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