CWB Level 2 Study Modules 4-5-6-7-8-9-12-17-18-19-22
Study online at https://quizlet.com/_1fgi1t
1. During arc welding there is a zone adjacent to the weld metal that reaches
high temperatures but does not melt. What is the name of this region?: Heat
Affect Zone (HAZ)
2. In parallel electrical circuits, the voltage across each resistor is the same
since each path is connected to the same voltage source. Select the correct
statement.
A. in each parallel path the resistance must be equalized to create equal
voltage.
B. the current flowing in each parallel path must be the same as the voltage.
C. the current flowing in each parallel path depends on the resistance in each
path
D. the current flowing in each parallel path depends on the capacitance in
each path: C. the current flowing in each parallel path depends on the resistance in each path
3. Welding is a joining process that by definition requires:: The application of either heat
or pressure
4. The duty cycle of a welding power supply is based upon delivering its rated
output for a
given number of minutes. Which of the following statements is correct.
A. a 300 amp/60% duty cycle machine is rated to deliver 300 amps for 6
minutes in a ten minute period
B. a 300 amp/30% duty cycle machine is rated to deliver 300 amps in a ten
minute period
C. a 250 amp/30% duty cycle machine is rated to deliver 250 amps for 30
minutes separated by 10 minutes at rest
D. a 300 amp/60% duty cycle machine is rated to deliver 500 amps maximum
for 6 minutes in a ten minute period: A. a 300 amp/60% duty cycle machine is rated to deliver 300
amps for 6 minutes in a ten minute period
5. Conventional transformer-rectifiers;
A. convert direct current into alternating current
B. convert alternating current into direct current
C. convert alternating current into pulsed current
D. convert direct current into pulsed current: B. convert alternating current into direct current
, CWB Level 2 Study Modules 4-5-6-7-8-9-12-17-18-19-22
Study online at https://quizlet.com/_1fgi1t
6. A conventional diode placed in a circuit allows the passage of current in one
direction only. A silicon controlled rectifier(SCR) operates slightly differently.
How does it work?
A. an SCR conducts current in both directions until turned on and current flow
is then prevented
B. an SCR is non-conductive until turned onland then allows current to flow in
both directions
C. an SCR is non-conductive until turned on, allowing current to flow in one
direction only until the flow of current stops
D. an SCR is a unique rectifying device which allows only alternating c1:1rrent
to flow until turned off: C. an SCR is non-conductive until turned on, allowing current to flow in one
direction only until the flow of current stops
7. What is the term for voltage measured across the output terminals of a
welding
machine when no current is being drawn?
A. diode voltage
B. operating voltage
C. open circuit voltage
D. terminal voltage: C. open circuit voltage
8. A 60% duty cycle means that the power supply can deliver its rated output
for:
A 60% of the rated output only
B. 60% over the rated output followed by 4 minutes at rest
C. 6 minutes at rest followed by 4 minutes at rated output
D. 6 minutes at rated output followed by 4 minutes at rest: D. 6 minutes at rated output
followed by 4 minutes at rest
9. The DC output of a single phase power supply can be "ripply" and does not
produce
the friendliest DC arc. How is this problem overcome?
A. single phase power supplies produce the smoothest DC of all common
machines
B. a third transformer is added to the output circuit to filter out instability
, CWB Level 2 Study Modules 4-5-6-7-8-9-12-17-18-19-22
Study online at https://quizlet.com/_1fgi1t
C. a capacitor or capacitor bank is added to the output circuit
D. a 'dual' rectifier bridge is used to filter the transformer output: C. a capacitor or
capacitor bank is added to the output circuit
10. One of the simplest ways of controlling the output of a welding transformer
is to change
the efficiency of coupling between the primary and secondary coils. How can
this be done?
