NYC DCAS ELECTRICIAN EXAM ULTIMATE PRACTICE QUESTION
BANK: 200 COMPREHENSIVE MULTIPLE-CHOICE QUESTIONS
STRICTLY BASED ON THE NATIONAL ELECTRICAL CODE (NEC
2020), NEW YORK CITY LOCAL ELECTRICAL AMENDMENTS,
AND GENERAL ELECTRICAL TRADE THEORY – COMPLETE WITH
VERIFIED CORRECT ANSWERS AND THOROUGH RATIONALES
FOR EXAM MASTERY
1. According to Ohm's Law, what is the correct formula for calculating
voltage?
A) V = I / R
B) V = I × R
C) V = R / I
D) V = P × I
Correct Answer: B
Rationale: Ohm's Law states that voltage equals current multiplied by
resistance (V = I × R).
2. What is the unit of electrical resistance?
A) Volt
B) Ampere
C) Ohm
D) Watt
Correct Answer: C
Rationale: The ohm (Ω) is the SI unit of electrical resistance.
,3. 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
Rationale: Using the power formula P = V × I, rearrange to I = P ÷ V =
4800W ÷ 240V = 20 amperes.
4. What is the frequency of standard AC power in NYC?
A) 50 Hz
B) 60 Hz
C) 120 Hz
D) 400 Hz
Correct Answer: B
Rationale: The United States, including New York City, operates on 60
Hz AC power.
5. What is the minimum clear working space depth in front of
electrical equipment operating at 120V to ground where live parts are
exposed on one side and grounded parts on the other?
A) 2 feet
B) 3 feet
C) 4 feet
D) 6 feet
Correct Answer: B
Rationale: Per NEC Article 110.26(A)(1), Condition 2, the minimum clear
working space depth for voltages 0–150 volts to ground is 3 feet.
,6. Under NYC Electrical Code amendments, which wiring method is
generally prohibited for commercial structural installations?
A) Rigid Metal Conduit (RMC)
B) Electrical Metallic Tubing (EMT)
C) Nonmetallic-Sheathed Cable (NM-B / Romex)
D) Metal-Clad Cable (MC)
Correct Answer: C
Rationale: NYC Electrical Code heavily restricts the use of NM-B
(Romex) cable in commercial structures, mandating metal raceways or
armored cables.
7. What is the primary purpose of equipment bonding?
A) To reduce voltage during normal operation
B) To protect equipment from lightning strikes
C) To establish a low-impedance fault current path
D) To ground the neutral wire
Correct Answer: C
Rationale: Equipment bonding connects non-current-carrying metal
parts together to ensure a low-impedance path exists to trip the circuit
breaker quickly during a fault.
8. According to the NEC, what is the minimum size copper equipment
grounding conductor required for a 20-ampere branch circuit?
A) 14 AWG
B) 12 AWG
C) 10 AWG
D) 8 AWG
Correct Answer: B
Rationale: NEC Table 250.122 requires a 12 AWG copper equipment
grounding conductor for a 20-amp overcurrent device.
, 9. In a dwelling unit, where is AFCI protection required for 120-volt,
15-amp and 20-amp circuits?
A) Bathrooms only
B) Kitchens only
C) All habitable rooms per NEC 210.12
D) Outdoor receptacles only
Correct Answer: C
Rationale: NEC 210.12 requires AFCI protection in dwelling units for all
120V, 15A and 20A circuits in family rooms, dining rooms, living rooms,
bedrooms, and similar rooms.
10. What is the maximum number of 14 AWG conductors allowed in a
4-inch square metal box that is 1.5 inches deep?
A) 6
B) 8
C) 10
D) 12
Correct Answer: C
Rationale: Box fill calculations per NEC 314.16 determine conductor
capacity based on box volume and conductor size.
11. Which of the following is used to calculate electrical power?
A) Resistance and voltage
B) Impedance and frequency
C) Current and voltage
D) Current and resistance
Correct Answer: C
Rationale: Joule's Law states that Power (P) = Current (I) × Voltage (V).
