Texas Master Electrician Licensing Exam
Practice Questions and Correct Answers
(Verified Answers) Plus Rationales 2027
Q&A | Instant Download Pdf
1. Which edition of the National Electrical Code is currently used as the primary
technical standard for Texas electrical licensing examinations?
A. 2017 NEC
B. 2020 NEC
C. 2023 NEC
D. 2026 NEC
Correct Answer: C. 2023 NEC
Rationale: Texas currently bases its electrical licensing examinations on the 2023
National Electrical Code, together with applicable Texas statutes, administrative
rules, and licensing requirements.
2. What is the primary function of an equipment grounding conductor?
A. Carry normal neutral current
B. Provide a low-impedance path for fault current
C. Increase circuit voltage
D. Provide the normal return path for a 120-volt load
Correct Answer: B. Provide a low-impedance path for fault current
Rationale: An equipment grounding conductor provides a conductive path for fault
current back to the source. This allows the overcurrent protective device to
operate and clear the fault.
,3. A 240-volt single-phase heater is rated at 4,800 watts. What is its operating
current?
A. 10 A
B. 15 A
C. 20 A
D. 30 A
Correct Answer: C. 20 A
Rationale: For a resistive load, current is calculated using I = P ÷ E. Therefore,
4,800 watts ÷ 240 volts = 20 amperes.
4. What is the primary purpose of the grounded conductor in a typical 120/240-
volt single-phase system?
A. Provide a return path for line-to-neutral loads
B. Serve as the equipment grounding conductor
C. Protect branch-circuit conductors from overload
D. Provide mechanical support for the service conductors
Correct Answer: A. Provide a return path for line-to-neutral loads
Rationale: The grounded conductor carries current from line-to-neutral loads back
to the source. It is distinct from the equipment grounding conductor, which is
intended to carry fault current.
5. What is the primary purpose of a main bonding jumper at service equipment?
A. Increase service voltage
B. Connect the grounded conductor to the equipment grounding and bonding
system
C. Protect the service from overload
D. Provide a second neutral conductor
Correct Answer: B. Connect the grounded conductor to the equipment
grounding and bonding system
,Rationale: The main bonding jumper establishes the connection between the
grounded conductor and the equipment grounding/bonding system at the service
disconnecting means.
6. What does the ampacity of a conductor indicate?
A. Its physical diameter only
B. Its maximum permitted current under specified conditions
C. Its insulation color
D. Its maximum voltage regardless of insulation type
Correct Answer: B. Its maximum permitted current under specified conditions
Rationale: Ampacity is the maximum current a conductor can carry continuously
under the conditions of use without exceeding its temperature rating.
7. Which factor can require adjustment of conductor ampacity?
A. The number of current-carrying conductors in a raceway
B. The color of the raceway
C. The number of switches on a wall
D. The length of the building name
Correct Answer: A. The number of current-carrying conductors in a raceway
Rationale: Multiple current-carrying conductors installed together can increase
heat buildup. The NEC provides adjustment factors to account for these
conditions.
8. What is the primary purpose of overcurrent protection?
A. Increase circuit efficiency
B. Protect conductors and equipment from excessive current
C. Increase available fault current
D. Replace grounding and bonding
Correct Answer: B. Protect conductors and equipment from excessive current
, Rationale: Fuses and circuit breakers interrupt excessive current resulting from
overloads, short circuits, and certain fault conditions, protecting conductors and
equipment.
9. What is the primary purpose of a GFCI?
A. Detect current imbalance associated with a ground fault
B. Protect motors from normal starting current
C. Increase circuit voltage
D. Provide overvoltage protection
Correct Answer: A. Detect current imbalance associated with a ground fault
Rationale: A GFCI compares current flowing through the circuit conductors. An
imbalance indicates that some current may be taking an unintended path, and the
device interrupts the circuit.
10. What is the primary purpose of AFCI protection?
A. Protect against certain hazardous arcing conditions
B. Increase transformer efficiency
C. Provide motor overload protection
D. Replace the service disconnect
Correct Answer: A. Protect against certain hazardous arcing conditions
Rationale: Arc-fault circuit interrupters detect specified characteristics of
dangerous arcing and interrupt the circuit to reduce the risk of electrical fires.
