NFPA 70 NATIONAL ELECTRICAL CODE PRACTICE
EXAM QUESTIONS WITH VERIFIED ANSWERS
200 QUESTIONS AND ANSWERS
1. :: What is the purpose of NFPA 70? Answer: The purpose of NFPA 70
(National Electrical Code) is the practical safeguarding of persons and
property from hazards arising from the use of electricity.
2. :: How often is the National Electrical Code typically updated? Answer:
The National Electrical Code is updated and published on a 3-year cycle.
3. :: According to the NEC, what color are isolated ground receptacles
typically required to be? Answer: Orange is the identifying color for
isolated ground receptacles.
4. :: What is the minimum working space depth required in front of
electrical equipment operating at 480 volts or less where live parts are
exposed? Answer: 3 feet (900 mm) minimum.
5. :: What height must a disconnect be mounted at to be considered
"readily accessible"? Answer: A maximum of 6 feet 7 inches (2.0 m)
above the floor or working platform.
6. :: What is the maximum number of overcurrent devices permitted in a
panelboard used as service equipment for a one-family dwelling?
Answer: 42 overcurrent devices.
7. :: When installing nonmetallic-sheathed cable through wood framing
members, what is the minimum distance from the edge of the framing
member that requires protection for the cable? Answer: 1¼ inches (32
mm).
8. :: What is the minimum burial depth for direct-buried UF cable used for
a residential branch circuit rated at 120V? Answer: 24 inches (600 mm).
, 9. :: What is the maximum number of current-carrying conductors
permitted in a single raceway without applying derating factors?
Answer: 3 current-carrying conductors.
10.:: What is the standard ampacity of 12 AWG copper wire with THWN
insulation at an ambient temperature of 30°C? Answer: 20 amperes.
Branch Circuits and Feeders
11.:: What is the minimum number of 20-ampere branch circuits required
for small appliances in a kitchen? Answer: Two 20-ampere branch
circuits.
12.:: In a dwelling unit, what is the maximum number of outlets permitted
on a 15-ampere general-purpose branch circuit? Answer: The NEC does
not specify a maximum number, but the total load must not exceed 80%
of the circuit rating (12 amperes) for continuous loads.
13.:: What is the maximum rating for a branch circuit used to supply a single
kitchen appliance rated at 10 amperes? Answer: 20 amperes.
14.:: What is the minimum number of branch circuits required for a
dwelling unit laundry area? Answer: One 20-ampere branch circuit.
15.:: What is the required GFCI protection amperage trip level for personnel
protection? Answer: 5 milliamperes (mA).
Grounding and Bonding
16.:: What is the maximum size of the grounding electrode conductor
required for a 200-ampere service using copper conductors? Answer: 4
AWG copper.
17.:: What is the minimum size equipment grounding conductor required
for a 60-ampere circuit? Answer: 10 AWG copper.
18.:: When is a separately derived system required to be grounded?
Answer: When the system voltage to ground is over 50 volts.
19.:: What size copper bonding jumper is required for a 100-ampere
service? Answer: 8 AWG copper.
20.:: What is the maximum distance allowed between pipe clamps for a
copper water pipe used as a grounding electrode? Answer: 5 feet.
, Special Locations and Equipment
21.:: What is the maximum mounting height above the floor for receptacles
installed above a countertop in a kitchen? Answer: 20 inches (508 mm).
22.:: In a bathroom, what is the minimum distance from a receptacle to the
outside edge of a sink? Answer: 3 feet (900 mm), unless the receptacle
is GFCI protected.
23.:: What is the minimum distance required between combustible
materials and recessed lighting fixtures marked "Type IC"? Answer: Type
IC fixtures can be in direct contact with combustible materials and
thermal insulation.
24.:: What is the maximum spacing allowed between supports for EMT
(Electrical Metallic Tubing) with a trade size of 1 inch? Answer: 10 feet.
25.:: In a swimming pool area, what is the minimum height required for
mounting luminaires above the maximum water level? Answer: 12 feet
if over the water, 5 feet if adjacent to the water.
Calculations
26.:: Calculate the minimum size service for a dwelling unit with the
following loads:
o General lighting load for 2,000 square feet: 2,000 × 3VA = 6,000
VA
o Electric range: 8,000 VA
o Electric water heater: 4,500 VA
o Clothes dryer: 5,000 VA
o Dishwasher: 1,200 VA
o Central A/C: 6,000 VA
Answer: The service calculation would be:
o First 10,000 VA at 100%: 10,000 VA
o Remainder at 40%: (6,000 + 8,000 + 4,500 + 5,000 + 1,200 + 6,000
- 10,000) × 0.4 = 8,280 VA
o Total: 18,280 VA
EXAM QUESTIONS WITH VERIFIED ANSWERS
200 QUESTIONS AND ANSWERS
1. :: What is the purpose of NFPA 70? Answer: The purpose of NFPA 70
(National Electrical Code) is the practical safeguarding of persons and
property from hazards arising from the use of electricity.
