Welding Final (WELD 10) Part II
What is the minimum recommended filter lens to be used when PAC? (a) #6 (b) #9 (c) #12 (d) #14
#9
Temperatures used during the plasma cutting process range between ____. (a) 3000°F-7000°F (1600°C-3900°C) (b) 10,000°F-15,000°F (5500°C-8300°C) (c) 18,000°F-25,000°F (10,000°C-14,000°C) (d) 26,000°F-30,000°F (14,000°C-17,000°C)
18,000°F-25,000°F (10,000°C-14,000°C)
What arc voltage is required when welding mild steel using short circuiting transfer and .035² wire? (a) 15 volts (b) 20 volts (c) 25 volts (d) 30 volts
20 volts
What wire feed speed is required when welding mild steel using short circuiting transfer and .035² wire? (a) 100 in/min (b) 150 in/min (c) 200 in/min (d) 400 in/min
200 in/min
What arc voltage is required when welding mild steel using spray transfer and .035² wire? (a) 15 volts (b) 20 volts (c) 25 volts (d) 30 volts
25 volts
What wire feed speed is required when welding mild steel using spray transfer and .035² wire? (a) 100 in/min (b) 150 in/min (c) 200 in/min (d) 400 in/min
400 in/min
The loud noise sometimes present with PAC is caused by a(n) (a) inverter power supply (b) improperly assembled electrode and nozzle (c) high-amperage cutting arc (d) high-velocity gas
high-velocity gas
If dross is difficult to remove, decrease the travel speed.
true
Some wire feeders have two drive rolls while other wire feeders have ____ drive roll(s). (a) one (b) three (c) four (d) six
four
The purpose of the ____ is to protect the torch from the high heat of the cutting process. (a) constricting nozzle (b) swirl ring (c) heat shield (d) gas connection
heat shield
When comparing spray transfer to short circuiting transfer, which of the following is true? (a) lower current and voltage are required (b) higher current and lower voltage are required (c) lower current and higher voltage are required (d) higher current and voltage are required
higher current and voltage are required
To prevent damage to the arc welding machine, the electrode holder must always be hung on a(n) ____ when it is not in the welder's hand. (a) table edge (b) insulated hook (c) workpiece (d) power supply
insulated hook
Oxygen (O2) with air shielding has excellent cut quality and speed on which of the following materials? (a) Mild steel (b) Aluminum (c) Stainless steel (d) None of the above
mild steel
Holes in the side curtains or walls of the arc welding booth may expose ____ to arc flashes. (a) the welder (b) the weld (c) nearby workers (d) the welding machine
nearby workers
The welder should ____ make current changes with the electrode touching the workpiece, worktable, or while welding. (a) always (b) never (c) try to (d) allow a supervisor to
never
During welding, spatter gets into the ____ and onto the ____. (a) welding gun, shielding gas cylinders (b) weld wire, electrode (c) liner, weld wire (d) nozzle, contact tube
nozzle, contact tube
To establish shielding gas flow so the flow rate can be adjusted, set the ____ for 15-20 seconds and pull the gun trigger for one second or less. (a) pressure roll timer (b) remote control contactor (c) Pressure adjusting knob (d) Post flow adjustment
post flow adjustment
To prevent electrical shock, the power to the arc welding machine must be ____ whenever a safety check of the welding station is made. (a) set to AC welding (b) set to DC welding (c) turned off (d) set to low current DCEN
turned off
A ball-float flowmeter must be installed in a ____ position to operate properly. (a) horizontal (b) vertical (c) parallel (d) diagonal
vertical
Which of the following is not a method for reducing exposure to the loud noises created by automated PAC? (a) wear earplugs (b) use a water jacket (c) wear a cap (d) wear earmuffs
wear a cap
The constricting nozzle has one center hole surrounded by 4 or 6 additional holes.
false
The dual purpose cable provides electrical connection to the electrode in PAC.
false
The force of the shielding gas removes the molten metal from the part being cut.
false
The most common gas used for manual plasma arc cutting is argon.
false
The same constricting nozzle is used for both PAC cutting and gouging.
false
Torches used for cutting thick material and using a high-duty cycle are air cooled.
false
Equipment used for plasma arc cutting is very similar to equipment used for oxyfuel gas cutting.
false
Gas cylinders are not necessary when the cutting operation is done in the field.
false
Which person should permanently wire the welding machine to the commercial power source? (a) Instructor (b) Welder (c) Plumber (d) Electrician
Electrician
The voltage on the welding machine cannot be higher than 20V or the circuit breaker may fault.
