Latest Welding MCQs Questions and Answers | Welding Exam Preparation 2025
If you’re preparing for welding exams, ITI Welder trade tests, RRB, SSC JE, Diploma, or technical interviews, this page will help you revise important Welding MCQs in one place.
We have compiled a set of important multiple-choice questions (MCQs) on welding covering:
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Arc Welding
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Gas Welding
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TIG & MIG Welding
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Resistance Welding (Spot, Seam, Projection, Butt)
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Thermit & Electroslag Welding
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Submerged Arc Welding
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Welding Joints, Flames, HAZ & Polarity
You can use these questions for self-practice, mock tests, or quick revision before an exam.
How to Use This Welding MCQ Set?
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Read the question carefully
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Try to answer before checking the correct option
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Use it as a daily practice set to build confidence
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Suitable for students, trainees, and working welders
Latest Welding MCQs (With Answers)
You can keep the format exactly like this for all questions:
Question → Options (a–d) → Correct Answer
Who Can Use These Welding MCQs?
This question bank is useful for:
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ITI Welder students
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Polytechnic & Diploma students
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Apprentice & trade test candidates
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RRB, SSC JE, State JE aspirants
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Working welders revising theory for interviews or promotions
Latest Welding MCQs – Click to View Answers
1. Which welding process is used to join two thick plates in one single pass?
a) Oxy-acetylene welding
b) TIG
c) MIG
d) Electroslag welding
Answer: d
b) TIG
c) MIG
d) Electroslag welding
Answer: d
2. The welding process used to weld fastener to plates without drilling or punching holes?
a) Electroslag
b) Oxy-acetylene
c) Butt welding
d) Stud welding
Answer: d
b) Oxy-acetylene
c) Butt welding
d) Stud welding
Answer: d
3. For underwater welding, which process is NOT used?
a) Electroslag
b) SMAW
c) GTAW
d) MIG
Answer: a
b) SMAW
c) GTAW
d) MIG
Answer: a
4. Welding process with greater directional stability due to copper orifice?
a) Oxy-acetylene
b) MIG
c) TIG
d) Plasma arc welding
Answer: d
b) MIG
c) TIG
d) Plasma arc welding
Answer: d
5. Process using exothermal chemical reaction for high temperature:
a) Electroslag
b) Plasma arc
c) Thermit welding
d) Stud welding
Answer: c
b) Plasma arc
c) Thermit welding
d) Stud welding
Answer: c
6. Temperature during exothermal chemical reaction in Thermit welding:
a) 2100°C
b) 2700°C
c) 3100°C
d) 3500°C
Answer: b
b) 2700°C
c) 3100°C
d) 3500°C
Answer: b
7. Process used for repairing tracks and spokes of driving wheels:
