Residential Wiring Exam Practice Questions with
Correct Verified Solutions
According to the NEC_________, the minimum-size service required for a one-
family dwelling is__________ amperes.
What are the demand factors for the general lighting load of a residence?
100% demand factor (first 3000 VA)
35% demand factor (3001 VA to 120,000 VA)
25% demand factor (remainder over 120,000 VA)
What is the unit load per ft^2 for the general lighting load of a residence?
1812 ft^2 @ 3 VA per ft^2 = 5436 VA
or
3 VA per ft^2
What is the ampere rating of the circuits that are provided for the small-appliance
loads?
1500 volt-amperes (VA)
What is the minimum number of small-appliance circuits permitted by code?
Two 20-amp branch circuits
Why is the air conditioning load for this residence omitted in the service
calculations?
, The air conditioner is a smaller size than all the other appliances
What demand factor may be applied when four or more fixed appliances are
connected to a service, in addition to an electric range, air conditioner, clothes
dryer, or space-heating equipment?
75% demand factor
What load may be used for an electric range rated at not over 12 kW?
On what basis is the neutral conductor of a service entrance determined?
For a 208Y/120-volt, 3-phase system which is common for the arrangement to be used
for feeders to individual apartments of multi-family buildings.
Why is it permissible to omit an electric space heater, water heater, and certain
other 240-volt equipment when calculating the neutral service-entrance conductor
for a residence?
A. What part of the NEC Article contains an optional method for determining
residential-service loads?
NEC Article 220, Part IV (4)
B. Is this section (Article 220, Part 4) applicable to a two-family residence?
Yes
Calculate the minimum size of copper service-entrance conductors required for a
residence service residence containing the following: floor area is 24 ft x 38 ft (7.3 m
Correct Verified Solutions
According to the NEC_________, the minimum-size service required for a one-
family dwelling is__________ amperes.
What are the demand factors for the general lighting load of a residence?
100% demand factor (first 3000 VA)
35% demand factor (3001 VA to 120,000 VA)
25% demand factor (remainder over 120,000 VA)
What is the unit load per ft^2 for the general lighting load of a residence?
1812 ft^2 @ 3 VA per ft^2 = 5436 VA
or
3 VA per ft^2
What is the ampere rating of the circuits that are provided for the small-appliance
loads?
1500 volt-amperes (VA)
What is the minimum number of small-appliance circuits permitted by code?
Two 20-amp branch circuits
Why is the air conditioning load for this residence omitted in the service
calculations?
, The air conditioner is a smaller size than all the other appliances
What demand factor may be applied when four or more fixed appliances are
connected to a service, in addition to an electric range, air conditioner, clothes
dryer, or space-heating equipment?
75% demand factor
What load may be used for an electric range rated at not over 12 kW?
On what basis is the neutral conductor of a service entrance determined?
For a 208Y/120-volt, 3-phase system which is common for the arrangement to be used
for feeders to individual apartments of multi-family buildings.
Why is it permissible to omit an electric space heater, water heater, and certain
other 240-volt equipment when calculating the neutral service-entrance conductor
for a residence?
A. What part of the NEC Article contains an optional method for determining
residential-service loads?
NEC Article 220, Part IV (4)
B. Is this section (Article 220, Part 4) applicable to a two-family residence?
Yes
Calculate the minimum size of copper service-entrance conductors required for a
residence service residence containing the following: floor area is 24 ft x 38 ft (7.3 m