False
The voltage set on the welding machine is the closed circuit voltage.
False
Three hours of constant welding with a steel electrode will wear a contact tube badly enough that it will need to be replaced.
False
Tighten output leads to the welding machine using any available wrench.
False
To protect cables that run across an aisle, place a pipe across the floor to slow any traffic.
False
Ventilation systems should not pull fumes from the welding area.
False
Welding machines used for direct current welding require a polarity switch.
False
Questions 64-65 from week 5, chapter 16
Look @ them
When a separate wire feeder is used, it is usually placed under the welding machine.
False
What is the recommended nozzle-to-work distance for manual PAC? (a) 1/32²-1/16² (b) 1/16²-1/8² (c) 1/8²-3/16² (d) 3/16²-3/8²
1/16²-1/8²
Which of the following is not a recommended shielding gas for welding carbon steel with short circuiting transfer? (a) 90% helium-7.5% argon-2.5% carbon dioxide. (b) 100% carbon dioxide. (c) Argon with 15%-25% carbon dioxide. (d) Argon with 50% carbon dioxide.
90% helium-7.5% argon-2.5% carbon dioxide.
Which of the following would not cause the cut quality to become worse? (a) A water jacket is used (b) the electrode is pitted (c) the hole in the constricting nozzle is blocked (d) the hole in the constricting nozzle is enlarged
A water jacket is used
On a permanent installation, where should welding cables not be run? (a) Across an aisle (b) Inside conduit (c) Overhead (d) Under the floor
Across an aisle
What should be done if the drive rolls slip while feeding the electrode wire? (a) Align the inlet and outlet guides (b) Adjust the drive housing (c) Change electrode wire diameter (d) Adjust the pressure adjusting knob
Adjust the pressure adjusting knob
What gas is most commonly used for manual plasma arc cutting? (a) air (b) argon (c) Argon with 2% oxygen. (d) Helium with 35% nitrogen.
Air
When connecting a lead to a welding machine terminal using a lug, crimp or solder through the insulation to avoid getting shocked.
False
Which of the following does not need to be checked daily, prior to welding? (a) The welding gun, wire feeder, and welding machine are properly connected. (b) The regulator and flowmeter are correctly installed on the cylinder. (c) Alloy composition of the welding wire meets AWS standards. (d) Adequate ventilation is present for removing fumes and shielding gases.
Alloy composition of the welding wire meets AWS standards.
What type shielding gas is used to weld .1² (.25 mm) aluminum alloys with spray transfer? (a) Helium (b) Helium with carbon dioxide (c) Argon with carbon dioxide (d) Argon
Argon
What type of shielding gas is used to weld low-alloy steels with spray transfer? (a) Argon with 15-25% helium. (b) Argon with 15-25% carbon dioxide. (c) Argon with 2% oxygen. (d) Argon
Argon with 2% oxygen.
Wire feed speed and current required for GMAW spray transfer is higher than that required for short circuiting transfer but less than globular transfer.
False
Which of the following is not a method used to connect the workpiece and electrode leads to the power supply? (a) Brazed connection (b) Quick-connect terminal (c) Lug with hex or wing nut (d) None of the above
Brazed connection
Workpiece leads must be connected tightly to the power supply but can be connected loosely to the worktable or workpiece.
False
The outlet on the shielding gas cylinder must be cleaned before attaching a regulator to it. This is done by quickly opening and closing the cylinder valve.
True
The shielding gas flow rate is set after the regulator and flowmeter have been attached to the cylinder.
True
What is the function of a rectifier? (a) Changing AC current into DC current (b) Providing input power greater than 208V (c) Smoothing the variation in AC power at less than 100A current (d) Cooling the welding transformer
Changing AC current into DC current
Which of the following is not a connection required when setting up a GMAW outfit? (a) Connect shielding gas to the welding machine (b) Connect the contact tube and adapter to the machine (c) connect electrical power to a power source (d) connect the gun cable to the machine or wire feeder
Connect the contact tube and adapter to the machine.
