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NYC MASTER ELECTRICIAN EXAM
PREP WITH ACCURATE SOLUTIONS
1. Cartridge fuses of the renewable type shall be permitted to be used only for replacement in existing installations where there is no evidence of over-fusing or tampering. Which of the following is correct? A) They can be used in new installations B) They may only replace existing fuses where over-fusing or tampering is absent ✓ C) They can be installed in any equipment regardless of past issues D) They are never allowed in any installation
Explanation: Renewable cartridge fuses are outdated and considered unsafe
for new installations. They may only replace existing fuses where there is no sign of over-fusing or tampering. This ensures system safety without introducing old components into modern circuits.
2. A Class HA 100 HP DC motor at 220V with 90% efficiency requires a fuse size of: A) 400 A B) 500 A C) 600 A ✓ D) 700 A
Explanation: To determine fuse size, calculate full-load current and then
select a fuse that meets or slightly exceeds it. For a 100 HP DC motor at 220V with 90% efficiency, the current is approximately 545 A. A 600 A fuse is appropriate to protect the motor without nuisance trippin
3. A 15A or 20A, 125V receptacle outlet shall be located within 25 feet of heating, air-conditioning, and refrigeration equipment for which occupancies? A) Residential only B) Commercial only C) Industrial only D) Dwelling, commercial, and industrial occupancies ✓
Explanation: The NEC requires a nearby receptacle for service and
maintenance tools. This rule applies to all occupancies to ensure safe and
convenient equipment servicing.
4. A branch circuit that supplies only one utilization equipment is called: A) General branch circuit B) Individual branch circuit ✓ C) Multi-use branch circuit D) Dedicated sub-circuit
Explanation: An individual branch circuit is designed to serve a single piece
of equipment. This allows proper sizing and protection according to the load requirements of that equipment.
5. A disconnecting means that serves a hermetic refrigerant motor- compressor shall have an ampere rating of at least: A) 100% of nameplate current B) 115% of the nameplate rated load current to branch circuit selection current, whichever is greater ✓ C) 150% of motor full-load current D) 200% of the nameplate current
Explanation: Hermetic compressors require disconnects rated at 115% of the
full-load current or branch circuit selection current to prevent nuisance tripping while protecting the motor. This ensures proper safety margin for motor startup and overload conditions.
6. A door used by personnel to exit a workspace that is less than 25 feet from the working space shall: A) Swing inward B) Swing outward with simple pressure ✓ C) Slide sideways D) Remain fixed
Explanation: Doors in close proximity to working spaces must swing outward
to ensure quick egress in case of emergencies. Simple pressure operation ensures that personnel can exit without obstruction.
7. Fixed storage type water heaters of 120 gallons or less shall be considered a continuous load, and the branch circuit conductors shall have an ampacity of: A) 100% of the nameplate rating B) 125% of the nameplate rating ✓
11. In a 12-unit multifamily building with 120/240V, single-phase supply, the following appliance loads exist: Dishwasher 1.5 kVA, Water Heater 4 kW, Dryer 4.5 kW, Washing Machine 1.2 kVA, Range 14.45 kW, A/C (230V) 3 HP, A/C fan motor 1/8 HP, Heat 5 kW. Which of the following is true? A) Only one branch circuit needed for all units B) Individual branch circuits required for major appliances ✓ C) All units can share the same general branch circuit D) Only lighting requires individual branch circuits
Explanation: Each major appliance requires its own branch circuit to comply
with NEC and NYC Electrical Code. This ensures proper protection and avoids nuisance tripping.
12. A separate branch circuit shall supply the elevator hoistway pit lighting and receptacle. The required lighting shall not be connected to: A) General lighting circuit B) Load side of a GFCI ✓ C) HVAC circuit D) General-purpose outlet
Explanation: Elevator pit circuits require dedicated supply for safety.
Connecting to a GFCI or other general circuits can cause unnecessary tripping, endangering maintenance personnel.
13. A separation of at least ____ is required between network communication cable and power cables. A) 2 inches B) 3 inches C) 4 inches ✓ D) 6 inches
Explanation: NEC 800.133 requires a minimum 4-inch separation to prevent
electromagnetic interference between communication and power circuits. Proper spacing ensures signal integrity.
14. A separation of at least ____ feet shall be maintained between communication wires and building lighting conductors where practicable. A) 4 feet B) 5 feet
C) 6 feet ✓ D) 8 feet
Explanation: Maintaining 6 feet of separation prevents electromagnetic
interference that could affect data and communication signals. This is recommended “where practicable” to balance safety and building constraints.
