# Welding Questions and Answers – Oxy-Acetylene Welding

This set of Welding Multiple Choice Questions & Answers (MCQs) focuses on “Oxy-Acetylene Welding”.

1. Oxy-acetylene process is most suited for which of the following process of joining?
a) Metal wires
b) Metal sheets
c) Metal tubes
d) Metal bars

Explanation: Oxy-acetylene process is most suited for the joining of metal sheets or for joining metal plates which are having a thickness of 2mm to 50mm. While joining, the molten metal flows together to form a continuous joint.

2. For what thickness of a material, in an oxy-acetylene is a welding rod used?
a) 10 mm
b) 15 mm
c) 20 mm
d) 25 mm

Explanation: Oxy-acetylene processes are mainly used for the joining of metal sheets or for joining metal plates which are having a thickness of 2mm to 50mm. When the thickness of the material is more than 15 mm, an additional filler metal is added like a welding rod.

3. What is the flame temperature of city gas?
a) 1500°C
b) 1600°C
c) 1700°C
d) 1800°C

Explanation: City gas is a type of fuel gas that is used for the welding of thin sheets of steel which have a thickness of up to 3 mm. The flame temperature of city gas is approximately about 1700°C.

4. In a neutral flame, what is the temperature in the inner core?
a) 3200°C
b) 2100°C
c) 1250°C
d) 2700°C

Explanation: When equal amount of oxygen and acetylene is made to react in a torch, a neutral flame gets produced. The inner core has a temperature of 3200°C, whereas the tip of the neutral flame has a temperature of 1250°C.

5. What is the flame temperature of water gas?
a) 2500°C
b) 2800°C
c) 2300°C
d) 3100°C

Explanation: Water gas is a type of fuel gas that is used for the welding of thin sheets of steel which have a thickness of up to 8 mm. The flame temperature of water gas is approximately about 2300°C.

6. Carburising flame has excess of oxygen supply.
a) True
b) False

Explanation: None.

7. What is the flame temperature of methane?
a) 2000°C
b) 1200°C
c) 2700°C
d) 3300°C

Explanation: None.

8. Oxidizing flame has equal volumes of oxygen and acetylene supply.
a) True
b) False

Explanation: A neutral flame is the one in which there is an equal amount of supply of oxygen and acetylene. A carburising flame is the one in which the supply of acetylene is much more than that of oxygen and an oxidizing flame is the one where there is ample supply of oxygen compared to acetylene.

9. What is the flame temperature of acetylene?
a) 1700°C
b) 2200°C
c) 2800°C
d) 3200°C

Explanation: Acetylene gas is a type of fuel gas that is used for the welding of thin sheets of steel which have a thickness of up to 50 mm. The flame temperature of acetylene gas is approximately about 3200°C.

10. What is the flame temperature of hydrogen?
a) 2000°C
b) 1200°C
c) 2700°C
d) 3300°C

Explanation: None.

Sanfoundry Global Education & Learning Series – Welding.

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