CALFORNIA C10 ELECTRICAL TEST PAPER 2025/2026
QUESTIONS WITH ANSWERS RATED A+
✔✔The main service disconnecting means should be located _____.
A-at or near the point where the service-entrance conductors enter the building
B-at least 20 feet from the point where the service-entrance conductors enter the
building
C-at least 30 feet from the point where the service-entrance conductors enter the
building
D-at least 50 feet from the point where the service-entrance conductors enter the
building - ✔✔The Correct Answer Is A
The service disconnecting means must be installed at a readily accessible location
either outside of a building or structure, or inside, nearest the point of entrance of the
service conductors. NEC Section 230.70 (A).
✔✔The NEC requires that all circuits over 150 volts to ground containing fuses have a
disconnecting means located _____.
A-outside
B-on supply side of all fuses
C-on load side of all fuses
D-where convenient - ✔✔The Correct Answer Is B
Disconnecting means must be provided on the supply side of all fuses in circuits of over
150 volts to ground.
✔✔The general lighting load for residential services is calculated at _____.
A-1 watt per square foot
B-2 watts per square foot
C-3 watts per square foot
D-4 watts per square foot - ✔✔The Correct Answer Is C
NEC Table 220.3(A) shows that the general lighting load for dwelling units is calculated
at 3 volt-amperes per square foot.
✔✔Residential small appliance circuits are calculated at _____.
A-1500 watts each
B-2000 watts each
C-2500 watts each
D-3000 watts each - ✔✔The Correct Answer Is A
In addition to the number of branch circuits determined by the square-foot method
(based on 3 volt-amperes per square foot), two or more 20-ampere small appliance
branch circuits must be provided for all receptacle outlets in the kitchen, pantry,
breakfast room, dining room, or similar area of a dwelling unit. NEC Section 220.16.
✔✔All metal enclosures for service conductors and equipment must be _____.
A-watertight
B-painted
,C-locked
D-grounded - ✔✔The Correct Answer Is D
NEC Section 250.80 states that all metal enclosures for service conductors and
equipment must be grounded.
✔✔A lighting and appliance panelboard is a panelboard in which more than 10 percent
of its overcurrent devices are rated 30 amperes or less and have _____.
A-ungrounded connections only
B-GFCIs installed
C-branch-circuit grounded conductors
D-switched neutral - ✔✔The Correct Answer Is C
A lighting and appliance branch-circuit panelboard is one having more than 10 percent
of its overcurrent devices rated 30 amperes or less, for which branch-circuit grounded-
conductor connections are provided. NEC Section 408.14(A)
✔✔All metal enclosures for service conductors and equipment must be _____.
A-grounded
B-ungrounded
C-made from 10 guage steel or above
D-PVC (plastic) - ✔✔The Correct Answer Is A
Metal enclosures such as metal conduit, pull boxes, panelboard housings, and the like,
must be grounded to comply with NEC Article 250.
✔✔A 200-ampere panelboard may supply a maximum load of _____.
A-100 amperes
B-180 amperes
C-160 amperes
D-200 amperes - ✔✔The Correct Answer Is D
A panelboard may supply a load not in excess of its rating.
✔✔The terminal bar in a panelboard is connected to the neutral bar only when the
panelboard is used as _____.
A-motor control feeders
B-low-voltage feeders
C-service equipment
D-machinery feeders - ✔✔The Correct Answer Is C
The terminal bar used for equipment grounding (bonding) in a panelboard may be
connected together only when used as service equipment. When used otherwise, the
terminal bar and neutral bar must be isolated from each other. NEC Section 250.24(A)
✔✔A lighting and appliance branch-circuit panelboard has 10 percent or more of its
overcurrent devices rated _____.
A-30 amperes or less
B-25 amperes or less
C-20 amperes or less
, D-15 amperes or less - ✔✔The Correct Answer Is A
A lighting and appliance branch-circuit panelboard is one having more than 10 percent
of its overcurrent devices rated 30 amperes or less, for which branch-circuit grounded
connections are provided. NEC Section 408.14.
✔✔In a data-processing room the disconnecting means must be at _____.
A-each group of computers
B-the principal exit door
C-each piece of electronic equipment
D-the main service entrance - ✔✔The Correct Answer Is B
The disconnect switches for electrical feeders in a computer or data-processing room
must be located at the principal exit door to deenergize all equipment upon exiting the
room. NEC Section 645.10 now allows the disconnecting means to be in the form of a
pushbutton.
✔✔What is the maximum number of overcurrent devices, excluding the mains, allowed
in a lighting and appliance panelboard?
A-38
B-40
C-42
D-44 - ✔✔The Correct Answer Is C
The maximum number of overcurrent devices in a three-phase, 4-wire system is 42.
✔✔Insulated grounded conductors, in sizes larger than No. 6 AWG, may be identified
by _____.
A-a continuous white or natural gray outer finish
B-three continuous white stripes on a purple outer covering
C-distinctive white markings encircling the conductor at its terminations
D-All the above. - ✔✔The Correct Answer Is D
NEC Sections 200.6(B) permits grounded conductors to be identified by a white or gray
outer finish, or by three continuous white stripes along their entire length on other than
green insulation. However, only sizes larger than No. 6 AWG are permitted to be
marked as white or grey at points of termination and such markings must encircle the
entire conductor.
✔✔The minimum size copper equipment grounding conductor for a 200-ampere circuit
is _____.
A-No. 3 AWG
B-No. 6 AWG
C-No. 8 AWG
D-No. 10 AWG - ✔✔The Correct Answer Is B
NEC Table 250.122 gives No. 6 AWG copper wire as the minimum size for a 200-
ampere circuit.