15. A service switchboard sized over 5000A with a 100% rating shall have copper bus bars sized on an ampacity of: A) 500 A per square inch B) 600 A per square inch C) 700 A per square inch ✓ D) 800 A per square inch
Explanation: Large switchboards require appropriately sized bus bars to
safely carry rated currents without overheating. Copper bus bars with 700 A per square inch meet NYC code requirements for this size of equipment.
16. A storage battery supplying emergency lighting and power shall maintain not less than ____ of full load for a period of at least 1. hours. A) 75% B) 80% C) 87.5% ✓ D) 90%
Explanation: Emergency batteries must sustain at least 87.5% of rated load
to ensure reliable operation of emergency systems during outages. This prevents total power loss for essential loads.
17. AC or DC general-use snap switches may be used for control of inductive loads not exceeding: A) 25% of ampere rating B) 50% of ampere rating ✓ C) 75% of ampere rating D) 100% of ampere rating
Explanation: Snap switches are rated for resistive and inductive loads. For
safety, inductive loads (like motors or transformers) should not exceed 50% of the switch rating to avoid arcing and premature failure.
Explanation: Total work hours = 8 × 5 = 40 hours. Rooms completed = 40 ÷
2.6 ≈ 15.38, so 15 full rooms are completed.
22. An electrician buys 100 units of armored cable connectors at $2.10 each and sells them at $3.00 per unit. Assuming overhead is 30%, what is his profit? A) $27 ✓ B) $ C) $ D) $
Explanation: Cost per unit = $2.10; selling price = $3.00; overhead = 30% of
$2.10 = $0.63. Profit per unit = $3.00 − ($2.10 + $0.63) = $0.27. Total profit = $0.27 × 100 = $27.
23. An insulated grounded conductor of #6 AWG or smaller shall be identified by: A) Continuous green finish B) Continuous white or gray finish, or three continuous white stripes on other than green insulation ✓ C) Continuous black finish D) Red tape at each end
Explanation: Grounded conductors must be clearly identified to prevent
miswiring. White, gray, or three white stripes are the NEC standard for safety and consistency.
24. As per NYC NEC, in addition to the number of branch circuits required in a dwelling unit, an individual branch circuit shall be provided for: A) Each oven B) Each dishwasher C) Each air conditioner receptacle ✓ D) Each lighting fixture
Explanation: Air conditioners are considered high-load, continuous duty
equipment. Providing a dedicated branch circuit prevents overloads and ensures code compliance.
25. At least one 125V, single-phase, 15A or 20A duplex receptacle shall be provided in: A) Elevator hoistway pit ✓
B) Kitchen C) Laundry room D) Basement
Explanation: Elevator pit receptacles are required to power maintenance
tools. This receptacle must be readily accessible for personnel working in the pit.
26. At least one entrance to enclosures for electrical installations over 600V nominal shall be: A) 24 inches wide and 5 ft high B) 30 inches wide and 6 ft high ✓ C) 36 inches wide and 7 ft high D) 40 inches wide and 6.5 ft high
Explanation: Adequate access ensures safe work around high-voltage
equipment. The 30 × 72-inch minimum allows personnel to enter and exit safely with tools.
27. Audible and visual signal devices for an emergency system shall be provided, where practicable, for the purpose of: A) Indicating that the battery is carrying load ✓ B) Controlling normal lighting C) Switching HVAC D) Signaling only outside the building
Explanation: Emergency signals alert personnel to system status. Audible
and visual indicators ensure immediate awareness of battery load, derangement, or charger failure.
28. Automatic transfer switches shall be: A) Manually operated and mechanically held B) Electrically operated and mechanically held ✓ C) Mechanically operated only D) Electrically operated only
Explanation: Automatic transfer switches must operate electrically to switch
power quickly and be mechanically held to maintain contact during faults. This ensures reliable emergency power transfer.
29. Bending radius in type AC cable shall be made such that: A) The cable is not damaged, and the radius of the curve of the inner edge of
33. In NYC, cartridge fuses of renewable type are allowed in which of the following scenarios? A) New installations B) Replacements in existing installations with no evidence of over-fusing or tampering ✓ C) Temporary construction circuits D) Anywhere in commercial buildings
Explanation: Renewable cartridge fuses are considered outdated and are not
allowed in new installations. They may only replace existing fuses where no tampering or over-fusing is present. This protects the system from potential overloads.