Which of these electrodes can be used in all welding positions? (a) E81T-X (b) E80T-X (c) E70T-X (d) E308T-X
E81T-X
Which of the following electrodes is a metal cored electrode? (a) ER80T-B2 (b) ER80M-6 (c) ER80C-6 (d) ER80S-6-D2
ER80C-6
____ is the term used for metal removed during a cut that becomes attached to the metal surface. (a) Gangue (b) Sludge (c) Kerflage (d) Dross
Dross
Which of the following is not an advantage of PAC? (a) The ability to cut all metals (b) Equipment cost (c) Cutting speeds are faster than oxyfuel cutting (d) Distortion and heat-affected zones are minimized
Equipment cost
A quick-connect terminal is used to connect input power to the welding machine.
False
A rectifier is used to turn DC current into AC current.
False
A safety cap must be in place when a gas cylinder is in use.
False
All welding machines used for SMAW have a range switch.
False
Any electrode wire can be used to make quality welds on mild steel using GMAW.
False
As the distance to the job increases, smaller-diameter workpiece and electrode leads are required.
False
Base metal must be chemically cleaned prior to GMAW.
False
Each welding station requires a flowmeter so that each welder can fine-tune the gas mixture ratio.
False
FCAW electrodes are limited to welding steel, stainless steel, and magnesium base metals.
False
Fine current adjustments are made using alternating current, and coarse adjustments are made using DCEP.
False
For the best results, you should adjust the amperage or polarity while an arc is being drawn.
False
Hang the electrode holder from an insulted hook while welding.
False
Large-diameter wires are used for out-of-position welding, except for overhead welding.
False
Most flux-cored electrodes are designed to be used to weld in the flat position or to weld vertical fillet and butt welds.
False
One mixture of shielding gas recommended for welding low alloy steel using spray transfer is argon with 20%-25% oxygen.
False
Other workers in the area must be greater than five feet away when a cylinder valve is opened to clean it.
False
Selecting a coarse amperage range can be done by inserting the electrode lead into the positive or negative jack on the machine.
False
Shielding gas is always connected to the welding machine.
False
Shielding gas is connected to either the welding machine or the welding gun.
False
Small-diameter electrodes deposit small amounts of metal using spray transfer.
False
The diameter of a electrode is selected before the type of electrode is chosen.
False
The electrode holder and electrode should be on the worktable when the machine is started.
False
The knob(s) on top of the drive housing is used to eliminate the pressure exerted on the electrode wire.
False
The two settings that must be made on the welding machine are voltage and wire feed speed.
True
To feed electrode wire properly, the correct amount of pressure must be applied to the electrode wire by the drive and pressure rolls.
True
Which of the following is not a method of attaching a workpiece lead to a worktable or workpiece? (a) Bolt (b) spring loaded clamp (c) magnet or C-clamp (d) Insulated hook
Insulated hook
Which of the following is not a reason copper foil is wrapped around bare wires when connecting the end of the electrode lead to the electrode holder? (a) It keeps wires from unwrapping (b) It prevents electrical shock (c) It provides good electrical current (d) All of the above
It prevents electrical shock
Which of the following statements is not true for the output connections of an arc welding machine? (a) Large slip-joint pliers may be used to tighten the hex nuts on the lead connections (b) The connections must always be tight. (c) A cam lock-style cable connector plugs into a female socket on the machine. (d) Wing nuts may be used to connect the welding leads.
Large slip-joint pliers may be used to tighten the hex nuts on the lead connections
Which of the following is not a disadvantage of PAC? (a) The cost of equipment can be higher than for other processes. (b) A source of electricity is needed (c) The metal fumes created can be a health hazard (d) No hazardous or explosive gases are used
No hazardous or explosive gases are used
Ventilation systems should pull fumes away from the welder's breathing area.
True
The most common states of matter are solid, liquid, and gas. Which of the following is also a state of matter? (a) Kerf (b) Phlebitis (c) Plamsa (d) Dross
Plasma
Which of the following statements is not true? (a) Plasma is an ionized gas (b) Plasma conducts electricity (c) Plasma is present only in welding and cutting processes that use a constricting nozzle. (d) Plasma is a state of matter
Plasma is present only in welding and cutting processes that use a constricting nozzle.
