NYC DCAS Electrician Exam – 100 Practice Questions with Rationales (2026/2027) – Pass the New York City Civil Service Electrician Test on Your First Attempt

NYC DCAS Electrician Exam – 100 Practice
Questions with Rationales (2026/2027) – Pass the
New York City Civil Service Electrician Test on
Your First Attempt

About this resource:
This document contains verified questions and answers for the NYC DCAS Electrician
Civil Service Exam based on 2026/2027 curriculum materials. All answers are in bold
italic with italic rationales. Topics include electrical theory (Ohm's Law, power calculations,
three-phase systems), NEC Articles (110, 210, 250, 300, 314, 358, 430, 700), grounding
and bonding, GFCI/AFCI requirements, conduit fill calculations (Chapter 9, Table 1), motor
calculations, transformer vault requirements, box fill calculations (314.16), hazardous
locations, lockout/tagout safety, NYC-specific voltage drop amendments, and exam
administration (70% passing score, 5 years experience requirement, Pearson VUE testing
SECTION 1: ELECTRICAL THEORY & OHM'S LAW (Q1–15)
Q1. According to Ohm's Law, what is the formula for voltage?
 A. V = I × R
 B. V = I / R
 C. V = R / I
 D. V = P × I
*Correct Answer: A) V = I × R *
Ohm's Law states that voltage equals current multiplied by resistance. Option B calculates
current, option C inverts the relationship, and option D is a power formula .
Q2. A 240V single-phase circuit supplies a 4800W electric water heater. What is the
current draw?
 A. 15A
 B. 20A
 C. 25A

,  D. 30A
*Correct Answer: B) 20A *
* Current = Power ÷ Voltage = 4800W ÷ 240V = 20A. This is a fundamental power
calculation using P = V × I .*
Q3. What is the unit of electrical resistance?
 A. Volt
 B. Ampere
 C. Ohm
 D. Watt
*Correct Answer: C) Ohm *
The ohm (Ω) is the SI unit of electrical resistance. Volts measure voltage, amperes
measure current, and watts measure power .
Q4. In a DC circuit, current flows:
 A. Alternating direction
 B. Only in one direction
 C. Randomly
 D. Only in transformers
*Correct Answer: B) Only in one direction *
Direct current (DC) is unidirectional—it flows in only one direction. Alternating current (AC)
reverses direction periodically (60 Hz in the US).
Q5. A 10Ω resistor carries 2A current. What is the voltage across it?
 A. 5V
 B. 12V
 C. 18V
 D. 20V
*Correct Answer: D) 20V *
* Using Ohm's Law: V = I × R = 2A × 10Ω = 20 volts.*

,Q6. A three-phase, 208V system supplies a 10 kW balanced load. What is the
approximate line current?
 A. 27.8A
 B. 34.7A
 C. 48.1A
 D. 60.0A
*Correct Answer: A) 27.8A *
* Use the three-phase power formula: I = P / (√3 × V) = 10,000W / (1.732 × 208V) ≈ 27.8A.
Option B would result from using the single-phase formula incorrectly .*
Q7. What is the unit of electric power?
 A. Volt
 B. Ampere
 C. Watt
 D. Ohm
*Correct Answer: C) Watt *
The watt (W) is the SI unit of electric power, measuring the rate of energy transfer. One
watt equals one joule per second .
Q8. Frequency in AC systems is measured in:
 A. Watts
 B. Hertz
 C. Ohms
 D. Joules
*Correct Answer: B) Hertz *
Frequency is measured in hertz (Hz), which equals cycles per second. The standard utility
frequency in the US is 60 Hz .
Q9. The power factor of a system or circuit is:
 A. The ratio of true power to apparent power
 B. The ratio of impedance to reactance

,  C. The relationship of volts and ohms
 D. The product of voltage and current
*Correct Answer: A) The ratio of true power to apparent power *
Power factor = True Power (watts) / Apparent Power (volt-amperes). Low PF indicates
reactive loads (motors, transformers).
Q10. Resistance increases when wire length:
 A. Decreases
 B. Increases
 C. Stays the same
 D. Becomes zero
*Correct Answer: B) Increases *
Resistance is directly proportional to the length of a conductor (R = ρL/A). Doubling the
length doubles the resistance .
Q11. A transformer operates at 95% efficiency. If output is 9.5 kW, what is the input
power?
 A. 9.0 kW
 B. 9.5 kW
 C. 10.0 kW
 D. 10.5 kW
*Correct Answer: C) 10.0 kW *
* Input = Output / Efficiency = 9.5 kW ÷ 0.95 = 10.0 kW. The 0.5 kW difference is lost as
heat .*
Q12. A 120V branch circuit supplies a continuous load of 16A. What is the minimum
ampere rating for the overcurrent protective device?
 A. 16A
 B. 20A
 C. 25A
 D. 30A