Question 1
Which of the following is a planar imperfection?
A) Slag inclusion
B) Lack of sidewall fusion
C) Porosity
D) Tungsten inclusion
Answer: B
Explanation: Planar imperfections are two-dimensional defects, such as cracks or lack of fusion. Lack of sidewall fusion is a planar defect as it occurs along a plane. Slag inclusion, porosity, and tungsten inclusion are volumetric (three-dimensional) defects.
Question 2
In a fillet weld, what is meant by “a”?
A) Throat thickness
B) Leg length
C) Penetration depth
D) Weld width
Answer: A
Explanation: “a” mean fillet weld throat size.
Question 3
Which welding process uses a non-consumable electrode?
A) MIG/MAG
B) TIG/GTAW
C) Submerged Arc Welding (SAW)
D) Manual Metal Arc (MMA)
Answer: B
Explanation: TIG (GTAW) uses a non-consumable tungsten electrode to create the arc, with filler material added separately if needed. MIG, SAW, and MMA use consumable electrodes.
Question 4
A solid inclusion in a weld is most likely to be:
A) Entrapped gas
B) Entrapped slag
C) Lack of inter-run fusion
D) Porosity
Answer: B
Explanation: A solid inclusion refers to non-metallic material trapped in the weld, such as slag. Entrapped gas causes porosity, and lack of fusion is not an inclusion.
Question 5
Which type of submerged arc welding flux is most susceptible to moisture pick-up?
A) Fused flux
B) Bonded flux
C) Agglomerated flux
D) Neutral flux
Answer: C
Explanation: Agglomerated fluxes are more porous and chemically bonded, making them highly susceptible to moisture absorption compared to fused fluxes, which are more resistant.
Question 6
What is the term for arc deflection caused by magnetic forces?
A) Arc blow
B) Arc wander
C) Arc instability
D) Arc drift
Answer: A
Explanation: Arc blow occurs when magnetic fields interfere with the welding arc, causing it to the arc’s path, making welding difficult to control.
Question 7
For MMA welding, when ‘hydrogen control’ is specified, the electrode is typically:
A) Cellulosic
B) Rutile
C) Basic
D) Iron oxide
Answer: C
Explanation: Basic (low-hydrogen) electrodes are used for hydrogen-controlled welding to minimize hydrogen-induced cracking in the weld. Cellulosic electrodes have high hydrogen content, and rutile is not low-hydrogen.
Question 8
Which defect is associated with insufficient throat thickness in a fillet weld?
A) Incomplete penetration
B) Undercut
C) Underfill
D) Lack of fusion
Answer: C
Explanation: Underfill in a fillet weld occurs when the weld metal does not sufficiently fill the joint, resulting in a reduced throat thickness, compromising strength.
Question 9
What is the primary purpose of preheating before welding?
A) Increase weld pool fluidity
B) Reduce residual stresses and hydrogen cracking risk
C) Improve electrode performance
D) Enhance arc stability
Answer: B
Explanation: Preheating slows the cooling rate, reducing residual stresses and the risk of hydrogen-induced cracking, particularly in high-strength steels.
Question 10
Which welding process is most suitable for welding aluminum?
A) MMA
B) TIG
C) SAW
D) FCAW
Answer: B
Explanation: TIG (GTAW) is ideal for aluminum due to its precise control, ability to weld thin materials, and use of AC to break the oxide layer.
Question 11
A single-V butt weld is most susceptible to which defect during MMA welding?
A) Lack of sidewall fusion
B) Slag inclusion
C) Porosity
D) Burn-through
Answer: A
Explanation: Single-V butt welds in MMA are prone to lack of sidewall fusion due to limited access to the sidewalls and improper electrode angle.
Question 12
What is the typical acceptance criterion for undercut in a weld?
A) No undercut is permitted
B) Depth up to 0.5 mm is acceptable
C) Depth up to 1 mm is acceptable
D) Depends on the standard
Answer: D
Explanation: Acceptance criteria for undercut vary depending on the applicable standard (e.g., EN ISO 5817 or ASME IX). Typically, small depths (e.g., 0.5–1 mm) are allowed for certain quality levels.
Question 13
Which NDT method is best for detecting surface cracks?
A) Ultrasonic Testing (UT)
B) Radiographic Testing (RT)
C) Magnetic Particle Inspection (MPI)
D) Eddy Current Testing
Answer: C
Explanation: MPI is highly effective for detecting surface and near-surface cracks in ferromagnetic materials by using magnetic fields and particles.