Welding leads should not be laid across an aisle or other heavy-traffic area.
True
In a welding shop, what is the typical source of 120V or 240V input power required for an AC or DC arc welding machine? (a) Engine-driven alternators (b) Coal power plant (c) Power lines to the building (d) Inverter power supply
Power lines to the building
Welding machines can produce current in several amperage ranges, known as coarse amperage ranges.
True
Welding machines used only for alternating current welding do not require a polarity switch.
True
Of the following methods, which is the best way to stop a plasma cutting arc? (a) Pull the cutting torch away from the base metal (b) Release the switch (c) Cut to the end of the part and continue with a nontransferred arc (d) None of the above
Release the switch
When a separate wire feeder and welding machine are used, where is the cable from the wire feeder plugged into? (a) Remote voltage receptacle (b) Remote contactor receptacle (c) Remote current receptacle (d) Flow control
Remote contactor receptacle
When selecting electrode wire for GMAW, the proper composition is selected first, and then the electrode diameter is determined.
True
When the purge switch is pressed, gas will flow.
True
What does the "S" in ER70S-3 stand for? (a) Standard alloy electrode (b) Steel electrode (c) Solid electrode (d) Stainless steel electrode
Solid electrode
Most welding machines using more than 240V are usually hardwired into a building's electrical system, but some electrical codes permit them to be plugged into special wall receptacles.
True
On a microprocessor machine, the base metal type (steel), electrode diameter, and shielding gas or gas mixture are entered into the welding machine.
True
Shielding gas is stored in cylinders is very high pressures.
True
The GMAW and FCAW processes can produce flying particles in the air.
True
The design of the PAC torch must create the plasma and properly direct it to perform the cutting operation.
True
Which of the following metals is not used to make PAC electrodes? (a) Hafnium (b) Zirconium (c) Titanium (d) Tungsten
Titanium
There are two key considerations in determining the size (diameter) of the electrode and workpiece leads to be used. One is the maximum amperage to be carried. What is the other? (a) The polarity of the welding machine (b) The open circuit voltage required (c) The type of lead connection being used (d) Total distance to the work and back
Total distance to the work and back
A safety cap must be in place when a gas cylinder is being transported.
True
A socket is an internal connection on a welding machine.
True
A wire feeder may require 120VAC or 240VAC or 24VDC for operation.
True
A wire feeder should pull the electrode wire smoothly from the spool and push it to the welding gun.
True
Arc voltage required for GMAW spray transfer is higher than the arc voltage required for short circuiting transfer.
True
Cuts and worn insulation on electrode and workpiece leads are not acceptable.
True
Flux-cored electrodes produce some gases to protect the welding area.
True
Metal to be welded by GMAW or FCAW should be cleaned.
True
The diameters of the workpiece lead and the electrode lead should always be the same.
True
Hafnium electrodes are used when argon or argon-hydrogen is used as the plasma gas.
false
Which of the following is not a cause of stubbing an electrode on the base metal? (a) Welding gun is too close to the work when starting the arc (b) Wrong electrode diameter is being used (c) Wire feed speed is too fast (d) Voltage setting is too low
Wrong electrode diameter is being used
To change the fine amperage adjustment on the arc welding machine, some machines use a knob and others use ____. (a) multiple taps (b) a range switch (c) a crank or digital settings (d) a polarity switch
a crank or digital settings
Increase travel speed if the dross is difficult to remove.
false
Most PAC torches are cooled by liquid (water).
false
Nozzles on most manual PAC torches are nearly parallel to the torch body.
false
Oxygen (O2) is a good plasma gas for cutting stainless steel.
false
Plasma arc cutting speed is rather slow.
false
Plasma gas is not present in all arc welding processes.
false
Prior to cutting, adjust the desired voltage using a knob usually on the front of the power supply.