A slide a piece of wood between the primary and the secondary coils
B. design the transformer with either a moving core or moving primary coils
C. design the transformer with a number of taps to select different output
curves
D. use the timed firing of SCR's to control total conduction time: B. design the
transformer with either a moving core or moving primary coils
11. When choosing between AC and DC output;
A. the process generally determines the type of current
B. high current output machines are always both AC/DC
C. DC is generally used for very high output applications
D. most supplies are equipped with constant voltage/constant current op-
tions: A. the process generally determines the type of current
12. Which of the following metals has the lowest electrical resistivity?
A aluminum
B. tungsten
C. copper
D. iron: C. copper
13. What is the purpose of an inverter?
A. to convert AC current to DC current of the same frequency
B. to convert DC current to high frequency AC current
C. to convert AC current to DC current
D. to convert electrode positive to electrode negative: B. to convert DC current to high
frequency AC current
14. How is power flow analyzed in alternating current circuits?
A. AC circuits can be evaluated the same as DC circuits when RMS values of
, CWB Level 2 Study Modules 4-5-6-7-8-9-12-17-18-19-22
Study online at https://quizlet.com/_1fgi1t
voltage
and current are used
B. when analysing AC circuits, inductive and capacitive reactance must be
included
C. average current in an AC circuit is zero and therefore no work is done
D. the peaks and valleys of sine wave curves balance to zero with the load: C.
average current in an AC circuit is zero and therefore no work is done
15. Which of the following methods is commonly used to control the output of
a transformer?
A. an auxiliary power supply which feeds the secondary as required
B. a saturable reactor in series with the output
C. resistance placed in parallel with the primary of the transformer
D. taps on the secondary of the transformer: D. taps on the secondary of the transformer
16. A transformer type welding power source without a rectifier outputs what
type of current?
A. direct current
B. alternating current
C. high frequency current
D. pulsed direct current: B. alternating current
17. When gas tungsten arc welding steels electrode polarity is most common-
ly;
A. electrode positive
B. electrode negative
C. alternating current
D. electrode square wave: B. electrode negative
18. A disadvantage of SCR control is that the output is very 'choppy'. How is the
output made more suitable for welding?
A. the output is smoothed out by the addition of capacitors
B. the large inductor or choke will be added to the circuit
C. the output from an SCR bridge is smooth enough for welding purposes
D. the diodes added to all SCR controlled machines to prevent "choppy"
output: A. the output is smoothed out by the addition of capacitor
Study online at https://quizlet.com/_1fgi1t
1. During arc welding there is a zone adjacent to the weld metal that reaches
high temperatures but does not melt. What is the name of this region?: Heat
Affect Zone (HAZ)
2. In parallel electrical circuits, the voltage across each resistor is the same
since each path is connected to the same voltage source. Select the correct
statement.
A. in each parallel path the resistance must be equalized to create equal
voltage.
B. the current flowing in each parallel path must be the same as the voltage.
C. the current flowing in each parallel path depends on the resistance in each
path
D. the current flowing in each parallel path depends on the capacitance in
each path: C. the current flowing in each parallel path depends on the resistance in each path
3. Welding is a joining process that by definition requires:: The application of either heat
or pressure
4. The duty cycle of a welding power supply is based upon delivering its rated
output for a
given number of minutes. Which of the following statements is correct.
A. a 300 amp/60% duty cycle machine is rated to deliver 300 amps for 6
minutes in a ten minute period
B. a 300 amp/30% duty cycle machine is rated to deliver 300 amps in a ten
minute period
C. a 250 amp/30% duty cycle machine is rated to deliver 250 amps for 30
minutes separated by 10 minutes at rest
D. a 300 amp/60% duty cycle machine is rated to deliver 500 amps maximum
for 6 minutes in a ten minute period: A. a 300 amp/60% duty cycle machine is rated to deliver 300
amps for 6 minutes in a ten minute period
5. Conventional transformer-rectifiers;
A. convert direct current into alternating current
B. convert alternating current into direct current
C. convert alternating current into pulsed current
D. convert direct current into pulsed current: B. convert alternating current into direct current
, CWB Level 2 Study Modules 4-5-6-7-8-9-12-17-18-19-22
Study online at https://quizlet.com/_1fgi1t
6. A conventional diode placed in a circuit allows the passage of current in one
direction only. A silicon controlled rectifier(SCR) operates slightly differently.
How does it work?
