WELDING MCQ SET 4
Q1. Cracks in weld metal are caused by:
A) Slow cooling
B) High current
C) Improper cooling and high stress
D) Correct welding speed
Answer: C) Improper cooling and high stress
Explanation: Uneven temperature and shrinkage stresses cause cracks in welded joints.
Q2. The angle between the plates in butt welding is called:
A) Groove angle
B) Bevel angle
C) Root angle
D) Included angle
Answer: D) Included angle
Explanation: The total angle formed between the prepared edges of the plates is called the included angle.
Q3. Which welding position is easiest to perform?
A) Vertical
B) Overhead
C) Flat position
D) Horizontal
Answer: C) Flat position
Explanation: In flat welding, molten metal remains stable and easier to control due to gravity.
Q4. In vertical welding, molten metal tends to:
A) Flow upward
B) Flow downward
C) Stay still
D) Flow sideways
Answer: B) Flow downward
Explanation: Gravity causes molten metal to flow down, making vertical welding more difficult.
Q5. The polarity commonly used in DC arc welding for deep penetration is:
A) DCEN (Direct Current Electrode Negative)
B) DCEP (Direct Current Electrode Positive)
C) AC
D) Neutral
Answer: A) DCEN
Explanation: In DCEN, more heat is concentrated on the workpiece, giving deeper penetration.
Q6. Which gas is commonly used in plasma arc welding?
A) Oxygen
B) Argon
C) Hydrogen
D) Nitrogen
Answer: B) Argon
Explanation: Argon provides good arc stability and protection in plasma welding.
Q7. Submerged Arc Welding (SAW) is mainly used for:
A) Thin sheets
B) Thick plates
C) Aluminum
D) Non-metallic materials
Answer: B) Thick plates
Explanation: SAW is suitable for welding heavy sections with high deposition rates.
Q8. The flux used in SAW is in the form of:
A) Powder
B) Liquid
C) Gas
D) Rod
Answer: A) Powder
Explanation: Granulated flux covers the arc completely in SAW to prevent contamination.
Q9. The current used in resistance spot welding is:
A) Low current, high voltage
B) High current, low voltage
C) Low current, low voltage
D) High current, high voltage
Answer: B) High current, low voltage
Explanation: Spot welding requires high current (up to 10,000 A) and low voltage for local heating.
Q10. The two electrodes used in resistance welding are made of:
A) Copper
B) Steel
C) Aluminum
D) Brass
Answer: A) Copper
Explanation: Copper electrodes are used for their high electrical and thermal conductivity.
Leave a Reply