NYC Electrician Exam Prep- Real Questions & Verified
Answers (2026 Edition) NEW!!!
Section 1: Electrical Theory, Formulas & Calculations
• 1. What wire material has the highest resistance?
o Answer: Chromium
• 2. $Z$ - Impedance:
o Definition: The total opposition to an AC circuit, combining all resistances.
o Formula: $Z = \sqrt{R^2 + (X_L - X_C)^2}$
• 3. True Power:
o Definition: Total power of a circuit in Watts.
o Formula: $P_{\text{true}} = P_{\text{apparent}} \times PF$
• 4. Oil is used in many large transformers to:
o Answer: Insulate the coils (and provide cooling)
• 5. Apparent Power:
o Definition: Starting power measured in Volt-Amperes (VA).
o Formula: $P_{\text{apparent}} = E \times I$
• 6. Power Factor ($PF$):
o Formula: $PF = \frac{P_{\text{true}}}{P_{\text{apparent}}}$ or $PF = \frac{R}{Z}$
• 7. $X_C$ = Capacitive Reactance:
o Formula: $X_C = \frac{1}{2\pi fC}$ or $X_C = \frac{159,000}{f \times \mu\text{fd}}$
• 8. $X_L$ = Inductive Reactance:
o Formula: $X_L = 2\pi fL$
• 9. The cold resistance of a conductor is ________ than its hot resistance.
o Answer: Less than
• 10. Celsius to Fahrenheit conversion:
o Formula: $F = \frac{9}{5}C + 32$
• 11. Voltage is ________ to the number of turns in a transformer winding.
o Answer: Proportional
• 12. Internal Resistance:
o Definition: Resistance encountered inside a battery or generator (DC source).
• 13. Square Mils:
o Formulas: $\text{Square Mils} = \text{width} \times \text{thickness}$ or $\text{Square Mils} = \text{CMA}
\times 0.78$
• 14. What is the Circular Mil Area (CMA) of a 10 AWG wire?
o Answer: 10,383 CMA
• 15. Resistance Value ($K$-Factor) Chart:
o At 20°C: $K = 10.4$ for Copper ($\text{Cu}$) or $17$ for Aluminum ($\text{Al}$)
o At 75°C: $K = 12.9$ for Copper ($\text{Cu}$) or $21$ for Aluminum ($\text{Al}$)
• 16. One mil is equal to:
o Answer: $\frac{1}{1000}$ of an inch ($0.001$ inch)
• 17. What is the rule for Inductance in series versus parallel circuits?
o Series: Additive
o Parallel: Inversely additive
• 18. In an AC circuit, if the voltage and current are in phase, the circuit is purely:
o Answer: Resistive
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, • 19. For an inductor, $X_L$ is ________ proportional to the frequency.
o Answer: Directly
• 20. If a coil is to be wound for a lower frequency than originally designed, the number of turns must be:
o Answer: More
• 21. The sum of the voltage drops in a series circuit is equal to:
o Answer: The source voltage
• 22. Batteries are rated by voltage and:
o Answer: Amp-hours ($\text{Ah}$)
Section 2: National Electrical Code (NEC) & NYC Regulations
• 23. Circuit breakers used for switching luminaires shall be marked:
o Answer: SWD (Switching Duty) or HID (High-Intensity Discharge)
• 24. An insulated wire shall have its AWG marking repeated every ________ feet.
o Answer: Two feet (24 inches)
• 25. Wire Temperature Abbreviations and ratings:
o No "H" (e.g., TW) = 60°C
o 1 "H" (e.g., THW) = 75°C
o 2 "H" (e.g., THHN) = 90°C
• 26. To select the proper fuse, it is necessary to know the:
o Answer: Voltage and amperage
• 27. Under ordinary conditions, device boxes for concealed work shall have a minimum depth of:
o Answer: $\frac{1}{2}$ inch
• 28. The largest size conductor that may be used in an underfloor raceway is:
o Answer: The maximum size for which the specific raceway is designed
• 29. A 277V lighting circuit may not be used to supply:
o Answer: A standard medium-base lampholder
• 30. Fixed appliance versus portable appliance branch-circuit ampacity load ratings:
o Fixed Appliance: Maximum 50% of branch rating if other loads are served
o Portable Appliance: Maximum 80% of branch rating
• 31. In a three-wire attachment plug:
o Answer: You must identify one of the terminals (specifically the grounded/neutral terminal)
• 32. Fuse holders for current-limiting fuses shall prevent the insertion of fuses that are:
o Answer: (1) Smaller ratings, (2) Non-current-limiting types, and (3) Higher voltages
• 33. Coordination of service overcurrent protective devices (OCPD) and secondary OCPD is required when
the service OCPD is rated above:
o Answer: 1204A (Note: Standard NEC thresholds often point to 1200A or higher)
• 34. Plug fuses having a hexagonal-shaped window have a maximum rating of:
o Answer: 15A
• 35. A fuse or circuit breaker should be provided at every point where:
o Answer: A change is made in the size of the wire
• 36. Circuit breakers shall clearly indicate their interrupting capacity when that value exceeds:
o Answer: 5,000 AIC (Ampere Interrupting Capacity)
• 37. For a feeder run over 200 feet long, you would generally use:
o Answer: Larger wire than originally calculated (to compensate for voltage drop)
• 38. Which conductor insulation material type has the highest current capacity/temperature rating?
o Answer: TFE
• 39. Voltage drop should not exceed what cumulative percentage from the service to the farthest branch
circuit?
o Answer: 5%
• 40. Copper busbars are rated at how many Amperes per square inch?
o Answer: 1000A per square inch
• 41. The maximum permitted percentage of cross-sectional conduit fill on rewiring installations is:
o Answer: 40%
• 42. If installed in dry locations, wireways may be used for circuits of not more than:
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Answers (2026 Edition) NEW!!!