a) Electroslag
b) Plasma arc
c) Thermit welding
d) Electron beam welding
Answer: c
b) Plasma arc
c) Thermit welding
d) Electron beam welding
Answer: c
8. Process allowing deep fusion welds with minimum width:
a) Electron beam welding
b) Ultrasonic welding
c) Plasma arc welding
d) Friction welding
Answer: a
b) Ultrasonic welding
c) Plasma arc welding
d) Friction welding
Answer: a
9. In inert gas arc welding magnesium is welded using:
A) Non-combustible electrode + helium + DC
B) AC + Argon
C) DCSP
D) CO₂
Answer: A
B) AC + Argon
C) DCSP
D) CO₂
Answer: A
10. Carbon arc welding is:
A) Iron oxide + aluminium
B) Metal pool
C) Used to weld carbon rods
D) None
Answer: D
B) Metal pool
C) Used to weld carbon rods
D) None
Answer: D
11. Thermit welding is:
A) Iron oxide + aluminium
B) Molten pool
C) Arc under flux
D) None
Answer: A
B) Molten pool
C) Arc under flux
D) None
Answer: A
12. Most commonly used flame in gas welding:
a) Neutral
b) Oxidising
c) Carburising
d) All
Answer: a
b) Oxidising
c) Carburising
d) All
Answer: a
13. Arc-welding uses which electric supply?
a) AC
b) DC
c) Both
d) Spiral
Answer: c
b) DC
c) Both
d) Spiral
Answer: c
14. Electroslag welding is:
a) Iron oxide + aluminium
b) Metal pool between plates
c) Arc under flux
d) None
Answer: b
b) Metal pool between plates
c) Arc under flux
d) None
Answer: b
15. Submerged arc welding is:
a) Thermit reaction
b) Metal pool
c) Arc under flux blanket
d) All
Answer: c
b) Metal pool
c) Arc under flux blanket
d) All
Answer: c
16. Depth of projection in projection welding is:
a) 20%
b) 40%
c) 60%
d) 80%
Answer: c
b) 40%
c) 60%
d) 80%
Answer: c
17. Large number of welds can be carried out simultaneously in:
a) Spot welding
b) Projection welding
c) Seam welding
d) Percussion welding
Answer: b
b) Projection welding
c) Seam welding
d) Percussion welding
Answer: b
18. Continuous welds between overlapping sheet metals in:
a) Projection welding
b) Seam welding
c) Flash welding
d) Percussion welding
Answer: b
b) Seam welding
c) Flash welding
d) Percussion welding
Answer: b
19. Current is NOT passed continuously in:
a) Projection welding
b) Seam welding
c) Flash welding
d) Percussion welding
Answer: b
b) Seam welding
c) Flash welding
d) Percussion welding
Answer: b
20. Resistance welding process using electrodes of copper wheels:
a) Projection welding
b) Seam welding
c) Flash welding
d) Percussion welding
Answer: b
b) Seam welding
c) Flash welding
d) Percussion welding
Answer: b
21. ERW pipes are manufactured by:
a) Projection
b) Seam
c) Percussion
d) Flash
Answer: b
b) Seam
c) Percussion
d) Flash
Answer: b
22. Electrode tip diameter:
a) √t
b) √2t
c) 2√t
d) √3t
Answer: a
b) √2t
c) 2√t
d) √3t
Answer: a
23. Flame temperature in oxy-acetylene welding:
a) 1600–1700°C
b) 2000–2100°C
c) 2500–2600°C
d) 3200–3300°C
Answer: d
b) 2000–2100°C
c) 2500–2600°C
d) 3200–3300°C
Answer: d
24. Colour of oxygen cylinder:
a) Red
b) Maroon
c) Black
d) Brown
Answer: c
b) Maroon
c) Black
d) Brown
Answer: c
25. Colour of acetylene cylinder:
a) Red
b) Maroon
c) Black
d) Brown
Answer: b
b) Maroon
c) Black
d) Brown
Answer: b
26. Acetylene is prepared by:
a) Water + CaC₂
b) Water + CaCO₃
c) Hydrogen + CaC₂
d) H₂ + CaCO₃
Answer: a
b) Water + CaCO₃
c) Hydrogen + CaC₂
d) H₂ + CaCO₃
Answer: a
27. Flame suitable for welding Fe, Cu, Al alloys:
