WBPSC JE MECHANICAL ENGINEERING Previous year (2018) Question Papers with Answers

WBPSC JE (Junior Engineer) exam is conducted by the West Bengal Public Service Commission for the recruitment of Junior Engineers in various departments of the West Bengal government. The exam typically consists of a written test(100 Questions X 2 Marks each =200 Marks, 2 Hours) and an interview. The written test typically includes technical subjects related to the candidate’s field of engineering. The interview is used to assess the candidate’s technical knowledge, problem solving ability and communication skills. The selection process may vary depending on the specific post for which the candidate is applying.

As we all know Previous year’s exam question paper is not available for many of aspirants so we decided to collect it and upload all previous year’s Question at one place. Now you can practice the questions anytime anywhere through your Smartphone. Here we uploading WBPSC JE MECHANICAL (2018) Questions. Soon we upload all previous year questions of 2005, 2009, 2016 and so on.

You can also practice WBPSC JE MECHANICAL ENGINEERING Previous Year (2004) Question Papers With Answers.

Now You can also get full KMC Mechanical SAE Previous Year 2020 Question Papers with Answers. 

 N.B- All questions are taken from WBPSC exam’s original question paper to help students at free of cost. we try our best to provide the same questions, if any Questions found incorrect we really sorry for that, please give us your valuable feedback so that we can Improve ourselves to give you better content in future.

WBPSC JE MECHANICAL (2018) QUESTION PAPER

1. According to I.B.R., the thickness of the boiler shell should not be less than

(A) 4mm
(B) 5mm
(C) 6nm
(D) 7mm
View Answer

2. The neutral axis of the cross-section of a beam is that axis at which the bending stress is

(A) zero
(B) minimum
(C) maximum
(D) infinity
View Answer

3. If the tearing efficiency of a rivet joints 70%, then the ratio of diameter to the pitch is

(A) 0.20
(B) 0.30
(c) 0.5
(D) 0.70
View Answer

4. The bending moment of a cantilever beam of length L and carrying a gradually varying load from zero at free end & w per unit length towards the fixed end is _________ at the fixed end

(A)wL/2
(B) wL
(C)wL²/2
(D)wL²/6
View Answer

5. The strain energy stored in a body when the load is gradually applied is

(A) σE/V
(B) σV/E
(C) σ²E/2V
(D) σ²V/2E
where σ= Stress in the material of the body
V= Volume of the body and
E = Modulus of elasticity of the material.
View Answer

6. The Poisson’s ratio for cast iron varies from

(A) 0.23 to0.27
(B) 0.25 to 0’33
(C) 0.31 to 0.34
(D) 0.32 to 0.42
View Answer

7. The ratio of the lateral strain to the linear strain is called

(A) Modulus of elasticity
(B) Modulus of rigidity
(C) Bulk modulus
(D) Poisson’s ratio
View Answer

8. When a bar of length I and diameter d is rigidly fixed at the upper end and hanging freely, then the total elongation produced in the bar due to its own weight is

(A) wL/2E
(B) wL²/2E
(C) wL³/2E
(D) wL⁴/2E
where w = weight per unit volume of the bar.
View Answer

9. Thermit welding is often used

(A) replacing broken gear tooth.
(B) repairing broken shears.
(C) joining rails, rucks and locomotives frames.
(D) All of the above
View Answer

10. Gear burnishing is a process for

(A) surface finishing.
(B) under cut gear.
(C) producing cycloidal gears.
(D) removing residual stress from teeth roots.
View Answer

11. A diamond locating pin is used in jigs and fixtures because

(A) diamond is very hard and wear resistance.
(B) it occupies very little space.
(C) it helps in assemble with tolerance on canter distance.
(D) it has long life.
View Answer

12. Jigs are used

(A) For holding and guiding the tool in drilling, reaming or tapping operations.
(B) For holding the work in milling, grinding, planning or turning operations.
(C) To check the accuracy of the work piece.
(D) None of the above.
View Answer

13. Which of the following processes is used for preparing parts having large curved surfaces and thin sections?

(A) Hot machining
(B) Ultrasonic machining
(C) ECM process
(D) Chemical milling
View Answer

14. In Electro chemical machining the gap between tool and work piece is kept as

(A) 0.1 mm
(B) 0.25 mm
(C) 0.4 mm
(D) 0’75 mm
View Answer

15. In ultrasonic machining tool is made of

(A) Tungsten carbide
(B) Brass or Copper
(C) Diamond
(D) Stainless steel
View Answer