34. A 100 HP DC motor running at 220V and 90% efficiency requires a fuse. Which size is appropriate? A) 500 A B) 550 A C) 600 A ✓ D) 650 A
Explanation: Calculating full-load current and accounting for motor efficiency,
a 600 A fuse provides adequate protection. It prevents nuisance tripping while protecting the motor from overload.
35. Which type of branch circuit serves only one utilization equipment? A) Multi-purpose branch circuit B) Individual branch circuit ✓ C) General lighting circuit D) Shared motor branch
Explanation: Individual branch circuits are designed for a single appliance or
motor. This ensures proper sizing of overcurrent protection devices and safe operation of the equipment.
36. The disconnecting means for a hermetic refrigerant motor- compressor must have an ampere rating of at least: A) 100% of motor full-load current B) 115% of nameplate rated load current or branch circuit selection current, whichever is greater ✓ C) 125% of motor full-load current D) 150% of motor full-load current
Explanation: NEC requires 115% minimum to ensure safety during startup
and overload conditions. This helps prevent nuisance tripping and allows the compressor to operate safely.
37. A door used for personnel egress within 25 feet of working space must: A) Slide horizontally B) Swing inward C) Swing outward with simple pressure ✓ D) Be lockable only
Explanation: Outward swinging doors ensure quick and safe exit in
emergencies. Simple pressure operation allows easy egress without mechanical obstruction.
38. Fixed storage water heaters 120 gallons or less are considered: A) Intermittent load B) Continuous load ✓ C) Non-continuous load D) Emergency load
Explanation: Continuous loads require branch circuits sized at 125% of
nameplate current to handle sustained operation safely. This prevents overheating of conductors and ensures long-term reliability.
39. A hospital is a building used for care of how many patients on a 24-hour basis? A) 2 or more B) 3 or more C) 4 or more ✓ D) 5 or more
Explanation: NEC defines a hospital as serving four or more patients
continuously. This classification affects branch circuit and emergency system requirements.
40. A limited care facility is defined as an area used on a ____ basis for housing four or more persons incapable of self-preservation. A) 8-hour B) 12-hour C) 24-hour ✓ D) 48-hour
Explanation: NEC 800.133 requires 4-inch separation to prevent
electromagnetic interference, maintaining signal integrity.
45. Minimum separation between communication wires and building lighting conductors is: A) 4 feet B) 5 feet C) 6 feet ✓ D) 8 feet
Explanation: Maintaining 6 feet of separation prevents EMI and ensures
reliable operation of communication systems.
46. Copper bus bars for a switchboard rated over 5000 A must have an ampacity of: A) 500 A per sq in B) 600 A per sq in C) 700 A per sq in ✓ D) 800 A per sq in
Explanation: Adequate bus bar ampacity prevents overheating and allows
safe current distribution. NYC code specifies 700 A per square inch for these switchboards.
47. Storage batteries for emergency lighting must maintain at least: A) 80% load B) 85% load C) 87.5% load ✓ D) 90% load
Explanation: Batteries must supply 87.5% of full load for at least 1.5 hours to
ensure emergency systems operate reliably during outages.
48. AC or DC snap switches may control inductive loads not exceeding: A) 25% B) 50% ✓ C) 75% D) 100%
Explanation: Snap switches have limited capacity for inductive loads.
Limiting to 50% prevents arcing and extends switch life.
49. Minimum access opening in a manhole is: A) 24 inches B) 26 inches ✓ C) 28 inches D) 30 inches
Explanation: Manhole access openings must be at least 26 inches to allow
safe entry and exit. This ensures safe working conditions.
50. Bare live parts are guarded from the public by all the following EXCEPT: A) Enclosure B) Location out of reach C) Protected by fireproof curtain ✓ D) Insulation
Explanation: Bare live parts must not rely on fireproof curtains for safety.
Acceptable methods include enclosures, restricted locations, or insulation.
51. Snap switches for AC control may handle: A) Resistive and inductive loads ≤ amp & voltage rating, tungsten lamp loads ≤ rating at 120V, motor loads ≤ 80% of rating ✓ B) Only resistive loads C) Only motor loads D) Only lighting circuits
Explanation: Snap switches are rated for different types of loads, but motor
loads are limited to 80% of rating to prevent overheating.
52. If 2.6 hours are required to install outlets in one room, how many rooms can 2 electricians complete in 5 days, working 8 hours/day? A) 15 B) 30 ✓ C) 20 D) 25
57. Minimum entrance to enclosures for equipment over 600V nominal is: A) 24" wide × 5' high B) 30" wide × 6' high ✓ C) 36" wide × 6' high D) 40" wide × 7' high
Explanation: Adequate access is required to allow safe operation and
maintenance of high-voltage equipment.