Question 14
What does the term ‘HAZ’ refer to in welding?
A) Heat-Affected Zone
B) High-Arc Zone
C) Hydrogen-Affected Zone
D) Hardened Alloy Zone
Answer: A
Explanation: The Heat-Affected Zone (HAZ) is the area of base material adjacent to the weld that undergoes microstructural changes due to welding heat.
Question 15
Which electrode coating produces the highest hydrogen content?
A) Rutile
B) Basic
C) Cellulosic
D) Iron powder
Answer: C
Explanation: Cellulosic electrodes produce high hydrogen levels due to their organic coating, increasing the risk of hydrogen-induced cracking.
Question 16
What is the purpose of post-weld heat treatment (PWHT)?
A) Increase weld strength
B) Reduce residual stresses and improve toughness
C) Remove surface oxides
D) Enhance corrosion resistance
Answer: B
Explanation: PWHT relieves residual stresses from welding and improves the weld’s toughness by tempering the microstructure.
Question 17
Which weld imperfection is caused by rapid cooling?
A) Slag inclusion
B) Crater crack
C) Porosity
D) Undercut
Answer: B
Explanation: Crater cracks form at the end of a weld due to rapid cooling of the weld pool, causing shrinkage stresses.
Question 18
What is the typical shielding gas for MIG welding of carbon steel?
A) 100% Argon
B) 100% CO2
C) Argon + CO2 mixture
D) Helium
Answer: C
Explanation: A mixture of Argon and CO2 (e.g., 80/20) is commonly used for MIG welding carbon steel, balancing arc stability and penetration.
Question 19
Which welding position is designated as ‘PA’ in EN ISO 6947?
A) Flat
B) Horizontal
C) Vertical-up
D) Overhead
Answer: A
Explanation: In EN ISO 6947, ‘PA’ refers to the flat welding position, where the weld is performed on the upper side of a horizontal joint.
Question 20
What is the main advantage of using AC in TIG welding?
A) Deeper penetration
B) Cleaning action on oxides
C) Reduced arc blow
D) Higher deposition rate
Answer: B
Explanation: AC in TIG welding alternates polarity, providing a cleaning action that removes oxides, especially when welding aluminum.
Question 21
Which defect appears as a groove along the weld toe?
A) Undercut
B) Overlap
C) Lack of fusion
D) Crater pipe
Answer: A
Explanation: Undercut is a groove melted into the base metal adjacent to the weld toe, often due to excessive current or improper technique.
Question 22
What is the primary function of flux in submerged arc welding?
A) Provide shielding and slag formation
B) Increase weld pool fluidity
C) Enhance arc stability
D) Reduce weld cooling rate
Answer: A
Explanation: Flux in SAW shields the arc from the atmosphere, forms slag to protect the weld, and can influence weld properties.
Question 23
Which material is non-magnetic and commonly welded?
A) Carbon steel
B) Stainless steel (austenitic)
C) Low-alloy steel
D) Cast iron
Answer: B
Explanation: Austenitic stainless steel (e.g., 304, 316) is non-magnetic and widely welded in industries due to its corrosion resistance.
Question 24
What is the typical range of carbon equivalent (CE) for weldable carbon steels?
A) 0.1–0.2
B) 0.3–0.6
C) 0.7–1.0
D) Above 1.0
Answer: B
Explanation: Carbon equivalent (CE) for weldable carbon steels typically ranges from 0.3 to 0.6, indicating good weldability with proper precautions.
Question 25
Which welding process is most prone to slag inclusions?
A) TIG
B) MIG
C) MMA
D) Plasma Arc
Answer: C
Explanation: MMA welding uses flux-coated electrodes, which can trap slag in the weld if not properly removed between passes.
Question 26
What is the purpose of a root gap in a butt weld?
A) Reduce distortion
B) Ensure full penetration
C) Improve arc stability
D) Decrease welding speed
Answer: B
Explanation: A root gap allows the welding arc to penetrate fully to the root of the joint, ensuring complete fusion.
Question 27
Which NDT method can detect both surface and subsurface defects in welds?
A) Dye Penetrant Testing (DPT)
B) Magnetic Particle Inspection (MPI)
C) Ultrasonic Testing (UT)
D) Visual Inspection
Answer: C
Explanation: UT uses high-frequency sound waves to detect both surface and subsurface defects, including cracks and inclusions.
