Structural Repair Practice Examination

FAA Repairman Certificate – Welding & Structural Repair Practice Examination Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• What type of welding process uses a non-consumable tungsten

electrode?

a) MIG welding

b) TIG welding

c) Stick welding

d) Flux core welding

Rationale: TIG (Tungsten Inert Gas) welding uses a non-consumable

tungsten electrode and inert gas to protect the weld from contamination.

• Which of the following metals requires preheating before welding to

avoid cracking?

a) Aluminum 1 / 4

b) High carbon steel

c) Stainless steel

d) Copper

Rationale: High carbon steels are prone to cracking due to high

hardenability; preheating helps reduce thermal stress.

• What is the main function of a shielding gas in TIG welding?

a) To cool the weld

b) To speed up solidification

c) To prevent atmospheric contamination

d) To increase penetration

Rationale: Shielding gas prevents oxygen and nitrogen from

contaminating the molten weld pool.

• What is the typical filler material used in oxy-acetylene welding of mild

steel?

a) Bronze rod

b) Aluminum rod

c) Mild steel rod

d) Stainless rod

Rationale: A mild steel filler rod matches the composition and

properties of the base metal.

• What type of current is generally used for TIG welding aluminum?

a) DCEN

b) DCEP 2 / 4

c) AC

d) Pulsed DC

Rationale: Alternating current helps clean the oxide layer on

aluminum during TIG welding.

• What welding process uses a consumable electrode and shielding gas?

a) MIG welding

b) TIG welding

c) Oxy-fuel welding

d) Spot welding

Rationale: MIG (Metal Inert Gas) welding employs a consumable

wire electrode and inert shielding gas.

• Which defect is caused by insufficient heat during welding?

a) Burn-through

b) Lack of fusion

c) Porosity

d) Undercut

Rationale: Lack of fusion results when the metal surfaces do not

reach proper melting temperature.

• What safety device prevents a flashback in oxy-acetylene equipment?

a) Regulator

b) Flashback arrestor

c) Check valve

d) Pressure gauge 3 / 4

Rationale: Flashback arrestors stop flame propagation back into

hoses and regulators.

• Which welding process is best suited for thin aluminum sheets?

a) MIG

b) TIG

c) Stick

d) Submerged arc

Rationale: TIG welding offers precise control and minimal heat

distortion, ideal for thin materials.

• What color is typically used to identify an oxygen hose?

a) Green

b) Red

c) Blue

d) Black

Rationale: In welding color coding, green hoses are designated for

oxygen.

11. The acetylene cylinder valve should be opened:

• 1/4 to 1/2 turn

b) Fully open

c) One full turn

d) Until the pressure stabilizes

Rationale: Acetylene valves must be opened slightly for quick shutoff

in emergencies.

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