CWB LEVEL 2 STUDY MODULES 4-5-6-7-8-9-12-17-
18-19-22 NEWEST 2026/ 2027 | COMPLETE WITH
REAL EXAM QUESTIONS AND CORRECT DETAILED
ANSWERS (VERIFIED ANSWERS) GRADED A+
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
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
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
,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
options
A. the process generally determines the type of current
Which of the following metals has the lowest electrical resistivity?
A aluminum
B. tungsten
C. copper
D. iron
C. copper
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
How is power flow analyzed in alternating current circuits?
A. AC circuits can be evaluated the same as DC circuits when RMS values
of 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
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
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)
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
Welding is a joining process that by definition requires:
The application of either heat or pressure
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
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
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
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
18-19-22 NEWEST 2026/ 2027 | COMPLETE WITH
REAL EXAM QUESTIONS AND CORRECT DETAILED
ANSWERS (VERIFIED ANSWERS) GRADED A+
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
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
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
,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
options
A. the process generally determines the type of current
Which of the following metals has the lowest electrical resistivity?
A aluminum
B. tungsten
C. copper
D. iron
C. copper
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
How is power flow analyzed in alternating current circuits?
A. AC circuits can be evaluated the same as DC circuits when RMS values
of 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
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
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)
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
Welding is a joining process that by definition requires:
The application of either heat or pressure
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
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
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
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