Question 28
What is the typical acceptance criterion for porosity in a weld?
A) No porosity allowed
B) Limited size and distribution per standard
C) Porosity is always acceptable
D) Only surface porosity is acceptable
Answer: B
Explanation: Standards like EN ISO 5817 specify acceptable limits for porosity size, number, and distribution based on quality levels.
Question 29
Which welding process uses a flux-cored wire?
A) TIG
B) FCAW
C) SAW
D) MMA
Answer: B
Explanation: Flux-Cored Arc Welding (FCAW) uses a tubular wire filled with flux, which provides shielding and slag formation.
Question 30
What is the effect of excessive welding current in MMA?
A) Reduced penetration
B) Increased spatter and undercut
C) Improved arc stability
D) Decreased slag formation
Answer: B
Explanation: Excessive current in MMA causes increased spatter, undercut, and potential burn-through due to an overly intense arc.
Question 31
Which weld imperfection is caused by incomplete filling at the weld root?
A) Lack of fusion
B) Incomplete penetration
C) Undercut
D) Slag inclusion
Answer: B
Explanation: Incomplete penetration occurs when the weld metal does not fully penetrate the root of the joint, often due to insufficient current or improper technique.
Question 32
What is the typical shielding gas for TIG welding of stainless steel?
A) CO2
B) Argon
C) Helium
D) Argon + CO2
Answer: B
Explanation: Pure Argon is commonly used for TIG welding stainless steel, providing excellent arc stability and shielding.
Question 33
Which welding position is most challenging for a welder?
A) Flat (PA)
B) Horizontal (PC)
C) Vertical-up (PF)
D) Overhead (PE)
Answer: D
Explanation: Overhead (PE) welding is the most challenging due to gravity affecting the weld pool, increasing the risk of defects like sagging.
Question 34
What is the primary cause of hydrogen-induced cracking?
A) High welding speed
B) Presence of hydrogen, stress, and susceptible microstructure
C) Excessive preheat
D) Improper electrode angle
Answer: B
Explanation: Hydrogen-induced cracking requires diffusible hydrogen, tensile stresses, and a susceptible microstructure (e.g., martensite).
Question 35
Which defect is detected by visual inspection of a fillet weld?
A) Slag inclusion
B) Lack of fusion
C) Surface cracks
D) Incomplete penetration
Answer: C
Explanation: Visual inspection can detect surface cracks, undercut, or overlap, but not subsurface defects like slag inclusion or lack of fusion.
Question 36
**What is the purpose of a backing strip in welding?
A) Increase weld strength
B) Support the root pass
C) Reduce welding time
D) Improve electrode efficiency
Answer: B
Explanation: A backing strip supports the root pass, ensuring full penetration and preventing burn-through or root defects.
Question 37
Which welding process is critical for current return connections to avoid arc instability?
A) TIG
B) MIG/MAG
C) MMA
D) CO2 welding
Answer: B
Explanation: In MIG/MAG (including CO2 welding), poor current return connections can cause arc length fluctuations, affecting weld quality and consistency.
Question 38
What is the typical preheat temperature for low-alloy steel with CE > 0.45?
A) 50–100 °C
B) 100–150 °C
C) 150–250 °C
D) No preheat needed
Answer: C
Explanation: Low-alloy steels with CE > 0.4 often require preheating (150–250°C) to reduce the risk of hydrogen cracking and control cooling rates.
Question 39
Which imperfection is caused by excessive weave width in welding?
A) Undercut
B) Lack of fusion
C) Overlap
D) Porosity
Answer: B
Explanation: Excessive weave width can reduce heat input to the sidewalls, leading to lack of fusion.
Question 40
What is the typical range for interpass temperature in carbon steel welding?
A) 50–100 °C
B) 100–250 °C
C) 250–350 °C
D) Above 350 °C
Answer: B
Explanation: Interpass temperature for carbon steel is usually maintained between 100–250 °C to control cooling rates and prevent defects.
Question 41
Which NDT method requires access to both sides of the weld?
A) Radiographic Testing (RT)
B) Ultrasonic Testing (UT)
C) Magnetic Particle Inspection (MPI)
D) Dye Penetrant Testing (DPT)
Answer: A
Explanation: RT requires a radiation source on one side and a detector/film on the other, needing access to both sides of the weld.
