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NYC Electrician (CUNY) Exam Practice Questions
Section 1: Electrical Theory & Calculations (Q1–Q20)
Q1. What is the SI unit of electrical current?
A) Volt
B) Ohm
C) Ampere
D) Watt
Answer: C
Rationale: The ampere (A) is the SI base unit for electric current, representing the flow of
one coulomb of charge per second .
Q2. According to Ohm's Law, if voltage increases while resistance remains constant,
current will:
A) Decrease
B) Remain the same
C) Increase
D) Fluctuate
Answer: C
Rationale: Ohm's Law states 𝐼 = 𝑉/𝑅. With 𝑅constant, current is directly proportional to
voltage .
Q3. What is the total resistance of three 12Ω resistors connected in parallel?
A) 4Ω
B) 12Ω
C) 36Ω
D) 3Ω
Answer: A
Rationale: For parallel resistors: 1/𝑅𝑡 = 1/12 + 1/12 + 1/12 = 3/12, so 𝑅𝑡 = 4Ω.
Q4. What is the power dissipated by a 10Ω resistor with 2 amperes of current flowing
through it?
A) 20W
B) 40W
C) 5W
D) 100W
Answer: B
Rationale: Power = 𝐼 2 × 𝑅 = (2𝐴)2 × 10Ω = 40𝑊.
Q5. The resistance of a conductor is directly proportional to its:
A) Cross-sectional area
B) Length
C) Conductivity
, 2
D) Temperature coefficient
Answer: B
Rationale: Resistance is directly proportional to length (𝑅 ∝ 𝐿) and inversely proportional to
cross-sectional area .
Q6. In a series circuit, the current is:
A) Different at each load
B) The same through all components
C) Zero at the end
D) Divided among branches
Answer: B
Rationale: In a series circuit, there is only one path for current, so it is the same through all
components.
Q7. What is the formula for calculating power in a DC circuit?
A) P = V × I
B) P = V / I
C) P = I / V
D) P = V + I
Answer: A
Rationale: Power in watts equals voltage multiplied by current (𝑃 = 𝑉 × 𝐼).
Q8. A 120V circuit has a resistance of 20Ω. What is the current?
A) 6A
B) 10A
C) 2A
D) 2400A
Answer: A
Rationale: 𝐼 = 𝑉/𝑅 = 120𝑉/20Ω = 6𝐴.
Q9. What is the voltage drop across a 5Ω resistor with 4A of current?
A) 9V
B) 20V
C) 1.25V
D) 4.5V
Answer: B
Rationale: 𝑉 = 𝐼 × 𝑅 = 4𝐴 × 5Ω = 20𝑉.
Q10. In a three-phase system, the voltage between any two phases is called:
A) Phase voltage
B) Line voltage
C) Neutral voltage
D) Ground voltage
, 3
Answer: B
Rationale: Line voltage is the voltage measured between any two phases in a three-phase
system.
Q11. What is the relationship between line voltage and phase voltage in a Wye (Y)
connected system?
A) Line voltage = Phase voltage
B) Line voltage = Phase voltage × √3
C) Line voltage = Phase voltage / √3
D) Line voltage = Phase voltage × 2
Answer: B
Rationale: In a Wye connection, 𝑉𝐿𝑖𝑛𝑒 = 𝑉𝑃ℎ𝑎𝑠𝑒 × √3(approximately 1.732).
Q12. A 240V single-phase motor draws 28A. What is the minimum breaker size?
A) 30A
B) 35A
C) 40A
D) 50A
Answer: B
Rationale: Continuous loads must not exceed 80% of breaker rating. 28𝐴/0.8 = 35𝐴.
Q13. What is the maximum continuous load allowed on a 20A breaker?
A) 16A
B) 18A
C) 20A
D) 25A
Answer: A
Rationale: Continuous loads must not exceed 80% of breaker rating (20𝐴 × 0.8 = 16𝐴) .
Q14. What is the unit of measurement for electrical power?
A) Volt
B) Ampere
C) Watt
D) Ohm
Answer: C
Rationale: The watt (W) is the SI unit of power.