58. Audible and visual emergency signals indicate: A) Normal power B) Battery carrying load, derangement of emergency source, charger malfunction ✓ C) HVAC status D) General lighting fault
Explanation: Emergency signals alert personnel to the status of critical
systems for safety.
59. Automatic transfer switches are: A) Manually operated B) Electrically operated and mechanically held ✓ C) Mechanically operated only D) Electrically operated only
Explanation: Proper operation ensures reliable transfer of power and system
stability.
60. Type AC cable bending radius must be at least: A) 3× cable diameter B) 4× cable diameter C) 5× cable diameter ✓ D) 6× cable diameter
Explanation: Maintaining the proper bend radius prevents insulation and
conductor damage.
61. Branch circuit conductors for a single continuous-duty motor must be rated at: A) 100% FLC B) 115% FLC
C) 125% FLC ✓
D) 150% FLC
Explanation: NEC requires 125% ampacity for continuous loads to ensure
safe operation.
62. Conductors within 3 inches of a ballast must have insulation rating of: A) 75°C B) 90°C (194°F) ✓ C) 105°C D) 60°C
Explanation: High-temperature insulation prevents heat damage from nearby
ballasts.
63. ROMEX cable can enter surface-mounted enclosures through non-flexible raceways not less than: A) 12 inches B) 18 inches ✓ C) 24 inches D) 6 inches
Explanation: NEC requires this minimum length for protection and strain
relief.
64. Branch circuit conductors near a ballast must be rated at minimum: A) 60°C B) 75°C C) 90°C (194°F) ✓ D) 105°C
Explanation: Conductors near heat-producing equipment must handle higher
temperatures.
65. Elevator hoistway pit lighting cannot be connected to: A) Dedicated branch circuit B) Load side of a GFCI ✓ C) General lighting D) General-purpose outlets
B) 26 inches ✓ C) 28 inches D) 30 inches
71. Bare live parts must be guarded from public contact. Which of the following is NOT an acceptable method? A) Enclosure B) Location out of reach C) Protected by fireproof curtain ✓ D) Insulation
Explanation: NEC requires that live parts be safely guarded using enclosures,
insulation, or by placing them out of reach. Fireproof curtains do not provide adequate protection and are not permitted.
72. For AC general-use snap switches controlling motors, the maximum allowed load is: A) 50% of switch rating B) 60% of switch rating C) 80% of ampere and voltage rating ✓ D) 100% of switch rating
Explanation: To prevent arcing and overheating, snap switches may only
control motor loads up to 80% of their rated ampere and voltage. This ensures safe operation of motor loads.
73. If an electrician works 8 hours/day for 5 days and each room takes 2.6 hours to install outlets, how many rooms are completed? A) 14 B) 15 ✓ C) 16 D) 18
Explanation: Total hours = 8 × 5 = 40 hours. Rooms completed = 40 ÷ 2.6 ≈
15.38, so 15 rooms are completed.
74. An electrician purchases 100 armored cable connectors at $2. each and sells them at $3.00 with 30% overhead. Profit is: A) $27 ✓ B) $ C) $ D) $
Explanation: Cost per unit + overhead = $2.10 + $0.63 = $2.73. Selling at
$3.00 gives profit of $0.27 × 100 = $27.
75. Grounded conductors of #6 AWG or smaller must be identified by: A) Continuous green B) Continuous white or gray, or 3 white stripes ✓ C) Black insulation D) Red tape
Explanation: NEC requires grounded conductors to be clearly identified to
avoid wiring errors. White/gray or three stripes on non-green insulation is standard.
76. Each dwelling unit must provide a separate branch circuit for: A) Lighting B) Air conditioner receptacle ✓ C) Dishwasher D) Refrigerator
Explanation: Dedicated circuits are required for AC units to handle high-load
equipment safely and prevent overloads.
77. Minimum 125V, 15A or 20A duplex receptacle in an elevator hoistway pit is required for: A) Lighting only B) Maintenance tools ✓ C) HVAC D) General-purpose loads
Explanation: NEC requires a receptacle in the elevator pit to power
maintenance equipment safely.
78. Minimum entrance to electrical enclosures over 600V nominal must be: A) 24" × 5' B) 30" × 6' ✓ C) 36" × 6' D) 40" × 7'
