NYC Master Electrician License Exam 2026 – 190 Professional
Certification Practice Questions with Answers & Detailed
Rationales, Electrical Theory, Load Calculations, Grounding and
Bonding, Motors, Transformers, Safety & NYC Electrical Code
Section 1: Electrical Theory and Basic Calculations (Questions 1–25)
Question 1
A 240-volt single-phase circuit has a resistance of 12 ohms. What is the current flowing
through the circuit?
A. 10 A
B. 20 A
C. 24 A
D. 30 A
Correct Answer: B
Explanation: Using Ohm's Law, I = E / R = 240 V / 12 Ω = 20 A. This fundamental relationship
between voltage, current, and resistance is essential for all electrical calculations and
troubleshooting.
Question 2
What is the power consumed in watts by a 12 AWG conductor that is 100 feet long with a
resistance of 0.20 ohms, carrying a current of 16 A?
A. 32 W
B. 51 W
C. 64 W
D. 80 W
,Correct Answer: B
Explanation: Power loss in a conductor is calculated as P = I² × R = 16² × 0.20 = 256 × 0.20 =
51.2 W. Conductor power loss represents wasted energy that must be accounted for in
voltage drop calculations.
Question 3
A continuous load requires an overcurrent device sized no smaller than 125 percent of the
load. What is the maximum continuous load permitted on a 100 A overcurrent device?
A. 75 A
B. 80 A
C. 100 A
D. 125 A
Correct Answer: B
Explanation: Maximum continuous load = 100 A / 1.25 = 80 A. The 125% factor accounts for
the heat generated by continuous loads, which can degrade overcurrent devices if loaded to
100% capacity.
Question 4
What is the approximate area in square inches of a trade size 2 raceway (assuming an
internal diameter of 2 inches)?
A. 1.5 sq in
B. 2.0 sq in
C. 3.14 sq in
D. 4.0 sq in
,Correct Answer: C
Explanation: Area = π × r² = 3.14 × (1)² = 3.14 sq in. Raceway area calculations are essential
for determining allowable conductor fill per NEC Chapter 9.
Question 5
What is the current in amperes of an 18 kW, 208 V, three-phase load?
A. 25 A
B. 50 A
C. 75 A
D. 100 A
Correct Answer: B
Explanation: I = VA / (E × √3) = 18,000 / (208 × 1.732) = 18,.3 = 49.96 A,
approximately 50 A. This formula is essential for sizing three-phase branch circuits and
feeders.
Question 6
What is the reciprocal of 1.25?
A. 0.75
B. 0.80
C. 1.10
D. 1.50
Correct Answer: B
, Explanation: The reciprocal of a number is 1 divided by that number: .25 = 0.80.
Reciprocals are used in parallel resistance calculations and when working with per-unit
values.
Question 7
What is the numeric equivalent of 12²?
A. 24
B. 144
C. 1,728
D. 3.46
Correct Answer: B
Explanation: Squaring a number means multiplying it by itself: 12 × 12 = 144. This operation
is fundamental for power calculations involving current squared (I²R).
Question 8
A 300 W load is connected to a 120 V source. What is the current drawn by the load?
A. 1.5 A
B. 2.5 A
C. 3.0 A
D. 4.0 A
Correct Answer: B
Certification Practice Questions with Answers & Detailed
Rationales, Electrical Theory, Load Calculations, Grounding and
Bonding, Motors, Transformers, Safety & NYC Electrical Code
Section 1: Electrical Theory and Basic Calculations (Questions 1–25)
Question 1
A 240-volt single-phase circuit has a resistance of 12 ohms. What is the current flowing
through the circuit?
A. 10 A
B. 20 A
C. 24 A
D. 30 A
Correct Answer: B
Explanation: Using Ohm's Law, I = E / R = 240 V / 12 Ω = 20 A. This fundamental relationship
between voltage, current, and resistance is essential for all electrical calculations and
troubleshooting.
Question 2
What is the power consumed in watts by a 12 AWG conductor that is 100 feet long with a
resistance of 0.20 ohms, carrying a current of 16 A?
A. 32 W
B. 51 W
C. 64 W
D. 80 W
,Correct Answer: B
Explanation: Power loss in a conductor is calculated as P = I² × R = 16² × 0.20 = 256 × 0.20 =
51.2 W. Conductor power loss represents wasted energy that must be accounted for in
voltage drop calculations.
Question 3
A continuous load requires an overcurrent device sized no smaller than 125 percent of the
load. What is the maximum continuous load permitted on a 100 A overcurrent device?
A. 75 A
B. 80 A
C. 100 A
D. 125 A
Correct Answer: B
Explanation: Maximum continuous load = 100 A / 1.25 = 80 A. The 125% factor accounts for
the heat generated by continuous loads, which can degrade overcurrent devices if loaded to
100% capacity.
Question 4
What is the approximate area in square inches of a trade size 2 raceway (assuming an
internal diameter of 2 inches)?
A. 1.5 sq in
B. 2.0 sq in
C. 3.14 sq in
D. 4.0 sq in
,Correct Answer: C
Explanation: Area = π × r² = 3.14 × (1)² = 3.14 sq in. Raceway area calculations are essential
for determining allowable conductor fill per NEC Chapter 9.
Question 5
What is the current in amperes of an 18 kW, 208 V, three-phase load?
A. 25 A
B. 50 A
C. 75 A
D. 100 A
Correct Answer: B
Explanation: I = VA / (E × √3) = 18,000 / (208 × 1.732) = 18,.3 = 49.96 A,
approximately 50 A. This formula is essential for sizing three-phase branch circuits and
feeders.
Question 6
What is the reciprocal of 1.25?
A. 0.75
B. 0.80
C. 1.10
D. 1.50
Correct Answer: B
, Explanation: The reciprocal of a number is 1 divided by that number: .25 = 0.80.
Reciprocals are used in parallel resistance calculations and when working with per-unit
values.
Question 7
What is the numeric equivalent of 12²?
A. 24
B. 144
C. 1,728
D. 3.46
Correct Answer: B
Explanation: Squaring a number means multiplying it by itself: 12 × 12 = 144. This operation
is fundamental for power calculations involving current squared (I²R).
Question 8
A 300 W load is connected to a 120 V source. What is the current drawn by the load?
A. 1.5 A
B. 2.5 A
C. 3.0 A
D. 4.0 A
Correct Answer: B
