Welding MCQs Quiz Multiple Choice Questions & Answers

1. In a gas cut plate, the cut shows grooves and has deep drag lines. This is due to

1. less oxygen pressure
2. smaller size cutting nozzle
3. tip too close to the cut surface
4. too much travel speed

2. One of the functions of electrode coating is

1. to prevent rusting
2. to control arc temperature
3. to increase welding current
4. to stabilize the arc

3. In an acetylene cylinder, the acetylene is dissolved in

1. Acetone
2. Mercury
3. Water
4. Carbon Dioxide

4. Which one of the following is a temporary joint?

1. Soldered joint
2. Press fit joint
3. Welded joint
4. Riveted joint

5. In fusion welding, penetration is the ratio of

1. depth of the weld to its width
2. depth of the weld to its length
3. width of the weld to its depth
4. length of the weld to its depth

6. Which of the following joint have high corrosion resistance?

1. Bolted joint
2. None of the above
3. Welding joint
4. Riveted joint

7. Which of the following is a design recommendation for welding?

1. The buildup of weld fillets should be kept to a minimum
2. Locate welds where special finishing operations are required
3. Welded assemblies should have more parts
4. Welding should be done horizontally, with the stick or electrode holder pointing upward during welding

8. Which of the following processes do not use flux during welding?

1. Flux Cored Arc
2. Friction
3. Submerged Arc
4. Oxyfuel

9. Which of the following is not a resistance welding?

1. Pressure welding
2. Percussion welding
3. Spot welding
4. Butt welding

10. The resistance welding process suitable for welding ferrous and non-ferrous metals upto 8mm thickness is

1. Butt welding
2. Pressure welding
3. Spot welding
4. Projection welding

11. Which of the following is false regarding welding process and its corresponding minimum thickness of plate material?

1. Flux-Cored Weldments: minimum thickness - 4.5 mm
2. Gas-Metal Arc Weldments: minimum thickness - 0.5 mm and even thinner
3. Shielded-Metal Arc or Stick Weldments: minimum thickness - 1.5 mm
4. Submerged Arc Weldments: minimum thickness - 4.5mm

12. Which of the following welding process is used for welding of sheet metals in automobile and air craft industries?

1. Thermit welding
2. Resistance welding
3. Shield metal arc welding
4. Gas tungsten arc welding

13. Heat is created by the chemical reaction in

1. Tungsten arc welding
2. Thermit welding
3. Resistance welding
4. Oxy-acetylene welding

14. Which of the processes can be classified as solid state welding?

1. Diffusion welding
2. Resistance welding
3. Oxyfuel welding
4. Electron beam welding

15. Which flame is suitable for welding of ferrous metals, Cu and Al alloys?

1. Neutral flame
2. None of the above
3. Oxidising flame
4. Carburising flame

16. Which flame is suitable for cutting operations?

1. Neutral flame
2. None of the above
3. Oxidising flame
4. Carburising flame

17. Which flame is suitable for welding of non ferrous metals (brasses and bronzes)?

1. Neutral flame
2. None of the above
3. Oxidising flame
4. Carburising flame

18. Which flame is suitable for welding steel?

1. Neutral flame
2. None of the above
3. Oxidising flame
4. Carburising flame

19. Which of the following is false regarding material to be welded and its corresponding welding process?

1. Stainless steel - GTAW, GMAW and shielded-metal arc welding
2. Aluminium alloys - GMAW or GTAW process
3. high-carbon steel - shielded-metal arc, flux-cored arc, and submerged arc welding
4. higher-alloy steels - GMAW and GTAW welding

20. Which of the following is not true for gas welding?

1. It is slower than arc welding
2. There are safety problems in storing and handling the gases
3. Heat effected zone and distortion are less as compare to arc welding
4. It is suitable for thin sheets

21. Which of the welding processes utilize a non-consumable electrode?

1. Shielded Metal Arc and Gas-Metal Arc
2. Gas-Metal Arc and Plasma Arc
3. Gas-tungsten Arc and Plasma Arc
4. Plasma Arc and Shielded Metal Arc

