NYC DCAS Electrician Exam Study Guide Questions And Well Graded Solutions With Rationales Updated

NYC DCAS Electrician Exam Study Guide
Questions And Well Graded Solutions
With Rationales Updated 2026-2027


Diagram: AC Parallel RLC Circuit Reference
text
I_total ──►
┌───────────┬───────────┬───────────┐
│ │ │ │
┌─┴─┐ ┌─┴─┐ ┌─┴─┐ ┌─┴─┐
Source │ ~ │ │ R │ │ L │ │ C │
240V AC └─┬─┘ └─┬─┘ └─┬─┘ └─┬─┘
│ │ │ │
└───────────┴───────────┴───────────┘

Diagram: Conduit Fill Reference
text
┌─────────────────────────────────┐
│ Conduit Cross Section │
│ ┌─────────────────┐ │
│ │ O O O O │ │ <─── Multiple Conductors
│ └─────────────────┘ │
└─────────────────────────────────┘
Maximum Fill: 40% for 3 or more conductors



NYC DCAS Electrician Practice Questions (1-70)
Question 1
A 240-volt parallel RLC circuit contains a pure resistor drawing 12 A, a pure inductor
drawing 16 A, and a pure capacitor drawing 7 A. What is the total line current drawn
from the source?
A) 12.0 A
B) 15.0 A
C) 15.0 A
D) 35.0 A

,Rationale: In a parallel RLC circuit, total current is found using the formula: I_total =
√(I_R^2 + (I_L - I_C)^2). Substituting the values: I_total = √(12^2 + (16 - 7)^2) =
√(144 + 9^2) = √(144 + 81) = √225 = 15 Amperes.

Question 2
What is the minimum clear working space depth required in front of live electrical
equipment operating at 480 volts to ground where there are exposed live parts on
one side and a grounded brick wall on the opposite side (Condition 2)?
A) 3.0 feet
B) 3.5 feet
C) 4.0 feet
D) 4.5 feet
Rationale: Per NEC Table 110.26(A)(1), for voltages between 151 and 600 volts to
ground, Condition 2 (exposed live parts on one side and grounded parts on the
other) requires a minimum workspace depth of 3.5 feet.

Question 3
An industrial motor branch circuit uses THHN copper conductors run through an
ambient temperature environment of 113°F (45°C). What correction factor must be
applied to the conductor ampacity rating?
A) 1.00
B) 0.91
C) 0.87
D) 0.71
Rationale: According to the NEC Table 310.15(B)(1) ambient temperature correction
table based on 30°C, THHN insulation (rated 90°C) must be multiplied by a
correction factor of 0.87 when operating in an ambient temperature between 105°F
and 113°F.

Question 4
How many 12 AWG THHN conductors can be safely installed inside a 3/4-inch
Electrical Metallic Tubing (EMT) trade size conduit under standard 40% fill
conditions?
A) 9
B) 16
C) 22
D) 26
Rationale: Per NEC Chapter 9, Table 4 for EMT and Table 5 for dimensions, a 3/4-
inch EMT has a total area of 0.533 sq in, and 40% fill equals 0.213 sq in. A 12 AWG

,THHN conductor has an area of 0.0133 sq in. 0..0133 = 16.01, allowing a
maximum of 16 conductors.

Question 5
Which type of DC motor provides the highest starting torque but exhibits poor speed
regulation when operating under light loads?
A) Shunt motor
B) Series motor
C) Cumulative compound motor
D) Differential compound motor
Rationale: A DC series motor develops very high starting torque because field
current equals armature current. However, under no-load or light-load conditions,
field flux drops drastically, which can cause the motor speed to rise dangerously
high.

Question 6
A 3-phase, delta-connected transformer bank supplies a balanced load. If the line
current is measured at 45 Amperes, what is the value of the phase current inside the
transformer windings?
A) 15.0 A
B) 26.0 A
C) 45.0 A
D) 77.9 A
Rationale: In a balanced delta system, line current is equal to phase current
multiplied by the square root of 3 (√3 ≈ 1.732). Therefore, Phase Current = Line
Current / √3. Computing .732 results in approximately 26.0 Amperes.

Question 7
What is the minimum bending radius for a 1-inch trade size Rigid Metal Conduit
(RMC) containing conductors without a lead sheath, using a standard shop bender?
A) 4.5 inches
B) 5.75 inches
C) 6.0 inches
D) 8.0 inches
Rationale: Per NEC Chapter 9, Table 2 (Radius of Conduit Bends), the minimum
radius for a 1-inch trade size conduit utilizing a standard bend execution is 5.75
inches to prevent conductor damage.

Question 8

, What is the required color code assignment for the high-leg conductor of a 120/240V
4-wire, delta-connected system according to the NYC Electrical Code?
A) Red
B) Blue
C) Orange
D) Yellow
Rationale: NEC Article 110.15 mandates that the high-leg conductor (the phase with
the higher voltage-to-ground, usually Phase B) must be durably and permanently
marked by an outer finish that is orange in color.

Question 9
A 10 kW electric unit heater is connected to a single-phase 240-volt branch circuit.
What is the calculated continuous load current for this equipment?
A) 34.7 A
B) 41.7 A
C) 52.1 A
D) 60.0 A
Rationale: First, calculate full load current: I = P / V = 10000W / 240V = 41.67
Amperes. Since electric space heating is considered a continuous load, the branch
circuit must be sized at 125% for protection devices, but the fundamental continuous
load current value remains 41.7 A.

Question 10
Which electrical test instrument is designed explicitly to measure insulation
resistance inside high-voltage underground cables?
A) Clamp-on ammeter
B) Wheatstone bridge
C) Megohmmeter
D) Digital multimeter
Rationale: A megohmmeter (often called a Megger) applies a high voltage (typically
500V to 5000V DC) across insulation systems to measure resistance in megohms,
identifying insulation breakdown or moisture ingress.

Question 11
What is the maximum permissible distance for a horizontal run of 1/2-inch Liquidtight
Flexible Metal Conduit (LFMC) between its point of securement and a junction box?
A) 12 inches
B) 12 inches