Manufacturing Process MCQs with Answers
Foundry, Welding, Metal Forming & Powder Metallurgy – Hard Level MCQs
Mechanical Engineering competitive examinations such as TNPSC CTSE, SSC JE, RRB JE, GATE, ISRO, BHEL, DRDO, and various Diploma recruitment examinations frequently include questions from manufacturing processes. Among these topics, Foundry Technology, Welding, Metal Forming, Powder Metallurgy, and Plastic Processing are considered scoring areas.
The following 100 hard-level multiple-choice questions are designed according to the latest competitive examination pattern.
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Foundry, Pattern Making & Moulding Technology – Hard Level MCQs (Questions 1–20)
1. Which pattern is most suitable for high-volume production using machine moulding?
A. Sweep pattern
B. Skeleton pattern
C. Match plate pattern
D. Loose piece pattern
Answer: C. Match plate pattern
2. Shake allowance provided on a pattern is generally
A. Positive allowance
B. Negative allowance
C. Equal to machining allowance
D. Equal to draft allowance
Answer: B. Negative allowance
3. Which property of moulding sand mainly controls the escape of gases during pouring?
A. Plasticity
B. Permeability
C. Flowability
D. Adhesiveness
Answer: B. Permeability
4. A pattern is made slightly larger than the casting to compensate for
A. Machining error
B. Solidification shrinkage
C. Sand expansion
D. Pouring temperature
Answer: B. Solidification shrinkage
5. Which of the following pattern materials provides the highest dimensional stability?
A. Wood
B. Plastic
C. Aluminium alloy
D. Wax
Answer: C. Aluminium alloy
6. Which casting defect is primarily caused by entrapped gases?
A. Misrun
B. Blowhole
C. Hot tear
D. Cold shut
Answer: B. Blowhole
7. Which moulding process uses resin-coated sand?
A. Green sand moulding
B. Dry sand moulding
C. Shell moulding
D. Loam moulding
Answer: C. Shell moulding
8. The principal function of a riser is to
A. Remove slag
B. Feed molten metal during solidification
C. Increase pouring speed
D. Improve mould strength
Answer: B. Feed molten metal during solidification
9. Which gating element is primarily responsible for reducing turbulence?
A. Runner
B. Pouring basin
C. Ingate
D. Riser
Answer: B. Pouring basin
10. Which furnace is most commonly used for melting cast iron in foundries?
A. Crucible furnace
B. Electric arc furnace
C. Cupola furnace
D. Induction furnace
Answer: C. Cupola furnace
11. A chaplet is used when
A. A pattern is damaged
B. A core requires additional support
C. Pouring temperature is low
D. Sand strength is poor
Answer: B. A core requires additional support
12. Which defect occurs due to incomplete filling of the mould cavity?
A. Blowhole
B. Cold shut
C. Misrun
D. Scab
Answer: C. Misrun
13. Which allowance is not intentionally provided on patterns?
A. Draft allowance
B. Machining allowance
C. Distortion allowance
D. Heat treatment allowance
Answer: D. Heat treatment allowance
14. The function of a core print is to
A. Improve surface finish
B. Position and support the core inside the mould
C. Increase mould hardness
D. Reduce shrinkage
Answer: B. Position and support the core inside the mould
15. Which moulding sand property enables it to retain its shape after the pattern is withdrawn?
A. Refractoriness
B. Green strength
C. Permeability
D. Collapsibility
Answer: B. Green strength
16. Hot tears in castings are mainly caused by
A. Excessive gas content
B. Restriction of contraction during solidification
C. Low pouring temperature
D. High moisture content in sand
Answer: B. Restriction of contraction during solidification
17. Which of the following patterns is most economical for producing very large axisymmetric castings?
A. Match plate pattern
B. Sweep pattern
C. Split pattern
D. Loose piece pattern
Answer: B. Sweep pattern
18. Directional solidification in castings is achieved mainly by
A. Increasing moisture content
B. Using risers and chills effectively
C. Reducing gating area
D. Increasing mould hardness uniformly
Answer: B. Using risers and chills effectively
19. Chills are used in casting to
A. Delay solidification
B. Promote rapid local solidification
C. Reduce pouring temperature
D. Improve mould permeability
