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CWB WELDING INSPECTOR LEVEL III
STUDY GUIDE QUESTIONS AND
ANSWERS 2025
Which of the following metals has the highest thermal
conductivity?
(a) carbon steel
(b) stainless steel
(c) aluminum - correct answer- (c)
The Ellingham diagram
(a) is a plot of thermal conductivity against temperature,
(b) shows the free energy of oxide formation against
temperature.
(c) shows the rate of oxidation of metals against temperature. -
correct answer- (b)
True or False?
A metal with a high negative free energy of oxide formation will
generally require greater shielding from the atmosphere during
welding. - correct answer- True
Electricity can be conducted by:
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(a) atoms and electrons.
(b) electrons and ions.
(c) only ions. - correct answer- (b)
Which of the following elements is often present in submerged
arc fluxes to improve arc stability?
(a) copper
(b) potassium
(c) nickel
(d) tungsten - correct answer- (b)
Thoria is added to tunsten electrodes for what purpose? -
correct answer- To increase thermionic emission by lowering
the work function.
True or False?
All pure metals have the same crystal structure. - correct
answer- False. Metals generally have one of three basic
structures.
Which crystal structure(s) is (are) composed of close-packed
planes? - correct answer- FCC and HCP
CWB WELDING INSPECTOR LEVEL III
STUDY GUIDE QUESTIONS AND
ANSWERS 2025
Which of the following metals has the highest thermal
conductivity?
(a) carbon steel
(b) stainless steel
(c) aluminum - correct answer- (c)
The Ellingham diagram
(a) is a plot of thermal conductivity against temperature,
(b) shows the free energy of oxide formation against
temperature.
(c) shows the rate of oxidation of metals against temperature. -
correct answer- (b)
True or False?
A metal with a high negative free energy of oxide formation will
generally require greater shielding from the atmosphere during
welding. - correct answer- True
Electricity can be conducted by:
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(a) atoms and electrons.
(b) electrons and ions.
(c) only ions. - correct answer- (b)
Which of the following elements is often present in submerged
arc fluxes to improve arc stability?
(a) copper
(b) potassium
(c) nickel
(d) tungsten - correct answer- (b)
Thoria is added to tunsten electrodes for what purpose? -
correct answer- To increase thermionic emission by lowering
the work function.
True or False?
All pure metals have the same crystal structure. - correct
answer- False. Metals generally have one of three basic
structures.
Which crystal structure(s) is (are) composed of close-packed
planes? - correct answer- FCC and HCP
