Stainless steel is welded using
A. oxy-acetylene flame
B. oxy-hydrogen flame
C. arc welding
D. inert gas arc welding
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The nature of submerged arc welding flux with basicity index of 0.5 is
A. neutral
B. basic
C. semi-basic
D. acidic
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Lap joints are preferred over butt joints in soldering/brazing because
A. these are weaker in tension but stronger in shear
B. these are weaker in shear but stronger in tension
C. these are stronger in both shear and tension
D. the lap joints are easily made
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For a good quality brazing, the molten filler alloy should have
A. low contact angle with the base metal
B. low density
C. high surface tension
D. high viscosity
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Determine the correctness or otherwise of the following Assertion [a] and the Reason [r] .
Assertion: In a pure metal weld, elastic modulus in the heat affected zone (HAZ) is the same as that in the base metal.
Reason: Coarse grained microstructure in the HAZ results in lower hardness.
A. Both [a] and [r] are true and [r] is the correct reason for [a]
B. Both [a] and [r] are true and [r] is not the correct reason for [a]
C. Both [a] and [r] are false
D. [a] is true but [r] is false
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Preheating of steel plate during welding is required to
A. reduce the heat input
B. increase the heat input
C. increase the cooling rate
D. decrease the cooling rate
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Which of the following is not a solid state welding process?
A. Friction stir welding
B. Ultrasonic welding
C. Explosive welding
D. Flux cored arc welding
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Which one of the following welding processes uses a non-consumable electrode?
A. Gas tungsten arc welding
B. Gas metal arc welding
C. Submerged arc welding
D. Flux cored arc welding
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A weldment consists of
A. fused part of the weld
B. fused part and the heat affected zone (HAZ)
C. fused part + HAZ + base metal
D. HAZ
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Preheating prior to welding is done for the purpose of
A. decreasing cooling rate
B. facilitating fusion of high melting metals
C. preventing hot cracking
D. ensuring full penetration
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Match the joining processes in
Group 1 with the filler material in
Group 2 .
Group 1
Group 2
P. Soldering
1. Silver-titanium alloy
Q. Welding
2. Silver-tin alloy
R. Brazing
3. Mild steel
4. Lead fluoride
A. P-2, Q-3, R-1
B. P-1, Q-2, R-3
C. P-3, Q-1, R-2
D. P-2, Q-4, R-1
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Determine the correctness or otherwise of the following Assertion (a) and Reason (r) .
Assertion (a): During welding of aluminium alloys by the gas tungsten arc welding process, direct current reverse polarity (DCRP) mode is used.
Reason (r): DCRP facilitate breaking up of the oxide film on the workpiece surface.
A. a is true but r is false
B. a is false but r is true
C. both a and r are true, and r is the reason for a
D. both a and r are true, and r is not the reason for a
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"Cold cracking" in the heat affected zone of a high strength steel weld can take place because of
A. retained austenite
B. martensite formation
C. relatively high sulphur content in the base metal
D. sufficient hydrogen present in the welding arc
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Steels with high carbon equivalent have poor weldability because in these steels during welding
A. carbon and other alloying elements get oxidised from the weld pool
B. excessive ferrite forms in the heat affected zone leading to the poor toughness of the weld
C. martensite forms in the heat affected zone leading to poor toughness/ductility of the weld
D. segregation of carbon and other elements occurs in the weld pool leading to poor properties of the weld
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Which of the following is not a fusion welding process?
A. Arc welding
B. Gas welding
C. Resistance welding
D. Friction stir welding
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Of the following welding processes
[P] Laser Beam Welding
[Q] Submerged Arc Welding
[R] Metal Inert Gas Welding
the width of the heat-affected zone in decreasing order is
A. P > Q > R
B. Q > R > P
C. R > P > Q
D. P > R > Q
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In TIG welding thoriated tungsten electrodes are used because it
A. has higher current carrying capacity
B. has better electron emissivity
C. is stronger than ordinary tungsten
D. is easy to prepare
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In the consumable electrode shielded metal arc welding process, which of the following observations are correct?
P. The, weld composition does not depend upon the basicity of the slag.
Q. Basic flux is used to achieve low hydrogen content-and low inclusion content in the weld metal.
R. Reverse polarity of the direct current power source is used to weld thin sheets.
S. Coated electrodes are classified by tensile strength of the weld metal deposit.
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In an arc welding experiment, the current, voltage and electrode travel speed were 140 A, 22 V, and 15 cm/min respectively. The heat input per unit length of the weld is given by . . . . . . . . kJ/cm.
A. 24.64
B. 4.62
C. 9.24
D. 12.32
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Match the welding process in
Group 1 with the source of heat in
Group 2 .
Group 1
Group 2
P. Ultrasonic welding
1. Thermochemical
Q. Spot welding
2. Electrical resistance
R. SMAW
3. Friction
S. Thermit welding
4. Electric arc
A. P-3, Q-2, R-1, S-4
B. P-4, Q-3, R-2, S-1
C. P-1, Q-3, R-4, S-2
D. P-3, Q-2, R-4, S-1
Select an option to see the answer and solution.