16. In a cold chamber die casting machine

(A) melting pot is separate from the machine.
(B) melting pot is an integral part of the machine.
(C) melting pot may have any location.
(B) low temperature and pressure is used.
View Answer

17. ln a hot chamber die casting machine

(A) melting pot is separate from the machine.
(B) melting pot is an integral part of the machine
(C) melting pot may have any location.
(D) high temperature and pressure is used.
View Answer

18. The casting method adopted for ornaments and toys of non-ferrous alloys is

(A) permanent mould casting
(B) slush casting
(C) die casting
(D) centrifugal casting
View Answer

19. In die casting, machining allowance is

(A) small
(B) large
(C) very large
(D) not provided
View Answer

20. A jolt machine is used to

(A) ram the sand harder at the pattern face with decreasing hardness towards the back of the mould.
(B) ram the sand harder at the back of the mould and softer on the Patten face.
(C) produce uniform sand hardness throughout the mould.
(D) produce uniform packing of sand in the mould.
View Answer

21. Swab is used for

(A) smoothing and cleaning out depressions in the mould.
(B) cleaning the moulding sand.
(C) moistening the sand around the edge before removing Pattern.
(D) reinforcement of sand in the op part of the moulding box.
View Answer

22. Chills are used in casting mould to

(A) achieve directional solidification.
(B) reduce blow holes.
(C) reduce the freezing time.
(D) increase the smoothness of the casting surface.
View Answer

23. When a mould is made h three parts, the top part is known as a

(A) drag
(B) cheek
(C) cope
(D) None of the above
View Answer

24. Aluminum is the best material for making pattens because it is

(A) light in weight
(B) easy to work
(C) corrosion resistant
(D) All of the above
View Answer

25. Metal patterns are used for

(A) small castings
(B) large castings
(C) complicated castings
(D) large scale production of castings
View Answer

26. The expansion ratio R is the ratio of

(A)v₁/v₂
(B)v₂/v₁
(C)(v₁+v₂)/v₁
(D)(v₁+v₂)/v₂
where v₁ = volume at the beginning of expansion and
v₂= volume at the end of expansion.
View Answer

27. Work-done during adiabatic expansion is given by

(A) (P₁v₁ – P₂v₂)/(γ-l)
(B) mR(T₁-T₂)/(γ-1)
(c) mRT₁/(γ-l)x(1- P₂v₂/P₁v₁)
(D) All of the above
where P₁,v₁,T₁ Pressure, volume and temperature for the initial condition of gas,
P₂, v₂, T₂ = Corresponding values for the final condition of gas,
R = Gas constant, and
γ = Ratio of specific heats
View Answer

28. The unit of surface tension is

(A) N/m
(B) N/m²
(C) N/m³
(D) N-m
View Answer

29. A vessel of 4m³ contains oil which weighs 30 kN. the specific weight of the oil is

(A) 4.5 kN/m³
(B) 6 kN/m³
(C) 7.5 kN/m³
(D) 10 kN/m³
View Answer

30. A path 1-2-3 is given a system absorbs 100 kJ as heat and does 60 kJ of work while along the path l-4-3, it does 20 kJ of work. The heat absorbed during the cycle 1-4-3 is

31. According to Kelvin-Plank’s statement of second law of thermodynamics

(A) it is impossible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work.
(B) it is possible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work.
(C) it is impossible to construct a device which operates in a cyclic process and produces no effect other than transfer of heat from a cold body to a hot body.
(D) None of the above
View Answer

32. Kelvin-Plank’s statement deals with

(A) Conservation of work
(B) Conservation of heat
(C) Conservation of heat into work
(D) Conservation of work into heat
View Answer

33. First law of thermodynamics deals with

(A) Conservation of heat
(B) Conservation of momentum
(C) Conservation of mass
(D) Conservation of energy
View Answer

34. The value of pressure represented by 1 mm of Hg is equal to

(A) 1.333 N/m²
(B) 13.33 N/m²
(C) 133.3 N/m²
(D) 1333 N/m²
View Answer

35. Which of the following is correct?

(A) Absolute pressure = Gauge pressure + Atmospheric pressure
(B) Gauge pressure = Absolute pressure + Atmospheric pressure
(C) Atmospheric pressure = Absolute pressure + Gauge pressure
(D) Absolute pressure = Gauge pressure + Atmospheric pressure
View Answer