Section 1: Electrical Theory, Formulas & Calculations
• 1. What wire material has the highest resistance?
o Answer: Chromium
• 2. $Z$ - Impedance:
o Definition: The total opposition to an AC circuit, combining all resistances.
o Formula: $Z = \sqrt{R^2 + (X_L - X_C)^2}$
• 3. True Power:
o Definition: Total power of a circuit in Watts.
o Formula: $P_{\text{true}} = P_{\text{apparent}} \times PF$
• 4. Oil is used in many large transformers to:
o Answer: Insulate the coils (and provide cooling)
• 5. Apparent Power:
o Definition: Starting power measured in Volt-Amperes (VA).
o Formula: $P_{\text{apparent}} = E \times I$
• 6. Power Factor ($PF$):
o Formula: $PF = \frac{P_{\text{true}}}{P_{\text{apparent}}}$ or $PF = \frac{R}{Z}$
• 7. $X_C$ = Capacitive Reactance:
o Formula: $X_C = \frac{1}{2\pi fC}$ or $X_C = \frac{159,000}{f \times \mu\text{fd}}$
• 8. $X_L$ = Inductive Reactance:
o Formula: $X_L = 2\pi fL$
• 9. The cold resistance of a conductor is ________ than its hot resistance.
o Answer: Less than
• 10. Celsius to Fahrenheit conversion:
o Formula: $F = \frac{9}{5}C + 32$
• 11. Voltage is ________ to the number of turns in a transformer winding.
o Answer: Proportional
• 12. Internal Resistance:
o Definition: Resistance encountered inside a battery or generator (DC source).
• 13. Square Mils:
o Formulas: $\text{Square Mils} = \text{width} \times \text{thickness}$ or $\text{Square Mils} = \text{CMA}
\times 0.78$
• 14. What is the Circular Mil Area (CMA) of a 10 AWG wire?
o Answer: 10,383 CMA
• 15. Resistance Value ($K$-Factor) Chart:
o At 20°C: $K = 10.4$ for Copper ($\text{Cu}$) or $17$ for Aluminum ($\text{Al}$)
o At 75°C: $K = 12.9$ for Copper ($\text{Cu}$) or $21$ for Aluminum ($\text{Al}$)
• 16. One mil is equal to:
o Answer: $\frac{1}{1000}$ of an inch ($0.001$ inch)
• 17. What is the rule for Inductance in series versus parallel circuits?
o Series: Additive
o Parallel: Inversely additive
• 18. In an AC circuit, if the voltage and current are in phase, the circuit is purely:
o Answer: Resistive
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, • 19. For an inductor, $X_L$ is ________ proportional to the frequency.
o Answer: Directly
• 20. If a coil is to be wound for a lower frequency than originally designed, the number of turns must be:
o Answer: More
• 21. The sum of the voltage drops in a series circuit is equal to:
o Answer: The source voltage
• 22. Batteries are rated by voltage and:
o Answer: Amp-hours ($\text{Ah}$)
Section 2: National Electrical Code (NEC) & NYC Regulations
• 23. Circuit breakers used for switching luminaires shall be marked:
o Answer: SWD (Switching Duty) or HID (High-Intensity Discharge)
• 24. An insulated wire shall have its AWG marking repeated every ________ feet.
o Answer: Two feet (24 inches)
• 25. Wire Temperature Abbreviations and ratings:
o No "H" (e.g., TW) = 60°C
o 1 "H" (e.g., THW) = 75°C
o 2 "H" (e.g., THHN) = 90°C
• 26. To select the proper fuse, it is necessary to know the:
o Answer: Voltage and amperage
• 27. Under ordinary conditions, device boxes for concealed work shall have a minimum depth of:
o Answer: $\frac{1}{2}$ inch
• 28. The largest size conductor that may be used in an underfloor raceway is:
o Answer: The maximum size for which the specific raceway is designed
• 29. A 277V lighting circuit may not be used to supply:
o Answer: A standard medium-base lampholder
• 30. Fixed appliance versus portable appliance branch-circuit ampacity load ratings:
o Fixed Appliance: Maximum 50% of branch rating if other loads are served
o Portable Appliance: Maximum 80% of branch rating
• 31. In a three-wire attachment plug:
o Answer: You must identify one of the terminals (specifically the grounded/neutral terminal)
• 32. Fuse holders for current-limiting fuses shall prevent the insertion of fuses that are:
o Answer: (1) Smaller ratings, (2) Non-current-limiting types, and (3) Higher voltages
• 33. Coordination of service overcurrent protective devices (OCPD) and secondary OCPD is required when
the service OCPD is rated above:
o Answer: 1204A (Note: Standard NEC thresholds often point to 1200A or higher)
• 34. Plug fuses having a hexagonal-shaped window have a maximum rating of:
o Answer: 15A
• 35. A fuse or circuit breaker should be provided at every point where:
o Answer: A change is made in the size of the wire
• 36. Circuit breakers shall clearly indicate their interrupting capacity when that value exceeds:
o Answer: 5,000 AIC (Ampere Interrupting Capacity)
• 37. For a feeder run over 200 feet long, you would generally use:
o Answer: Larger wire than originally calculated (to compensate for voltage drop)
• 38. Which conductor insulation material type has the highest current capacity/temperature rating?
o Answer: TFE
• 39. Voltage drop should not exceed what cumulative percentage from the service to the farthest branch
circuit?
o Answer: 5%
• 40. Copper busbars are rated at how many Amperes per square inch?
o Answer: 1000A per square inch
• 41. The maximum permitted percentage of cross-sectional conduit fill on rewiring installations is:
o Answer: 40%
• 42. If installed in dry locations, wireways may be used for circuits of not more than:
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