CO MASTER ELECTRICIAN EXAM QUESTIONS
AND CORRECT ANSWERS (VERIFIED
ANSWERS) WITH RATIONALES EXPERT
VERIFIED FOR GUARANTEED PASS | LATEST
UPDATE
SECTION 1: DEFINITIONS & TERMINOLOGY (Article 100)
Question 1:
What is the term for the portion of a wiring system extending beyond the final
overcurrent device?
A) Feeder
B) Branch circuit
C) Service conductors
D) Tap conductors
Answer: B) Branch circuit
Rationale: A branch circuit is defined as the portion of a wiring system extending
beyond the final overcurrent device. The feeder, by contrast, is the portion between
the point of distribution and the branch circuit overcurrent device. Understanding
this distinction is critical for proper circuit identification and code compliance.
Question 2:
What is the term for equipment that admits close approach and is not guarded by
locked doors, elevation, or other effective means?
A) Readily accessible
B) Accessible (as applied to equipment)
C) Accessible (as applied to wiring methods)
D) Exposed
Answer: B) Accessible (as applied to equipment)
Rationale: The NEC defines "Accessible (as applied to equipment)" as admitting
close approach, not guarded by locked doors, elevation, or other effective means.
This differs from "Readily accessible" which means capable of being reached
,quickly without portable ladders, and from "Accessible (as applied to wiring
methods)" which means capable of being removed without damaging the building
structure.
Question 3:
Which of the following best describes a "Controller" as defined in the NEC?
A) A device that opens and closes a circuit by nonautomatic means
B) A unit of an electrical system that carries or controls electric energy as its
principal function
C) A device that governs, in some predetermined manner, the electric power
delivered to the apparatus to which it is connected
D) A device by which the conductors of a circuit can be disconnected from their
source of supply
Answer: C) A device that governs, in some predetermined manner, the
electric power delivered to the apparatus to which it is connected
Rationale: Article 100 defines a controller as a device that governs, in some
predetermined manner, the electric power delivered to the apparatus to which it is
connected. This distinguishes it from a "device" (general term), "disconnecting
means" (disconnects from source), or "circuit breaker" (overcurrent protection).
Question 4:
What is the definition of a "Bathroom" according to the NEC?
A) Any room containing a toilet
B) An area that includes a basin with a toilet, tub, or shower
C) Any room with plumbing fixtures
D) A room with a sink and toilet
Answer: B) An area that includes a basin with a toilet, tub, or shower
Rationale: The NEC specifically defines a bathroom as an area that includes a
basin with a toilet, tub, or shower. This definition is important because bathrooms
have specific GFCI and other requirements that apply based on this definition.
Question 5:
What is the NEC definition of "Ampacity"?
A) The maximum voltage a conductor can carry
B) The current in amperes a conductor can carry continuously without exceeding
,its temperature rating
C) The resistance of a conductor per unit length
D) The power rating of a conductor
Answer: B) The current in amperes a conductor can carry continuously
without exceeding its temperature rating
Rationale: Ampacity is defined as the current in amperes a conductor can carry
continuously under the conditions of use without exceeding its temperature rating.
This is a fundamental concept that underlies all conductor sizing calculations and
is critical for electrical design.
Question 6:
What does the term "Approved" mean in the NEC context?
A) Tested by a recognized laboratory
B) Acceptable to the authority having jurisdiction
C) Listed by Underwriters Laboratories
D) Complies with all code requirements
Answer: B) Acceptable to the authority having jurisdiction
Rationale: In NEC terminology, "Approved" means acceptable to the authority
having jurisdiction (AHJ). This is distinct from "Listed" which means equipment is
on a list published by a testing laboratory. The AHJ has the final say on what is
approved for an installation.
Question 7:
What is a "Continuous Load" as defined by the NEC?
A) A load that operates 24 hours a day
B) A load where the maximum current is expected to continue for 3 hours or more
C) A load that never cycles off
D) A load that operates at maximum capacity
Answer: B) A load where the maximum current is expected to continue for 3
hours or more
Rationale: The NEC defines a continuous load as one where the maximum current
is expected to continue for 3 hours or more. This definition is critical because
continuous loads require branch circuits to be sized at 125% of the continuous
load, a key calculation in electrical design.
, Question 8:
What is a "Multi-wire Branch Circuit"?
A) Multiple conductors made up in the form of a cable
B) Conductors used to connect the non-current-carrying metal parts of appliances
C) A circuit that direct connects the service equipment to the main circuit breaker
D) A circuit that consists of two or more ungrounded conductors and a grounded
conductor
Answer: D) A circuit that consists of two or more ungrounded conductors and
a grounded conductor
Rationale: Article 100 defines a multi-wire branch circuit as a circuit that consists
of two or more ungrounded conductors and a grounded conductor. This is
important because multi-wire branch circuits have special requirements for
disconnecting means and continuity of the grounded conductor.
Question 9:
What is a "Feeder" as defined by the NEC?
A) The portion of a wiring system extending beyond the final overcurrent device
B) The portion of a wiring system between a point of distribution and the branch
circuit overcurrent device
C) The conductors from the service point to the service disconnecting means
D) The conductors that supply power to individual outlets
Answer: B) The portion of a wiring system between a point of distribution and
the branch circuit overcurrent device
Rationale: A feeder is defined as the portion of a wiring system between a point of
distribution and the branch circuit overcurrent device. This is distinct from a
branch circuit (beyond the final overcurrent device) and service conductors (from
the utility to the service disconnect).
Question 10:
What is an "Outlet" as defined by the NEC?
