1|Page
NYC DCAS ELECTRICIAN EXAM QUESTIONS
WITH CORRECT ANSWERS (VERIFIED
ANSWERS) PLUS RATIONALES 2026 Q&A |
INSTANT DOWNLOAD PDF
# Domain 1: Electrical Theory and Calculations
## Questions 1-40
**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). Option A calculates current (I = V/R), option C inverts the
relationship, and option D uses the power formula (P = V × I) incorrectly
rearranged .
---
,2|Page
**2. 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. This is a fundamental application of the power
formula that appears frequently on the exam .
---
**3. What is the unit of electrical resistance?**
A) Volt
B) Ampere
C) Ohm
D) Watt
**Correct Answer: C**
,3|Page
**Rationale:** The ohm (Ω) is the SI unit of electrical resistance. Volts measure
voltage (electrical pressure), amperes measure current (flow rate), and watts
measure power (rate of energy transfer) .
---
**4. A 10Ω resistor carries 2A of current. What is the voltage across it?**
A) 5V
B) 12V
C) 20V
D) 24V
**Correct Answer: C**
**Rationale:** Using Ohm's Law: V = I × R = 2A × 10Ω = 20V. This demonstrates
the direct relationship between voltage, current, and resistance .
---
**5. In a series circuit, the total resistance is:**
A) Less than the smallest resistor
B) Equal to the sum of all resistors
, 4|Page
C) Equal to the reciprocal of the sum of reciprocals
D) Divided equally among components
**Correct Answer: B**
**Rationale:** In a series circuit, current has only one path, so resistances add
directly: R_total = R₁ + R₂ + R₃... This is a fundamental concept in circuit analysis .
---
**6. In a parallel circuit, voltage is:**
A) Different across each branch
B) The same across all branches
C) The sum of branch voltages
D) Divided by the number of branches
**Correct Answer: B**
**Rationale:** Voltage is constant across all branches in a parallel circuit; each
branch receives the full source voltage. This is a key distinction from series circuits
where current is constant .
---
NYC DCAS ELECTRICIAN EXAM QUESTIONS
WITH CORRECT ANSWERS (VERIFIED
ANSWERS) PLUS RATIONALES 2026 Q&A |
INSTANT DOWNLOAD PDF
# Domain 1: Electrical Theory and Calculations
## Questions 1-40
**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). Option A calculates current (I = V/R), option C inverts the
relationship, and option D uses the power formula (P = V × I) incorrectly
rearranged .
---
,2|Page
**2. 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. This is a fundamental application of the power
formula that appears frequently on the exam .
---
**3. What is the unit of electrical resistance?**
A) Volt
B) Ampere
C) Ohm
D) Watt
**Correct Answer: C**
,3|Page
**Rationale:** The ohm (Ω) is the SI unit of electrical resistance. Volts measure
voltage (electrical pressure), amperes measure current (flow rate), and watts
measure power (rate of energy transfer) .
---
**4. A 10Ω resistor carries 2A of current. What is the voltage across it?**
A) 5V
B) 12V
C) 20V
D) 24V
**Correct Answer: C**
**Rationale:** Using Ohm's Law: V = I × R = 2A × 10Ω = 20V. This demonstrates
the direct relationship between voltage, current, and resistance .
---
**5. In a series circuit, the total resistance is:**
A) Less than the smallest resistor
B) Equal to the sum of all resistors
, 4|Page
C) Equal to the reciprocal of the sum of reciprocals
D) Divided equally among components
**Correct Answer: B**
**Rationale:** In a series circuit, current has only one path, so resistances add
directly: R_total = R₁ + R₂ + R₃... This is a fundamental concept in circuit analysis .
---
**6. In a parallel circuit, voltage is:**
A) Different across each branch
B) The same across all branches
C) The sum of branch voltages
D) Divided by the number of branches
**Correct Answer: B**
**Rationale:** Voltage is constant across all branches in a parallel circuit; each
branch receives the full source voltage. This is a key distinction from series circuits
where current is constant .
---
