WELDER IMPORTANT NIMI BASED MCQ

Which polarity is used in welding with heavy and super heavy coated electrodes?
A. AC Transformer
B. Reverse polarity
C. Straight polarity
D. AC Motor generator

Which polarity used in welding cast iron?
A. Rectifier set
B. AC Transformer
C. Reverse polarity
D. Straight polarity

What should be the angle of electrode in the flat position welding?
A. 50° to 70°
B. 60° to 70°
C. 70° to 80°
D. 80° to 90°

What is the size of nozzle suitable for welding 50mm dia pipe, with 3.15mm wall thickness?
A. 5
B. 7
C. 10
D. 13

What is the purpose of wrapping the weld cable around the job in welding?
A. To control arc blow
B. To control arc speed
C. To control arc length
D. To control distortion

What is the purpose of fixing run on, run off plates in arc welding?
A. Control arc blow
B. Control porosity
C. Control distortion
D. Control over heating

Which defect can be controlled by keeping a magnetic bridge on the top of the groove joint?
A. Arc blow
B. Distortion
C. Uneven bead
D. Slag inclusion

Which among the joints are covered under fillet group?
A. T joint, Lap joint
B. T joint, Corner joint
C. Corner joint, Edge joint
D. T joint, Lap joint, Corner joint, Edge joint

What happens if the root gap is lesser than one sixth of plate thickness?
A. More chances of distortion
B. More penetration will result
C. Likely defects like blowhole, porosity
D. Base metal not fused till the bottom of joint

Which arc length produces popping sound?
A. Long arc length
B. Short arc length
C. Normal arc length
D. Too long arc length

What arc length should be used to reduce the spatter?
A. Long arc length
B. Short arc length
C. Normal arc length
D. Too long arc length

What is the indication of wrong polarity in DC welding?
A. Electrode become red hot
B. Electrode will freeze with the job
C. Excess spatters and poor penetration
D. It will produce edge of plates melted off

How do you name the depression formed at the end of the weld?
A. Crack
B. Crater
C. Pin hole
D. Blow hole

What defect will occur due to magnetic field while using DC supply in arc welding?
A. Crack
B. Arc blow
C. Over lap
D. Distortion

Which defect will occur, when the equipment is changed for AC to DC supply in arc welding?
A. Arc blow
B. Over lap
C. Weld crack
D. Distortion

What is the current range required for 3.15mm dia MS electrode in arc welding?
A. 40 – 50 A
B. 50 – 60 A
C. 70 – 80 A
D. 100 – 110 A

What is the name of last bit of an discarded electrode?
A. Red end
B. Dead end
C. Stub end
D. Waste end

How many groups of mild steel pipes are there?
A. Two groups
B. Five groups
C. Four groups
D. Three groups

How a pipe is specified?
A. Dia only
B. Length only
C. Outer dia only
D. Outer dia x inner dia x length

What should be the bevel angle for edge preparation of 6mm thick pipe welding?
A. 30° – 35°
B. 40° – 45°
C. 60° – 65°
D. 70° – 75°