2. :: How often is the National Electrical Code typically updated? Answer:
The National Electrical Code is updated and published on a 3-year cycle.
3. :: According to the NEC, what color are isolated ground receptacles
typically required to be? Answer: Orange is the identifying color for
isolated ground receptacles.
4. :: What is the minimum working space depth required in front of
electrical equipment operating at 480 volts or less where live parts are
exposed? Answer: 3 feet (900 mm) minimum.
5. :: What height must a disconnect be mounted at to be considered
"readily accessible"? Answer: A maximum of 6 feet 7 inches (2.0 m)
above the floor or working platform.
6. :: What is the maximum number of overcurrent devices permitted in a
panelboard used as service equipment for a one-family dwelling?
Answer: 42 overcurrent devices.
7. :: When installing nonmetallic-sheathed cable through wood framing
members, what is the minimum distance from the edge of the framing
member that requires protection for the cable? Answer: 1¼ inches (32
mm).
8. :: What is the minimum burial depth for direct-buried UF cable used for
a residential branch circuit rated at 120V? Answer: 24 inches (600 mm).
, 9. :: What is the maximum number of current-carrying conductors
permitted in a single raceway without applying derating factors?
Answer: 3 current-carrying conductors.
10.:: What is the standard ampacity of 12 AWG copper wire with THWN
insulation at an ambient temperature of 30°C? Answer: 20 amperes.
Branch Circuits and Feeders
11.:: What is the minimum number of 20-ampere branch circuits required
for small appliances in a kitchen? Answer: Two 20-ampere branch
circuits.
12.:: In a dwelling unit, what is the maximum number of outlets permitted
on a 15-ampere general-purpose branch circuit? Answer: The NEC does
not specify a maximum number, but the total load must not exceed 80%
of the circuit rating (12 amperes) for continuous loads.
13.:: What is the maximum rating for a branch circuit used to supply a single
kitchen appliance rated at 10 amperes? Answer: 20 amperes.
14.:: What is the minimum number of branch circuits required for a
dwelling unit laundry area? Answer: One 20-ampere branch circuit.
15.:: What is the required GFCI protection amperage trip level for personnel
protection? Answer: 5 milliamperes (mA).
Grounding and Bonding
16.:: What is the maximum size of the grounding electrode conductor
required for a 200-ampere service using copper conductors? Answer: 4
AWG copper.
17.:: What is the minimum size equipment grounding conductor required
for a 60-ampere circuit? Answer: 10 AWG copper.
18.:: When is a separately derived system required to be grounded?
Answer: When the system voltage to ground is over 50 volts.
19.:: What size copper bonding jumper is required for a 100-ampere
service? Answer: 8 AWG copper.
20.:: What is the maximum distance allowed between pipe clamps for a
copper water pipe used as a grounding electrode? Answer: 5 feet.
, Special Locations and Equipment
21.:: What is the maximum mounting height above the floor for receptacles
installed above a countertop in a kitchen? Answer: 20 inches (508 mm).
22.:: In a bathroom, what is the minimum distance from a receptacle to the
outside edge of a sink? Answer: 3 feet (900 mm), unless the receptacle
is GFCI protected.
23.:: What is the minimum distance required between combustible
materials and recessed lighting fixtures marked "Type IC"? Answer: Type
IC fixtures can be in direct contact with combustible materials and
thermal insulation.
24.:: What is the maximum spacing allowed between supports for EMT
(Electrical Metallic Tubing) with a trade size of 1 inch? Answer: 10 feet.
25.:: In a swimming pool area, what is the minimum height required for
mounting luminaires above the maximum water level? Answer: 12 feet
if over the water, 5 feet if adjacent to the water.
Calculations
26.:: Calculate the minimum size service for a dwelling unit with the
following loads:
o General lighting load for 2,000 square feet: 2,000 × 3VA = 6,000
VA
o Electric range: 8,000 VA
o Electric water heater: 4,500 VA
o Clothes dryer: 5,000 VA
o Dishwasher: 1,200 VA
o Central A/C: 6,000 VA
Answer: The service calculation would be:
o First 10,000 VA at 100%: 10,000 VA
o Remainder at 40%: (6,000 + 8,000 + 4,500 + 5,000 + 1,200 + 6,000
- 10,000) × 0.4 = 8,280 VA
o Total: 18,280 VA