36. Which of the following is the extensive property of a thermodynamic system?

(A) Pressure
(B) Volume
(C) Temperature
(D) Density
View Answer

37. In a diesel engine the duration between the time of injection and time of ignition is called

(A) Period of ignition
(B) Explosion period
(C) Pre-ignition period
(D) Delay period
View Answer

38. Morse test is conducted on

(A) Single cylinder engines
(B) Multi-cylinder engines
(C) Vee engines
(D) Horizonal engines
View Answer

39. The top ring nearest to the piston crown is known as

(A) Oil ring
(B) Scrapper ring
(C) Compression ring
(D) Groove ring
View Answer

40. The function of piston rings in an internal combustion engine is

(A) to prevent lubricating oil from entering the combustion space.
(B) to prevent leakage of combustion chamber products.
(C) to transfer heat from piston to cylinder walls.
(D) All of the above
View Answer

41. Units of Kinematic viscosity are

(A) m²/sec
(B) kg/sec/m2
(C) Newton-sec/m²
(D) Newton-sec2/m
View Answer

42. A Piezometer cannot be used for pressure measurement in pipes when

(A) pressure difference is low.
(B) velocity is high.
(C) fluid in the pipe is a gas.
(D) fluid is highly viscous.
View Answer

43. Capillarity is due to

(A) Cohesion
(B) Adhesion
(C) Adhesion and Cohesion
(D) Molecular structure
View Answer

44. The electron beam welding can be carried out in

(A) open air
(B) a shielded gas environment
(C) vacuum
(D) a pressurized inert gas chamber
View Answer

45. For measuring flow by a venturi meter, it should be installed in

(A) Vertical line
(B) Horizontal line
(C) Inclined line with upward flow
(D) In any direction and in any location
View Answer

46. In steady flow of a fluid, the acceleration of any fluid particle is

(A) Constant
(B) Variable
(C) Zero
(D) Never zero
View Answer

47. Rain drops are spherical because of

(A) Viscosity
(B) Air resistance
(C) Surface tension
(D) Atmospheric pressure
View Answer

48. The point in the immersed body through which the resultant pressure of the liquid be taken to act is known as

(A) Metacentre
(B) Centre of pressure
(C) Centre of buoyancy
(D) Centre of gravity
View Answer

49. Head loss due to a sudden enlargement in a pipe

(A) (v₁² – v₂²)/2g
(B) (v₁ – v₂)²/2g
(C) (v₁ – v₂)²/g
(D) (v₁² – v₂²)/g
View Answer

50. Kinematic viscosity is equal to

(A) Dynamic viscosity/Density
(B) Dynamic viscosity x Density
(C) Density/Dynamic viscosity
(D)1/(Dynamic viscosity x Density)
View Answer

51. The polar modulus for a solid shaft of diameter D is

(A) πD²/4
(B) πD³/16
(c) πD²/32
(D) πD⁴/64
View Answer

52. When a shaft of diameter D is subjected to a twisting moment T and bending moment M, then the maximum normal stress is given by

(A) 16/[πD³√ (M² + T²)]
(B) 16/[πD³√ (M² – T²)]
(C) 16/[πD³{M +√ (M² + T²)}]
(D) 16/[πD³{M -√ (M² + T²)}]
View Answer

53. Two closely-coiled helical springs ‘A’ and ‘B’ of the same material, same number of turns and made from same wire are subjected to an axial load W. The mean diameter of spring ‘A’ is double the mean diameter of spring ‘B’. The ratio of deflections in spring .B, to spring ‘A’ will be

(A) 1/8
(B) 1/4
(c) 2
(D) 4
View Answer

54. According to Unwin’s formula, the relation between diameter of rivet hole d and thickness of plate t is given by

(A) d=t
(B) d=1.6√ t
(C) d=2t
(D) d=6√ t
where d and t are in mm.
View Answer

55. In order to avoid tearing off the plate at an edge, the distance from the centre of the rivet hole to the nearest edge of the plate (i.e. margin) should be

(A) d
(B) 1.5d
(C) u
(D) 2.sd
where d = diameter of rivet hole in mm.
View Answer

56. The tensile strength of the welded joint for double fillet is

(A) 0.5slσ_t
(B) slσ_t
(C) √ 2*slσ_t
(D) 2slσ_t
where r = leg or size of the weld,
l = length of the weld and
σ_t = allowable tensile stress for weld metal.
View Answer

