SAMPLE PAPER FOR BLOG ON viva-written-format-equal-opportunity

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VIVA: WRITTEN FORMAT, EQUAL OPPORTUNITY EVALUATION PROCEDURE (SAMPLE)

Programme		Course No. & Name			Semester, Session
MM: 100	Practical Quiz		Venue	Time		Date

 

Name:

Roll No.:

Signature:

 

• True / False statements. Answer all statements by checking the appropriate box, ‘T’ for True, or ‘F’ for False.
• ONE mark would be awarded for each correct answer, but TWO marks would be deducted (-2) for each wrong answer.
• No marks would be deducted for unattempted statements or skipped statements. Therefore ATTEMPT ONLY WHEN SURE. Please note, engineering education has no room for guessing.

 

#	Statement	T/F
1.	Metal transfer through the arc stream varies greatly with different gas shielding.	T
2.	The stickout is the distance between the end of the contact tube and the tip of the welding arc in semi-automatic welding processes.	T
3.	At the same weld speed, decrease in electrode size will increase the cross-sectional area of weld bead in SMAW process.	F
4.	Welding in ‘Vertical-up’ direction is more difficult than vertical-down direction in arc welding.	T
5.	Primary of the transformer power source can’t be connected to DC suppy.	F
6.	A manual metal arc covered electrode can have a metal deposition efficiency greater than 130%	T
7.	Weld bead penetration increases with increase in thermal conductivity of the weld metal.	F
8.	Moisture is one of the major causes of cold cracking in welds.	T
9.	DCEP- is the specific direction of current flow through a welding circuit.	T
10.	Inverter-Power source is one, which converts AC-DC-AC.	T
11.	Oxygen or carbon dioxide additions to the inert shielding gas stabilizes the arc, but usually results in increased fume formation rates.	T
12.	SAW has the lowest fume formation rate amongst all the arc processes,.	T
13.	Electrode size is nominated by diameter of the covered core wire.	T
14.	Increase in carbon weight percentage will increase ductility of steels.	F
15.	The droopers are commonly known as constant voltage welding machines.	F
16.	The portion of the base metal which doesn’t melt during arc welding is called fusion zone.	F
17.	A cavity formed by gas entrapment during welding is called inclusion.	F
18.	Heat Affected Zone stand for the portion of the base metal affected by the heat of the welding arc but doesn’t experience melting.	T
19.	The penetration can be reduced by simple manipulation of the arc gap, at the same welding current.	T
20.	Micro-hardness testing is best suitable for materials with very fine multi-phase microstructure.	T
21.	Ceramic materials can be tested by Vickers hardness testing.	T
22.	SMAW is the preferred process for reactive metals.	F
23.	Change in type of shielding gas will affect the weld bead geometry.	T
24.	‘Drag electrode’ is a term used in SMAW process.	T
25.	SMAW is the preferred process for zinc and zirconium.	F
26.	The maximum allowable current is determined by the length of the stick electrode.	F
27.	Metal fumes of some metals are carcinogenic.	T
28.	Any increase in arc voltage with constant current will increase the weld bead width in SAW process.	T
29.	DCEP is also known as ‘straight polarity’.	F
30.	Arc length increases with the increase in arc voltage.	T
31.	Heavy coated iron powder electrodes are designed for high deposition welding.	T
32.	Low hydrogen electrodes are used to weld hardenable steels.	T
33.	DCEN is preferable than DCEP for surfacing process with SMAW process.	F
34.	Toughness of mild steel is more at –20 °C than at 30°C.	F
35.	Autogenous welds are not possible with GTAW.	F
36.	Post weld cleaning is more in GMAW process.	F
37.	GTAW gives the best quality welding compared to GMAW and SAW.	T
38.	GMAW is best suitable for inaccessible positional welding.	F
39.	The arc in helium is more penetrating than Argon.	T
40.	GTAW is a preferred process for thicker sections.	F
41.	GMAW is a recommended process for outdoor welding.	F
42.	Operator duty cycle of the welding power source is greater in SMAW process than that of GMAW process.	F
43.	Change in type of shielding gas will affect the weld pool shape at the same arc voltage.	T
44.	Electrodes with different tip shapes in GTAW affect the weld quality.	T
45.	The voltage drop across the welding cables is lower in case of AC supply when compared to DC supply.	T
46.	CO2 is the only reactive gas that is used as a shielding gas in GMAW.	T
47.	Droopers are the choice when using large diameter covered electrodes with higher coating ratios in SMAW.	T