Answer: B. Promote rapid local solidification
20. Which moulding sand property allows the mould to collapse after solidification, reducing the chances of hot tears?
A. Cohesiveness
B. Refractoriness
C. Collapsibility
D. Adhesiveness
Answer: C. Collapsibility
Special Casting Techniques & Welding Technology
21. In investment casting, the pattern is usually made of
A. Wood
B. Aluminium
C. Wax
D. Cast iron
Answer: C. Wax
22. Which casting process provides the highest dimensional accuracy and surface finish?
A. Sand casting
B. Investment casting
C. Shell moulding
D. Centrifugal casting
Answer: B. Investment casting
23. Which casting process is best suited for manufacturing hollow cylindrical components without using cores?
A. Die casting
B. Centrifugal casting
C. Investment casting
D. Shell moulding
Answer: B. Centrifugal casting
24. Hot chamber die casting is generally used for
A. Steel alloys
B. Cast iron
C. Zinc alloys
D. Stainless steel
Answer: C. Zinc alloys
25. Which die casting process is suitable for aluminium alloys?
A. Hot chamber die casting
B. Cold chamber die casting
C. Shell moulding
D. Slush casting
Answer: B. Cold chamber die casting
26. Shell moulding mainly uses sand bonded with
A. Bentonite clay
B. Sodium silicate
C. Thermosetting resin
D. Cement
Answer: C. Thermosetting resin
27. Which casting process is most suitable for manufacturing turbine blades?
A. Green sand casting
B. Investment casting
C. Slush casting
D. Permanent mould casting
Answer: B. Investment casting
28. The primary advantage of squeeze casting is
A. Low equipment cost
B. High porosity
C. Improved mechanical properties due to reduced porosity
D. Easy mould preparation
Answer: C. Improved mechanical properties due to reduced porosity
29. Which casting method is commonly used for manufacturing engine pistons?
A. Shell moulding
B. Gravity die casting
C. Lost foam casting
D. Slush casting
Answer: B. Gravity die casting
30. Continuous casting is mainly employed to produce
A. Complex machine parts
B. Long billets, blooms and slabs
C. Small gears
D. Valve bodies
Answer: B. Long billets, blooms and slabs
Welding Technology
31. In Shielded Metal Arc Welding (SMAW), the flux coating mainly serves to
A. Increase welding speed only
B. Protect the molten weld pool from atmospheric contamination
C. Reduce current consumption
D. Increase electrode melting point
Answer: B. Protect the molten weld pool from atmospheric contamination
32. Which welding process uses a non-consumable tungsten electrode?
A. MIG welding
B. TIG welding
C. SAW
D. Resistance welding
Answer: B. TIG welding
33. Which inert gas is most commonly used in TIG welding of aluminium?
A. Nitrogen
B. Oxygen
C. Argon
D. Carbon dioxide
Answer: C. Argon
34. In MIG welding, the electrode is
A. Carbon rod
B. Tungsten rod
C. Continuously fed consumable wire
D. Cast iron rod
Answer: C. Continuously fed consumable wire
35. Which welding process is capable of achieving the highest deposition rate?
A. Gas welding
B. TIG welding
C. Submerged Arc Welding (SAW)
D. Resistance welding
Answer: C. Submerged Arc Welding (SAW)
36. Which type of flame is generally preferred for welding mild steel using oxy-acetylene welding?
A. Oxidizing flame
B. Neutral flame
C. Carburizing flame
D. Reducing flame
Answer: B. Neutral flame
37. Which welding defect is caused by the entrapment of gas bubbles in the weld metal?
A. Undercut
B. Porosity
C. Lack of penetration
D. Overlap
Answer: B. Porosity
38. Which welding process is most suitable for joining thin stainless steel sheets with excellent weld quality?
A. Oxy-acetylene welding
B. TIG welding
C. Thermit welding
D. Forge welding
Answer: B. TIG welding
39. In resistance spot welding, heat generation is proportional to
A. Voltage × Time
B. Current² × Resistance × Time
C. Current × Voltage
D. Resistance ÷ Time
Answer: B. Current² × Resistance × Time
40. Which of the following factors has the greatest influence on penetration in arc welding?
A. Electrode colour
B. Welding current
C. Electrode length
D. Flux coating thickness alone
Answer: B. Welding current
Advanced Welding Technology
These questions are designed for TNPSC CTSE, SSC JE, RRB JE, GATE, TRB, TNEB, ISRO, BHEL, Diploma Mechanical, and other competitive examinations.