57. A thin cylindrical shell of diameter d, length I, and thickness r is subjected to an internal pressure p. The hoop stress in the shell is

(A) pd/t
(B) pd/2t
(c) pd/4t
(D) pd/6t
View Answer

58. According to Euler’s column theory, the crippling load for a column of length l with one end fixed and the other end hinged is

(A) π²EI/l²
(B) π²EI/4l²
(C) 2π²EI/l²
(D) 4π²EI/l²
View Answer

59. The Rankine’s formula holds good for

(A) short columns
(B) long columns
(C) both short and long columns
(D) weak columns
View Answer

60. The tensile test is carried on which materials

(A) Ductile
(B) Brittle
(C) Malleable
(D) Plastic
View Answer

61. The compressive strength of brittle materials is ______ its tensile strength.

(A) equal to
(B) less than
(C) greater than
(D) double
View Answer

62. In compression test, the fracture in cast iron specimen would occur along

(A) the axis of load.
(B) an oblique plane.
(C) at right angles to the axis of specimen.
(D) would not occur.
View Answer

63. The railway carriage couplings have

(A) square thread
(B) acme threads
(C) knuckle threads
(D) buttress threads
View Answer

64. The eye bolts are used for

(A) transmission of power.
(B) locking devices.
(C) lifting and transporting heavy machines
(D) absorbing shocks and vibrations.
View Answer

65. In a steam engine, the valve rod is connected by an eccentric rod by means of

(A) cotter joint
(B) knuckle joint
(C) universal joint
(D) flange coupling
View Answer

66. The sleeve and muff coupling is designed as a

(A) thin cylinder
(B) thick cylinder
(C) solid shaft
(D) hollow shaft
View Answer

67. If the centre distance of a mating gear having involute teeth is varied within limits, the velocity ratio

(A) increases
(B) decreases
(C) remain unchanged
(D) None of the above
View Answer

68. The helix angle for double helical gears may be made up to

(A) 45°
(B) 60°
(c) 75°
(D) 90°
View Answer

69. The difference between the tooth space and the tooth thickness as measured on the pitch circle is called

(A) working depth
(B) clearance
(C) face width
(D) backlash
View Answer

70. The thermal conductivity is expressed as

(A) W/mK
(B) W/m²K
(C) W/hmK
(D) W/h²m²K
View Answer

71. Stefan-Boltzmann law is expressed as

(A) Q= σAT⁴
(B) Q=σA²T⁴
(C) Q=σAT²
(D) Q= AT⁴
View Answer

72. The quantity of heat radiation is dependent on

(A) area of the body only.
(B) shape of the body only.
(C) temperature of the body only.
(D) All of the above.
View Answer

73. A material is said to be allotropic, if it has

(A) fixed structure at all temperatures.
(B) atoms distributed in random pattern.
(C) different crystal structures at different temperatures.
(D) atoms distributed in crystalline pattern.
View Answer

74. According to Indian standards, the total number of tolerance grades are

(A) 8
(B) 12
(c) 18
(D) 20
View Answer

75. The optimum effective temperature for human comfort is

(A) higher in winter than in summer.
(B) lower in winter than in summer.
(C) same in winter and summer.
(D) not dependent on season.
View Answer

76. A mortise gauge is a

(A) striking tool
(B) planning tool
(C) boring tool
(D) marking tool
View Answer

77. In order to get uniform thickness of the plate by rolling process, one provides

(A) camber on the rolls
(B) offset on the rolls
(C) hardening of the rolls
(D) antifriction bearings
View Answer

78. Rotary swaging

(A) is extensively used for making bolts and rivets.
(B) is used for reducing the diameters of round bars and tubes by rotating dies which open and close rapidly on the work.
(C) is used to improve fatigue resistance of the metal by setting up compressive stresses in its surface.
(D) consists of pressing metal inside a chamber to force it out by high pressure through an orifice which is shaped to provide desired form of the finished part.
View Answer

79. In a four high rolling mill, there are four rolls out of which

(A) one is working roll and three are backing up rolls.
(B) two are working rolls and two are backing up rolls.
(C) three are working rolls and one is backing up roll.
(D) all of the four are working rolls.
View Answer

80. Which of the following methods can be used for manufacturing 2 m. long seamless metallic tubes?

(A) Drawing
(B) Extrusion
(C) Rolling
(D) Extrusion and Rolling
View Answer

81. The recrystallization temperature of steel is

(A) 400°C
(B) 600°C
(c) 800°C
(D) None of the above
View Answer

82. The machining of titanium is difficult due to

(A) high thermal conductivity of titanium.
(B) chemical reaction between tool and work
(C) low tool-chip contact area.
(D) None of the above.
View Answer

