50. In straight polarity welding,
A.Electrode holder is connected to the negative and work to positive
B.Electrode holder is connected to the positive and work to negative
C.Work is positive and holder is earthed
D.Holder is positive and work is earthed

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51. In arc welding process the intense heat is developed between the work and the electrode largely due to
A.Current
B.Voltage
C.Electrical energy
D.Contact resistance

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52. In thermit welding, he iron oxide and aluminium oxide are mixed in the proportion of
A.1 : 1
B.3 : 1
C.1 : 3
D.Mixture is of different oxides

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53. TIG welding is best suited for welding
A.Mild steel
B.Aluminium
C.Carbon steel
D.Silver

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54. In the manual TIG welding, the angle of the electrode holder with the direction of welding is ,
A.30°
B.45°
C.60°
D.70°

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55. Arc stability is better with
A.AC welding
B.DC welding
C.Both AC and DC welding
D.Specially designed wave forms

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56. The following welding process uses consumable electrode
A.TIG
B.MIG
C.Thermit
D.Laser

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