NYC ELECTRICIAN (NYC HEALTH + HOSPITALS – NYC H+H)
EXAMNCOMPREHENSIVE PRACTICE EXAM QUESTIONS
VERIFIED ANSWERS WITH DETAILED RATIONALES|
LATEST UPDATE
This guide covers all 12 exam domains: Electrical Theory, NEC, Conduit & Wiring,
Grounding & Bonding, Calculations, Motors & Controls, Transformers, Lighting,
Hospital Systems, Blueprints, Troubleshooting, and Safety. Each rationale is
designed to reinforce both the correct answer and the technical reasoning
behind it.
SECTION 1 – ELECTRICAL THEORY FUNDAMENTALS (Questions 1–40)
1. What is the unit of measurement for electrical current?
A) Volts
B) Ohms
C) Amperes
D) Watts
Correct Answer: C
Rationale: Amperes (amps) measure the rate of electron flow (current).
Volts (A) measure electrical pressure or potential difference. Ohms (B)
measure resistance, the opposition to current flow. Watts (D) measure
real power, the rate of energy consumption. Understanding these base units
is essential for all circuit calculations.
2. What is the unit of measurement for electrical resistance?
A) Volts
B) Ohms
C) Amperes
D) Siemens
Correct Answer: B
Rationale: The ohm (Ω) is the SI unit of resistance. Volts (A) measure
potential, amperes (C) measure current, and siemens (D) measure conductance
1
, (the inverse of resistance). A conductor with lower ohms allows more
current for a given voltage.
3. According to Ohm’s Law, what is the formula for calculating voltage?
A) V = I × R
B) V = I / R
C) V = R / I
D) V = I² × R
Correct Answer: A
Rationale: Ohm’s Law states that voltage equals current times resistance.
Option B (I/R) is not a standard electrical formula. Option C (R/I) is
also incorrect. Option D (I²×R) is the formula for power dissipated in a
resistor, not voltage. Mastery of V=I×R is fundamental to every circuit
analysis problem.
4. If a circuit has a resistance of 10 Ω and a voltage of 120 V, what is the
current?
A) 1.2 A
B) 12 A
C) 120 A
D) 0.12 A
Correct Answer: B
Rationale: Using I = V / R = = 12 A. 1.2 A (A) would result from
12 V across 10 Ω. 120 A (C) would be 120 V across 1 Ω. 0.12 A (D) would
be 1.2 V across 10 Ω. This direct application of Ohm’s Law is a core skill.
5. What is the power dissipated by a 10 Ω resistor with 5 A flowing through it?
A) 50 W
B) 250 W
C) 25 W
D) 500 W
Correct Answer: B
Rationale: P = I² × R = 5² × 10 = 25 × 10 = 250 W. 50 W (A) would be
2
, I × R (without squaring). 25 W (C) would be I × R with R=5. 500 W (D)
would be V×I with V=100. Always use the correct power formula for the
given variables.
6. In a series circuit, which of the following is the same for all components?
A) Voltage
B) Current
C) Resistance
D) Power
Correct Answer: B
Rationale: In a series circuit, there is only one path, so current is
identical through every component. Voltage (A) divides across each
resistor in proportion to its resistance. Total resistance (C) is the sum
of individual resistances. Power (D) is dissipated individually and adds
to total power.
7. In a parallel circuit, which of the following is the same for all branches?
A) Current
B) Voltage
C) Resistance
D) Power
Correct Answer: B
Rationale: In a parallel circuit, voltage is the same across every branch
because each branch is directly connected to the same two nodes. Current
(A) divides inversely to branch resistance. Total resistance (C) is less
than the smallest branch resistor. Power (D) is dissipated individually in
each branch.
8. A 20 Ω resistor and a 30 Ω resistor are connected in series to a 120 V
source. What is the total current?
A) 2.4 A
B) 6 A
C) 4 A
3
, D) 10 A
Correct Answer: A
Rationale: R_total = 20 + 30 = 50 Ω. I = V / R = = 2.4 A. 6 A (B)
would be current through the 20 Ω alone (ignoring the 30 Ω). 4 A (C) would
be 120 V / 30 Ω (ignoring the 20 Ω). 10 A (D) would be if total resistance
were 12 Ω. Series resistors add directly.
9. Two resistors, 20 Ω and 30 Ω, are connected in parallel to a 120 V source.
What is the total current?
A) 10 A
B) 4 A
C) 6 A
D) 2.4 A
Correct Answer: A
Rationale: 1/R_total = 1/20 + 1/30 = (3+2)/60 = 5/60 → R_total = 12 Ω.
I = = 10 A. 4 A (B) is the current through the 30 Ω branch alone.
6 A (C) is the current through the 20 Ω branch alone. 2.4 A (D) is the
series current (from Q8). In parallel, currents add.
10. What is the total capacitance of two 10 µF capacitors connected in parallel?
A) 5 µF
B) 10 µF
C) 20 µF
D) 100 µF
Correct Answer: C
Rationale: Capacitors in parallel add directly: C_total = C1 + C2 =
10 + 10 = 20 µF. 5 µF (A) would be the series combination of two equal
capacitors. 10 µF (B) would be just one capacitor. 100 µF (D) would be
product (incorrect). Parallel connection increases total capacitance.