false
Adjusting voltage and wire speed determines the ____ and ____. (a) arc length, current (b) voltage, amount of electrode wire needed (c) shielding gas, current (d) current, polarity
arc length, current
The type of shielding gas recommended for welding magnesium using spray transfer is ____. (a) argon (b) oxygen (c) helium (d) argon with 15% - 25% carbon dioxide
argon
Occasionally, the electrode wire in the wire feeder will become tangled and produce a ____. (a) bird's nest (b) birdhouse (c) hen's nest (d) pressure ball
bird's nest
Which of the following is not a method used to adjust the coarse amperage range? (a) change the range switch (b) Insert electrode lead into a different range jack (c) choose alternating current (d) none of the above
choose alternating current
Which of the following is not a method used to change DC polarity on a welding machine? (a) Connecting the workpiece lead to the electrode holder (b) Flipping a switch (c) Reversing the workpiece electrode leads (d) Both A and B
connecting the workpiece lead to the electrode holder
What part of the welding gun needs to be replaced most often? (a) nozzle (b) liner (c) switch (d) contact tube
contact tube
Lugs are attached to welding leads using ____. (a) brazing or welding (b) crimping or soldering (c) mechanical means or welding (d) electrical tape
crimping or soldering
Often, a single combination cable is used to connect the torch to the power supply. Which of the following is not a connection made by the combination cable? (a) cylinder gas connection (b) electrical control wire (c) trigger control wire (d) pilot arc control wire
cylinder gas connection
A Teflon® liner should be used with steel, stainless steel, and all soft electrodes.
false
A constant voltage machine is used for PAC.
false
A pilot arc is between the electrode and the work.
false
A power supply used for plasma arc cutting is a sporadic current machine.
false
Air is expensive but easily accessible.
false
An inverter power supply has a large but lightweight transformer.
false
As a torch is moving along the path to be cut, metal continues to be removed. The slot created in the base metal is called a dross.
false
Because of the plasma present in this process, a workpiece lead is not required.
false
Direct current electrode positive is used when plasma arc cutting.
false
What are internal welding lead connections on the face of a welding machine called? (a) lugs (b) terminals (c) sockets (d) fine current control
sockets
The dash number in a FCAW designation indicates all the following information about the electrode, except____. (a) the current type to use (b) tensile strength in 1000 psi (c) what shielding gas to use (d) the polarity to use
tensile strength in 1000 psi
If the drive rolls in the wire feeder put too much pressure on the electrode wire, which of the following will occur? (a) the electrode wire will be flattened (b) the contact tube will not make good electrical contact with the electrode wire (c) the electrode will feed at a faster rate (d) the drive rolls will slip over the wire
the electrode wire will be flattened
A ____ is not a main part of a plasma arc cutting system. (a) power supply (b) torch (c) thermostat (d) supply of gas and a regulator
thermostat
Which of the following does not determine the type of metal transfer? (a) shielding gas (b) travel speed (c) voltage (d) wire feed speed
travel speed
"Ionized" means some electrons in a gas have broken free from their atoms.
true
A constricting nozzle is used to create, concentrate, and direct the high-velocity plasma.
true
A high-frequency voltage generator is used to initiate the PAC arc.
true
A transferred arc is between the electrode and the work.
true
Coarse adjustments using the range switch must not be made while welding.
true
GMAW and FCAW outfits must be properly assembled to operate correctly.
true
Gouging occurs when only a portion of the thickness of a metal is removed.
true
Inverter type machines are frequently used as the power supply for PAC.
true
Loud noise can be created when high-velocity gas passes through the constricting nozzle.
true
Most medium and heavy-duty PAC power supplies require 230V or 460V and use three-phase input.
true
Nitrogen is a good plasma gas choice when cutting stainless steel or aluminum.
true
Only processes that use a constricting nozzle to create the plasma arc condition are called plasma arc.
true
Plasma arc cutting (PAC) is a process that uses an arc and a high-velocity, ionized gas coming through a constricting nozzle.
true
Plasma arc cutting can be started from an edge or from the center of a part.
true
Plasma arc cutting is a combination of an arc process and a cutting process.
true
The pilot arc is the most common reason for wear in the electrode and constricting nozzle.
true
The plasma arc is started by pressing a switch or trigger on the torch.
true
The shielding gas may also be called the secondary gas.
true
To prevent oxidation, use argon or nitrogen as the plasma gas and use nitrogen, water, or CO2 for shielding.
true
Two nozzles are used in a PAC torch.
true
When nearing the end of a cut, point the nozzle forward.
true