48.	OCV will remain constant on both during and after welding in SMAW.	F
49.	The maximum temperature that is reached in SMAW arc is around 5000 ~ 6000 °C.	T
50.	Charpy V notch test is conducted for determining the hardness of the composite metal.	F
51.	Cellulosic electrodes are the most efficient electrodes for high carbon steels.	F
52.	The study of weldability is usually confined to the weld metal of the joint.	F
53.	The best welding technique for obtaining sound weld for any material is the one that gives maximum linear heat input.	F
54.	Medium carbon steels have better weldability than mild carbon steels.	F
55.	High hardenable materials have low weldability.	T
56.	Larger the weldment reinforcement, better the rigidity and strength of the joint.	F
57.	Stress relieving may be necessary for Q&T steels to prevent cracking.	T
58.	The intensity of welding heat source is distributed uniformly over the contact area.	F
59.	The most difficult material to weld is low carbon steel.	F
60.	High heat input and slower cooling always increase the amount of dilution.	T
61.	The main cause for HAZ cracking in base metal is lack of shielding.	F
62.	Pre / post weld heating are the common methods applied to control the weld metal dilution.	F
63.	The volume of deposited metal is greater in single ‘V’ groove joint than a double ‘V’ groove joint.	T
64.	Vertical down welding is an example of “out of position welding”.	T
65.	Increase in welding speed during SAW reduces cooling rate.	F
66.	Weldability is reduced by the presence of Sulphur and Phosphorous in the base metal.	T
67.	Unequal leg size is a defect for fillet welds.	T
68.	The intensity of heat from a welding heat source cannot generally be expressed as a precise number.	T
69.	Self-shielded flux cored arc welding (FCAW-S) can’t be used for welding of cross country pipelines.	F
70.	With the increase in viscosity of molten metal there are more chances of lack of fusion.	T
71.	Sulphur increases the cold cracking susceptibility in the weld metal.	F
72.	Increase in carbon weight percentage will decrease the melting temperature and ductility in steels.	T
73.	Strength to weight ratio of pure aluminum is more than high strength steel.	T
74.	If you double the amperage in a given welding cable then the heat produced will also be doubled.	F
75.	If a welding cable produces too much heat, the remedy would be to reduce the diameter of the cable.	F
76.	Cold cracking defect is associated with phosphorous presence in weld metal.	F
77.	Increase in welding current during welding causes increase in weld penetration.	T
78.	Charpy impact test is an example of NDT.	F
79.	Cracks occur because the stress at the point in the weldment exceeds the yield strength.	T
80.	DC of the equivalent voltage and amperage is more dangerous than of an A.C. line in welding.	T
81.	The delayed cracking in welds is due to the presence of moisture during welding.	T
82.	Phosphorous increases the hot cracking susceptibility in base metal	T
83.	It is difficult to define the area of contact between the heat source and the work piece in welding.	T
84.	Inter-pass cleaning is done for avoiding slag inclusion.	T
85.	Presence of Carbon in iron is an example of substitutional solid solution.	F
86.	In SAW process increase in arc voltage with constant welding current will increase the flux consumption.	T
87.	Flame hardening is a case hardening process.	T
88.	Arc welding can produce Ozone.	T
89.	Heat balance is not important criteria in resistance welding materials of different electrical conductivities.	F
90.	Super conductivity is a phenomenon associated with metals at room to elevated temperatures.	T
91.	The arc in Helium is more penetrating than Argon.	T
92.	The droopers are commonly known as constant voltage welding machines	F
93.	Gas is also used as a coolant in GTAW process.	T
94.	GMAW is a better process for reactive materials than GTAW.	F
95.	The best welding technique for obtaining sound weld for any material is the one that gives maximum linear heat input.	F
96.	Medium carbon steels have better weldability than mild carbon steels.	F
97.	Chlorinated hydrocarbons should never be used for degreasing the joint surfaces during arc welding.	T
98.	Larger the weldment reinforcement, better the rigidity and strength of the joint.	F
99.	Deadly nerve gas Phosgene can also be produced during arc welding if proper precautions are not taken.	T
100.	Infrared radiation is more harmful than UV radiation.	F