11. What is the total inductance of two 5 mH inductors connected in series?
A) 2.5 mH
B) 5 mH
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EXAMNCOMPREHENSIVE PRACTICE EXAM QUESTIONS
VERIFIED ANSWERS WITH DETAILED RATIONALES|
LATEST UPDATE
This guide covers all 12 exam domains: Electrical Theory, NEC, Conduit & Wiring,
Grounding & Bonding, Calculations, Motors & Controls, Transformers, Lighting,
Hospital Systems, Blueprints, Troubleshooting, and Safety. Each rationale is
designed to reinforce both the correct answer and the technical reasoning
behind it.
SECTION 1 – ELECTRICAL THEORY FUNDAMENTALS (Questions 1–40)
1. What is the unit of measurement for electrical current?
A) Volts
B) Ohms
C) Amperes
D) Watts
Correct Answer: C
Rationale: Amperes (amps) measure the rate of electron flow (current).
Volts (A) measure electrical pressure or potential difference. Ohms (B)
measure resistance, the opposition to current flow. Watts (D) measure
real power, the rate of energy consumption. Understanding these base units
is essential for all circuit calculations.
2. What is the unit of measurement for electrical resistance?
A) Volts
B) Ohms
C) Amperes
D) Siemens
Correct Answer: B
Rationale: The ohm (Ω) is the SI unit of resistance. Volts (A) measure
potential, amperes (C) measure current, and siemens (D) measure conductance
1
, (the inverse of resistance). A conductor with lower ohms allows more
current for a given voltage.
3. According to Ohm’s Law, what is the formula for calculating voltage?
A) V = I × R
B) V = I / R
C) V = R / I
D) V = I² × R
Correct Answer: A
Rationale: Ohm’s Law states that voltage equals current times resistance.
Option B (I/R) is not a standard electrical formula. Option C (R/I) is
also incorrect. Option D (I²×R) is the formula for power dissipated in a
resistor, not voltage. Mastery of V=I×R is fundamental to every circuit
analysis problem.
4. If a circuit has a resistance of 10 Ω and a voltage of 120 V, what is the
current?
A) 1.2 A
B) 12 A
C) 120 A
D) 0.12 A
Correct Answer: B
Rationale: Using I = V / R = = 12 A. 1.2 A (A) would result from
12 V across 10 Ω. 120 A (C) would be 120 V across 1 Ω. 0.12 A (D) would
be 1.2 V across 10 Ω. This direct application of Ohm’s Law is a core skill.
5. What is the power dissipated by a 10 Ω resistor with 5 A flowing through it?
A) 50 W
B) 250 W
C) 25 W
D) 500 W
Correct Answer: B
Rationale: P = I² × R = 5² × 10 = 25 × 10 = 250 W. 50 W (A) would be
2
, I × R (without squaring). 25 W (C) would be I × R with R=5. 500 W (D)
would be V×I with V=100. Always use the correct power formula for the
given variables.
6. In a series circuit, which of the following is the same for all components?
A) Voltage
B) Current
C) Resistance
D) Power
Correct Answer: B
Rationale: In a series circuit, there is only one path, so current is
identical through every component. Voltage (A) divides across each
resistor in proportion to its resistance. Total resistance (C) is the sum
of individual resistances. Power (D) is dissipated individually and adds
to total power.
7. In a parallel circuit, which of the following is the same for all branches?
A) Current
B) Voltage
C) Resistance
D) Power
Correct Answer: B
Rationale: In a parallel circuit, voltage is the same across every branch
because each branch is directly connected to the same two nodes. Current
(A) divides inversely to branch resistance. Total resistance (C) is less
than the smallest branch resistor. Power (D) is dissipated individually in
each branch.
8. A 20 Ω resistor and a 30 Ω resistor are connected in series to a 120 V
source. What is the total current?
A) 2.4 A
B) 6 A
C) 4 A
3
, D) 10 A
Correct Answer: A
Rationale: R_total = 20 + 30 = 50 Ω. I = V / R = = 2.4 A. 6 A (B)
would be current through the 20 Ω alone (ignoring the 30 Ω). 4 A (C) would
be 120 V / 30 Ω (ignoring the 20 Ω). 10 A (D) would be if total resistance
were 12 Ω. Series resistors add directly.
9. Two resistors, 20 Ω and 30 Ω, are connected in parallel to a 120 V source.
What is the total current?
A) 10 A
B) 4 A
C) 6 A
D) 2.4 A
Correct Answer: A
Rationale: 1/R_total = 1/20 + 1/30 = (3+2)/60 = 5/60 → R_total = 12 Ω.
I = = 10 A. 4 A (B) is the current through the 30 Ω branch alone.
6 A (C) is the current through the 20 Ω branch alone. 2.4 A (D) is the
series current (from Q8). In parallel, currents add.
10. What is the total capacitance of two 10 µF capacitors connected in parallel?
A) 5 µF
B) 10 µF
C) 20 µF
D) 100 µF
Correct Answer: C
Rationale: Capacitors in parallel add directly: C_total = C1 + C2 =
10 + 10 = 20 µF. 5 µF (A) would be the series combination of two equal
capacitors. 10 µF (B) would be just one capacitor. 100 µF (D) would be
product (incorrect). Parallel connection increases total capacitance.
11. What is the total inductance of two 5 mH inductors connected in series?
A) 2.5 mH
B) 5 mH
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