IEC 119 Study Guide Exam ACTUAL EXAM
2026/2027 | Inside Electrical Construction
Apprenticeship | Verified Q&A | Pass
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TABLE OF CONTENTS
Table
Section Title Number of
Questions
Section NEC Fundamentals & Electrical Theory 20 Questions
A
1.1 Electrical Theory Basics (Ohm's Law, Watt's Law, Q1–Q6
Series/Parallel Circuits)
1.2 Electrical Calculations & Formulas Q7–Q12
1.3 NEC Structure & Terminology Q13–Q20
Section Wiring Methods & Materials 16 Questions
B
2.1 Conductors & Cables (Types, Sizing, Ampacity) Q21–Q28
2.2 Raceways, Boxes, & Enclosures Q29–Q36
,Section Title Number of
Questions
Section Overcurrent Protection & Grounding 18 Questions
C
3.1 Overcurrent Protection Devices (Fuses, Circuit Breakers) Q37–Q43
3.2 Grounding & Bonding Requirements Q44–Q54
Section NFPA 70E Electrical Safety 16 Questions
D
4.1 Shock & Arc Flash Hazards Q55–Q61
4.2 PPE Requirements & Safe Work Practices Q62–Q70
Section Equipment Installation & Special Occupancies 18 Questions
E
5.1 Motors, Transformers, & Generators Q71–Q77
5.2 Special Occupancies & Hazardous Locations Q78–Q88
Section F NEC Calculations & Code Application 12 Questions
6.1 Load Calculations & Service Sizing Q89–Q94
6.2 Voltage Drop & Conductor Sizing Q95–Q100
Total 100 Questions
,SECTION A: NEC FUNDAMENTALS & ELECTRICAL THEORY
Subsection 1.1: Electrical Theory Basics
Q1: A circuit has a voltage of 120 volts and a resistance of 24 ohms. What is the current flowing through
the circuit?
A. 2.5 amperes
B. 4.0 amperes
C. 5.0 amperes [CORRECT]
D. 6.0 amperes
Correct Answer: C
Rationale: Using Ohm's Law (I = E ÷ R), current = 120 volts ÷ 24 ohms = 5.0 amperes. Ohm's Law is the
fundamental relationship in electrical theory that allows electricians to calculate any one of three
variables (voltage, current, resistance) when the other two are known. Mastery of this formula is
essential for circuit analysis, troubleshooting, and conductor sizing in the field.
Q2: A 240-volt electric water heater draws 18.75 amperes. What is the power consumption in watts?
A. 2,880 watts
B. 3,600 watts
C. 4,500 watts [CORRECT]
D. 5,400 watts
Correct Answer: C
Rationale: Using Watt's Law (P = E × I), power = 240 volts × 18.75 amperes = 4,500 watts. Watt's Law
combines Ohm's Law with power calculations to determine the rate of electrical energy consumption.
This calculation is critical for load calculations, service sizing, and energy cost estimation in residential
and commercial electrical installations.
Q3: Three resistors (10 ohms, 20 ohms, and 30 ohms) are connected in series to a 120-volt source. What
is the total circuit current?
A. 1.0 ampere
B. 1.5 amperes
C. 2.0 amperes [CORRECT]
D. 3.0 amperes
, Correct Answer: C
Rationale: In a series circuit, total resistance (Rₜ) = R₁ + R₂ + R₃ = 10 + 20 + 30 = 60 ohms. Using Ohm's
Law (I = E ÷ R), current = 120 volts ÷ 60 ohms = 2.0 amperes. In series circuits, current is constant
throughout, while voltage divides across resistors proportionally to their resistance values. This principle
is fundamental for understanding voltage drop and series circuit troubleshooting.
Q4: Two resistors (12 ohms and 24 ohms) are connected in parallel across a 120-volt source. What is the
total circuit current?
A. 5.0 amperes
B. 10.0 amperes
C. 15.0 amperes [CORRECT]
D. 20.0 amperes
Correct Answer: C
Rationale: In a parallel circuit, total resistance is calculated using the reciprocal formula: 1/Rₜ = 1/12 +
1/24 = 2/24 + 1/24 = 3/24, so Rₜ = 8 ohms. Total current = 120 volts ÷ 8 ohms = 15.0 amperes.
Alternatively, calculate branch currents (I₁ = 120/12 = 10A; I₂ = 120/24 = 5A) and sum them: 10 + 5 = 15A.
Parallel circuits are essential for branch circuit design because they maintain constant voltage while
current divides inversely with resistance.
Q5: According to Kirchhoff's Voltage Law, in a closed series circuit, the sum of all voltage drops equals:
A. The total resistance divided by the current
B. The source voltage [CORRECT]
C. The power consumed by the circuit
D. The total current multiplied by the smallest resistance
Correct Answer: B
Rationale: Kirchhoff's Voltage Law (KVL) states that the algebraic sum of all voltages around any closed
loop in a circuit must equal zero, which means the sum of all voltage drops across loads equals the
source voltage. This principle is essential for troubleshooting voltage drop issues, verifying proper circuit
operation, and ensuring that conductors and connections are not causing excessive voltage loss that
could impair equipment performance.
Q6: In a parallel circuit with three branches, the current through each branch is 4A, 6A, and 8A
respectively. What is the total current supplied by the source?