Question 42
What is the effect of too low a welding current in TIG?
A) Excessive penetration
B) Incomplete fusion
C) Increased spatter
D) Reduced arc length
Answer: B
Explanation: Low current in TIG reduces heat input, leading to incomplete fusion or insufficient penetration.
Question 43
Which welding consumable is identified by the code ‘E7018’?
A) Cellulosic electrode
B) Rutile electrode
C) Basic low-hydrogen electrode
D) Iron powder electrode
Answer: C
Explanation: E7018 is a basic low-hydrogen electrode used for MMA, designed to minimize hydrogen-induced cracking.
Question 44
What is the primary cause of porosity in welds?
A) Excessive current
B) Contamination or gas entrapment
C) Rapid cooling
D) Improper electrode storage
Answer: B
Explanation: Porosity is caused by gas entrapment in the weld pool, often due to contamination (e.g., oil, moisture) or inadequate shielding.
Question 45
Which defect is associated with a lack of welder skill?
A) Crater pipe
B) Burn-through
C) Slag inclusion
D) All of the above
Answer: D
Explanation: Crater pipe, burn-through, and slag inclusion can all result from poor welder technique, such as improper arc termination or slag removal.
Question 46
What is the term for a weld that extends beyond the joint?
A) Overlap
B) Undercut
C) Reinforcement
D) Lack of fusion
Answer: A
Explanation: Overlap occurs when weld metal flows over the joint without fusing to the base metal, often due to low heat input or improper technique.
Question 47
Which welding process is automated and uses a granular flux?
A) MIG/MAG
B) Submerged arc welding (SAW)
C) FCAW
D) TIG
Answer: B
Explanation: SAW is an automated process that uses a continuous wire electrode and granular flux to shield the arc and form slag.
Question 48
What is the typical acceptance criterion for excess weld metal?
A) No excess allowed
B) Height limited by standard
C) Excess is always acceptable
D) Only occurs in fillet welds
Answer: B
Explanation: Standards like EN ISO 5817 specify acceptable heights for excess weld metal based on quality levels to ensure structural integrity.
Question 49
Which material requires special care to avoid cracking during welding?
A) Aluminum
B) Austenitic stainless steel
C) High-carbon steel
D) Copper
Answer: C
Explanation: High-carbon steel is prone to cracking due to its high hardenability and sensitivity to hydrogen, requiring preheating and controlled cooling.
Question 50
What is the purpose of a welding procedure specification (WPS)?
A) To record welder performance
B) To provide welding parameters and instructions
C) To certify weld quality
D) To document NDT results
Answer: B
Explanation: A WPS provides detailed instructions, including parameters like current, voltage, and preheat, to ensure consistent weld quality.
Question 51
Which welding imperfection is caused by a misaligned joint?
A) Incomplete penetration
B) Misalignment
C) Undercut
D) Slag inclusion
Answer: B
Explanation: Misalignment refers to the improper positioning of the joint before welding, leading to uneven weld appearance and stress concentration.
Question 52
What is the typical voltage range for MIG welding of carbon steel?
A) 10–15 V
B) 16–30 V
C) 30–40 V
D) Above 40 V
Answer: B
Explanation: MIG welding of carbon steel typically uses voltages between 16–30 V, depending on wire diameter, and material thickness.
Question 53
Which NDT method is unsuitable for non-ferromagnetic materials?
A) Ultrasonic Testing (UT)
B) Radiographic Testing (RT)
C) Magnetic Particle Inspection (MPI)
D) Dye Penetrant Testing (DPT)
Answer: C
Explanation: MPI relies on magnetic fields, making it unsuitable for non-ferromagnetic materials like aluminum or austenitic stainless steel.
Question 54
What is the effect of excessive travel speed in welding?
A) Increased penetration
B) Reduced weld bead size and lack of fusion
C) Improved arc stability
D) Decreased spatter
Answer: B
Explanation: Excessive travel speed reduces heat input, resulting in a smaller weld bead and potential lack of fusion.
Question 55
Which weld imperfection is caused by improper electrode angle in MMA?
A) Slag inclusion
B) Lack of sidewall fusion
C) Porosity
D) Crater crack
Answer: B
Explanation: An incorrect electrode angle in MMA can prevent proper fusion to the sidewall, causing a lack of sidewall fusion.
Question 56
What is the typical shielding gas for FCAW welding?
