Manufacturing Engineering Puzzles on “Fusion Welding Processes-2”.
1. Which of the following is used to generate Acetylene gas?
a) Calcium
b) Carbon
c) Calcium carbonate
d) Calcium carbide
Answer: d
Clarification: Acetylene is a hydrocarbon consisting of two carbon atoms and two hydrogen atoms. The simplest process reacts calcium carbide with water to produce acetylene gas and a calcium carbonate slurry, called hydrated lime. The chemical reaction may be written as CaC2 + 2H2O → C2H2 + Ca (OH)2.
2. Striking voltage as compared to a voltage during arc welding is?
a) less
b) same
c) more
d) can’t say
Answer: c
Clarification: The minimum voltage enough to arc across a given gap is called as the striking voltage. It is more than the arc voltage in arc welding.
3. How many zones are there in a carburising flame?
a) one
b) two
c) three
d) four
Answer: c
Clarification: If the oxygen is insufficient for full combustion, the flame is known as a reducing, or carburizing, flame. The temperature of a reducing flame is lower; hence, such a flame is suitable for applications requiring low heat, such as brazing, soldering, and flame-hardening operations.
4. Due to which of the following reasons distortion in welding occurs?
a) Oxidation of weld pool
b) Use of high voltage
c) Improper clamping
d) Use of high current
Answer: c
Clarification: As if the clamping is improper the weld will not be at the right place.
5. In reverse polarity welding _____________
a) work piece is connected as negative, and holder is earthed
b) electrode holder is connected to negative and work piece to positive
c) electrode holder is connected to positive and work piece to negative
d) both electrode holder and work piece are connected to negative
Answer: c
Clarification: In direct current reverse polarity (DCRP) or direct current electrode positive (DCEP), when base metals relate to the negative terminal of the power source and electrode relates to the positive terminal.
6. Where does maximum flame temperature occur?
a) Next to inner cone
b) At the inner cone
c) At the tip of the flame
d) At the outer cone
Answer: b
Clarification: Maximum flame temperature occur at inner cone. As flame moves from inner to outer temperature drop takes places.
7. In which of the following welding processes, electrode gets consumed?
a) TIG welding
b) Resistance welding
c) Thermit welding
d) Arc welding
Answer: d
Clarification: As in arc welding, welding is totally dependent on electrode, so it will be consumed.
8. Which of the following statements about welding is incorrect?
a) Increased corrosion resistance
b) Even materials like stainless steel and aluminium can be welded
c) No flux required
d) High welding speed
Answer: c
Clarification: Flux is mainly used for the following purposes: (a) It prevents the oxidation o the surface of the weld which can contaminate the welded potion, (b) It helps in forming alloy at the welded portion which improves the strength, (c) In arc welding the flux coating helps in directing the spark that’s why the electrode is kept concave in shape so that spark can be precisely directed towards the cavity where welding has to be performed.
9. Where is half corner weld used?
a) where efficiency of the joint should be 50 percent
b) where longitudinal shear is present
c) where severe loading is encountered, and the upper surfaces of both pieces must be in the same plane
d) For welding materials heavier than 12 gauge