Certificate of Qualification Construction &
Maintenance Electrician (309A) Practice Exam
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
Download Pdf
1. The main purpose of a bonding conductor is to
a) Reduce voltage drop
b) Ensure electrical continuity and safety
c) Increase current flow
d) Protect insulation from heat
Bonding conductors create a low-resistance path to carry fault
currents safely to ground.
2. In a three-phase, four-wire system, the voltage between any two
phase conductors is 208 V. The voltage between a phase
conductor and neutral is
a) 208 V
b) 120 V
c) 120 V (for a 208Y/120 system)
d) 240 V
In a 208Y/120 V system, line-to-neutral voltage is 120 V, while line-
to-line voltage is 208 V.
3. Which of the following devices is used to protect circuits from
overcurrent caused by short circuits or overloads?
, a) Contactor
b) Transformer
c) Circuit breaker
d) Relay
Circuit breakers automatically interrupt the circuit when current
exceeds rated limits.
4. The NEC requires that nonmetallic-sheathed cable (NM) be
supported within what distance of a box?
a) 100 mm
b) 150 mm
c) 200 mm
d) 300 mm
Supporting NM cable within 300 mm (12 in) of a box prevents
undue stress and protects terminations.
5. The term “short circuit” refers to
a) Normal operation of a motor
b) High-resistance connections
c) A low-resistance connection between two points of different
potential
d) Lightning strike on a conductor
Short circuits cause excessive current flow due to a low-resistance
path, which can damage equipment.
6. The purpose of a ground fault circuit interrupter (GFCI) is to
a) Reduce power consumption
b) Protect people from electric shock
c) Increase voltage stability
d) Regulate current
, GFCIs detect leakage currents and disconnect the circuit to prevent
shock.
7. When installing conduit in a damp location, which material is most
suitable?
a) PVC
b) Aluminum
c) Galvanized steel
d) EMT
Galvanized steel conduit resists corrosion in damp environments,
ensuring long-term safety.
8. What is the standard colour code for grounding conductors in
Canada?
a) Red or black
b) Green or bare
c) White
d) Blue
Grounding conductors must be green or bare to identify them
clearly for safety.
9. What is the primary function of a transformer?
a) Increase current only
b) Change voltage levels
c) Convert AC to DC
d) Store energy
Transformers transfer electrical energy between circuits at
different voltage levels using electromagnetic induction.
10. Which of the following devices is considered a disconnecting
means?
Maintenance Electrician (309A) Practice Exam
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
Download Pdf
1. The main purpose of a bonding conductor is to
a) Reduce voltage drop
b) Ensure electrical continuity and safety
c) Increase current flow
d) Protect insulation from heat
Bonding conductors create a low-resistance path to carry fault
currents safely to ground.
2. In a three-phase, four-wire system, the voltage between any two
phase conductors is 208 V. The voltage between a phase
conductor and neutral is
a) 208 V
b) 120 V
c) 120 V (for a 208Y/120 system)
d) 240 V
In a 208Y/120 V system, line-to-neutral voltage is 120 V, while line-
to-line voltage is 208 V.
3. Which of the following devices is used to protect circuits from
overcurrent caused by short circuits or overloads?
, a) Contactor
b) Transformer
c) Circuit breaker
d) Relay
Circuit breakers automatically interrupt the circuit when current
exceeds rated limits.
4. The NEC requires that nonmetallic-sheathed cable (NM) be
supported within what distance of a box?
a) 100 mm
b) 150 mm
c) 200 mm
d) 300 mm
Supporting NM cable within 300 mm (12 in) of a box prevents
undue stress and protects terminations.
5. The term “short circuit” refers to
a) Normal operation of a motor
b) High-resistance connections
c) A low-resistance connection between two points of different
potential
d) Lightning strike on a conductor
Short circuits cause excessive current flow due to a low-resistance
path, which can damage equipment.
6. The purpose of a ground fault circuit interrupter (GFCI) is to
a) Reduce power consumption
b) Protect people from electric shock
c) Increase voltage stability
d) Regulate current
, GFCIs detect leakage currents and disconnect the circuit to prevent
shock.
7. When installing conduit in a damp location, which material is most
suitable?
a) PVC
b) Aluminum
c) Galvanized steel
d) EMT
Galvanized steel conduit resists corrosion in damp environments,
ensuring long-term safety.
8. What is the standard colour code for grounding conductors in
Canada?
a) Red or black
b) Green or bare
c) White
d) Blue
Grounding conductors must be green or bare to identify them
clearly for safety.
9. What is the primary function of a transformer?
a) Increase current only
b) Change voltage levels
c) Convert AC to DC
d) Store energy
Transformers transfer electrical energy between circuits at
different voltage levels using electromagnetic induction.
10. Which of the following devices is considered a disconnecting
means?