A) 100% Argon
B) CO2 or Argon/CO2 mixture
C) Helium
D) No gas required
Answer: B
Explanation: FCAW often uses CO2 or an Argon/CO2 mixture for shielding, depending on the wire type (gas-shielded vs. self-shielded).
Question 57
Which welding process is best for high-precision thin materials?
A) MMA
B) TIG
C) SAW
D) FCAW
Answer: B
Explanation: TIG offers precise control, making it ideal for thin materials like stainless steel or aluminum.
Question 58
What is the purpose of a run-on/run-off tab in welding?
A) Improve arc stability
B) Prevent weld imperfections at the start/end
C) Reduce preheat requirements
D) Enhance weld penetration
Answer: B
Explanation: Run-on/run-off tabs allow the welder to start and stop outside the joint, avoiding defects like crater cracks or porosity.
Question 59
Which defect is caused by moisture in the electrode coating?
A) Lack of fusion
B) Porosity
C) Undercut
D) Overlap
Answer: B
Explanation: Moisture in the electrode coating (e.g., in MMA) can release hydrogen or water vapor, causing porosity in the weld.
Question 60
What is the typical acceptance criterion for slag inclusions?
A) No slag inclusions allowed
B) Limited size and distribution per standard
C) Slag inclusions are always acceptable
D) Only surface slag is acceptable
Answer: B
Explanation: Standards like EN ISO 5817 specify acceptable limits for slag inclusion size and distribution based on quality levels.
Question 61
Which welding process uses a constant current power source?
A) MIG/MAG
B) TIG
C) SAW
D) FCAW
Answer: B
Explanation: TIG typically uses a constant current power source to maintain a stable arc, especially for manual welding.
Question 62
What is the effect of too high a preheat temperature?
A) Reduced risk of cracking
B) Increased grain growth and reduced toughness
C) Improved weld penetration
D) Decreased residual stresses
Answer: B
Explanation: Excessive preheat can cause grain growth in the HAZ, reducing material toughness and mechanical properties.
Question 63
Which imperfection is caused by improper cleaning between weld passes?
A) Lack of fusion
B) Slag inclusion
C) Porosity
D) Crater crack
Answer: B
Explanation: Failure to remove slag between passes in MMA or SAW can trap slag, forming inclusions in the weld.
Question 64
What is the typical current type for TIG welding of aluminum?
A) DCEN
B) DCEP
C) AC
D) Pulsed DC
Answer: C
Explanation: AC is used for TIG welding aluminum to provide cleaning action during the positive cycle and penetration during the negative cycle.
Question 65
Which welding position is designated as ‘PF’ in EN ISO 6947?
A) Flat
B) Horizontal
C) Vertical-up
D) Overhead
Answer: C
Explanation: ‘PF’ denotes the vertical-up welding position, where the welder moves upward against gravity.
Question 66
What is the primary cause of undercut in MIG welding?
A) Low current
B) Excessive voltage or travel speed
C) Insufficient shielding gas
D) Improper joint preparation
Answer: B
Explanation: Excessive voltage or travel speed in MIG can cause an unstable arc, leading to undercut along the weld toe.
Question 67
Which NDT method is best for detecting volumetric defects?
A) Magnetic Particle Inspection (MPI)
B) Dye Penetrant Testing (DPT)
C) Radiographic Testing (RT)
D) Visual Inspection
Answer: C
Explanation: RT is ideal for detecting volumetric defects like porosity and slag inclusions by penetrating the weld with X-rays.
Question 68
What is the effect of a too-short arc length in MMA?
A) Increased penetration
B) Incomplete arc
C) Electrode sticking
D)
Answer: C
Explanation: A too-short arc length in MMA reduces arc voltage, causing the electrode to stick to the workpiece.
Question 69
Which welding consumable is used for high-strength steel?
A) E6013
B) E7018
C) 7018
D)
Answer: E7018
Explanation: E7018 is a low-hydrogen electrode suitable for high-strength steel, providing strong welds with low cracking risk.
Question 70
What is the purpose of a welding procedure qualification record (WPQR)?
A) Provide welding parameters
B) Verify welder skill
C) Document test results to qualify a WPS
D) Certify weld quality
Answer: C
Explanation: A WPQR records test results to validate that a WPS produces acceptable welds as per standards.
Question 71
Which defect is caused by excessive current in TIG welding?
