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Most frequently asked mechanical Objective Questions MCQ

Most frequently asked mechanical Objective Questions MCQ .

Mechanical MCQ
Mechanical MCQ

1. The hardest known material is
a) Ceramic
b) High speed steel
c) Cemented carbide
d) Diamond

2. Which of the following welding process uses consumable electrodes
a) TIG
b) MIG
c) Thermit
d) Laser

3. Wire is made by
a) Drawing
b) Forging
c) Rolling
d) Casting

4. A 1000 tonne press implies that
a) The weight of press is 1000 tonne
b) The press can handle works weighing up to 1000 tonne
c) It can exert pressure up to 1000 tonne
d) Its turn over in a day is 1000 tonne

5. Swaging is an operation of
a) Extrusion
b) Forging
c) Casting
d) Rolling

6. Which of the following is the most ductile material
a) Lead
b) Copper
c) Mild steel
d) Vanadium

7. Casting defects caused by the molten metal is
a) Blow holes
b) Swell
c) Scab
d) All of the above

8. Forming operation which does not involve rotation of work piece is
a) Spinning
b) Thread rolling
c) Ring rolling d) Upsetting

9. Seamless rings are made by the process
a) Super-plastic forming
b) Mandrel forging
c) Ring rolling
d) Diffusion bonding

10. Trimming process is associated with
a) Polishing of metals
b) Machining
c) Electroplating
d) Forging

11. Brinell hardness tester uses a hardened steel ball of size
a) 1 mm
b) 5 mm
c) 10 mm
d) 15 mm

12. The crystal structure of alpha iron
a) BCC
b) FCC
c) HCP
d) Cubic

13. The phenomenon of weld decay occurs in
a) Cast iron
b) Brass
c) Bronze
d) Stainless steel

14. Turbine rotor is made by
a) Rolling
b) Sand casting
c) Forging
d) Extrusion

15. Greater forging capacity is achieved with
a) Mechanical press
b) Power hammer
c) Hydraulic press
d) Non of them

16. Spring back phenomenon occurs in
a) Forging
b) Hot penning
c) Spinning
d) Bending

17. Pre heating is essential in welding of
a) High speed steel
b) German steel
c) Stainless steel
d) Cast iron

18. The transistor is made of
a) Silver
b) Germanium
c) Copper
d) Cast iron

19. Foundry crucible is made of
a) Stainless steel
b) Mild steel
c) Lead
d) Graphite

20. Age hardening is related with
a) Stainless steel
b) Duralumin
c) Gun metal
d) Cast iron

21. In hot working process
a) Poor surface finish is produced
b) Scale formed
c) Close tolerance is difficult to maintain
d) All of the above

22. Forming operation which does not involve rotation of work piece is
a) Spinning
b) Thread rolling
c) Ring rolling
d) Upsetting

23. Casting defects caused by the molten metal is
a) Blow holes
b) Swell
c) Scab
d) All of the above

24. Severe quenching can cause
a) Blow holes
b) Warping
c) Inclusions
d) Non of them

25. Sprue in casting refers to
a) Gate
b) Runner
c) Riser
d) Vertical passage

26. Fettling is an operation performed
a) Before casting
b) After casting
c) During casting
d) After heat treatment

27. Slag inclusion in the casting is a
a) Surface defects
b) Internal defect
c) Crack
d) Notch

28. Draft on pattern means
b) Allowance for machining
c) Locating pad
d) Compensate for stripping
e) Compensation for shrinkage

29. The tool life is influenced maximum by
a) Cutting speed
b) Tool material and geometry
c) Cutting fluid
d) Surface conditions of the workpiece
e) Skill of the operator

30. Tool life may be measured by the
a) Total time the tool has been in contact with the job
b) Quantity of material removed between the total sharpening
c) Number of work pieces machined between tool sharpening
d) Time for the flank wear to reach a certain dimension
e) Any one of the above

31. Choose the coolant that would be most appropriate for light cuts on aluminum alloys
a) Kerosene
b) Mineral oil
c) Soluble oil or emulsions
d) Straight fatty oil

32. Which is not the primary function of coolant in a metal cutting operation
a) To cool the tool and work piece and conduct the heat generated
b) To improve the cutting action
c) To help in giving bright shining surface to the job
d) To reduce the friction at the cutting point

