weldingtheory
1 Which of the following gas is essential for fire?
A) Nitrogen B) Carbon dioxide
C) Oxygen D) None of these
2 Which of the following gas percentage is maximum in atmosphere?
A) Oxygen B) Nitrogen
C) Acetylene D) Co2
3 Which of the following is not found in nonferrous alloys?
A) Lead B) Tin
C) Zinc D) Iron
4 Which of the following welding process uses non-consumable electrode ?
A) Gas Tungsten arc welding
B) Shielded metal arc welding
C) Co2 Shielded welding
D) None of above
5 Heat is created by the chemical reaction in which of the following process?
A) Resistance welding
B) Friction welding
C) Tungsten arc welding
D) Thermite welding
6 The heat generated (H) in resistance welding is expressed by:
A) I2Rt B) IR2t C) IRt2 D) 2IRT
7 The voltage needed in resistance welding does not depend upon:
A) Composition B) Area
C) Thickness of weld D) Length of weld
8 Which of the following is not a resistance welding?
A) Spot welding
B) Butt welding
C) Pressure welding
D) Percussion welding
9 Which flame is suitable for cutting operations?
A) Neutral flame
B) Carburizing flame
C) Oxidizing flame
D) None of the above
10 In arc welding, the three elements to be controlled to obtain satisfactory welding
operation are:
A) Current, voltage and speed of travel
B) Current, voltage and arc length
C) Current, arc length and speed of travel
D) Voltage, arc length and speed of travel
11 The commonly used flux in brazing is:
A) Rosin B) Borax
C) Lead sulphide D) Zinc chloride
12 Projection welding is…....
A) Multi-spot welding process
B) Continuous spot welding process
C) Used to form mesh
D) Used to make cantilevers
13 Seam-welding is…......
A) Multi-spot welding process
B) Continuous spot welding process
C) Used to form mesh
D) Used for welding cylindrical objects
14 In reverse polarity welding.......
A) Electrode holder is connected to the negative and work to positive
B) Electrode holder is connected to the positive and work to negative
C) Work is positive and holder is earthed
D) Holder is positive and work is earthed
15 Flash butt welding is.......
A) Gas welding
B) Arc welding with straight polarity
C) Arc welding with reverse polarity
D) Resistance welding
16 Preheating is essential in welding for......
A) High speed steel B) Stainless steel
C) Cast iron D) German silver
17 Weld spelter is.......
A) Flux B) Electrode coating
C) Welding defect D) Welding test
18 In MIG welding helium or argon is used in order to......
A) Provide cooling effect
B) Act as flux
C) Protect electrode
D) Act as shielding medium
19 Oxidizing flame is used to weld metals like.......
A) Steel
B) Copper and brass
C) Carburized steel
D) aluminum, stainless steel
20 Actylene is stored in gas cylinder in.......
A) In gaseous form B) In liquid form
C) In solid form D) All of above
21 Neutral flame is used to weld metals like......
A) Steel B) Copper and brass
C) Carburized steel
D) Aluminum, stainless steel, zinc die casting, nickel, monel etc.
22 The distance between root and fillet weld is called:
A) Reinforcement B) Leg length
C) Root gap D) Throat thickness
23 The principal material used in soldering are:
A) Tin and copper B) Copper and lead
C) Tin and lead D) Zinc and lead
24 In fusion welding process, penetration is the ratio of:
A) Depth of weld to length
B) Depth of weld to width
C) Width of weld to depth
D) Length of weld to depth
25 Forge welding is classified as:
A) Fusion welding with pressure
B) Fusion welding without pressure
C) Non-fusion welding with pressure
D) Non-fusion welding without pressure
26 Which of the following statement is not true regarding laser beam welding process?
A) The process uses amplified light energy as a source of welding
B) The process essentially requires vacuum
C) Power density of laser beam is much higher compared to an arc welding process
D) All of the above
27 In plasma arc welding process, the plasma is generated by:
A) Low frequency AC voltage
B) Low frequency AC current
C) High frequency AC voltage
D) High frequency AC current
28 Backfire, a small explosion of flame occurring at the tip torch in oxy-acetylene process is due to :
A) Gas pressure setting too low
B) Nozzle overheated
C) Nozzle orifice blocked by carbon deposits
D) Any of the above
29 Which of the following combination provide highest temperature?
A) oxy –hydrogen B) oxy-LPG
C) oxy-acetylene D) Air-acetylene
30 What is the purpose of flux in soldering?
A) Prevent formation of oxide
B) Lower the melting point of solder
C) Wash away the surplus solder
D) All of the above
1 C 2 B 3 D 4 A 5 D 6 A 7 D 8 C 9 C 10 A 11 B 12 A 13 B 14 B 15 D 16 C 17 C 18 D 19 B
20 B 21 A 22 B 23 C 24 C 25 A 26 B 27 D 28 D 29 C 30 A
