CTVET Certificate II in Welding and Fabrication (Ghana)

Which shade of filter lens is recommended as the minimum eye protection for manual metal arc welding (SMAW) operating between 75 and 200 amperes?

• AShade 10 to 11
• BShade 4 to 5
• CShade 7 to 8
• DShade 14 to 15

Which safety device is designed to extinguish a flame and stop the reverse flow of gas in oxy-acetylene welding and cutting systems?

• AFlashback arrestor
• BNon-return valve (check valve)
• CPressure regulator
• DCylinder manifold

How are the cylinder valve connection threads for combustible gases like acetylene and LPG differentiated from non-combustible gas connections?

• AThey have left-hand threads with a groove cut into the nut.
• BThey have right-hand threads with a smooth nut surface.
• CThey are color-coded green with extra-fine threads.
• DThey use female quick-release snap couplings only.

What is the correct procedure for storing oxygen and acetylene cylinders when they are not in active use in a welding shop?

• AStored upright, secured with chains, and separated by a fire-resistant wall of at least 1…
• BLaid horizontally on racks together to prevent them from falling over.
• CStored in a tightly sealed storage container to keep out dust and moisture.
• DChained together in a single group to maximize space saving.

Which of the following is the most appropriate first-aid response for a minor, closed heat burn on a welder's forearm?

• AImmerse the burned area in cool, clean water for at least 10 to 15 minutes.
• BApply welding grease or petroleum jelly immediately to soothe the pain.
• CPop any blisters that form to speed up the skin's healing process.
• DApply ice directly to the burn to reduce swelling rapidly.

Why is it critical to wear safety glasses under a welding helmet during welding operations?

• ATo protect the eyes from flying slag and spatter when the helmet is flipped up.
• BTo double the shade value of the welding helmet's filter lens.
• CTo prevent the helmet from sliding off the welder's head.
• DTo filter out high-frequency sound waves from the arc.

Which type of fire extinguisher is mandatory to have near a welding station specifically for electrical fires involving energized equipment?

• AClass C (CO2 or dry chemical) extinguisher
• BClass A (pressurized water) extinguisher
• CClass D (special dry powder) extinguisher
• DSoda-acid extinguisher

What health hazard is caused by inhaling the white fumes generated when welding galvanized steel, and how is it prevented?

• AZinc fume fever; prevented by local exhaust ventilation and respirator use.
• BSilicosis; prevented by wearing leather aprons and safety boots.
• CAsbestosis; prevented by using water-cooled torches.
• DCarbon monoxide poisoning; prevented by using carbon dioxide shielding gas.

What is the primary function of local exhaust ventilation (LEV) systems in a vocational welding workshop?

• ATo capture and remove welding fumes and gases at their source before they reach the welde…
• BTo cool down the welding workpiece during high-current operations.
• CTo provide a clean supply of pure oxygen to support the arc.
• DTo blow away shielding gases to speed up weld solidification.

If a fellow student is in contact with an active, live electrical wire in the welding shop, what is the first action you should take?

• ATurn off or isolate the main power source immediately before touching the victim.
• BGrab the victim's arms and pull them away from the wire as fast as possible.
• CThrow cold water over the victim to disrupt the electrical current.
• DWrap a wet rag around the wire to insulate it from the ground.

Why are synthetic clothing materials, such as polyester or nylon, strictly forbidden in a welding workshop?

• AThey melt easily when exposed to sparks and stick to the skin, causing severe deep burns.
• BThey attract magnetic particles which block the welding current.
• CThey insulate the welder's body too much, causing heat exhaustion.
• DThey react chemically with argon gas to produce toxic chlorine fumes.

What is the extreme danger associated with using oil or grease to lubricate the threads of an oxygen cylinder regulator?

• AHigh-pressure oxygen reacts violently with hydrocarbons (oil/grease), causing spontaneous…
• BThe oil will contaminate the gas, causing severe weld porosity.
• CThe grease will clog the regulator diaphragm, preventing gas flow.
• DOil causes the brass threads to corrode and seize permanently.

What is the maximum safe working pressure for acetylene gas in its free state, beyond which it becomes highly unstable and can explode?

• A15 psi (1.03 bar)
• B150 psi (10.3 bar)
• C2.5 psi (0.17 bar)
• D250 psi (17.2 bar)

What is the medical term for the painful eye condition caused by exposure of unprotected eyes to ultraviolet (UV) rays from a welding arc?

• APhotokeratitis (arc eye)
• BGlaucoma
• CCataracts
• DAstigmatism

Why must welding work boots be equipped with steel toes and have their laces covered by leather spats or be laceless?

• ATo prevent falling heavy metal plates from crushing toes and to stop hot slag from burnin…
• BTo make the boots electrically conductive to ground the welder's body.
• CTo increase the welder's height and improve their view of the weld pool.
• DTo absorb excess electromagnetic radiation generated by high-frequency arcs.