A) Incomplete fusion
B) Tungsten inclusion
C) Porosity
D) Lack of penetration
Answer: B
Explanation: Excessive current in TIG can overheat the tungsten electrode, causing tungsten particles to deposit in the weld.
Question 72
What is the typical interpass temperature for austenitic stainless steel?
A) 50–100 °C
B) 100–150 °C
C) 150–200 °C
D) Above 200 °C
Answer: B
Explanation: Austenitic stainless steel typically requires an interpass temperature of 100–150 °C to prevent sensitization and cracking.
Question 73
Which welding process is unsuitable for outdoor applications?
A) MMA
B) FCAW (self-shielded)
C) TIG
D) SAW
Answer: C
Explanation: TIG is sensitive to drafts and wind, which can disrupt shielding gas, making it unsuitable for outdoor use.
Question 74
What is the effect of insufficient shielding gas in MIG?
A) Increased penetration
B) Porosity
C) Reduced spatter
D) Improved fusion
Answer: B
Explanation: Insufficient shielding gas allows atmospheric gases to enter the weld pool, causing porosity.
Question 75
**Which weld imperfection is caused by improper joint fit-up?
A) Lack of fusion
B) Incomplete penetration
C) Undercut
D) Slag inclusion
Answer: B
Explanation: Poor joint fit-up, such as a tight root gap, can prevent full penetration, leading to incomplete penetration.
Question 76
What is the typical current type for SAW welding?
A) AC
B) DCEN
C) DCEP
D) or AC
Answer: D
Explanation: SAW can use AC or DCEP, depending on the flux and desired penetration characteristics.
Question 77
Which NDT method is limited to non-porous surfaces?
A) Ultrasonic Testing (UT)
B) Radiographic Testing (RT)
C) Dye Penetrant Testing (DPT)
D) Magnetic Particle Inspection (MPI)
Answer: C
Explanation: DPT requires a non-porous surface for the penetrant to work effectively in detecting surface defects.
Question 78
What is the effect of a too-high arc voltage in MMA?
A) Narrow weld bead
B) Excessive spatter and undercut
C) Incomplete fusion
D) Reduced penetration
Answer: B
Explanation: High arc voltage in MMA increases arc length, causing excessive spatter and undercut.
Question 79
Which welding process uses a plasma arc?
A) TIG
B) MIG
C) Plasma Arc Welding (PAW)
D) FCAW
Answer: C
Explanation: PAW uses a constricted plasma arc for high-precision welding, offering deeper penetration than TIG.
Question 80
What is the purpose of a fillet weld throat thickness measurement?
A) Verify weld strength
B) Ensure penetration
C) Check for undercut
D) Measure leg length
Answer: A
Explanation: Throat thickness determines the load-carrying capacity of a fillet weld, directly affecting its strength.
Question 81
Which defect is caused by improper termination of a weld?
A) Crater crack
B) Lack of fusion
C) Slag inclusion
D) Undercut
Answer: A
Explanation: Improper termination, such as abrupt arc stoppage, causes a crater that may crack due to shrinkage stresses.
Question 82
What is the typical shielding gas for MIG welding of stainless steel?
A) 100% CO2
B) Argon + Helium + CO2
C) 100% Argon
D) Helium
Answer: B
Explanation: A tri-mix gas (Argon + Helium + CO2) is commonly used for MIG welding stainless steel to balance arc stability and penetration.
Question 83
Which welding position is designated as ‘PE’ in EN ISO 6947?
A) Flat
B) Horizontal
C) Vertical-up
D) Overhead
Answer: D
Explanation: ‘PE’ denotes the overhead welding position, where welding is performed downward against gravity.
Question 84
What is the effect of a high carbon equivalent (CE) in steel?
A) Improved weldability
B) Increased risk of cracking
C) Reduced hardness
D) Enhanced corrosion resistance
Answer: B
Explanation: A high CE increases hardenability, making the steel more susceptible to cracking, requiring preheating and controlled welding.
Question 85
Which welding process is most prone to lack of fusion?
A) TIG welding
B) MIG welding
C) MMA welding
D) SAW welding
Answer: C
Answer: C
Explanation: MMA welding is prone to a lack of fusion due to improper electrode manipulation or insufficient heat input, especially in multi-pass welds.
Question 86
What is the purpose of a welding inspector’s visual inspection?