41. The Heat Affected Zone (HAZ) is the region
A. Completely melted during welding
B. Adjacent to the weld metal where the microstructure changes without melting
C. Away from the weld and unaffected by heat
D. Filled by filler metal only
Answer: B
42. Which welding process produces the narrowest Heat Affected Zone (HAZ)?
A. Oxy-acetylene welding
B. Shielded Metal Arc Welding (SMAW)
C. Laser Beam Welding (LBW)
D. Thermit welding
Answer: C
43. Which of the following is the primary cause of residual stresses in welded joints?
A. Uniform heating and cooling
B. Uneven heating and contraction during cooling
C. Improper electrode storage
D. Excessive shielding gas flow
Answer: B
44. Preheating before welding is mainly done to
A. Increase welding speed
B. Reduce cooling rate and prevent cracking
C. Increase arc voltage
D. Reduce electrode consumption
Answer: B
45. Which welding process is commonly used for joining railway tracks?
A. TIG welding
B. Thermit welding
C. MIG welding
D. Spot welding
Answer: B
46. Which defect occurs when molten weld metal flows onto the base metal without proper fusion?
A. Undercut
B. Porosity
C. Overlap
D. Slag inclusion
Answer: C
47. Which of the following is a non-destructive testing (NDT) method for weld inspection?
A. Tensile test
B. Bend test
C. Radiographic test
D. Compression test
Answer: C
48. Which electrode coating produces the smoothest weld bead with low hydrogen content?
A. Cellulosic coating
B. Rutile coating
C. Basic (Low Hydrogen) coating
D. Acid coating
Answer: C
49. The main purpose of post-weld heat treatment (PWHT) is to
A. Increase welding current
B. Relieve residual stresses and improve toughness
C. Increase arc length
D. Improve electrode efficiency
Answer: B
50. Which welding process is best suited for underwater repair work?
A. Oxy-acetylene welding
B. Shielded Metal Arc Welding using waterproof electrodes
C. Resistance welding
D. Diffusion welding
Answer: B
51. Which welding process is capable of joining refractory metals in a vacuum environment?
A. TIG welding
B. Electron Beam Welding (EBW)
C. Spot welding
D. Gas welding
Answer: B
52. In plasma arc welding, the plasma is produced by
A. Burning acetylene gas
B. Constricting an electric arc through a fine nozzle
C. Chemical reaction of flux
D. Induction heating
Answer: B
53. Which welding process has the highest power density?
A. Oxy-acetylene welding
B. TIG welding
C. Electron Beam Welding
D. Resistance spot welding
Answer: C
54. Which shielding gas is generally used for MIG welding of carbon steel?
A. Hydrogen
B. Carbon dioxide (CO₂)
C. Nitrogen
D. Chlorine
Answer: B
55. Which welding symbol represents a fillet weld?
A. Square symbol
B. Triangle symbol
C. Circle symbol
D. Rectangle symbol
Answer: B
56. Arc blow is most likely to occur during
A. AC welding
B. DC welding
C. TIG welding only
D. Gas welding
Answer: B
57. Which factor primarily determines the penetration depth in arc welding?
A. Electrode color
B. Welding current
C. Flux thickness only
D. Electrode storage temperature
Answer: B
58. Which weld joint provides the highest strength when joining thick plates?
A. Lap joint
B. Butt joint with double-V groove
C. Edge joint
D. Corner joint
Answer: B
59. Flux in Submerged Arc Welding (SAW) primarily serves to
A. Increase welding speed only
B. Shield the molten weld pool and stabilize the arc
C. Reduce electrode diameter
D. Increase electrical resistance
Answer: B
60. Which welding process is most suitable for automated, high-speed welding of long straight seams in thick steel plates?
A. Gas welding
B. TIG welding
C. Submerged Arc Welding (SAW)
D. Forge welding
Answer: C
Hot Working, Cold Working, Rolling, Forging, Drawing & Extrusion
These questions are prepared for TNPSC CTSE, SSC JE, RRB JE, GATE, ISRO, BHEL, TRB, TNEB, and Diploma Mechanical Engineering examinations.