A. an SCR conducts current in both directions until turned on and current flow
is then prevented
B. an SCR is non-conductive until turned onland then allows current to flow in
both directions
C. an SCR is non-conductive until turned on, allowing current to flow in one
direction only until the flow of current stops
D. an SCR is a unique rectifying device which allows only alternating c1:1rrent
to flow until turned off: C. an SCR is non-conductive until turned on, allowing current to flow in one
direction only until the flow of current stops
7. What is the term for voltage measured across the output terminals of a
welding
machine when no current is being drawn?
A. diode voltage
B. operating voltage
C. open circuit voltage
D. terminal voltage: C. open circuit voltage
8. A 60% duty cycle means that the power supply can deliver its rated output
for:
A 60% of the rated output only
B. 60% over the rated output followed by 4 minutes at rest
C. 6 minutes at rest followed by 4 minutes at rated output
D. 6 minutes at rated output followed by 4 minutes at rest: D. 6 minutes at rated output
followed by 4 minutes at rest
9. The DC output of a single phase power supply can be "ripply" and does not
produce
the friendliest DC arc. How is this problem overcome?
A. single phase power supplies produce the smoothest DC of all common
machines
B. a third transformer is added to the output circuit to filter out instability
, CWB Level 2 Study Modules 4-5-6-7-8-9-12-17-18-19-22
Study online at https://quizlet.com/_1fgi1t
C. a capacitor or capacitor bank is added to the output circuit
D. a 'dual' rectifier bridge is used to filter the transformer output: C. a capacitor or
capacitor bank is added to the output circuit
10. One of the simplest ways of controlling the output of a welding transformer
is to change
the efficiency of coupling between the primary and secondary coils. How can
this be done?
A slide a piece of wood between the primary and the secondary coils
B. design the transformer with either a moving core or moving primary coils
C. design the transformer with a number of taps to select different output
curves
D. use the timed firing of SCR's to control total conduction time: B. design the
transformer with either a moving core or moving primary coils
11. When choosing between AC and DC output;
A. the process generally determines the type of current
B. high current output machines are always both AC/DC
C. DC is generally used for very high output applications
D. most supplies are equipped with constant voltage/constant current op-
tions: A. the process generally determines the type of current
12. Which of the following metals has the lowest electrical resistivity?
A aluminum
B. tungsten
C. copper
D. iron: C. copper
13. What is the purpose of an inverter?
A. to convert AC current to DC current of the same frequency
B. to convert DC current to high frequency AC current
C. to convert AC current to DC current
D. to convert electrode positive to electrode negative: B. to convert DC current to high
frequency AC current
14. How is power flow analyzed in alternating current circuits?
A. AC circuits can be evaluated the same as DC circuits when RMS values of
, CWB Level 2 Study Modules 4-5-6-7-8-9-12-17-18-19-22
Study online at https://quizlet.com/_1fgi1t
voltage
and current are used
B. when analysing AC circuits, inductive and capacitive reactance must be
included
C. average current in an AC circuit is zero and therefore no work is done
D. the peaks and valleys of sine wave curves balance to zero with the load: C.
average current in an AC circuit is zero and therefore no work is done
15. Which of the following methods is commonly used to control the output of
a transformer?
A. an auxiliary power supply which feeds the secondary as required
B. a saturable reactor in series with the output
C. resistance placed in parallel with the primary of the transformer
D. taps on the secondary of the transformer: D. taps on the secondary of the transformer
16. A transformer type welding power source without a rectifier outputs what
type of current?
A. direct current
B. alternating current
C. high frequency current
D. pulsed direct current: B. alternating current
17. When gas tungsten arc welding steels electrode polarity is most common-
ly;
A. electrode positive
B. electrode negative
C. alternating current
D. electrode square wave: B. electrode negative
18. A disadvantage of SCR control is that the output is very 'choppy'. How is the
output made more suitable for welding?
A. the output is smoothed out by the addition of capacitors
B. the large inductor or choke will be added to the circuit
C. the output from an SCR bridge is smooth enough for welding purposes
D. the diodes added to all SCR controlled machines to prevent "choppy"
output: A. the output is smoothed out by the addition of capacitor
