21. What does the term “pass’ refer to as regards welded joint?
(a) Depression in base metal
(c) Shape of weld bead
(b) Each layer of weld bead deposited
(d) Distance from electrode to metal
22. Metal particles expelled during welding are called –
(a) Porosity
(c) Spatter
(b) Overlap
(d) Undercut
23. The process of heating to a certain temperature and then quenching in order to make the
metal tough is the heat treatment process called –
(a) Hardening
(c) Tempering
(b) Annealing
(d) Normalizing
24. For submerged arc welding, what is the effect of raising arc voltage but keeping all other parameters the same?
(a) Weld bead width will increase
(c) Weld bead width will decrease
(b) Depth of penetration will increase
(d) Depth of penetration will decrease
25. What steps can be taken to prevent welding hazards in workshop?
(a) Identify risks
(c) Establish control methods
(b) Evaluate hazards
(d) All of these
26. Thermit welding uses what to work?
(a) Oxygen and acetylene combined to form a flame
(b) Resistance of two metals held under pressure
(c) Enveloping tungsten using hydrogen gas
(d) An exothermic reaction between aluminium powder and metal oxide
27. Rotation of one of the workpieces to be joined is required in –
(a) Thermit welding
(c) Friction welding
(b) Electroslag welding
(d) TIG welding
28. Nickel based hardfacing alloys –
(a) Increase wear resistance
(c) Increase hardenability
(b) Are highly resistant to corrosion
(d) Cannot be deposited on carbon and heat steels
29. Metal with highest resistivity and lowest conductivity is –
(a) Copper
(c) Nickel
(b) Iron
(d) Titanium
30. The purpose of backing material at the root of a weld is –
(a) To support molten weld metal
(c) To prevent lack of fusion
(b) A heat sink
(d) All of these