61. Hot working of metals is carried out
A. Below the recrystallization temperature
B. At the recrystallization temperature only
C. Above the recrystallization temperature
D. At the melting temperature
Answer: C
62. The primary advantage of hot working over cold working is
A. Better surface finish
B. No oxidation
C. Large deformation with lower forces
D. Higher dimensional accuracy
Answer: C
63. Which of the following is an advantage of cold working?
A. Grain refinement by recrystallization
B. Improved surface finish and dimensional accuracy
C. Lower strength
D. Elimination of strain hardening
Answer: B
64. Strain hardening is most significant during
A. Hot rolling
B. Hot forging
C. Cold working
D. Hot extrusion
Answer: C
65. During hot working, the metal continuously undergoes
A. Annealing and recrystallization
B. Carburizing
C. Nitriding
D. Tempering
Answer: A
66. Which rolling mill is commonly used for producing rails and structural sections?
A. Two-high rolling mill
B. Three-high rolling mill
C. Universal rolling mill
D. Cluster rolling mill
Answer: C
67. The neutral point in rolling is the point where
A. Roll pressure becomes zero
B. Strip speed equals roll surface speed
C. Friction becomes zero
D. Roll temperature is maximum
Answer: B
68. Which rolling defect is characterized by cracks along the edges of the rolled strip?
A. Alligatoring
B. Edge cracking
C. Waviness
D. Zipper crack
Answer: B
69. The rolling process in which the thickness decreases and the length increases is due to the principle of
A. Elastic deformation
B. Plastic deformation
C. Thermal expansion
D. Diffusion
Answer: B
70. Which rolling mill is best suited for rolling very thin sheets and foils?
A. Two-high mill
B. Planetary mill
C. Cluster (Sendzimir) mill
D. Universal mill
Answer: C
71. In open-die forging, deformation is mainly produced by
A. Closed impression dies
B. Compression between flat or simple dies
C. Centrifugal force
D. Internal pressure
Answer: B
72. Impression-die forging is also known as
A. Smith forging
B. Press forging
C. Closed-die forging
D. Roll forging
Answer: C
73. Which forging operation increases the cross-sectional area while reducing the length?
A. Drawing out
B. Upsetting
C. Punching
D. Swaging
Answer: B
74. Coining is mainly used for producing
A. Large shafts
B. Precision components with fine surface details
C. Pipes
D. Structural beams
Answer: B
75. Which forging defect is caused by improper metal flow inside the die cavity?
A. Scale pit
B. Cold shut
C. Underfilling
D. Flakes
Answer: C
76. Wire drawing differs from extrusion because
A. Drawing pulls the material, whereas extrusion pushes it
B. Drawing is performed only at high temperatures
C. Extrusion cannot produce long products
D. Drawing requires no die
Answer: A
77. Which extrusion process provides the lowest friction between billet and container wall?
A. Direct extrusion
B. Indirect extrusion
C. Hydrostatic extrusion
D. Impact extrusion
Answer: B
78. Hydrostatic extrusion is especially suitable for
A. Brittle materials
B. Wood
C. Rubber
D. Thermoplastics only
Answer: A
79. The principal purpose of lubrication during metal forming is to
A. Increase hardness
B. Reduce friction, wear, and forming load
C. Increase oxidation
D. Reduce ductility
Answer: B
80. Which of the following metal forming processes produces seamless tubes without welding?
A. Roll forming
B. Deep drawing
C. Tube extrusion
D. Piercing followed by rolling (Mannesmann process)
Answer: D
Powder Metallurgy – Questions 81–90
81. The process of heating a compacted metal powder below its melting point to develop strength through atomic bonding is called
A. Annealing
B. Sintering
C. Tempering
D. Normalizing
Answer: B. Sintering
82. Which powder production method is particularly suitable for producing fine powders of refractory metals such as tungsten?
A. Atomization
B. Mechanical crushing
C. Chemical reduction
D. Centrifugal disintegration
Answer: C. Chemical reduction
83. In powder metallurgy, “green strength” refers to the
A. Strength after sintering
B. Strength of the compact before sintering
C. Fatigue strength after heat treatment
D. Strength of individual powder particles
Answer: B. Strength of the compact before sintering
84. Which powder production process is most commonly used for manufacturing powders of metals with relatively low melting temperatures?