33. The cutting speed of a tool refers to
a) Revolution made by the tool in a specified time
b) Revolutions turned by the job in a specified time
c) Distance travelled by the tool in one revolution of the job
d) Rate at which cutting edge of the tool passes over the surface of work piece

34. Tool signature
a) Is a pictorial view of the tool
b) Outlines the orthographic projection of the tool
c) Represents complete specification of the tool
d) Is a numerical method of tool identification
e) Indicate life of tool

35. With an increase in nose radius of single point cutting tools
a) Tool life increases
b) Excessive heat is generated
c) Surface finish deteriorates
d) Cutting speeds have to be kept small

36. Single point thread cutting tool should ideally have
a) Zero rack angle
b) Positive rack
c) Negative rack
d) Normal rack

37. Cutting tool may be provided with large positive rack angle to
a) Have a better heat dissipation
b) Avoid rubbing with the finished surface
c) Increase the strength of cutting edge
d) Reduce the magnitude of cutting forces

38. The angle between the face and the flank of the single point cutting tool is known as
a) Rack angle
b) Clearance angle
c) Lip angle
d) Point angle

39. In metal cutting operation, the cutting angle is defined as the angle
a) between the flank and the horizontal machined surface
b) between the shear plane and the direction of tool travel
c) between the face of tool and the line tangent to the machined surface at the cutting point
d) between the tool face and the ground end surface of flank

40. The angle between the tool face and the plane parallel to the base of the cutting tool is called
a) Lip angle
b) Cutting angle
c) Rack angle
d) Shear angle

41. Identify the single point cutting tool
a) Milling cutter
b) Hacksaw blade
c) Grinding wheel
d) Cutting tool used in a slotting machine

42. Crater wear is predominant in
a) Carbon tool steels
b) Tungsten carbide tools
c) High speed steel tools
d) Ceramic tools

43. The crater wear of a cutting tool is due to
a) Chemical action of the coolant
b) Excessive heat generated during cutting operation
c) Rubbing of tool against the work piece
d) Abrasive action of the chip

44. Which part of the cutting tool is prone to crater wear
a) Flank
b) Face
c) Shank
d) Base

45. Metric thread have included angle:
a) 60°
b) 55°
c) 30°
d) None

46. During manufacturing of spring, the coiling pitch is assumed to be larger than specified pitch by
a) 5-8%
b) 10-12%
c) 2-5%
d) none

47. Stretching of rolled rings is done to
a) To meet dimensional requirement
b) To relieve stresses
c) To introduce stresses
d) To improve finish

48. Liquid nitrogen containers can be made from
a) Ferritic stainless steel
b) HSLA steel
c) Titanium
d) Austenitic stainless steel

49. Shell moulding process requires
a) Wooden pattern
b) Plastic pattern
c) Sand pattern
d) Metal pattern

50. The material of pattern in the investment casting is
a) Resin
b) Sand
c) Wax
d) Wood

51. Polymerization is associated with
a) Stainless steel
b) Cast iron
c) Thermoplastic
d) Duralumin

52. Which of the following is a non-destructive test
a) Impact test
b) Charpy test
c) Cupping test
d) Radiography test

53. The main purpose of heat treatment of steels is to change the
a) Chemical composition
b) Mechanical properties
c) Surface finish
d) Physical properties

54. Normalizing operation is carried out in
a) Water
b) Oil
c) Air
d) Furnace

55. What size of material required for making rolled threads?
(a) Pitch diameter
(b) Root diameter
(c) Major diameter
(d) None

56. Mohr’s circle can be used to determine following stress on inclined surface
(a) Principal stresses
(b) Normal stresses
(c) Maximum shear stresses
(d) All of the above

57. What is Hertzian stress?
(a) Tensile stress on inner surface of cylinder
(b) Bending stress on two contact surface
(c) Contact stress on two contact surfaces
(d) Shear stress on two contact surfaces

58. Antifriction bearings are
(a) Thick lubricated bearing
(b) Thin lubricated bearing
(c) Ball & roller bearing
(d) Plastic bearing