11. What is the primary purpose of a service disconnecting means?
A. Disconnect the premises wiring from the service supply
B. Control only lighting circuits
C. Replace branch-circuit breakers
D. Increase the service voltage
Correct Answer: A. Disconnect the premises wiring from the service supply
Practice Questions and Correct Answers
(Verified Answers) Plus Rationales 2027
Q&A | Instant Download Pdf
1. Which edition of the National Electrical Code is currently used as the primary
technical standard for Texas electrical licensing examinations?
A. 2017 NEC
B. 2020 NEC
C. 2023 NEC
D. 2026 NEC
Correct Answer: C. 2023 NEC
Rationale: Texas currently bases its electrical licensing examinations on the 2023
National Electrical Code, together with applicable Texas statutes, administrative
rules, and licensing requirements.
2. What is the primary function of an equipment grounding conductor?
A. Carry normal neutral current
B. Provide a low-impedance path for fault current
C. Increase circuit voltage
D. Provide the normal return path for a 120-volt load
Correct Answer: B. Provide a low-impedance path for fault current
Rationale: An equipment grounding conductor provides a conductive path for fault
current back to the source. This allows the overcurrent protective device to
operate and clear the fault.
,3. A 240-volt single-phase heater is rated at 4,800 watts. What is its operating
current?
A. 10 A
B. 15 A
C. 20 A
D. 30 A
Correct Answer: C. 20 A
Rationale: For a resistive load, current is calculated using I = P ÷ E. Therefore,
4,800 watts ÷ 240 volts = 20 amperes.
4. What is the primary purpose of the grounded conductor in a typical 120/240-
volt single-phase system?
A. Provide a return path for line-to-neutral loads
B. Serve as the equipment grounding conductor
C. Protect branch-circuit conductors from overload
D. Provide mechanical support for the service conductors
Correct Answer: A. Provide a return path for line-to-neutral loads
Rationale: The grounded conductor carries current from line-to-neutral loads back
to the source. It is distinct from the equipment grounding conductor, which is
intended to carry fault current.
5. What is the primary purpose of a main bonding jumper at service equipment?
A. Increase service voltage
B. Connect the grounded conductor to the equipment grounding and bonding
system
C. Protect the service from overload
D. Provide a second neutral conductor
Correct Answer: B. Connect the grounded conductor to the equipment
grounding and bonding system
,Rationale: The main bonding jumper establishes the connection between the
grounded conductor and the equipment grounding/bonding system at the service
disconnecting means.
6. What does the ampacity of a conductor indicate?
A. Its physical diameter only
B. Its maximum permitted current under specified conditions
C. Its insulation color
D. Its maximum voltage regardless of insulation type
Correct Answer: B. Its maximum permitted current under specified conditions
Rationale: Ampacity is the maximum current a conductor can carry continuously
under the conditions of use without exceeding its temperature rating.
7. Which factor can require adjustment of conductor ampacity?
A. The number of current-carrying conductors in a raceway
B. The color of the raceway
C. The number of switches on a wall
D. The length of the building name
Correct Answer: A. The number of current-carrying conductors in a raceway
Rationale: Multiple current-carrying conductors installed together can increase
heat buildup. The NEC provides adjustment factors to account for these
conditions.
8. What is the primary purpose of overcurrent protection?
A. Increase circuit efficiency
B. Protect conductors and equipment from excessive current
C. Increase available fault current
D. Replace grounding and bonding
Correct Answer: B. Protect conductors and equipment from excessive current
, Rationale: Fuses and circuit breakers interrupt excessive current resulting from
overloads, short circuits, and certain fault conditions, protecting conductors and
equipment.
9. What is the primary purpose of a GFCI?
A. Detect current imbalance associated with a ground fault
B. Protect motors from normal starting current
C. Increase circuit voltage
D. Provide overvoltage protection
Correct Answer: A. Detect current imbalance associated with a ground fault
Rationale: A GFCI compares current flowing through the circuit conductors. An
imbalance indicates that some current may be taking an unintended path, and the
device interrupts the circuit.
10. What is the primary purpose of AFCI protection?
A. Protect against certain hazardous arcing conditions
B. Increase transformer efficiency
C. Provide motor overload protection
D. Replace the service disconnect
Correct Answer: A. Protect against certain hazardous arcing conditions
Rationale: Arc-fault circuit interrupters detect specified characteristics of
dangerous arcing and interrupt the circuit to reduce the risk of electrical fires.
11. What is the primary purpose of a service disconnecting means?
A. Disconnect the premises wiring from the service supply
B. Control only lighting circuits
C. Replace branch-circuit breakers
D. Increase the service voltage
Correct Answer: A. Disconnect the premises wiring from the service supply
