Manufacturing Engineering Multiple Choice Questions on “Gas Welding and Gas Cutting”.
1. Which of the following is also called “gas welding”?
a) Oxy fuel gas welding
b) Metallic welding
c) Arc welding
d) Fuel gas welding
Answer: a
Clarification: Gas welding is also known as oxy fuel gas welding. In gas welding, fuel gases are used to generate high amount of heat and melt the metal.
2. How many types of flames are there in welding?
a) 1
b) 2
c) 3
d) 4
Answer: c
Clarification: There are three basic flame types: neutral (balanced), excess acetylene (carburizing), and excess oxygen (oxidizing) as shown below.
3. In which of the following type of flame, oxygen is of same proportion with acetylene?
a) Neutral flame
b) Oxidizing flame
c) Carburizing flame
d) Both oxidizing flame and carburizing flame
Answer: a
Clarification: In neutral flame oxygen is in the same proportion with acetylene. Neutral welding flames are commonly used to weld: mild steel, stainless steel, cast iron, copper, aluminium, etc.
4. In which of the following type of flame, oxygen is in excess proportion with acetylene?
a) Neutral flame
b) Oxidizing flame
c) Carburizing flame
d) Both oxidizing flame and carburizing flame
Answer: b
Clarification: Oxidizing welding flames are produced when slightly more than one volume of oxygen is mixed with one volume of acetylene. Oxidizing welding flames are commonly used to weld zinc, copper, manganese steel, cast iron, etc.
5. In which of the following type of flame, oxygen is deficient in proportion with acetylene?
a) Neutral flame
b) Oxidizing flame
c) Carburizing flame
d) Both oxidizing flame and carburizing flame
Answer: c
Clarification: The carburizing flame has excess acetylene then oxygen. Reducing flame is used for the welding of low carbon and alloy steel.
6. Which of the following flame is harmful to steel?
a) Neutral flame
b) Oxidizing flame
c) Carburizing flame
d) Both oxidizing flame and carburizing flame
Answer: b
Clarification: Oxidizing flame is harmful to steel. An oxidizing flame should not be used for welding steel because the deposited metal will be porous, oxidized and brittle. This flame will ruin most metals and should be avoided.
7. For brazing, soldering and flame hardening which of the following flame is used?
a) Neutral flame
b) Oxidizing flame
c) Carburizing flame
d) Both oxidizing flame and carburizing flame
Answer: c
Clarification: For brazing, soldering and flame hardening carburizing flame is used.
8. The inner cone of the flame in welding has the following nature?
a) Highest temperature
b) Coldest temperature
c) Moderate temperature
d) Uncertain
Answer: a
Clarification: The inner cone of the flame has the highest temperature (3500°C). The outer flame has the lowest temperature.
9. The oxy acetylene gas welding is a type of?
a) Endothermic reaction
b) Exothermic reaction
c) Neutral reaction
d) Both endothermic reaction and exothermic reaction
Answer: b
Clarification: The oxy acetylene gas welding is a type of exothermic reaction. 1 mole of acetylene can produce KJ/mol of heat.
10. The chemical formula of acetylene is?
a) C2H4
b) C2H6
c) C2H5OH
d) C2H2
Answer: d
Clarification: The chemical formula of acetylene is C2H2. 1 mole of acetylene can produce KJ/mol of heat.