59. When two elastic bodies collide with each other
(a) Two bodies will momentarily come to rest after collision
(b) The two bodies tend to compress & deform at the surface of contact
(c) Two bodies begins to retain their original shape
(d) All of the above

60. Teflon is used for bearings because of
(a) Low co-efficient of friction
(b) Better heat dissipation
(c) Smaller space constraint
(d) All of the above

61. Backlash is
(a) Sum of the clearance of two gears
(b) Mutual play between two gears
(c) Amount by which the width of a tooth space exceeds the thickness of the engaging tooth on pitch circle
(d) Any of the above

62. Principle effect of humidity is
(a) Corrosion
(b) Leaking from sealed enclosures
(c) Permanent set of packing and gaskets
(d) Differential contraction of metal parts

63. Stress concentration factor is defined as ratio of
(a) Max stress to endurance limit
(b) Nominal stress to endurance limit
(c) Max stress to nominal stress
(d) Nominal stress to max stress

64. A bolt of uniform strength can be developed by
(a) Keeping the core dia of threads equal to the dia of unthreaded ortion of bolt
(b) Keeping the core dia of threads smaller than the dia of unthreaded portion of bolt
(c) Keeping the nominal dia of threads equal to the dia of unthreaded portion of bolt
(d) None of the above

65. A closed cycle gas turbine works on
(a) Carnot cycle
(b) Rankine cycle
(c) Joule cycle
(d) Atkinson cycle

66. Thermal efficiency of a gas turbine plant as compared to diesel engine plant
(a) Higher
(b) Lower
(c) Same
(d) May be higher or lower

67. Centre of pressure of an aerofoil with an increase of angle of attack will
(a) Move forward
(b) Move backward
(c) Not move
(d) None of the above

68. Short columns are preferred over long columns from
(a) Strength consideration
(b) Buckling consideration
(c) Weight consideration
(d) None of the above

69. Mass balancing is done to
(a) Avoid flutter
(b) Increase bending stress
(c) Reduce drag
(d) Distributing mass on control surface

70. Slow plastic deformation of material under constant stress is
(a) Creep
(b) Fatigue
(c) Endurance
(d) Elastic deformation

71. Pitot tube is used for measurement of
(a) Pressure
(b) Temperature
(c) Discharge
(d) Velocity

72. In a refrigeration cycle, the moisture content is to be removed before it enters into which system
A. Cold side of system
B. Evaporator
C. compressor
D. condenser

73. In one ton refrigeration machine, the term “one ton” implies
A. One ton refrigerant is used
B. One ton water can be converted into ice
C. One ton ice when melts from and at 0oC in 24 hours, the refrigerating effects is equivalent to 3000 kcal/hour
D. None of the above

74. Capillary action of liquid is due to the
A. Viscosity of liquid
B. Cohesion of liquid particles
C. Surface tension
D. Adhesion of liquid particles on the surface

75. Cavitation in a pipe will begin when
A. Pressure at any location reaches pressure equal to the saturated vapour pressure of liquid
B. Pressure becomes more than critical pressure
C. Flow is increased
D. Pressure is increased

76. During idling process, a petrol engine requires
A. Lean mixture
B. Rich mixture
C. Variable mixture
D. None of above

77. A two-stroke engine is generally preferred to a four-stroke engine because
A. It offers low fuel consumption
B. It gives lesser shocks and vibrations
C. It can be easily started
D. It has smaller size for the same output.

78. In internal combustion engine piston the maximum temperature occurs at
A. Ring section
B. Gungeon pin
C. Bottom centre
D. Top centre

79. Power available at the shaft of an I.C engine is known is
A. Brake horse power
B. Indicated horse power
C. Net indicated horse power
D. Pumping power

80. In internal combustion (I.C.) engines, combustion of fuel takes place in
A. Outside the cylinder
B. Inside the cylinder
C. Not in the cylinder
D. None of the above

81. In an I –section beam, the bending moment is resisted mainly by
A. Flanges only
B. Web only
C. Both by flanges and web
D. None of the above

82. In a rectangular beam, when width, depth and length are doubled, the bending stress will be
A. Shall remain unchanged
B. Shall be doubled
C. Shall become ¼ th
D. Shall be halved