22. Which of the following is an example of plastic welding?

1. Forge welding
2. Thermit welding
3. Gas welding
4. Arc welding

23. Which of the following welding process uses non-consumable electrode?

1. CO2 shielded welding
2. Gas metal arc welding (MIG)
3. Gas tungsten arc welding (TIG)
4. Shielded metal arc welding

24. Which of the following ray is not produced during welding?

1. Infrared ray
2. Ultra violet rays
3. Gamma rays
4. Visible light rays

25. In which of the following process, heat is created by blacksmith fire

1. Projection welding
2. Seam welding
3. Forge welding
4. Spot welding

26. Which of the following is not true in regard to welding joint?

1. Economical
2. Have a pleasing appearance
3. Exhibit excellent strength characteristics equal to or even stronger than the base component
4. Heavy in weight

27. The voltage needed in resistance welding does not depend upon

1. Thickness of weld
2. Length of weld
3. Composition
4. Area

28. The metals having good weldability, in descending order are

1. iron, carbon steel, cast steel, cast iron
2. cast iron, iron, carbon steel, cast steel
3. cast steel, iron, carbon steel, cast iron
4. carbon steel, iron, cast steel, cast iron

29. Which of the following types is not fillet weld?

1. T-joint
2. Corner joint
3. butt joint
4. lap joint

30. Which of the following is a weld joint?

1. Corner joints and edge joints
2. all of the above
3. butt and lap joints
4. T joints

31. Which of the processes can be classified as fusion welding?

1. Friction welding and Ultrasonic welding
2. Ultrasonic welding and Laser beam welding
3. Arc welding and Laser beam welding
4. Friction welding and Laser beam welding

32. Which of the following is an example of fusion welding?

1. Resistance welding
2. Thermit welding with pressure
3. Arc welding
4. Forge welding

33. In resistance welding, two electrodes are made of

1. Iron
2. Bronze
3. Aluminium
4. Copper

34. In arc welding, arc initiation voltage is of the order

1. 100-140V
2. 140-180V
3. 20-60V
4. 60-100V

35. The temperature of arc in case of arc welding is

1. 3000°C
2. 3600°C
3. 2000°C
4. 2600°C

36. Single-V and single-U butt welds are used for sheets of thickness upto

1. 10-20mm
2. 15-25mm
3. 10mm
4. 5-15mm

37. The electrodes are manufactured in two standard lengths namely

1. 400 mm and 500 mm
2. 12 inches and 10 inches
3. 350 mm and 250 mm
4. 350 mm and 450 mm

38. Which fuel gas is used for cutting deep under water?

1. LPG
2. Methane
3. Acetylene
4. Hydrogen

39. While gas cutting the nozzle should

1. be 2 mm away from work
2. be 5 mm away from work
3. almost touch the work
4. be 10 mm away from work

40. If the blowpipe is moved to and fro frequently while cutting the kerf will

1. be less
2. not be affected
3. be more
4. of correct size

41. The electrode size refers to

1. thickness of flux coating
2. length of electrode
3. diameter of its core wire
4. diameter (overall) of electrode

42. The top edge is melted round and the cut face is not smooth in gas cutting. This is due to

1. the tip being held too high
2. too much cutting oxygen pressure
3. extremely slow cutting speed
4. insufficient acetylene pressure

43. The position in which it is easiest to weld is

1. Horizontal
2. Overhead
3. Flat
4. Vertical

44. Which type of fire extinguisher is used in a welding shop?

1. CO2 extinguisher
2. Halon extinguisher
3. Foam type extinguisher
4. Dry powder extinguisher

45. If a worker has suffered from electric shock, he should be

1. made to walk
2. kept warm and covered
3. given an alcoholic drink
4. given a cold drink

46. The arc utilized in electric arc welding is a

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

47. The size of a welding machine is determined by

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

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

1. L + 4 mm
2. L + 6 mm
3. L mm
4. L + 2 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. too slow cutting speed
2. smaller size cutting nozzle
3. less preheating flame
4. impure cutting oxygen

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

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