Welding Questions and Answers | Online Quiz for Practice

46. The arc utilized in electric arc welding is a

1. High voltage, high current discharge
2. Low voltage, low current discharge
3. Low voltage, high current discharge
4. High voltage, low current discharge

47. The size of a welding machine is determined by

1. Input amperage
2. Output amperage
3. Open circuit voltage
4. Closed circuit voltage

48. If L (mm) is the length of the inner cone of the flame, the tip-to-metal distance should be

1. L mm
2. L + 2 mm
3. L + 4 mm
4. L + 6 mm

49. In a gas cut plate, the cut is high quality although there is some surface roughness caused by vertical drag lines. This is due to

1. less preheating flame
2. impure cutting oxygen
3. too slow cutting speed
4. smaller size cutting nozzle

50. The welding machine, which is used to convert AC welding supply to DC welding supply is

1. Motor generator set
2. Engine generator set
3. Rectifier set
4. Welding transformer

51. The correct flame for preheating before cutting is

1. oxidizing flame
2. neutral flame
3. carburising flame
4. slightly carburizing flame

52. Neutral flame in gas welding contains

1. oxygen & Actylene in equal proportion
2. More oxygen than Acetylene
3. less oxygen than Acetylene
4. None of the above

53. In DC welding heat distribution is possible between electrode and the base metal due to the change of polarity. The distribution of heat is

1. Psitive 2/3 and negative 1 /3
2. Positive 1 /3 and negative 2/3
3. Positive 3/4 and negative 1/4
4. Positive 1/4 and negative 3/4

54. The correct colours for oxygen and acetylene hoses are:

1. Red for oxygen and blue for acetylene
2. Black for oxygen and red for acetylene
3. Black for oxygen and maroon for acetylene
4. Red for oxygen and maroon for acetylene

55. Which one of the following is the type of transformer used in arc welding?

1. Step down
2. Step up
3. One-to-one
4. Capable of increasing supply voltage

56. Cast iron contains two elements, which make it difficult to cut it by gas cutting. What are these elements?

1. Sulphur and phosphorous
2. Silicon and graphite
3. Graphite and phosphorous
4. Silicon and sulphur

57. The function of the central hole in the tip of the cutting blowpipe is

1. Supply oxygen for preheating
2. Supply acetylene for preheating
3. Supply oxygen for cutting
4. Supply acetylene for cutting

58. In gas cutting, if too little cutting oxygen is supplied

1. the metal will be cooled down
2. the kerf will be narrow
3. the kerf will be wide
4. the metal will fail to cut completely

59. The size of the cutting nozzle used in oxy-acetylene cutting process depends mainly on

1. thickness of metal to be cut
2. purity of oxygen
3. duration of cut
4. type of cutting blowpipe

60. Which of the gases can be used to form a protective envelope in arc welding?

1. Oxygen and Carbon dioxide
2. Hydrogen and Helium
3. Oxygen and Helium
4. Helium and Carbon dioxide