21. Which material is used to manufacture gas cutting blow pipe?
a) Copper
b) Brass
c) Aluminium
d) Stainless steel
22. Which problem is reduced by “Run ON and Run OFF” plates in DC welding?
a) Crack
b) Arc blow
c) Distortion
d) Weld decay
23. Name the joint setup for welding plates with perfect alignment and root gap.
a) Tack weld
b) Dressing
c) Skip weld
d) Penning
24. Which is the function of coating in electrode?
a) Prevent rusting
b) Stabilize the arc
c ) Control distortion
d) Increase the current
25. Which electrode contain large amount of iron powder in their coating?
a) Deep penetration electrode
b) Contact electrode
c) Cutting and gauging electrode
d) Low hydrogen electrode welding
26. Name the process of hammering the weld bead immediately after it is deposited.
a) Pinning
b) Peening
c) Pickling
d) Dressing
27. Which letter indicates the property of radio graphic quality in coding of electrodes?
a) R
b) C
c) X
d) A
28. What is the cause of hair line crack in welded joint?
a) Lack of preheating and post heating
b) Skip welding
c) Medium arc length
d) Slow cooling
29. What does the 2™ digit number “4” represent in the classification of electrode EB5426H 1JX?
a) Current range
b) Percentage of elongation
c) Welding position
d) Tensile strength
30. Which type of arc is to avoid underctit and reinforeetnent?
a) Arc blow
b) Short arc
c) Medium arc
d) Long are