BANK: 200 COMPREHENSIVE MULTIPLE-CHOICE QUESTIONS
STRICTLY BASED ON THE NATIONAL ELECTRICAL CODE (NEC
2020), NEW YORK CITY LOCAL ELECTRICAL AMENDMENTS,
AND GENERAL ELECTRICAL TRADE THEORY – COMPLETE WITH
VERIFIED CORRECT ANSWERS AND THOROUGH RATIONALES
FOR EXAM MASTERY
1. According to Ohm's Law, what is the correct formula for calculating
voltage?
A) V = I / R
B) V = I × R
C) V = R / I
D) V = P × I
Correct Answer: B
Rationale: Ohm's Law states that voltage equals current multiplied by
resistance (V = I × R).
2. What is the unit of electrical resistance?
A) Volt
B) Ampere
C) Ohm
D) Watt
Correct Answer: C
Rationale: The ohm (Ω) is the SI unit of electrical resistance.
,3. 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
Rationale: Using the power formula P = V × I, rearrange to I = P ÷ V =
4800W ÷ 240V = 20 amperes.
4. What is the frequency of standard AC power in NYC?
A) 50 Hz
B) 60 Hz
C) 120 Hz
D) 400 Hz
Correct Answer: B
Rationale: The United States, including New York City, operates on 60
Hz AC power.
5. What is the minimum clear working space depth in front of
electrical equipment operating at 120V to ground where live parts are
exposed on one side and grounded parts on the other?
A) 2 feet
B) 3 feet
C) 4 feet
D) 6 feet
Correct Answer: B
Rationale: Per NEC Article 110.26(A)(1), Condition 2, the minimum clear
working space depth for voltages 0–150 volts to ground is 3 feet.
,6. Under NYC Electrical Code amendments, which wiring method is
generally prohibited for commercial structural installations?
A) Rigid Metal Conduit (RMC)
B) Electrical Metallic Tubing (EMT)
C) Nonmetallic-Sheathed Cable (NM-B / Romex)
D) Metal-Clad Cable (MC)
Correct Answer: C
Rationale: NYC Electrical Code heavily restricts the use of NM-B
(Romex) cable in commercial structures, mandating metal raceways or
armored cables.
7. What is the primary purpose of equipment bonding?
A) To reduce voltage during normal operation
B) To protect equipment from lightning strikes
C) To establish a low-impedance fault current path
D) To ground the neutral wire
Correct Answer: C
Rationale: Equipment bonding connects non-current-carrying metal
parts together to ensure a low-impedance path exists to trip the circuit
breaker quickly during a fault.
8. According to the NEC, what is the minimum size copper equipment
grounding conductor required for a 20-ampere branch circuit?
A) 14 AWG
B) 12 AWG
C) 10 AWG
D) 8 AWG
Correct Answer: B
Rationale: NEC Table 250.122 requires a 12 AWG copper equipment
grounding conductor for a 20-amp overcurrent device.
, 9. In a dwelling unit, where is AFCI protection required for 120-volt,
15-amp and 20-amp circuits?
A) Bathrooms only
B) Kitchens only
C) All habitable rooms per NEC 210.12
D) Outdoor receptacles only
Correct Answer: C
Rationale: NEC 210.12 requires AFCI protection in dwelling units for all
120V, 15A and 20A circuits in family rooms, dining rooms, living rooms,
bedrooms, and similar rooms.
10. What is the maximum number of 14 AWG conductors allowed in a
4-inch square metal box that is 1.5 inches deep?
A) 6
B) 8
C) 10
D) 12
Correct Answer: C
Rationale: Box fill calculations per NEC 314.16 determine conductor
capacity based on box volume and conductor size.
11. Which of the following is used to calculate electrical power?
A) Resistance and voltage
B) Impedance and frequency
C) Current and voltage
D) Current and resistance
Correct Answer: C
Rationale: Joule's Law states that Power (P) = Current (I) × Voltage (V).
