Manufacturing Engineering Multiple Choice Questions on “Arc Welding”.
1. Amount of time during which the transformer will be used for welding under normal loading condition is known as?
a) Hold time
b) Off time
c) Weld time
d) Duty cycle
Answer: d
Clarification: Amount of time during which the transformer will be used for welding under normal loading condition is known as the duty cycle.
2. Amount of voltage required to generate the arc under no load condition is called?
a) Open circuit voltage
b) Closed circuit voltage
c) Short circuit voltage
d) Arc voltage
Answer: a
Clarification: Amount of current required to generate the arc under no load condition is called short circuit current (SCC).
3. Amount of current required to generate the arc under no load condition is called?
a) Open circuit current
b) Closed circuit current
c) Short circuit current
d) Arc current
Answer: c
Clarification: Amount of current required to generate the arc under no load condition is called short circuit current. It is represented by SCC.
4. If the open circuit voltage is 60 volt and the short circuit current is 20 amperes. Then determine the voltage required for welding if the current required during welding is 10 amperes?
a) 30 V
b) 60 V
c) 20 V
d) 40 V
Answer: a
Clarification: Voltage = OCV – ((frac{I}{SCC}))×OCV, where “OCV” is open circuit voltage, “SCC” is short circuit voltage and “I” represents the current in amperes.
5. How does the arc voltage V depends upon the length of arc L?
a) V = f(L)
b) V = 1/f(L)
c) V = f(L2)
d) V = f(√L)
Answer: a
Clarification: V= A+BL, where ‘V’ is the arc voltage and ‘L’ is the length of arc in cm, A & B are constants.
6. What is the function of flux in submerged arc welding?
a) To completely cover the welded zone
b) To prevent oxidation of joint
c) To prevent spattering of molten metal
d) To prevent sticking of molten metal
Answer: d
Clarification: Flux is used to completely cover the welded zone. It prevents oxidation of weld joint and spattering of molten metal.
7. In which of the following gas welding process a non-consumable electrode is used?
a) Submerged arc welding
b) Tungsten inert gas welding
c) Stud welding
d) Gas metal arc welding
Answer: b
Clarification: In tungsten inert gas welding process a non-consumable electrode is used, which is made of tungsten.
8. What is the only difference between Plasma arc welding and TIG welding?
a) Flux is not used
b) Construction of torch is different
c) Gas is not used
d) Tungsten electrode is not used
Answer: b
Clarification: Construction of the torch is the only difference between Plasma arc welding and TIG welding. Both the TIG and PAW are uses tungsten electrodes.
9. In plasma arc welding the gas is?
a) Ionized
b) Heated
c) Magnetized
d) Vaporized
Answer: a
Clarification: In plasma arc welding the gas is ionized. Electrode used is made of tungsten and filler metal is used addition to it.
10. If the heat transfer efficiency is 0.5 and the melting efficiency is 0.6, then the overall efficiency will be?
a) 0.83
b) 0.03
c) 0.30
d) 0.12