Texas Master Electrician Exam Newest (2026
Update) Actual Practice Questions – Set 100
Most Common Exam Questions And Answers
In Details 100% Verified Exam Highly
Recommendable For Grade A+
1. A 3-phase, 4-wire system has a measured line-to-line voltage of 480V. What
is the approximate line-to-neutral voltage?
A. 120V
B. 208V
C. 277V
D. 240V
✓ Correct Answer: (C. 277V)
Rationale: In a wye system, line-to-neutral voltage equals line-to-line
divided by √3; 480 ÷ 1.732 ≈ 277V.
2. According to NEC standards, which conductor is typically permitted to be
ungrounded in a DC system?
A. Neutral conductor
B. Equipment grounding conductor
C. Positive conductor
D. Bonding jumper
✓ Correct Answer: (C. Positive conductor)
Rationale: In DC systems, the positive or negative conductor may be
ungrounded depending on system design, but commonly the positive is
ungrounded.
3. What is the minimum working clearance required for 480V electrical
equipment with exposed live parts?
A. 3 feet
, B. 3.5 feet
C. 4 feet
D. 5 feet
✓ Correct Answer: (C. 4 feet)
Rationale: NEC Table 110.26 requires 4 feet minimum for 301–600V under
certain conditions.
4. A circuit has a load of 24A on a continuous basis. What is the minimum
conductor ampacity required?
A. 24A
B. 30A
C. 36A
D. 40A
✓ Correct Answer: (C. 30A)
Rationale: Continuous loads require 125% sizing; 24 × 1.25 = 30A
minimum.
5. Which device is primarily used to protect against arc fault conditions in
dwelling units?
A. GFCI
B. AFCI
C. Thermal relay
D. Disconnect switch
✓ Correct Answer: (B. AFCI)
Rationale: AFCIs detect arc faults and reduce fire hazards in branch
circuits.
6. What is the maximum voltage allowed on Class 2 circuits?
A. 24V
B. 48V
C. 60V
D. 1000V
✓ Correct Answer: (C. 60V)
Rationale: Class 2 circuits are limited to 60V DC or AC for safety.
, 7. A motor draws 40A full load. What is the minimum branch-circuit conductor
size multiplier for sizing?
A. 100%
B. 125%
C. 150%
D. 200%
✓ Correct Answer: (B. 125%)
Rationale: NEC requires motor conductors be sized at 125% of full-load
current.
8. Which grounding system directly connects neutral to earth at one point
only?
A. Floating system
B. TN system
C. Solidly grounded system
D. Ungrounded delta
✓ Correct Answer: (C. Solidly grounded system)
Rationale: A solidly grounded system bonds neutral to earth at a single
point.
9. What is the purpose of a bonding jumper?
A. Carry load current
B. Provide overcurrent protection
C. Ensure electrical continuity
D. Increase voltage stability
✓ Correct Answer: (C. Ensure electrical continuity)
Rationale: Bonding jumpers connect metal parts to maintain electrical
continuity.
10.A 120V circuit supplies 1800W load. What is the current?
A. 10A
B. 12A
C. 15A
D. 20A
Update) Actual Practice Questions – Set 100
Most Common Exam Questions And Answers
In Details 100% Verified Exam Highly
Recommendable For Grade A+
1. A 3-phase, 4-wire system has a measured line-to-line voltage of 480V. What
is the approximate line-to-neutral voltage?
A. 120V
B. 208V
C. 277V
D. 240V
✓ Correct Answer: (C. 277V)
Rationale: In a wye system, line-to-neutral voltage equals line-to-line
divided by √3; 480 ÷ 1.732 ≈ 277V.
2. According to NEC standards, which conductor is typically permitted to be
ungrounded in a DC system?
A. Neutral conductor
B. Equipment grounding conductor
C. Positive conductor
D. Bonding jumper
✓ Correct Answer: (C. Positive conductor)
Rationale: In DC systems, the positive or negative conductor may be
ungrounded depending on system design, but commonly the positive is
ungrounded.
3. What is the minimum working clearance required for 480V electrical
equipment with exposed live parts?
A. 3 feet
, B. 3.5 feet
C. 4 feet
D. 5 feet
✓ Correct Answer: (C. 4 feet)
Rationale: NEC Table 110.26 requires 4 feet minimum for 301–600V under
certain conditions.
4. A circuit has a load of 24A on a continuous basis. What is the minimum
conductor ampacity required?
A. 24A
B. 30A
C. 36A
D. 40A
✓ Correct Answer: (C. 30A)
Rationale: Continuous loads require 125% sizing; 24 × 1.25 = 30A
minimum.
5. Which device is primarily used to protect against arc fault conditions in
dwelling units?
A. GFCI
B. AFCI
C. Thermal relay
D. Disconnect switch
✓ Correct Answer: (B. AFCI)
Rationale: AFCIs detect arc faults and reduce fire hazards in branch
circuits.
6. What is the maximum voltage allowed on Class 2 circuits?
A. 24V
B. 48V
C. 60V
D. 1000V
✓ Correct Answer: (C. 60V)
Rationale: Class 2 circuits are limited to 60V DC or AC for safety.
, 7. A motor draws 40A full load. What is the minimum branch-circuit conductor
size multiplier for sizing?
A. 100%
B. 125%
C. 150%
D. 200%
✓ Correct Answer: (B. 125%)
Rationale: NEC requires motor conductors be sized at 125% of full-load
current.
8. Which grounding system directly connects neutral to earth at one point
only?
A. Floating system
B. TN system
C. Solidly grounded system
D. Ungrounded delta
✓ Correct Answer: (C. Solidly grounded system)
Rationale: A solidly grounded system bonds neutral to earth at a single
point.
9. What is the purpose of a bonding jumper?
A. Carry load current
B. Provide overcurrent protection
C. Ensure electrical continuity
D. Increase voltage stability
✓ Correct Answer: (C. Ensure electrical continuity)
Rationale: Bonding jumpers connect metal parts to maintain electrical
continuity.
10.A 120V circuit supplies 1800W load. What is the current?
A. 10A
B. 12A
C. 15A
D. 20A