a) Oxidising
b) Carburising
c) Neutral
d) None
Answer: c
b) Carburising
c) Neutral
d) None
Answer: c
28. Flame suitable for cutting:
a) Oxidising
b) Carburising
c) Neutral
d) None
Answer: a
b) Carburising
c) Neutral
d) None
Answer: a
29. Flame for welding brass and bronze:
a) Oxidising
b) Carburising
c) Neutral
d) None
Answer: a
b) Carburising
c) Neutral
d) None
Answer: a
30. Flame suitable for welding steel:
a) Oxidising
b) Carburising
c) Neutral
d) None
Answer: b
b) Carburising
c) Neutral
d) None
Answer: b
31. Which is NOT true for gas welding?
a) HAZ & distortion are less
b) Suitable for thin sheets
c) Slower than arc welding
d) Gas safety issues
Answer: a
b) Suitable for thin sheets
c) Slower than arc welding
d) Gas safety issues
Answer: a
32. Temperature of arc in arc welding:
a) 2000°C
b) 2600°C
c) 3000°C
d) 3600°C
Answer: d
b) 2600°C
c) 3000°C
d) 3600°C
Answer: d
33. Arc initiation voltage:
a) 20–60V
b) 60–100V
c) 100–140V
d) 140–180V
Answer: b
b) 60–100V
c) 100–140V
d) 140–180V
Answer: b
34. Gap for sound weld:
a) 1mm
b) 3mm
c) 5mm
d) 7mm
Answer: b
b) 3mm
c) 5mm
d) 7mm
Answer: b
35. Welding process using non-consumable electrode:
a) TIG
b) SMAW
c) CO₂ welding
d) MIG
Answer: a
b) SMAW
c) CO₂ welding
d) MIG
Answer: a
36. Elements controlled in arc welding:
a) Current, voltage, travel speed
b) Current, voltage, arc length
c) Current, arc length, speed
d) Voltage, arc length, speed
Answer: a
b) Current, voltage, arc length
c) Current, arc length, speed
d) Voltage, arc length, speed
Answer: a
37. Polarity used in TIG:
a) DCSP
b) DCRP
c) AC + HF
d) All of the above
Answer: d
b) DCRP
c) AC + HF
d) All of the above
Answer: d
38. Gas mixture NOT used in TIG:
a) Argon–Helium
b) Argon–Nitrogen
c) Argon–Hydrogen
d) Argon–CO₂
Answer: b
b) Argon–Nitrogen
c) Argon–Hydrogen
d) Argon–CO₂
Answer: b
39. Polarity generally used in MIG welding:
a) DCSP
b) DCRP
c) AC
d) All
Answer: a
b) DCRP
c) AC
d) All
Answer: a
40. Forge welding is best suited for:
a) Stainless steel
b) High carbon steel
c) Cast iron
d) Wrought iron
Answer: d
b) High carbon steel
c) Cast iron
d) Wrought iron
Answer: d
41. Temperature in arc welding (general):
a) 1000°C
b) 1500°C
c) 5500°C
d) 8000°C
Answer: c
b) 1500°C
c) 5500°C
d) 8000°C
Answer: c
42. Strongest brazing joint:
a) Butt
b) Scarf
c) Lap
d) All equal
Answer: c
b) Scarf
c) Lap
d) All equal
Answer: c
43. Carbon electrode arc welding uses:
a) AC
b) Rectifier
c) Motor generator
d) DC straight polarity
Answer: d
b) Rectifier
c) Motor generator
d) DC straight polarity
Answer: d
44. Reverse polarity welding:
a) Electrode – & work +
b) Electrode + & work –
c) Work + holder earthed
d) Holder + work earthed
Answer: b
b) Electrode + & work –
c) Work + holder earthed
d) Holder + work earthed
Answer: b
45. Metal transfer in MIG welding occurs as:
a) Fine spray
b) Molten drops
c) Weld pool
d) Molecules
Answer: a
b) Molten drops
c) Weld pool
d) Molecules
Answer: a
46. Distortion in welding occurs due to:
a) Excessive current
b) Improper clamping
c) Wrong electrodes
d) Oxidation
Answer: b
b) Improper clamping
c) Wrong electrodes
d) Oxidation
Answer: b
47. In inert gas welding of aluminium:
a) Helium + DC
b) Argon + AC
c) DCSP
d) CO₂
Answer: b
b) Argon + AC
c) DCSP
d) CO₂
Answer: b
48. Joint with best corrosion resistance:
a) Welded joint
b) Riveted
c) Bolted
d) None
Answer: a
b) Riveted
c) Bolted
d) None
Answer: a
49. Ray NOT produced during welding:
a) Gamma
b) Visible
c) Infrared
d) UV
Answer: a
b) Visible
c) Infrared
d) UV
Answer: a
50. Thickness for Single-V and Single-U butt welds:
a) Up to 10mm
b) 5–15mm
c) 10–20mm
d) 15–25mm
Answer: b
b) 5–15mm
c) 10–20mm
d) 15–25mm
Answer: b
51. Thickness for Double-V & Double-U welds:
a) 1–5mm
b) 5–10mm
c) 10–15mm
d) Over 15mm
Answer: d
b) 5–10mm
c) 10–15mm
d) Over 15mm
Answer: d
52. Which is NOT a fillet weld?
a) Butt joint
b) Lap joint
c) T-joint
d) Corner joint
Answer: a
b) Lap joint
c) T-joint
d) Corner joint
Answer: a
53. Metals with best weldability (in descending order) are:
a) Cast steel
b) Iron
c) Carbon steel
d) Cast iron
Answer: d
b) Iron
c) Carbon steel
d) Cast iron
Answer: d
54. Penetration is the ratio of:
a) Width/depth
b) Length/depth
c) Depth/width
d) Depth/length
Answer: a
b) Length/depth
c) Depth/width
d) Depth/length
Answer: a
55. Example of plastic welding:
a) Gas
b) Arc
c) Forge
d) Thermit pressure
Answer: c
b) Arc
c) Forge
d) Thermit pressure
Answer: c
56. Example of fusion welding:
a) Arc
b) Forge
c) Resistance
d) Thermit with pressure
Answer: a
b) Forge
c) Resistance
d) Thermit with pressure
Answer: a
57. Welding used in automobile & aircraft sheet metals:
a) SMAW
b) TIG
c) Thermit
d) Resistance welding
Answer: d
b) TIG
c) Thermit
d) Resistance welding
Answer: d
58. Heat is created by blacksmith fire in:
a) Forge welding
b) Spot welding
c) Projection
d) Seam
Answer: a
b) Spot welding
c) Projection
d) Seam
Answer: a
59. Heat created by chemical reaction in:
a) Resistance
b) Oxy-acetylene
c) TIG
d) Thermit welding
Answer: d
b) Oxy-acetylene
c) TIG
d) Thermit welding
Answer: d
60. Voltage used in resistance welding:
a) 4–12V
b) 12–20V
c) 20–28V
d) 28–36V
Answer: a
b) 12–20V
c) 20–28V
d) 28–36V
Answer: a
61. Heat generated formula in resistance welding:
a) I²Rt
b) IR²t
c) IRt²
d) 2IRT
Answer: a
b) IR²t
c) IRt²
d) 2IRT
Answer: a
62. Voltage in resistance welding does NOT depend on:
a) Composition
b) Area
c) Thickness
d) Length
Answer: d
b) Area
c) Thickness
d) Length
Answer: d
63. True statements for resistance welding:
i. Current flow time important
ii. Pressure maintained after current off
iii. Water cooling required
Answer: d (i, ii & iii)
ii. Pressure maintained after current off
iii. Water cooling required
Answer: d (i, ii & iii)
64. Electrodes in resistance welding are made of:
a) Aluminium
b) Copper
c) Iron
d) Bronze
Answer: b
b) Copper
c) Iron
d) Bronze
Answer: b
65. Which is NOT a resistance welding process?
a) Spot welding
b) Butt welding
c) Pressure welding
d) Percussion welding
Answer: c
b) Butt welding
c) Pressure welding
d) Percussion welding
Answer: c
66. Suitable process for welding metals up to 8mm:
a) Spot welding
b) Projection welding
c) Butt welding
d) Pressure welding
Answer: a
b) Projection welding
c) Butt welding
d) Pressure welding
Answer: a
67. Weld nugget diameter in spot welding:
a) 4t + 2.5
b) 8t + 2.5
c) 12t + 2.5
d) 2t + 2.5
Answer: d
b) 8t + 2.5
c) 12t + 2.5
d) 2t + 2.5
Answer: d
68. Spacing between spot welds:
a) 4t
b) 8t
c) 12t
d) 16t
Answer: c
b) 8t
c) 12t
d) 16t
Answer: c
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