Welding MCQ Multiple Choice Questions Answers for Practice

Q: 1. The electrodes are manufactured in two standard lengths namely

Correct Answer is: 350 mm and 450 mm

Q: 3. While gas cutting the nozzle should

Correct Answer is: be 2 mm away from work

Q: 4. If the blowpipe is moved to and fro frequently while cutting the kerf will

Correct Answer is: not be affected

Q: 5. The electrode size refers to

Correct Answer is: diameter of its core wire

Q: 6. The top edge is melted round and the cut face is not smooth in gas cutting. This is due to

Correct Answer is: too much cutting oxygen pressure

Q: 8. Which type of fire extinguisher is used in a welding shop?

Correct Answer is: CO2 extinguisher

Q: 9. If a worker has suffered from electric shock, he should be

Correct Answer is: kept warm and covered

Q: 10. The arc utilized in electric arc welding is a

Correct Answer is: Low voltage, high current discharge

Q: 11. The size of a welding machine is determined by

Correct Answer is: Output amperage

Q: 13. 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

Correct Answer is: less preheating flame

1. The electrodes are manufactured in two standard lengths namely

350 mm and 250 mm
350 mm and 450 mm
400 mm and 500 mm
12 inches and 10 inches

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

Acetylene
Hydrogen
LPG
Methane

3. While gas cutting the nozzle should

almost touch the work
be 10 mm away from work
be 2 mm away from work
be 5 mm away from work

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

be more
of correct size
be less
not be affected

5. The electrode size refers to

diameter of its core wire
diameter (overall) of electrode
thickness of flux coating
length of electrode

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

extremely slow cutting speed
insufficient acetylene pressure
the tip being held too high
too much cutting oxygen pressure

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

Flat
Vertical
Horizontal
Overhead

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

Foam type extinguisher
Dry powder extinguisher
CO2 extinguisher
Halon extinguisher

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

given an alcoholic drink
given a cold drink
made to walk
kept warm and covered

10. The arc utilized in electric arc welding is a

High voltage, high current discharge
Low voltage, low current discharge
Low voltage, high current discharge
High voltage, low current discharge

11. The size of a welding machine is determined by

Input amperage
Output amperage
Open circuit voltage
Closed circuit voltage

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

L mm
L + 2 mm
L + 4 mm
L + 6 mm

13. 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

less preheating flame
impure cutting oxygen
too slow cutting speed
smaller size cutting nozzle

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

Motor generator set
Engine generator set
Rectifier set
Welding transformer

15. The correct flame for preheating before cutting is

oxidizing flame
neutral flame
carburising flame
slightly carburizing flame

16. Neutral flame in gas welding contains

oxygen & Actylene in equal proportion
More oxygen than Acetylene
less oxygen than Acetylene
None of the above

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

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

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

Red for oxygen and blue for acetylene
Black for oxygen and red for acetylene
Black for oxygen and maroon for acetylene
Red for oxygen and maroon for acetylene

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

Step down
Step up
One-to-one
Capable of increasing supply voltage

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

Sulphur and phosphorous
Silicon and graphite
Graphite and phosphorous
Silicon and sulphur

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

Supply oxygen for preheating
Supply acetylene for preheating
Supply oxygen for cutting
Supply acetylene for cutting

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

the metal will be cooled down
the kerf will be narrow
the kerf will be wide
the metal will fail to cut completely

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

thickness of metal to be cut
purity of oxygen
duration of cut
type of cutting blowpipe

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

tip too close to the cut surface
too much travel speed
less oxygen pressure
smaller size cutting nozzle

25. One of the functions of electrode coating is

to increase welding current
to stabilize the arc
to prevent rusting
to control arc temperature

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

Water
Carbon Dioxide
Acetone
Mercury

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

Welded joint
Riveted joint
Soldered joint
Press fit joint

28. In fusion welding, penetration is the ratio of

width of the weld to its depth
length of the weld to its depth
depth of the weld to its width
depth of the weld to its length

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

Welding joint
Riveted joint
Bolted joint
None of the above

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

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

Welding multiple-choice questions (MCQs) are essential for students and exam aspirants to test and enhance their knowledge of welding techniques and principles. Practice these questions to excel in your exams and career.

About Welding MCQ Questions

Welding MCQs cover a wide range of topics, including types of welding processes, safety procedures, equipment usage, and material properties. These questions are designed to help you understand the fundamental and advanced concepts of welding, ensuring you are well-prepared for any academic or professional challenge.

Why Practice Welding Objective Questions?

Practicing Welding MCQs offers several benefits. It helps you reinforce your understanding of key concepts, prepares you for exams, and enhances your problem-solving skills. Regular practice also boosts your confidence for interviews and ensures you are up-to-date with the latest welding techniques and standards.

Who Should Use These MCQs?

Students preparing for school or college exams
Competitive exam aspirants
Candidates preparing for interviews