A) To detect subsurface defects
B) To assess surface quality and compliance
C) To measure weld strength
D) To perform NDT
Answer: B
Explanation: Visual inspection checks for surface imperfections, weld size, and compliance with standards, but cannot detect subsurface defects.
Question 87
What is the typical effect of welding high-sulfur steel?
A) Improved weldability
B) Increased risk of hot cracking
C) Reduced porosity
D) Enhanced toughness
Answer: B
Explanation: High sulfur content can form low-melting-point compounds, increasing the risk of hot cracking during weld solidification.
Question 88
Which NDT method uses sound wave reflections?
A) Radiographic Testing (RT)
B) Ultrasonic Testing (UT)
C) Magnetic Particle Inspection (MPI)
D) Dye Penetrant Testing (DPT)
Answer: B
Explanation: UT uses sound wave reflections to detect internal defects, measuring the time and amplitude of echoes.
Question 89
What is the effect of a too-high welding speed in TIG?
A) Increased penetration
B) Lack of fusion and reduced bead size
C) Improved arc stability
D) Decreased spatter
Answer: B
Explanation: High welding speed in TIG reduces heat input, leading to a lack of fusion and a smaller weld bead.
Question 90
Which welding consumable is most suitable for welding cast iron?
A) E6013
B) Nickel-based electrode
C) E7018
D) E701
Answer: B
Explanation: Nickel-based electrodes (e.g., ENiFe-CI) are used for cast iron welding due to welding due to their ductility and ability to tolerate impurities.
Question 91
What is the purpose of a welding procedure test?
A) To train welders
B) To qualify a welding procedure
C) To certify welders
D) To inspect welds
Answer: B
Explanation: A welding procedure test verifies that a WPS produces acceptable welds, qualifying it for production use.
Question 92
Which defect is caused by excessive electrode angle in MIG welding?
A) Porosity
B) Lack of fusion
C) Undercut
D) Slag inclusion
Answer: B
Explanation: An excessive electrode angle in MIG misdirects the arc, reducing sidewall fusion and causing a lack of fusion.
Question 93
What is the typical current type for FCAW welding?
A) AC
B) DCEN
C) DCEP
D) Pulsed DC
Answer: C
Explanation: FCAW typically uses DCEP (electrode positive) to ensure proper arc characteristics and deposition rate.
Question 94
What is the effect of a too-long arc length in TIG welding??
A) Increased penetration
B) Unstable arc and porosity
C) Reduced spatter
D) Improved fusion
Answer: B
Explanation: A long arc length in TIG increases arc stability issues, allowing atmospheric gases to enter and cause porosity.
Question 95
Which welding process welding process is most suitable for automated welding of thick sections??
A) TIG
B) SAW
C) MMA
D) FCAW
Answer: B
Explanation: SAW is highly automated, efficient, and ideal for welding thick sections due to high deposition rates and deep penetration.
Question 96
What is the purpose of a welder qualification test??
A) To develop a WPS
B) To certify a welder’s skill
C) To inspect welds
D) To qualify a welding procedure
Answer: B
Explanation: A welder qualification test verifies a welder’s ability to produce sound welds per a qualified WPS.
Question 97
Which welding imperfection is caused by a lack of filler metal at the weld toe??
A) Overlap
B) Undercut
C) Lack of fusion
D) Incomplete penetration
Answer: B
Explanation: Undercut is a groove at the weld toe due to melting of the base metal without sufficient filler metal to fill it.
Question 98
What is the typical voltage range for MMA welding?
A) 10–15 V
B) 16–40 V
C) 40–60 V
D) Above 60 V
Answer: B
Explanation: MMA welding typically operates between 16–40 V, depending on the electrode type and welding conditions.
Question 99
Which NDT method is most cost-effective for surface defect detection??
A) Radiographic Testing (RT)
B) Ultrasonic Testing (UT)
C) Dye Penetrant Testing (DPT)
D) Magnetic Particle Inspection (MPI)
Answer: C
Explanation: DPT is cost-effective and simple for detecting surface defects in non-porous materials, requiring minimal equipment.
Question 100
What is the effect of improper storage of low-hydrogen electrodes??
A) Reduced arc stability
B) Increased risk of porosity and cracking
C) Improved weld penetration
D) Decreased slag formation
Answer: B
Explanation: Improper storage (e.g., exposure to moisture) of low-hydrogen electrodes introduces hydrogen, increasing porosity and cracking risk.