In the AWS classification system for manual metal arc welding (SMAW) electrodes, what does the letter 'E' stand for?

• AElectrode
• BEngineered
• CElectricity
• DExtruded flux

What is represented by the first two digits (e.g., '70') of the AWS classification E7018 welding electrode?

• AThe minimum tensile strength of the deposited weld metal in thousands of pounds per squar…
• BThe maximum current carrying capacity in amperes.
• CThe percentage of iron powder contained in the flux coating.
• DThe minimum preheating temperature of the base metal in degrees Celsius.

Which welding positions are permitted when using an AWS E6013 electrode, as indicated by the third digit in its code?

• AAll positions (flat, horizontal, vertical, and overhead)
• BFlat and horizontal fillet positions only
• CFlat position only
• DVertical-down position only

What characteristics does the number '8' represent in the last digit of the AWS E7018 electrode code?

• ALow-hydrogen potassium coating with iron powder, compatible with AC or DCEP.
• BHigh cellulose sodium coating, compatible with DCEN only.
• CHigh titania potassium (rutile) coating, compatible with AC only.
• DIron oxide sodium coating, compatible with DCEP only.

When welding with Direct Current Electrode Negative (DCEN/straight polarity) in SMAW, how is the arc heat generally split between the workpiece and the electrode?

• AApproximately 70% of the heat is concentrated at the workpiece, and 30% is at the electro…
• BApproximately 70% of the heat is concentrated at the electrode, and 30% is at the workpie…
• CThe heat is distributed equally (50/50) between the workpiece and the electrode.
• D90% of the heat is concentrated at the electrode, leaving the plate cool.

What is the primary chemical constituent in the flux coating of an E6013 electrode, which gives it its smooth arc characteristics?

• ARutile (Titanium Dioxide)
• BCellulose (Wood flour)
• CCalcium carbonate (Lime)
• DIron powder only

Why must low-hydrogen electrodes like E7018 be stored in specialized holding ovens after their hermetically sealed containers are opened?

• ATo prevent the flux coating from absorbing moisture from the air, which causes hydrogen c…
• BTo preheat the core wire so it ignites the arc at lower welding voltages.
• CTo dry out toxic chemicals in the flux before they burn and release fumes.
• DTo melt the iron powder slightly to improve its binding with the flux.

Which of the following defects is most likely to occur in structural steel welds if wet or moisture-contaminated E7018 electrodes are used?

• APorosity and hydrogen-induced underbead cracking
• BSlag inclusions at the weld cap
• CExcessive root penetration
• DTungsten contamination of the weld pool

What is meant by the 'duty cycle' of a welding machine rating (e.g., 60% duty cycle at 200 A)?

• AThe percentage of a 10-minute period the machine can operate continuously at rated curren…
• BThe ratio of welding time to chipping and cleaning time in a shift.
• CThe electrical efficiency rating of the transformer under full load.
• DThe lifespan of the machine before internal component maintenance is required.

Why do manual welding processes like SMAW and GTAW require a Constant Current (CC) power source instead of a Constant Voltage (CV) power source?

• ATo keep the welding current relatively stable even when the welder's hand movements cause…
• BTo prevent the voltage from dropping when the electrode touches the plate.
• CTo allow the wire feeder to adjust its speed automatically.
• DTo ensure the welding machine consumes less grid electricity.

What is the phenomenon called when the welding arc is deflected from its intended path by magnetic forces during DC SMAW operations?

• AArc blow
• BBackfire
• CMagnetic decay
• DWandering current

Which of the following actions is a recognized method for reducing or eliminating arc blow when welding with DC current?

• ASwitching the welding machine output from DC to AC.
• BIncreasing the arc length as much as possible.
• CPositioning the ground clamp directly on the weld joint line.
• DUsing a larger diameter electrode with higher voltage settings.

As a general rule of thumb, what is the ideal arc length that a welder should maintain during manual metal arc welding?

• AApproximately equal to the diameter of the electrode's metallic core wire.
• BDouble the length of the entire electrode including the flux.
• CExactly 10 millimeters, regardless of electrode diameter.
• DAs close to zero as possible, keeping the flux coating dragging in the weld pool.

Which set of tools must a welder use to properly clean a manual metal arc weld bead between successive weld passes?

• AChipping hammer and wire brush
• BBall-peen hammer and cold chisel
• CAngle grinder with a cutting disc only
• DWet rag and steel wool

How does the selection of a larger electrode diameter affect the required welding current (amperage) in SMAW?

• AIt requires a higher welding current to melt the larger volume of metal.
• BIt requires a lower welding current to prevent the core wire from overheating.
• CThe current remains exactly the same; only the voltage must be increased.
• DIt requires alternating current (AC) only, rendering DC unusable.

What is the primary operational benefit of using a cellulosic electrode (such as E6010) compared to a rutile electrode (such as E6013)?

