice meter
• CA manometer
• DA barometer

68 The device which transfers energy from the _____to the _____ is known as hydraulic turbine ?

• AFluid: Rotor
• BAtmosphere: Fluid
• CRotor: fluid
• DFluid: atmosphere

69 .If a submerged body, displaced from its equilibrium position, returns to its original position, it is called _____ ?.

• AStable equilibrium
• BThermal equilibrium
• CUnstable equilibrium
• DNeutral equilibrium

70 .Aqua ammonia solution used in a vapour absorption refrigeration system is a solution of ammonia in _____ ?.

• AH₂O₂
• BLi-Br
• CH₂O
• DCF₃

71. 

______ falls under the category of a water tube boiler ?

• ACornish boiler
• BLocomotive boiler
• CLancashire boiler
• DLamont boiler

72 Which of the following does not represent a unit of viscosity?

• Am²/sec
• BStoke
• CN-m/sec
• DPoise

73. ___ in the fuel is oxidized during knocking.

• APhosphorus
• BWater
• CHydrocarbon
• DCoal

74. ____ valves are provided in reciprocating compressors.

• ASolenoid
• BPoppet
• CPlate
• Dsimply supported

75. What was the first refrigerant used in continuous refrigeration system?

• AWater
• BCarbon dioxide
• CAmmonia
• DAir

76. If the oil viscosity increases, then the wear loss ___ ?.

• ADecreases
• BRemains the same
• CIncreases
• DBecomes zero

77. Internal energy associated with kinetic energy of molecules is___ ?

• ALatent energy
• BSensible energy
• CChemical energy
• DNuclear energy

78. For a 2 m deep swimming pool, pressure difference between the top and the bottom of the pool is ______ kPa. ?

• A19.6
• B12
• C22
• D11

79. The reversed _____ cycle is employed for passenger aircraft systems ?

• AAtkinson
• BCarnot
• CEricsson
• DBrayton

80. When two elements of a pair are connected such that they can only turn about a fixed axis of another element, they are called _____?

• AA sliding pair
• BA turning pair
• CAspherical pair
• Da screw pair

81. _____ is useful for measuring flow of a conducting fluid ?

• AOrifice meter
• BElectro-magnetic flow meter
• CRotameter
• DVane meter

82. Percentage elongation measured during tensile testing indicates _____.?

• ADuctility
• BMalleability
• CFatigue strength
• DCreep

83. For a given centrifugal pump, discharge varies ____ with speed ?

• AInversely
• BLinearly
• CFifth power of
• DSquare root of

84. Otto cycle of a car engine consists of?

• AOne adiabatic cycle only
• BTwo isochore and two reversable adiabatic cycles
• COne isochore cycle only
• DFour adiabatic cycles

85.Determine the cop (coefficient of performance) of a heat pump if the rate of heat rejected is 360 kJ/min and power supplied is 2 kW. ?

• A4
• B3
• C2
• D1

86. Which of the following is not a part of the Rankine cycle?

• ACompressor
• BBoiler
• CTurbine
• DPump

87. Which of the following equipment gives direct reading of fluid flow rates?

• AOrifice meter
• BNutating disk flow meter
• CHot wire anemometer
• DRotameter

88. Which of the following statements is correct about a Benson boiler?

• AThere is no recirculation of water
• BAir is sent through the same direction
• CSteam is sent out in multiple directions
• DFlue gases pass only in one direction

89. For a floating body, if the metacenter is below the centre of gravity, then the body is said to be in _____ equilibrium ?

• AThermal
• BStable
• CNeutral
• DUnstable

90. Smoke emitting from a lighted cigarette represents _____?.

• AStreamline
• BPoint
• CStreak- line
• DPath- line

91. The compression ratio in ideal air standard cycles is the ratio of ?

• AMinimum pressure to maximum pressure
• BMinimum volume to maximum volume
• CMaximum volume to minimum volume
• DMaximum pressure to minimum pressure

92 _______ is defined as the ability of a material to resist deformation under action of an external load?

• AResilience
• BStiffness
• CBrittleness
• DToughness

93. The flash chamber in the single stage vcr cycle serves to ____?.

• ADecrease the compression ratio
• BDecrease the refrigerating effect
• CIncrease the compression ratio
• DIncrease the refrigerating effect

94. Which of the following processes is not part of an ideal otto cycle?

• AHeat addition at constant pressure
• BIsentropic compression
• CIsentropic expansion
• DHeat addition at constant volume

95. Flow velocity at the throat of a converging-diverging nozzle is ______, when designed for maximum discharge ?

• ASupersonic
• BSonic
• CSub-sonic
• DHypersonic

96. Stoke is another unit of ?

• ADynamic viscosity
• BShear stress
• CKinematic viscosity
• DVelocity gradient

97 .In the context of properties of steel, which of the following statements is highly relevant?

• APresence of carbon does not influence the heat-treatment process.
• BPresence of carbon does not influence the heat-treatment process.
• CPresence of manganese decreases strength.
• DPresence of carbon contents imparts strength to iron.

98. Where is air cycle refrigeration commonly used?

• ADomestic refrigerator
• BCold storage
• CAircraft conditioning
• DCar air conditioning

99. In high-speed aircrafts flying at high altitudes, why is cooling of the cabin required even if temperature outside is very low?

• ASince outside pressure is very high
• BDue to large internal heat generation
• CTo improve fuel efficiency
• DDue to absence of solar radiation

100. From among the given options, poisson’s ratio is the highest for ?

• AWood
• BCopper
• CRubber
• DIron

 

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