MCQ Metal joining

1. Objective Type Questions
Metal joining Technology Session 1
Marks
Qn: 1
Oxyacetylene reducing flame is used while
carrying out the welding on
(1)
(a) Mild steel (b) High carbon steel
(c) Grey cast iron (d) Alloy steels
Ans c
Qn: 2 The correct sequence of given materials in the ascending order of weldability (1)
a MS, copper, cast iron, aluminum b Cast iron, mild steel, aluminium, copper
c Copper, cast iron, mild steel, aluminum d Aluminum, copper, cast iron, mild steel
Ans d
Qn: 3
Consider the following statements: MIG welding uses
1. Consumable electrode, 2.Non-consumable electrode, 3. DC power, 4. AC power
Of these statements
(1)
a 2 and 4 are correct b 2 and 3 are correct
c 1 and 4 are correct d 1 and 3 are correct

2. Ans d
Qn: 4 Which one of the following is not a fusion welding process (1)
a Gas welding b Arc welding
c Brazing d Resistance welding
Ans c
Qn: 5
Which of the following gases can be used as shielding gas in GMAW
Argon, Oxygen, Carbon dioxide
Select the correct answer
(1)
a 1,2,3 b 1,2
c 2,3 d 1,3
Ans d
Qn: 6 Which of the following statements is correct? (1)
a No flux is used in mild steel gas welding b Borax is commonly used flux coating on
welded electrodes
c Laser beam welding employs a vacuum
chamber
d AC can be used in GTAW process
Ans d
Qn: 7 In MIG welding at high current, the metal is transferred in the form of (1)
a Fine spray b Molten drops
c Weld pool d Molecules

3. Ans a
Qn: 8 Pinch effect in welding is a result of (1)
a Expansion of gases in the arc b Electromagnetic forces
c Electric forces d Surface tension of molten metal
Ans b
Qn: 9 The maximum heat in resistance weldings at the (1)
a Tip of positive electrode b Tip of negative electrode
c Top surface of the plate at the time of
electric contact with the electrode
d Interface between the two plated being joined
Ans d
Qn:
10
In resistance welding the heat is generated due to the resistance between (1)
a Electrode and work piece b Asperities between the touching plates
c Two dissimilar metals being in contact d Inter atomic forces
Ans b
Qn:
11
In oxy acetylene gas welding, the temperature of inner cone of neutral flame is around (1)
a 3500 deg C b 3200 deg C
c 2900 deg C d 2550 deg C
Ans b

4. Qn:
12
The metal powder used in thermit welding of steel is (1)
a Al b Cu
c Pb d W
Ans a
Qn:
13
High speed electron beam welding is focussed on the weld spot by (1)
a Vacuum lens b Inert gas lens
c Optical lens d Magnetic lens
Ans d
Qn:
14
In which of the following welding techniques a vacuum environment is required (1)
a Ultrasonic welding b Laser beam welding
c Plasma arc welding d Electron beam welding
Ans d
Qn:
15
The material used for coating electrode is called (1)
a Binder b Slag
c De-oxidizer d Flux
Ans d

5. Qn:
16
In a fillet welded joint, the weakest area of the weld is (1)
a Toe b Root
c Throat d Face
Ans c
Qn:17 Arc stability is better with (1)
(a) AC welding (b) DC welding
(c) Both AC and DC welding (d) Specially designed waveforms
Ans (b)
Qn:18 Which one is not a solid state welding process (1)
(a) Friction welding (b) Explosive welding
(c) Forge welding (d) Resistance spot welding
Ans (d)
Qn:19 The acetylene cylinder is filled with ………. for stabilizing the gas (1)
(a) Calcium carbide (b) Calcium oxide
(c) Acetone (d) Acetylene
Ans (c)
Qn:20
Two 1 mm thick steel sheets are to be spot welded at a current of 5000 A. Assuming effective
resistance to be 200 micro-ohms and current flow time of 0.2 seconds, the heat generated during
the process will be
(1)

6. (a) 0.2 Joules (b) 1 Joule
(c) 5 Joules (d) 1000 Joules
Ans (d)
Qn:21 Ceramic ferrules are used in (1)
(a) TIG welding (b) Stud welding
(c) Arc welding (d) Percussion welding
Ans (b)