83. In a cantilever beam, maximum deflection occurs at where
A. Bending moment is zero
B. Bending moment is maximum
C. Shear force is zero
D. Slope is zero

84. A hollow shaft of same cross-section area as solid shaft transmits
A. Same torque
B. Less torque
C. More torque
D. Unpredictable

85. With rise in temperature , the specific heat of water
a) increases
b) decreases
c) first decreases to minimum and then increases
d) remains constant

86. A system comprising of a single phase , is known as
a) Open system
b) Closed system
c) Homogenous system
d) Heterogeneous system

87. In laminar flow , maximum velocity at the centre of the pipe is how many times the average velocity?
a) 2
b) 3
c) 4
d) None of these

88. The flow of water in the pipe of diameter 3000 mm can be measured by
a) Venturimeter
b) Rotameter
c) Pilot tube
d) Orifice plate

89. The starting torque of slip ring induction motor is increased by
a) Adding external resistance to the rotor
b) Adding external induction to the rotor
c) Increasing the voltage fed to the motor
d) Adding external capacitance to the rotor

90. The function of commutator in a DC machine is
a) To improve commutation
b) To improve efficiency of motor
c) To change alternative voltage to direct
d) To change direct voltage to alternative voltage

91. If A.C. is fed by mistake to a DC motor then DC motor will
a) Burn as the eddy current in the field produce heat
b) Run at its normal speed
c) Run at a lower speed
d) Run continuously but the sparking takes place at the brushes

92. A floating battery is one
a) Which is getting charged
b) In which feeding loads
c) In which battery voltage is equal to charger voltage
d) Which gets charged and discharged simultaneously

93. Which of the following parameter will be more for 16 gauge copper wire in comparison to 14 gauge copper wire
a) Cost
b) Strength
c) Resistance
d) Weight

94. The induction of a coil can be increased by
a) Decreasing number of turns
b) Increasing core length
c) Using core material of highly relative permeability
d) None of the above

95. Which of the following displays has minimum power consumption
a) light emitting diode (LED)
b) liquid crystal display (LCD)
c) nixie tube
d) fluorescent

96. Transistor interjunction capacitance causes the following in the amplifier
a) noise
b) harmonic distortion
c) phase shift
d) parasitic oscillation

97. Which of the following rays has the lowest wavelength
a) radio waves
b) x rays
c) infrared waves
d) ultraviolet waves

98. The weight of one cubic meter of air would be around
a) 13 gm
b) 130 gm
c) 1300 gm
d) 13000 gm

99. A real gas compared to idle gas at very high pressure occupies
a) Less volume
b) More volume
d) Same volume
c) More/less depending on gas

100. Sea water as compared to distilled water will boil at
a) Same temperature
b) Higher temperature
c) Lower temperature
d) Unpredictable

101. Which of the following has least hardness
a) Diamond
b) Topaz
c) Quartz
d) Talc

102. A solution that can resist change in its pH on addition of alkali/acid is called
a) Buffer solution
b) Neutral solution
c) Ideal solution
d) Zero pH solution

103. Brinell number of a metal or an alloy is a measure of its
a) tensile strength
b) toughness
c) malleability
d) hardness

104. Which of the following materials has a linear stress strain curve
a) low carbon steel
b) copper
c) aluminium
d) rubber

105. For a solid cone of height h, the CG lies on the axis at the distance above the base equal to
a) h/4
b) h/3
c) 2h/3
d) 3h/8

106. A particle covers equal distance around circular path in equal intervals of time. Which of the following parameters connected with the motion of particle remains constant with time?
a) displacement
b) speed
c) velocity
d) acceleration

107. In simple harmonic motion , acceleration is proportional to
a) displacement
b) linear velocity
c) angular velocity
d) rate of change of angular velocity

108. A Body is dropped from rest at height h. It covers a distance of 9/25 h in the last
second. The height is about
a) 100 m
b) 115 m
c) 125 m
d) 150 m

109. A system of three forces acts on a body and keeps it in equilibrium. The forces need to be
a) Coplanar Only
b) Concurrent Only
c) Coplanar as well as Concurrent
d) Coplanar but may be or may not be Concurrent

110. All of the following are scalar quantities except
a) Energy
b) Temperature
c) Time
d) Displacement


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