83. For machining a cast iron workpiece by a high speed steel tool, the average cutting speed is

(A) 10 m/min
(B) 15 m/min
(C) 22 m/min
(D) 30 m/min
View Answer

84. For machining a mild steel workpiece by a high speed steel tool, the average cutting speed is

(A) 5 m/min
(B) l0 m/min
(C) 15 m/min
(D) 30 m/min
View Answer

85. High speed steel cutting tools operate at cutting speeds _______ than carbon steel tools.

(A) 2 to 3 times lower
(B) 2 to 3 times higher
(C) 5 to 8 times higher
(D) 8 to 20 times higher
View Answer

86. With same tool life, the maximum material per minute is removed by

(A) increasing the cutting speed.
(B) decreasing the cutting speed.
(C) increasing the depth of cut.
(D) increasing the feed rate.
View Answer

87. The negative rake is usually provided on

(A) high carbon steel tools
(B) high speed steel tools
(C) cemented carbide tools
(D) AII of the above
View Answer

88. In American Standard Association (ASA) system, if the tool nomenclature is 8-6-5-5-10-15-2 mm, then the side rake will be

(A) 5°
(B) 6°
(C) 8°
(D) 10°
View Answer

89. If the body falls freely under gravity, then the gravitational acceleration is taken as

(A) + 8.9 m/sec
(B) – 8.9 m/sec
(C) + 9.8 m/sec
(D) – 9.8 m/sec
View Answer

90. Normalizing of steel is done to

(A) refine the grain structure.
(B) remove strain caused by cold working.
(C) remove dislocations caused in the internal structure due to hot working.
(D) Al1 of the above
View Answer

91. Duralumin contains

(A) 3.5% to 4.5% copper, O.4% to O.7% magnesium, 0.4% to 0.7% manganese and rest aluminium.
(B) 3.5% to 4.5% copper, 1.2% to l.7% manganese, l.8% to 2.3% Nickel, 0.6% each of silicon, magnesium and iron and rest aluminium.
(C) 4% to 4.5% magnesium,3% to 4% copper and rest aluminium.
(D) 5% to 6% tin, 2% to 3% copper and rest aluminium.
View Answer

92. Match the correct answer from Group B for the heat treatment processes given in Group A.

Group A (Heat treatment process)	Group B (Effect on the properties)
a. Annealing	A. Refines grain structure
b. Nitriding	B. Improves the hardness of the whole mass
c. Martempering	C. Increases surface hardness
d. Normalizing	D. Improves ductility

(A) DCBA
(B) BCDA
(C) ADCB
(D) ACBD
View Answer

93. Blast furnace is used to produce

(A) Pig iron
(B) Cast iron
(C) Wrought iron
(D) Steel
View Answer

94. A device used to heat feed water by utilizing the heat in the exhaust flue gases before leaving through the chimney, is known as

(A) Economizer
(B) Fusible plug
(C) Superheater
(D) Stop valve
View Answer

95. A safety valve mainly used with locomotive and marine boilers is

(A) lever safety valve
(B) dead weight safety valve
(C) high steam and low water safety valve
(D) spring loaded safety valve.
View Answer

96. The amount of heat generated per kg of fuel is known as

(A) Calorific value
(B) Heat energy
(C) Lower calorific value
(D) Higher calorific value
View Answer

97. The air standard efficiency of an Otto cycle is given by

(A) 1 – r^{γ – 1}
(B) 1 + r^{γ – 1}
(C) 1 – (l/r^{γ – 1})
(D) 1 + (l/r^{γ – 1})
where r= Compression ratio and γ= Ratio of specific heats.
View Answer

98. The compression ratio for petrol engines is

(A) 3 to 6
(B) 5 to 8
(C) 15 to 20
(D) 20 to 30
View Answer

99. The efficiency of Diesel cycle approaches to Otto cycle efficiency when

(A) cut-off is increased.
(B) cut off is decreased.
(C) cut -off is zero.
(D) cut-off is constant.
View Answer

100. The condition for a reversible cyclic process is

(A) ∮(𝜹Q/T)=0
(B) ∮(𝜹Q/T)<0
(C) ∮(𝜹Q/T)>0
(D)None of the above.
View Answer