Q15. Capacitance is measured in:
A) Henries
B) Farads
C) Ohms
D) Siemens
NYC Electrician (CUNY) Exam Practice Questions
Section 1: Electrical Theory & Calculations (Q1–Q20)
Q1. What is the SI unit of electrical current?
A) Volt
B) Ohm
C) Ampere
D) Watt
Answer: C
Rationale: The ampere (A) is the SI base unit for electric current, representing the flow of
one coulomb of charge per second .
Q2. According to Ohm's Law, if voltage increases while resistance remains constant,
current will:
A) Decrease
B) Remain the same
C) Increase
D) Fluctuate
Answer: C
Rationale: Ohm's Law states 𝐼 = 𝑉/𝑅. With 𝑅constant, current is directly proportional to
voltage .
Q3. What is the total resistance of three 12Ω resistors connected in parallel?
A) 4Ω
B) 12Ω
C) 36Ω
D) 3Ω
Answer: A
Rationale: For parallel resistors: 1/𝑅𝑡 = 1/12 + 1/12 + 1/12 = 3/12, so 𝑅𝑡 = 4Ω.
Q4. What is the power dissipated by a 10Ω resistor with 2 amperes of current flowing
through it?
A) 20W
B) 40W
C) 5W
D) 100W
Answer: B
Rationale: Power = 𝐼 2 × 𝑅 = (2𝐴)2 × 10Ω = 40𝑊.
Q5. The resistance of a conductor is directly proportional to its:
A) Cross-sectional area
B) Length
C) Conductivity
, 2
D) Temperature coefficient
Answer: B
Rationale: Resistance is directly proportional to length (𝑅 ∝ 𝐿) and inversely proportional to
cross-sectional area .
Q6. In a series circuit, the current is:
A) Different at each load
B) The same through all components
C) Zero at the end
D) Divided among branches
Answer: B
Rationale: In a series circuit, there is only one path for current, so it is the same through all
components.
Q7. What is the formula for calculating power in a DC circuit?
A) P = V × I
B) P = V / I
C) P = I / V
D) P = V + I
Answer: A
Rationale: Power in watts equals voltage multiplied by current (𝑃 = 𝑉 × 𝐼).
Q8. A 120V circuit has a resistance of 20Ω. What is the current?
A) 6A
B) 10A
C) 2A
D) 2400A
Answer: A
Rationale: 𝐼 = 𝑉/𝑅 = 120𝑉/20Ω = 6𝐴.
Q9. What is the voltage drop across a 5Ω resistor with 4A of current?
A) 9V
B) 20V
C) 1.25V
D) 4.5V
Answer: B
Rationale: 𝑉 = 𝐼 × 𝑅 = 4𝐴 × 5Ω = 20𝑉.
Q10. In a three-phase system, the voltage between any two phases is called:
A) Phase voltage
B) Line voltage
C) Neutral voltage
D) Ground voltage
, 3
Answer: B
Rationale: Line voltage is the voltage measured between any two phases in a three-phase
system.
Q11. What is the relationship between line voltage and phase voltage in a Wye (Y)
connected system?
A) Line voltage = Phase voltage
B) Line voltage = Phase voltage × √3
C) Line voltage = Phase voltage / √3
D) Line voltage = Phase voltage × 2
Answer: B
Rationale: In a Wye connection, 𝑉𝐿𝑖𝑛𝑒 = 𝑉𝑃ℎ𝑎𝑠𝑒 × √3(approximately 1.732).
Q12. A 240V single-phase motor draws 28A. What is the minimum breaker size?
A) 30A
B) 35A
C) 40A
D) 50A
Answer: B
Rationale: Continuous loads must not exceed 80% of breaker rating. 28𝐴/0.8 = 35𝐴.
Q13. What is the maximum continuous load allowed on a 20A breaker?
A) 16A
B) 18A
C) 20A
D) 25A
Answer: A
Rationale: Continuous loads must not exceed 80% of breaker rating (20𝐴 × 0.8 = 16𝐴) .
Q14. What is the unit of measurement for electrical power?
A) Volt
B) Ampere
C) Watt
D) Ohm
Answer: C
Rationale: The watt (W) is the SI unit of power.
Q15. Capacitance is measured in:
A) Henries
B) Farads
C) Ohms
D) Siemens
