NYC Civil Service Electrician (DCAS) Exam | Latest
Verified Questions and Detailed Answers
OVERVIEW DESCRIPTION:
This comprehensive set of multiple-choice questions is designed for the NYC Civil Service
Electrician exam, a computer-based test administered by the New York City Department of
Citywide Administrative Services (DCAS). The exam evaluates a candidate’s readiness to
install, repair, and maintain electrical systems for city agencies by assessing knowledge
across four critical domains: electrical theory and calculations (including Ohm’s Law,
AC/DC circuits, and power factor), practical installation, maintenance, and troubleshooting
skills, thorough understanding of the National Electrical Code and NYC local amendments
along with blueprint reading and safety practices, and supervisory and administrative
abilities such as task delegation, resource planning, and ethical conduct.
QUESTION 1
A circuit has a 120-volt source and a resistance of 24 ohms. What is the current flowing
in the circuit?
A. 2 A
B. 5 A
C. 10 A
D. 20 A
CORRECT ANSWER: B
EXPERT RATIONALE: Using Ohm’s Law (I = E/R), 120 V ÷ 24 Ω = 5 A. This is a
fundamental relationship required for all circuit analysis.
QUESTION 2
A three-phase, 208-volt motor draws 15 amperes at full load with a power factor of 0.85.
What is the approximate true power consumed?
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A. 2,650 W
B. 3,120 W
C. 4,590 W
D. 5,400 W
CORRECT ANSWER: C
EXPERT RATIONALE: True power P = √3 × V × I × PF = 1.732 × 208 × 15 × 0.85 ≈ 4,590
W. The power factor reduces the product of voltage and current to actual watts.
QUESTION 3
In a purely resistive AC circuit, what is the phase relationship between voltage and
current?
A. Current leads voltage by 90°
B. Current lags voltage by 90°
C. Current is in phase with voltage
D. Current leads voltage by 180°
CORRECT ANSWER: C
EXPERT RATIONALE: In a resistive circuit, there is no reactance to cause a phase shift, so
voltage and current are in phase. Inductive or capacitive components would create a
lead or lag.
QUESTION 4
What is the total capacitance of two 40 µF capacitors connected in series?
A. 20 µF
B. 40 µF
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C. 80 µF
D. 160 µF
CORRECT ANSWER: A
EXPERT RATIONALE: For series capacitors, total C = 1 / (1/C1 + 1/C2) = 1 / (1/40 + 1/40)
= 20 µF. Series connection reduces total capacitance.
QUESTION 5
A conductor carries 20 amperes. What size copper THHN conductor is required if there
are 10 current-carrying conductors in a raceway and the ambient temperature is 86°F?
A. 14 AWG
B. 12 AWG
C. 10 AWG
D. 8 AWG
CORRECT ANSWER: C
EXPERT RATIONALE: NEC Table 310.15(C)(1) requires a 50% adjustment factor for 10–20
current-carrying conductors. 20 A is the load; 12 AWG at 30 A × 0.50 = 15 A, insufficient.
10 AWG rated 40 A × 0.50 = 20 A, adequate.
QUESTION 6
An electrician is installing EMT and must make a 90° bend with a 6-inch radius. The gain
for this bend is 3 inches. What is the stub-up distance if the measured length to the
back of the bend is 24 inches?
A. 21 inches
B. 24 inches
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C. 27 inches
D. 30 inches
CORRECT ANSWER: C
EXPERT RATIONALE: Stub-up length = back-of-bend measurement plus gain. 24 in. + 3
in. = 27 in. The gain accounts for the radius take-up.
QUESTION 7
What is the minimum working clearance in front of a 480-volt panelboard with exposed
live parts on one side and a grounded concrete wall on the other, under Condition 2?
A. 3 feet
B. 3 feet 6 inches
C. 4 feet
D. 5 feet
CORRECT ANSWER: B
EXPERT RATIONALE: NEC Table 110.26(A)(1) requires 3 ft 6 in. for 151–600 V, Condition
2 (grounded wall opposite). This space ensures safe operation and maintenance.
QUESTION 8
Which of the following wiring methods is generally prohibited by the NYC Electrical
Code for new residential construction?
A. Electrical metallic tubing
B. Armored cable (Type AC)
C. Nonmetallic-sheathed cable (Type NM)
D. Rigid metal conduit