A) Any point on a wiring system where current is taken to supply utilization
equipment
B) A receptacle or switch
C) A point where conductors terminate
D) A junction box location
Answer: A) Any point on a wiring system where current is taken to supply
utilization equipment
AND CORRECT ANSWERS (VERIFIED
ANSWERS) WITH RATIONALES EXPERT
VERIFIED FOR GUARANTEED PASS | LATEST
UPDATE
SECTION 1: DEFINITIONS & TERMINOLOGY (Article 100)
Question 1:
What is the term for the portion of a wiring system extending beyond the final
overcurrent device?
A) Feeder
B) Branch circuit
C) Service conductors
D) Tap conductors
Answer: B) Branch circuit
Rationale: A branch circuit is defined as the portion of a wiring system extending
beyond the final overcurrent device. The feeder, by contrast, is the portion between
the point of distribution and the branch circuit overcurrent device. Understanding
this distinction is critical for proper circuit identification and code compliance.
Question 2:
What is the term for equipment that admits close approach and is not guarded by
locked doors, elevation, or other effective means?
A) Readily accessible
B) Accessible (as applied to equipment)
C) Accessible (as applied to wiring methods)
D) Exposed
Answer: B) Accessible (as applied to equipment)
Rationale: The NEC defines "Accessible (as applied to equipment)" as admitting
close approach, not guarded by locked doors, elevation, or other effective means.
This differs from "Readily accessible" which means capable of being reached
,quickly without portable ladders, and from "Accessible (as applied to wiring
methods)" which means capable of being removed without damaging the building
structure.
Question 3:
Which of the following best describes a "Controller" as defined in the NEC?
A) A device that opens and closes a circuit by nonautomatic means
B) A unit of an electrical system that carries or controls electric energy as its
principal function
C) A device that governs, in some predetermined manner, the electric power
delivered to the apparatus to which it is connected
D) A device by which the conductors of a circuit can be disconnected from their
source of supply
Answer: C) A device that governs, in some predetermined manner, the
electric power delivered to the apparatus to which it is connected
Rationale: Article 100 defines a controller as a device that governs, in some
predetermined manner, the electric power delivered to the apparatus to which it is
connected. This distinguishes it from a "device" (general term), "disconnecting
means" (disconnects from source), or "circuit breaker" (overcurrent protection).
Question 4:
What is the definition of a "Bathroom" according to the NEC?
A) Any room containing a toilet
B) An area that includes a basin with a toilet, tub, or shower
C) Any room with plumbing fixtures
D) A room with a sink and toilet
Answer: B) An area that includes a basin with a toilet, tub, or shower
Rationale: The NEC specifically defines a bathroom as an area that includes a
basin with a toilet, tub, or shower. This definition is important because bathrooms
have specific GFCI and other requirements that apply based on this definition.
Question 5:
What is the NEC definition of "Ampacity"?
A) The maximum voltage a conductor can carry
B) The current in amperes a conductor can carry continuously without exceeding
,its temperature rating
C) The resistance of a conductor per unit length
D) The power rating of a conductor
Answer: B) The current in amperes a conductor can carry continuously
without exceeding its temperature rating
Rationale: Ampacity is defined as the current in amperes a conductor can carry
continuously under the conditions of use without exceeding its temperature rating.
This is a fundamental concept that underlies all conductor sizing calculations and
is critical for electrical design.
Question 6:
What does the term "Approved" mean in the NEC context?
A) Tested by a recognized laboratory
B) Acceptable to the authority having jurisdiction
C) Listed by Underwriters Laboratories
D) Complies with all code requirements
Answer: B) Acceptable to the authority having jurisdiction
Rationale: In NEC terminology, "Approved" means acceptable to the authority
having jurisdiction (AHJ). This is distinct from "Listed" which means equipment is
on a list published by a testing laboratory. The AHJ has the final say on what is
approved for an installation.
Question 7:
What is a "Continuous Load" as defined by the NEC?
A) A load that operates 24 hours a day
B) A load where the maximum current is expected to continue for 3 hours or more
C) A load that never cycles off
D) A load that operates at maximum capacity
Answer: B) A load where the maximum current is expected to continue for 3
hours or more
Rationale: The NEC defines a continuous load as one where the maximum current
is expected to continue for 3 hours or more. This definition is critical because
continuous loads require branch circuits to be sized at 125% of the continuous
load, a key calculation in electrical design.
, Question 8:
What is a "Multi-wire Branch Circuit"?
A) Multiple conductors made up in the form of a cable
B) Conductors used to connect the non-current-carrying metal parts of appliances
C) A circuit that direct connects the service equipment to the main circuit breaker
D) A circuit that consists of two or more ungrounded conductors and a grounded
conductor
Answer: D) A circuit that consists of two or more ungrounded conductors and
a grounded conductor
Rationale: Article 100 defines a multi-wire branch circuit as a circuit that consists
of two or more ungrounded conductors and a grounded conductor. This is
important because multi-wire branch circuits have special requirements for
disconnecting means and continuity of the grounded conductor.
Question 9:
What is a "Feeder" as defined by the NEC?
A) The portion of a wiring system extending beyond the final overcurrent device
B) The portion of a wiring system between a point of distribution and the branch
circuit overcurrent device
C) The conductors from the service point to the service disconnecting means
D) The conductors that supply power to individual outlets
Answer: B) The portion of a wiring system between a point of distribution and
the branch circuit overcurrent device
Rationale: A feeder is defined as the portion of a wiring system between a point of
distribution and the branch circuit overcurrent device. This is distinct from a
branch circuit (beyond the final overcurrent device) and service conductors (from
the utility to the service disconnect).
Question 10:
What is an "Outlet" as defined by the NEC?
A) Any point on a wiring system where current is taken to supply utilization
equipment
B) A receptacle or switch
C) A point where conductors terminate
D) A junction box location
Answer: A) Any point on a wiring system where current is taken to supply
utilization equipment