✔✔Auxiliary gutters must not be filled to greater than _____.
QUESTIONS WITH ANSWERS RATED A+
✔✔The main service disconnecting means should be located _____.
A-at or near the point where the service-entrance conductors enter the building
B-at least 20 feet from the point where the service-entrance conductors enter the
building
C-at least 30 feet from the point where the service-entrance conductors enter the
building
D-at least 50 feet from the point where the service-entrance conductors enter the
building - ✔✔The Correct Answer Is A
The service disconnecting means must be installed at a readily accessible location
either outside of a building or structure, or inside, nearest the point of entrance of the
service conductors. NEC Section 230.70 (A).
✔✔The NEC requires that all circuits over 150 volts to ground containing fuses have a
disconnecting means located _____.
A-outside
B-on supply side of all fuses
C-on load side of all fuses
D-where convenient - ✔✔The Correct Answer Is B
Disconnecting means must be provided on the supply side of all fuses in circuits of over
150 volts to ground.
✔✔The general lighting load for residential services is calculated at _____.
A-1 watt per square foot
B-2 watts per square foot
C-3 watts per square foot
D-4 watts per square foot - ✔✔The Correct Answer Is C
NEC Table 220.3(A) shows that the general lighting load for dwelling units is calculated
at 3 volt-amperes per square foot.
✔✔Residential small appliance circuits are calculated at _____.
A-1500 watts each
B-2000 watts each
C-2500 watts each
D-3000 watts each - ✔✔The Correct Answer Is A
In addition to the number of branch circuits determined by the square-foot method
(based on 3 volt-amperes per square foot), two or more 20-ampere small appliance
branch circuits must be provided for all receptacle outlets in the kitchen, pantry,
breakfast room, dining room, or similar area of a dwelling unit. NEC Section 220.16.
✔✔All metal enclosures for service conductors and equipment must be _____.
A-watertight
B-painted
,C-locked
D-grounded - ✔✔The Correct Answer Is D
NEC Section 250.80 states that all metal enclosures for service conductors and
equipment must be grounded.
✔✔A lighting and appliance panelboard is a panelboard in which more than 10 percent
of its overcurrent devices are rated 30 amperes or less and have _____.
A-ungrounded connections only
B-GFCIs installed
C-branch-circuit grounded conductors
D-switched neutral - ✔✔The Correct Answer Is C
A lighting and appliance branch-circuit panelboard is one having more than 10 percent
of its overcurrent devices rated 30 amperes or less, for which branch-circuit grounded-
conductor connections are provided. NEC Section 408.14(A)
✔✔All metal enclosures for service conductors and equipment must be _____.
A-grounded
B-ungrounded
C-made from 10 guage steel or above
D-PVC (plastic) - ✔✔The Correct Answer Is A
Metal enclosures such as metal conduit, pull boxes, panelboard housings, and the like,
must be grounded to comply with NEC Article 250.
✔✔A 200-ampere panelboard may supply a maximum load of _____.
A-100 amperes
B-180 amperes
C-160 amperes
D-200 amperes - ✔✔The Correct Answer Is D
A panelboard may supply a load not in excess of its rating.
✔✔The terminal bar in a panelboard is connected to the neutral bar only when the
panelboard is used as _____.
A-motor control feeders
B-low-voltage feeders
C-service equipment
D-machinery feeders - ✔✔The Correct Answer Is C
The terminal bar used for equipment grounding (bonding) in a panelboard may be
connected together only when used as service equipment. When used otherwise, the
terminal bar and neutral bar must be isolated from each other. NEC Section 250.24(A)
✔✔A lighting and appliance branch-circuit panelboard has 10 percent or more of its
overcurrent devices rated _____.
A-30 amperes or less
B-25 amperes or less
C-20 amperes or less
, D-15 amperes or less - ✔✔The Correct Answer Is A
A lighting and appliance branch-circuit panelboard is one having more than 10 percent
of its overcurrent devices rated 30 amperes or less, for which branch-circuit grounded
connections are provided. NEC Section 408.14.
✔✔In a data-processing room the disconnecting means must be at _____.
A-each group of computers
B-the principal exit door
C-each piece of electronic equipment
D-the main service entrance - ✔✔The Correct Answer Is B
The disconnect switches for electrical feeders in a computer or data-processing room
must be located at the principal exit door to deenergize all equipment upon exiting the
room. NEC Section 645.10 now allows the disconnecting means to be in the form of a
pushbutton.
✔✔What is the maximum number of overcurrent devices, excluding the mains, allowed
in a lighting and appliance panelboard?
A-38
B-40
C-42
D-44 - ✔✔The Correct Answer Is C
The maximum number of overcurrent devices in a three-phase, 4-wire system is 42.
✔✔Insulated grounded conductors, in sizes larger than No. 6 AWG, may be identified
by _____.
A-a continuous white or natural gray outer finish
B-three continuous white stripes on a purple outer covering
C-distinctive white markings encircling the conductor at its terminations
D-All the above. - ✔✔The Correct Answer Is D
NEC Sections 200.6(B) permits grounded conductors to be identified by a white or gray
outer finish, or by three continuous white stripes along their entire length on other than
green insulation. However, only sizes larger than No. 6 AWG are permitted to be
marked as white or grey at points of termination and such markings must encircle the
entire conductor.
✔✔The minimum size copper equipment grounding conductor for a 200-ampere circuit
is _____.
A-No. 3 AWG
B-No. 6 AWG
C-No. 8 AWG
D-No. 10 AWG - ✔✔The Correct Answer Is B
NEC Table 250.122 gives No. 6 AWG copper wire as the minimum size for a 200-
ampere circuit.
✔✔Auxiliary gutters must not be filled to greater than _____.