A. Electrolysis
B. Atomization
C. Chemical reduction
D. Grinding
Answer: B. Atomization
85. During powder compaction, density variation within the component primarily results from
A. Excessive sintering temperature
B. Friction between powder particles and die walls
C. Oxidation after sintering
D. Excessive alloying elements
Answer: B. Friction between powder particles and die walls
86. The primary purpose of sintering in powder metallurgy is to
A. Completely melt the powder particles
B. Develop metallurgical bonding between particles
C. Increase porosity to its maximum value
D. Convert the metal into an amorphous state
Answer: B. Develop metallurgical bonding between particles
87. The process of filling the interconnected pores of a sintered component with oil or another lubricant is known as
A. Infiltration
B. Impregnation
C. Atomization
D. Granulation
Answer: B. Impregnation
88. In powder metallurgy, infiltration refers to
A. Filling pores with a lower-melting-point metal
B. Removing lubricant from the compact
C. Compressing powder using hydrostatic pressure
D. Heating powder above its boiling temperature
Answer: A. Filling pores with a lower-melting-point metal
89. Self-lubricating bearings produced by powder metallurgy operate effectively because
A. They contain no pores
B. Their pores are impregnated with lubricant
C. They continuously melt during operation
D. They have extremely high thermal expansion
Answer: B. Their pores are impregnated with lubricant
90. Which of the following components is particularly suitable for manufacture by powder metallurgy?
A. Very large ship propeller
B. Connecting rod requiring extensive directional grain flow
C. Porous self-lubricating bearing
D. Large welded pressure vessel
Answer: C. Porous self-lubricating bearing
Processing of Plastics – Questions 91–100
91. Which plastic processing method uses a reciprocating screw to plasticize and force molten polymer into a closed mould cavity?
A. Blow moulding
B. Injection moulding
C. Compression moulding
D. Thermoforming
Answer: B. Injection moulding
92. In injection moulding, insufficient filling of the mould cavity resulting in an incomplete component is known as
A. Flash
B. Sink mark
C. Short shot
D. Warpage
Answer: C. Short shot
93. Which plastic processing technique is most appropriate for producing continuous lengths of pipes, rods and profiles having a uniform cross-section?
A. Injection moulding
B. Transfer moulding
C. Extrusion
D. Rotational moulding
Answer: C. Extrusion
94. The primary difference between thermoplastics and thermosetting plastics is that thermoplastics
A. Cannot be softened after initial moulding
B. Can repeatedly soften upon heating and harden upon cooling
C. Always possess cross-linked molecular structures
D. Cannot undergo extrusion
Answer: B. Can repeatedly soften upon heating and harden upon cooling
95. Which moulding process is particularly suitable for manufacturing hollow plastic bottles in large quantities?
A. Compression moulding
B. Blow moulding
C. Transfer moulding
D. Calendering
Answer: B. Blow moulding
96. Compression moulding is particularly suitable for processing
A. Thermosetting plastics
B. Metallic powders only
C. Glass sheets only
D. Low-viscosity liquids only
Answer: A. Thermosetting plastics
97. In transfer moulding, the moulding material is
A. Rotated inside a heated hollow mould
B. Heated in a chamber and forced into a closed mould cavity
C. Continuously pulled through rollers
D. Sprayed onto an open mould surface
Answer: B. Heated in a chamber and forced into a closed mould cavity
98. Which plastic processing method involves heating a thermoplastic sheet until soft and shaping it over or into a mould using pressure or vacuum?
A. Calendaring
B. Transfer moulding
C. Thermoforming
D. Pultrusion
Answer: C. Thermoforming
99. Which process is commonly employed for producing plastic sheets and films by passing softened polymer through a series of heated rollers?
A. Calendering
B. Rotational moulding
C. Compression moulding
D. Casting
Answer: A. Calendering
100. A large, hollow, seamless plastic water storage tank with relatively uniform wall thickness is most appropriately manufactured by
A. Injection moulding
B. Compression moulding
C. Rotational moulding
D. Transfer moulding
Answer: C. Rotational moulding