• AIt provides deep weld penetration and a fast-freezing weld puddle, making it ideal for pi…
• BIt produces a highly aesthetic weld cap with virtually no spatter.
• CIt does not require slag removal between weld passes.
• DIt can weld thick steel without generating any toxic fumes.

In the Ghanaian vocational training context, which electrode is standard for students learning their first multi-pass structural plate welds, and why?

• AE6013, due to its easy arc striking, stable arc, and general versatility on mild steel.
• BE7024, because it can be welded in vertical-up and overhead positions easily.
• CE6010, because it works best on cheap alternating current (AC) buzzing machines.
• DE8018-B2, because it is specifically designed for welding high-purity aluminum plates.

What is the alternative name for the Direct Current Electrode Positive (DCEP) welding current setup?

• AReverse polarity
• BStraight polarity
• CAlternating phase
• DOpen-circuit potential

Which of the following is a primary function of the flux coating on an SMAW electrode during the welding process?

• ATo generate a shielding gas that protects the molten weld pool from oxygen and nitrogen i…
• BTo physically increase the diameter of the core wire to speed up welding.
• CTo act as a heat insulator to cool down the weld joint rapidly.
• DTo prevent the electrode holder from becoming electrically live.

What weld defect is characterized by a groove melted into the base metal adjacent to the weld toe that has not been filled with weld metal?

• AUndercut
• BOverlap
• CPorosity
• DLack of penetration

Which shielding gas mixture is most commonly used for Gas Metal Arc Welding (GMAW/MIG) on mild carbon steel to achieve a stable arc and low spatter?

• A75% Argon / 25% Carbon Dioxide (CO2)
• B100% Pure Argon
• C95% Nitrogen / 5% Hydrogen
• D100% Pure Helium

Which type of welding power source design is required for Gas Metal Arc Welding (GMAW) to maintain a stable arc length automatically?

• AConstant Voltage (CV)
• BConstant Current (CC)
• CHigh Frequency AC Transformer
• DVariable Resistance Generator

In Gas Tungsten Arc Welding (GTAW/TIG), what is the primary function of the shielding gas?

• ATo shield the hot tungsten electrode and the weld pool from atmospheric contamination.
• BTo react with the tungsten to generate filler metal.
• CTo cool the workpiece to prevent heat distortion.
• DTo add carbon to the weld pool to increase joint hardness.

Which color band designates a 2% Thoriated tungsten electrode, commonly used for TIG welding carbon and stainless steels on DC current?

• ARed
• BGreen
• CGold
• DBrown

Which tungsten electrode color code should be selected when setting up to weld aluminum plates using Alternating Current (AC) GTAW?

• AGreen (Pure Tungsten)
• BRed (2% Thoriated)
• CBlack (1% Lanthanated)
• DYellow (1% Thoriated)

What is the recommended flow rate range for argon shielding gas when performing general manual GTAW on 3mm thick steel plates?

• A5 to 10 liters per minute (10 to 20 CFH)
• B25 to 35 liters per minute (50 to 70 CFH)
• C0.5 to 1 liter per minute (1 to 2 CFH)
• D100 to 120 liters per minute (200 to 250 CFH)

Which Gas Metal Arc Welding (GMAW) metal transfer mode is characterized by a low heat input and a rapid cycle of wire short-circuiting into the weld pool?

• AShort-circuiting transfer
• BSpray transfer
• CGlobular transfer
• DPulsed spray transfer

Why is alternating current (AC) mandatory when TIG welding aluminum?

• AThe positive half of the AC cycle breaks off the tough aluminum oxide layer, while the ne…
• BAluminum has high electrical resistance and requires AC to prevent machine overheating.
• CAC prevents the aluminum filler rod from sticking to the contact tip.
• DAC current generates less light, preventing glare from the reflective aluminum surface.

What shape must the tip of a tungsten electrode be ground to when setting up for DC TIG welding on carbon steel?

• APointed (tapered) with the grind marks running longitudinally.
• BPerfect-sphere balled end.
• CFlat and square-cut with no taper.
• DSpiral-grooved end.

Which of the following is a common cause of gas shielding loss, leading to porosity in a MIG weld bead?

• AA drafty workspace blowing the gas away or spatter buildup inside the gas nozzle.
• BSetting the wire feed speed too low.
• CUsing a copper contact tip that matches the wire size.
• DWelding with DCEP polarity instead of DCEN.

In the MIG wire classification 'ER70S-6', what does the letter 'S' represent?

• ASolid wire
• BStainless steel
• CShielded core
• DStrength rating

What is a major process advantage of TIG (GTAW) welding compared to MIG (GMAW) welding?

• AIt allows precise control of heat input and produces high-quality, slag-free welds on thi…
• BIt has much higher metal deposition rates, speeding up structural plate welding.
• CIt is highly tolerant of rust, oil, and moisture on the base metal surface.
• DIt does not require any protective eye shield due to the low arc glare.