TEXAS MASTER SIGN ELECTRICIAN
LICENSE EXAM: COMPREHENSIVE
PRACTICE QUESTIONS WITH
DETAILED RATIONALES — A
COMPLETE STUDY GUIDE ALIGNED
WITH THE 2023 NEC AND TDLR
REQUIREMENTS
Section 1: Definitions, Calculations, and Theory
1. Which formula correctly expresses Ohm's Law for electrical power?
o A. P = V/I
o B. P = V × I
o C. P = I × R
o D. P = R/V
o Answer: B
o Rationale: Power (in watts) equals voltage multiplied by current. This is essential
for calculating sign circuit loads .
2. What is the total resistance in a series circuit with resistors of 10 Ω, 20 Ω, and
30 Ω?
o A. 10 Ω
o B. 20 Ω
o C. 30 Ω
o D. 60 Ω
,o Answer: D
o Rationale: In a series circuit, total resistance is the sum of individual resistances
(10 + 20 + 30 = 60 Ω) .
3. A sign draws 5 A through a 24 Ω load. What is the voltage?
o A. 100 V
o B. 120 V
o C. 24 V
o D. 240 V
o Answer: B
o Rationale: Voltage = Current × Resistance (V = I × R), so 5 A × 24 Ω = 120 V .
4. The ampacity of a conductor refers to:
o A. Its physical length
o B. Its ability to carry current safely
o C. Its insulation color
o D. Its voltage rating only
o Answer: B
o Rationale: Ampacity is the maximum current a conductor can carry without
exceeding its temperature limits .
5. A short circuit occurs when:
o A. Current follows an unintended low-resistance path
o B. Voltage disappears permanently
o C. A lamp is installed correctly
o D. A circuit is grounded properly
o Answer: A
o Rationale: A short circuit creates an unintended path for current, resulting in
excessive current flow .
6. What is the purpose of overcurrent protection?
o A. To increase voltage
o B. To open the circuit when current exceeds safe levels
, o C. To reduce wire size
o D. To create lighting effects
o Answer: B
o Rationale: Fuses or circuit breakers open circuits to protect conductors and
equipment from damage due to excessive current .
Section 2: Electrical Services, Service Equipment, and
Separately Derived Systems
7. Which NEC article covers grounding and bonding requirements?
o A. Article 250
o B. Article 100
o C. Article 300
o D. Article 430
o Answer: A
o Rationale: NEC Article 250 establishes the general rules for grounding and
bonding electrical systems .
8. The purpose of a grounding conductor is to:
o A. Increase voltage
o B. Provide a path for fault current
o C. Reduce wire size
o D. Create lighting effects
o Answer: B
o Rationale: The grounding conductor safely carries fault current back to the
source, allowing protective devices to operate .
9. What is the purpose of bonding metal sign parts?
o A. Increase lighting brightness
o B. Ensure metal parts remain at the same electrical potential
o C. Reduce lamp cost
o D. Improve appearance only
LICENSE EXAM: COMPREHENSIVE
PRACTICE QUESTIONS WITH
DETAILED RATIONALES — A
COMPLETE STUDY GUIDE ALIGNED
WITH THE 2023 NEC AND TDLR
REQUIREMENTS
Section 1: Definitions, Calculations, and Theory
1. Which formula correctly expresses Ohm's Law for electrical power?
o A. P = V/I
o B. P = V × I
o C. P = I × R
o D. P = R/V
o Answer: B
o Rationale: Power (in watts) equals voltage multiplied by current. This is essential
for calculating sign circuit loads .
2. What is the total resistance in a series circuit with resistors of 10 Ω, 20 Ω, and
30 Ω?
o A. 10 Ω
o B. 20 Ω
o C. 30 Ω
o D. 60 Ω
,o Answer: D
o Rationale: In a series circuit, total resistance is the sum of individual resistances
(10 + 20 + 30 = 60 Ω) .
3. A sign draws 5 A through a 24 Ω load. What is the voltage?
o A. 100 V
o B. 120 V
o C. 24 V
o D. 240 V
o Answer: B
o Rationale: Voltage = Current × Resistance (V = I × R), so 5 A × 24 Ω = 120 V .
4. The ampacity of a conductor refers to:
o A. Its physical length
o B. Its ability to carry current safely
o C. Its insulation color
o D. Its voltage rating only
o Answer: B
o Rationale: Ampacity is the maximum current a conductor can carry without
exceeding its temperature limits .
5. A short circuit occurs when:
o A. Current follows an unintended low-resistance path
o B. Voltage disappears permanently
o C. A lamp is installed correctly
o D. A circuit is grounded properly
o Answer: A
o Rationale: A short circuit creates an unintended path for current, resulting in
excessive current flow .
6. What is the purpose of overcurrent protection?
o A. To increase voltage
o B. To open the circuit when current exceeds safe levels
, o C. To reduce wire size
o D. To create lighting effects
o Answer: B
o Rationale: Fuses or circuit breakers open circuits to protect conductors and
equipment from damage due to excessive current .
Section 2: Electrical Services, Service Equipment, and
Separately Derived Systems
7. Which NEC article covers grounding and bonding requirements?
o A. Article 250
o B. Article 100
o C. Article 300
o D. Article 430
o Answer: A
o Rationale: NEC Article 250 establishes the general rules for grounding and
bonding electrical systems .
8. The purpose of a grounding conductor is to:
o A. Increase voltage
o B. Provide a path for fault current
o C. Reduce wire size
o D. Create lighting effects
o Answer: B
o Rationale: The grounding conductor safely carries fault current back to the
source, allowing protective devices to operate .
9. What is the purpose of bonding metal sign parts?
o A. Increase lighting brightness
o B. Ensure metal parts remain at the same electrical potential
o C. Reduce lamp cost
o D. Improve appearance only