2026/2027 | Inside Electrical Construction
Apprenticeship | Verified Q&A | Pass
Guaranteed - A+ Graded
TABLE OF CONTENTS
Table
Section Title Number of
Questions
Section NEC Fundamentals & Electrical Theory 20 Questions
A
1.1 Electrical Theory Basics (Ohm's Law, Watt's Law, Q1–Q6
Series/Parallel Circuits)
1.2 Electrical Calculations & Formulas Q7–Q12
1.3 NEC Structure & Terminology Q13–Q20
Section Wiring Methods & Materials 16 Questions
B
2.1 Conductors & Cables (Types, Sizing, Ampacity) Q21–Q28
2.2 Raceways, Boxes, & Enclosures Q29–Q36
,Section Title Number of
Questions
Section Overcurrent Protection & Grounding 18 Questions
C
3.1 Overcurrent Protection Devices (Fuses, Circuit Breakers) Q37–Q43
3.2 Grounding & Bonding Requirements Q44–Q54
Section NFPA 70E Electrical Safety 16 Questions
D
4.1 Shock & Arc Flash Hazards Q55–Q61
4.2 PPE Requirements & Safe Work Practices Q62–Q70
Section Equipment Installation & Special Occupancies 18 Questions
E
5.1 Motors, Transformers, & Generators Q71–Q77
5.2 Special Occupancies & Hazardous Locations Q78–Q88
Section F NEC Calculations & Code Application 12 Questions
6.1 Load Calculations & Service Sizing Q89–Q94
6.2 Voltage Drop & Conductor Sizing Q95–Q100
Total 100 Questions
,SECTION A: NEC FUNDAMENTALS & ELECTRICAL THEORY
Subsection 1.1: Electrical Theory Basics
Q1: A circuit has a voltage of 120 volts and a resistance of 24 ohms. What is the current flowing through
the circuit?
A. 2.5 amperes
B. 4.0 amperes
C. 5.0 amperes [CORRECT]
D. 6.0 amperes
Correct Answer: C
Rationale: Using Ohm's Law (I = E ÷ R), current = 120 volts ÷ 24 ohms = 5.0 amperes. Ohm's Law is the
fundamental relationship in electrical theory that allows electricians to calculate any one of three
variables (voltage, current, resistance) when the other two are known. Mastery of this formula is
essential for circuit analysis, troubleshooting, and conductor sizing in the field.
Q2: A 240-volt electric water heater draws 18.75 amperes. What is the power consumption in watts?
A. 2,880 watts
B. 3,600 watts
C. 4,500 watts [CORRECT]
D. 5,400 watts
Correct Answer: C
Rationale: Using Watt's Law (P = E × I), power = 240 volts × 18.75 amperes = 4,500 watts. Watt's Law
combines Ohm's Law with power calculations to determine the rate of electrical energy consumption.
This calculation is critical for load calculations, service sizing, and energy cost estimation in residential
and commercial electrical installations.
Q3: Three resistors (10 ohms, 20 ohms, and 30 ohms) are connected in series to a 120-volt source. What
is the total circuit current?
A. 1.0 ampere
B. 1.5 amperes
C. 2.0 amperes [CORRECT]
D. 3.0 amperes
, Correct Answer: C
Rationale: In a series circuit, total resistance (Rₜ) = R₁ + R₂ + R₃ = 10 + 20 + 30 = 60 ohms. Using Ohm's
Law (I = E ÷ R), current = 120 volts ÷ 60 ohms = 2.0 amperes. In series circuits, current is constant
throughout, while voltage divides across resistors proportionally to their resistance values. This principle
is fundamental for understanding voltage drop and series circuit troubleshooting.
Q4: Two resistors (12 ohms and 24 ohms) are connected in parallel across a 120-volt source. What is the
total circuit current?
A. 5.0 amperes
B. 10.0 amperes
C. 15.0 amperes [CORRECT]
D. 20.0 amperes
Correct Answer: C
Rationale: In a parallel circuit, total resistance is calculated using the reciprocal formula: 1/Rₜ = 1/12 +
1/24 = 2/24 + 1/24 = 3/24, so Rₜ = 8 ohms. Total current = 120 volts ÷ 8 ohms = 15.0 amperes.
Alternatively, calculate branch currents (I₁ = 120/12 = 10A; I₂ = 120/24 = 5A) and sum them: 10 + 5 = 15A.
Parallel circuits are essential for branch circuit design because they maintain constant voltage while
current divides inversely with resistance.
Q5: According to Kirchhoff's Voltage Law, in a closed series circuit, the sum of all voltage drops equals:
A. The total resistance divided by the current
B. The source voltage [CORRECT]
C. The power consumed by the circuit
D. The total current multiplied by the smallest resistance
Correct Answer: B
Rationale: Kirchhoff's Voltage Law (KVL) states that the algebraic sum of all voltages around any closed
loop in a circuit must equal zero, which means the sum of all voltage drops across loads equals the
source voltage. This principle is essential for troubleshooting voltage drop issues, verifying proper circuit
operation, and ensuring that conductors and connections are not causing excessive voltage loss that
could impair equipment performance.
Q6: In a parallel circuit with three branches, the current through each branch is 4A, 6A, and 8A
respectively. What is the total current supplied by the source?
