WELDER (THEORY) SEMESTER – I AITT JULY 2017 PAPER
31. Heat — affected zone is that portion of the metal which …………….
(a) Melts and becomes plastic
(b) Neither melts nor becomes plastic
(c) Melts but does not become plastic
(d) Does not melt but becomes plastic
32. Which one of the following gases is supporter of combustion?
(a) Oxygen
(b) Acetylene
(c) Nitrogen
(d) Carbon dioxide
33. The tips of blowpipes are made of ……………..
(a) Copper
(b) Brass
(c) Mild steel
(d) Bronze
34. Leftward gas welding technique is used for welding of mild steel plates upto a thickness of …
(a) 1.5 mm
(b) 3.0 mm
(c) 5.0 mm
(d) 10.0 mm .
35. …is the ability of a metal to be pulled into wires.
(a) Malleability
(b) Conductivity
(c) Lustre
(d) Ductility
36. Which of the following is an alloy?
(a) Lead
(b) Tin
(c) Brass
(d) Aluminium
37. Which one of the following elements has the highest influence on the metallurgical weldability of steel?
(a) Carbon
(b) Manganese
(c) Chromium
(d) Silicon
38. Which of the following rays are not produced during arc welding?
(a) Gamma rays
(b) Visible light rays
(c) Infrared rays
(d) Ultraviolet rays
39. Double — V and double — U arc butt welded joints are used for plates of thickness …………..
(a) 1-5mm
(b) 5-10 mm
(c) 10-15 mm
(d) Over 15 mm