Exam Questions And Correct Answers With
Rationales
1. Which type of metal is commonly used for ductwork in residential
HVAC systems?
a) Copper
b) Stainless steel
c) Galvanized steel
d) Aluminum
Galvanized steel is durable, resistant to corrosion, and cost-effective,
making it standard for residential ductwork.
2. What is the purpose of a slip joint in duct installation?
a) To increase airflow velocity
b) To reduce sound
c) To allow thermal expansion and contraction
d) To filter air
Slip joints accommodate the expansion and contraction of metal ducts
due to temperature changes.
3. Which tool is used to measure the thickness of sheet metal?
,a) Calipers
b) Micrometer
c) Tape measure
d) Spirit level
Micrometers provide precise measurements of thin materials like sheet
metal.
4. What type of seam is commonly used in round duct fabrication?
a) Lap seam
b) Drive seam
c) Butt seam
d) Welded seam
Drive seams provide a strong, leak-resistant joint for round ducts.
5. In sheet metal terminology, what does “gauge” refer to?
a) Thickness of the metal
b) Width of the sheet
c) Weight of the metal
d) Length of the sheet
Gauge indicates the thickness; a higher gauge means thinner metal.
6. What is the recommended safety practice when using a hand
shear?
,a) Wear open-toed shoes
b) Keep hands clear of the cutting area
c) Use excessive force to cut quickly
d) Cut without eye protection
Hand shears are sharp, so keeping hands away from the blade prevents
injuries.
7. What is the primary function of a turning vanes in ductwork?
a) To increase pressure loss
b) To reduce noise
c) To guide airflow smoothly through elbows
d) To filter dust
Turning vanes reduce turbulence in air traveling through duct elbows.
8. Which type of welding is most commonly used in sheet metal
fabrication?
a) Gas tungsten arc welding (GTAW)
b) Gas metal arc welding (GMAW / MIG)
c) Stick welding
d) Plasma arc welding
GMAW/MIG welding is fast and suitable for thin sheet metals used in
ductwork and HVAC systems.
9. What does HVAC stand for?
, a) High Velocity Air Circulation
b) Heat, Ventilation, and Vacuum
c) Heating, Ventilation, and Air Conditioning
d) Hot Ventilation and Air Control
HVAC refers to systems that provide heating, ventilation, and air
conditioning.
10. When fabricating a rectangular duct, what is the purpose of a lock-
forming machine?
a) Cut metal sheets
b) Form seams for assembly
c) Punch holes
d) Measure gauge
Lock-forming machines create interlocking seams that allow duct
sections to fit together securely.
11. Which personal protective equipment (PPE) is essential when
cutting sheet metal?
a) Rubber boots
b) Cotton gloves
c) Cut-resistant gloves and safety glasses
d) Hearing protection only
Cut-resistant gloves prevent hand injuries, and safety glasses protect the
eyes from flying metal shards.