46. A rectifier for welding has voltage/current characteristic as
(a) static
(b) variable
(c) drooping
(d) rising
47. Which of the following is net a welding accessory?
(a) Hand screen
(b) Cable
(c) Electrode holder
(d) Gloves
48. Gray iron is usually welded by
(a) Gas welding
(b) TIG welding
(c) MIG welding
(d) Arc welding
49. The welding load is always
(a) continuous but varying
(b) continuous and constant
(c) intermittent
(d) none of the above
50. TIG welding is
(a) thorium iodine gas welding
(b) thermally induced gas welding
(c) temperature insulated gas welding
(d) tungsten insert gas welding
51. Flux used in TIG welding is
(a) borax
(b) ammonium chloride
(c) ash
(d) none
52. For the welding of aluminium alloys which of the following methods would you recommend?
(a) Acetylene-oxygen gas welding
(b) D.C. arc welding
(c) A.C. arc welding
(d) Tungsten arc welding
53. Which of the following automatic welding processes is likely to give the maximum rate of metal deposition?
(a) Continuous flux covered electrode
(b) Multiple power submerged arc
(c) Gas shielded bare wire
(d) Submerged arc (single wire)
54. A 10 SWG electrode usually operates in the current range
(a) 300 to 400 amperes
(b) 95 to 135 amperes
(c) 50 to 65 amperes
(d) 20 to 30 amperes
55. Which of the following electrodes will have the least diameter?
(a) 20 SWG
(b) 16 SWG
(c) 14 SWG
(d) 4 SWG
56. The danger of shock is maximum
(a) before welding
(b) after arcing
(c) during arcing
(d) while inserting an electrode into the holder
57. The welding electric circuit is
(a) never earthed
(b) always earthed
(c) through cables only
58. Steel rails are welded by
(a) Gas welding
(b) Thermit welding
(c) Resistance welding
(d) Argon arc welding
59. In ultrasonic welding, the frequency range is generally
(a) 2000 to 3000 Hz
(b) 4000 to 20000 Hz
(c) 30000 to 40000 Hz
(d) 50000 to 80000 Hz
