Joining Methods: Welding Processes & Weld Defects is one of 9 topics in the Grade 11 Mechanical Technology CAPS syllabus, covered across 3 lessons on Study Vault. Below are real practice questions from this topic with full worked answers.
Sample practice questions
Easy
1. What produces the heat in oxy-acetylene (gas) welding?
Burning a controlled mixture of oxygen and acetylene at the torch tip
An electric arc between the electrode and work piece
Electrical resistance at the joint interface
A jet of ionised plasma gas
Answer: Burning a controlled mixture of oxygen and acetylene at the torch tip — Gas welding produces heat by burning a controlled mixture of oxygen and acetylene at the tip of a welding torch, creating a flame hot enough to melt the parent metal and filler rod.
Easy
2. In MIG welding, what does the continuously fed wire electrode do?
It both conducts the welding current and acts as the filler metal
It only shields the weld pool from air, without conducting current
It only conducts current and never becomes part of the weld
It is used purely to clean the joint before welding
Answer: It both conducts the welding current and acts as the filler metal — In MIG welding, the continuously fed wire electrode conducts the welding current (creating the arc) and simultaneously acts as the filler metal added to the joint.
Medium
3. Name the gas that flows around the MIG welding arc and weld pool to protect the molten metal from reacting with oxygen and nitrogen in the air.
Answer: shielding gas — The shielding gas (commonly an inert gas such as argon, or a mixture including carbon dioxide) protects the molten weld pool from reacting with atmospheric oxygen and nitrogen.
