WELDING MCQ SET 7
Q1. Overlap in welding is caused by:
A) Low current
B) Excessive electrode angle
C) Incorrect speed
D) B and C
Answer: D) B and C
Explanation: Improper electrode angle or speed causes weld metal to roll over base metal without fusion.
Q2. Slag inclusion in weld occurs due to:
A) Poor technique
B) Excessive flux
C) Welding in wrong position
D) All of the above
Answer: D) All of the above
Explanation: Slag inclusion is trapped flux in the weld, weakening the joint.
Q3. Crater cracks are caused by:
A) Improper current
B) Sudden interruption of welding
C) High speed
D) All
Answer: B) Sudden interruption of welding
Explanation: Crater cracks form at the end of the weld when molten metal cools quickly.
Q4. Burn-through in welding happens due to:
A) High current and thin metal
B) Low current
C) Proper travel speed
D) Too much flux
Answer: A) High current and thin metal
Explanation: Excessive heat melts through thin metal, causing burn-through.
Q5. Backstep welding is used to:
A) Reduce distortion
B) Increase weld size
C) Improve arc stability
D) Reduce current
Answer: A) Reduce distortion
Explanation: Welding in opposite short segments minimizes heat accumulation and distortion.
Q6. Welding of stainless steel requires:
A) Ordinary electrodes
B) Low hydrogen electrodes
C) High carbon electrodes
D) Aluminum electrodes
Answer: B) Low hydrogen electrodes
Explanation: Low hydrogen prevents cracking in stainless steel welds.
Q7. The term โweld shrinkageโ refers to:
A) Cooling of molten weld
B) Contraction of weld metal after solidification
C) Expansion during heating
D) Melting point variation
Answer: B) Contraction of weld metal after solidification
Explanation: Shrinkage may cause distortion and requires proper fixtures.
Q8. Preheating is required in welding to:
A) Reduce thermal stress
B) Improve weld penetration
C) Prevent cracking
D) All of the above
Answer: D) All of the above
Explanation: Preheating minimizes thermal gradients, improves fusion, and reduces cracks.
Q9. Post-weld heat treatment (PWHT) is done to:
A) Harden the weld
B) Relieve residual stress
C) Reduce ductility
D) Increase porosity
Answer: B) Relieve residual stress
Explanation: PWHT reduces stress and improves toughness and dimensional stability.
Q10. Welding distortion can be minimized by:
A) Proper joint design
B) Balanced welding sequence
C) Clamping
D) All of the above
Answer: D) All of the above
Explanation: Controlling heat, sequence, and restraints reduces distortion.
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