Texas Contractor Licensing Exam 2026 – 190 Practice Questions
with Correct Answers & Detailed Rationales, Electrical, HVAC and
Refrigeration, Plumbing, Business and Law, Trade Regulations,
Safety Standards, Code Compliance & Texas TDLR/TSBPE Licensing
Preparation
SECTION 1: ELECTRICAL CONTRACTOR — NEC & TEXAS LAW (QUESTIONS 1–45)
Question 1
A licensed electrical contractor in Texas is primarily responsible for which of the following?
A. Inspecting all electrical installations for the state
B. Ensuring electrical work complies with applicable laws, codes, and permit requirements
while supervising work performed under the license
C. Manufacturing electrical equipment for commercial use
D. Certifying architects' electrical drawings
Correct Answer: B
Explanation: Texas electrical contractors must ensure code compliance, obtain permits, and
supervise all work performed under their license. This is a fundamental legal responsibility .
Question 2
Why is overcurrent protection installed in electrical systems?
A. To increase conductor ampacity
,B. To protect conductors and equipment from excessive current caused by overloads and
short circuits
C. To improve lighting efficiency only
D. To reduce grounding resistance
Correct Answer: B
Explanation: Overcurrent devices like breakers and fuses prevent conductor overheating and
equipment damage by interrupting excessive current during faults or overloads .
Question 3
Which conductor normally carries current during standard operation in a single-phase
120/240-volt system?
A. Equipment grounding conductor
B. Grounding electrode conductor
C. Neutral and ungrounded conductors depending on circuit operation
D. Metal conduit only
Correct Answer: C
Explanation: Ungrounded (hot) conductors carry load current, while the grounded neutral
carries return current for line-to-neutral loads. Equipment grounding conductors should not
carry current normally .
Question 4
What is the primary purpose of bonding in an electrical system?
,A. Reduce utility bills
B. Electrically connect conductive parts together to establish an effective fault-current path
C. Increase conductor insulation resistance
D. Prevent voltage drop
Correct Answer: B
Explanation: Bonding ensures conductive components remain at equal potential and
provides low-impedance fault-current paths for protective device operation .
Question 5
A 20-ampere branch circuit supplying continuous loads should generally not exceed what
continuous load?
A. 20 amperes
B. 18 amperes
C. 16 amperes
D. 12 amperes
Correct Answer: C
Explanation: Continuous loads are limited to 80% of circuit rating unless equipment is listed
for 100% operation. 80% of 20A equals 16A .
Question 6
Which conductor insulation type is commonly rated for 90°C in dry and wet locations?
, A. TW
B. THHN/THWN-2
C. UF only
D. SEU only
Correct Answer: B
Explanation: THHN/THWN-2 conductors are rated for 90°C in dry locations and wet locations
when marked THWN-2 .
Question 7
What is voltage drop primarily caused by?
A. Excessive grounding electrodes
B. Resistance within conductors carrying current
C. Circuit breakers operating normally
D. Increased insulation thickness
Correct Answer: B
Explanation: Voltage drop results from conductor resistance and current flow. Excessive
voltage drop reduces equipment performance and efficiency .
Question 8
Which wiring method provides excellent mechanical protection in commercial construction?
with Correct Answers & Detailed Rationales, Electrical, HVAC and
Refrigeration, Plumbing, Business and Law, Trade Regulations,
Safety Standards, Code Compliance & Texas TDLR/TSBPE Licensing
Preparation
SECTION 1: ELECTRICAL CONTRACTOR — NEC & TEXAS LAW (QUESTIONS 1–45)
Question 1
A licensed electrical contractor in Texas is primarily responsible for which of the following?
A. Inspecting all electrical installations for the state
B. Ensuring electrical work complies with applicable laws, codes, and permit requirements
while supervising work performed under the license
C. Manufacturing electrical equipment for commercial use
D. Certifying architects' electrical drawings
Correct Answer: B
Explanation: Texas electrical contractors must ensure code compliance, obtain permits, and
supervise all work performed under their license. This is a fundamental legal responsibility .
Question 2
Why is overcurrent protection installed in electrical systems?
A. To increase conductor ampacity
,B. To protect conductors and equipment from excessive current caused by overloads and
short circuits
C. To improve lighting efficiency only
D. To reduce grounding resistance
Correct Answer: B
Explanation: Overcurrent devices like breakers and fuses prevent conductor overheating and
equipment damage by interrupting excessive current during faults or overloads .
Question 3
Which conductor normally carries current during standard operation in a single-phase
120/240-volt system?
A. Equipment grounding conductor
B. Grounding electrode conductor
C. Neutral and ungrounded conductors depending on circuit operation
D. Metal conduit only
Correct Answer: C
Explanation: Ungrounded (hot) conductors carry load current, while the grounded neutral
carries return current for line-to-neutral loads. Equipment grounding conductors should not
carry current normally .
Question 4
What is the primary purpose of bonding in an electrical system?
,A. Reduce utility bills
B. Electrically connect conductive parts together to establish an effective fault-current path
C. Increase conductor insulation resistance
D. Prevent voltage drop
Correct Answer: B
Explanation: Bonding ensures conductive components remain at equal potential and
provides low-impedance fault-current paths for protective device operation .
Question 5
A 20-ampere branch circuit supplying continuous loads should generally not exceed what
continuous load?
A. 20 amperes
B. 18 amperes
C. 16 amperes
D. 12 amperes
Correct Answer: C
Explanation: Continuous loads are limited to 80% of circuit rating unless equipment is listed
for 100% operation. 80% of 20A equals 16A .
Question 6
Which conductor insulation type is commonly rated for 90°C in dry and wet locations?
, A. TW
B. THHN/THWN-2
C. UF only
D. SEU only
Correct Answer: B
Explanation: THHN/THWN-2 conductors are rated for 90°C in dry locations and wet locations
when marked THWN-2 .
Question 7
What is voltage drop primarily caused by?
A. Excessive grounding electrodes
B. Resistance within conductors carrying current
C. Circuit breakers operating normally
D. Increased insulation thickness
Correct Answer: B
Explanation: Voltage drop results from conductor resistance and current flow. Excessive
voltage drop reduces equipment performance and efficiency .
Question 8
Which wiring method provides excellent mechanical protection in commercial construction?
