CSLB C-10 Electrical Test 1 (2025/2026 Latest
Update) | Licensed Electrician Exam Q&A PDF
| Accurate & Verified Study Guide
Overhead service conductors OF NOT OVER 1000 VOLTS must maintain a minimum
clearance of _______ above the surface of a roof:
A: 3'5″
B. 4'4″
C. 8'6″
D. 10'5″ - correct answerC: 8'6"
Above Roofs Overhead spans of open conductors and open multiconductor cables shall
have a vertical clearance of not less than 2.7 m (8 ft 6 in.) above the roof surface. The
vertical clearance above the roof level shall be maintained for a distance not less than
900 mm (3 ft) in all directions from the edge of the roof. ~
3' refers to clearance at edge of roof.
Service conductors must have a clearance of not less than _____ from windows.
A. 3′
B. 4′
C. 8′
D. 10′ - correct answerA: 3'
Service conductors installed as open conductors or multiconductor cable without an
overall outer jacket shall have a clearance of not less than 900 mm (3 ft) from windows
that are designed to be opened, doors, porches, balconies, ladders, stairs, fire escapes,
or similar locations. (2022 California Electrical Code, 230.9(A))
An appliance on a 20-amp branch circuit should not draw more than:
A. 5 amps
B. 12 amps
C. 16 amps
D. 20 amps - correct answerC: 16 amps
C. The maximum connected load for a 20-amp receptacle is 16 amps. All of the
appliances on a branch circuit cannot exceed 80% of the rating of the branch circuit. 20
amps × 0.8 = 16 amps (rating of branch circuit) × 0.8 = (the amps of all appliances on
this circuit cannot exceed 16 amps)
What is the minimum clear working space in front of a 480 V panel opposite exposed
live parts?
,A. 24″
B. 36″
C. 42″
D. 48″ - correct answerD: 48'
The minimum clear working space for 0-150 V is 3 feet. The minimum clear working
space for 151-600 V is 4 feet.
The minimum size overhead service entrance cable permitted is:
A. No. 8 copper
B. No. 6 copper
C. No. 4 aluminum
D. No. 2 copper-clad aluminum - correct answerA. No. 8 copper
No. 8 copper. 2022 CEC 230.23(B) Minimum Size The conductors shall not be smaller
than 8 AWG copper or 6 AWG aluminum or copper-clad aluminum. Exception:
Conductors supplying only limited loads of a single branch circuit — such as small
polyphase power, controlled water heaters, and similar loads — shall not be smaller
than 12 AWG hard-drawn copper or equivalent.
A 50 kVA transformer supplies 480 V and 40 A. What is its kW rating?
A. 19 kW
B. 40 kW
C. 68 kW
D. 77 kW - correct answerA. 19kW
kW [single phase] = (E x I)/1000 = (480 V x 40 A)/1000 = 19.2 kW. Note: Do not use the
square root of 3. This is only for 3 phase not single phase.
What is the minimum clear working space in front of a 480 V panel opposite a grounded
wall?
A. 24″
B. 36″
C. 42″
D. 48″ - correct answerC. 42'
The minimum clear working space for 0-150V is 3 feet. The minimum clear working
space for 151-600V is 3 feet 6 inches.
The cable that has an internal bonding strip of copper or aluminum in contact with armor
for its entire length is:
A. MI
B. AC
C. NMC
D. RMC - correct answerB. Type AC.
, 2022 CEC 320.1 Scope. This article covers the use, installation, and construction
specifications for armored cable, Type AC.
The lead wire on a heating cable is red. This indicates:
A. 120 V
B. 208 V
C. 240 V
D. either B or C - correct answerD. 208 volts refers to three phase power where two of
the three legs are used to power equipment. 240 volts refers to single phase power that
is comprised of two legs (both hot). The color red denotes a hot wire that carries
electricity. Thus, red is to be used for both three phase (208 volts) and single phase
(240 volts). For 120 volts, a black OR RED conductor can be used; however, black is
the default color. Be aware that the NEC does NOT allow current carrying conductors to
be white, gray or green. This is the only color restriction.
he following should not be used on a live circuit:
A. voltmeter
B. ohmmeter
C. ammeter
D. wattmeter - correct answerB:
You cannot measure resistance with an ohmmeter on a "live" circuit! The reason for this
is simple: the ohmmeter's accurate indication depends on the only source of voltage
being its internal battery.
The minimum permitted size fixture wire is:
A. No. 14
B. No. 16
C. No. 18
D. No. 20 - correct answerC.
#14 is the smallest wire used in circuits. #18 is flexible wire.
The instrument that tests the resistance of wire insulation is a(n):
A. ohmmeter
B. voltmeter
C. galvanometer
D. Megger - correct answerD.
An ordinary ohmmeter cannot do an adequate job of checking the condition of insulation
subjected to high voltages. A Megger is also called an "insulation tester".
The maximum voltage for a plug fuse is:
Update) | Licensed Electrician Exam Q&A PDF
| Accurate & Verified Study Guide
Overhead service conductors OF NOT OVER 1000 VOLTS must maintain a minimum
clearance of _______ above the surface of a roof:
A: 3'5″
B. 4'4″
C. 8'6″
D. 10'5″ - correct answerC: 8'6"
Above Roofs Overhead spans of open conductors and open multiconductor cables shall
have a vertical clearance of not less than 2.7 m (8 ft 6 in.) above the roof surface. The
vertical clearance above the roof level shall be maintained for a distance not less than
900 mm (3 ft) in all directions from the edge of the roof. ~
3' refers to clearance at edge of roof.
Service conductors must have a clearance of not less than _____ from windows.
A. 3′
B. 4′
C. 8′
D. 10′ - correct answerA: 3'
Service conductors installed as open conductors or multiconductor cable without an
overall outer jacket shall have a clearance of not less than 900 mm (3 ft) from windows
that are designed to be opened, doors, porches, balconies, ladders, stairs, fire escapes,
or similar locations. (2022 California Electrical Code, 230.9(A))
An appliance on a 20-amp branch circuit should not draw more than:
A. 5 amps
B. 12 amps
C. 16 amps
D. 20 amps - correct answerC: 16 amps
C. The maximum connected load for a 20-amp receptacle is 16 amps. All of the
appliances on a branch circuit cannot exceed 80% of the rating of the branch circuit. 20
amps × 0.8 = 16 amps (rating of branch circuit) × 0.8 = (the amps of all appliances on
this circuit cannot exceed 16 amps)
What is the minimum clear working space in front of a 480 V panel opposite exposed
live parts?
,A. 24″
B. 36″
C. 42″
D. 48″ - correct answerD: 48'
The minimum clear working space for 0-150 V is 3 feet. The minimum clear working
space for 151-600 V is 4 feet.
The minimum size overhead service entrance cable permitted is:
A. No. 8 copper
B. No. 6 copper
C. No. 4 aluminum
D. No. 2 copper-clad aluminum - correct answerA. No. 8 copper
No. 8 copper. 2022 CEC 230.23(B) Minimum Size The conductors shall not be smaller
than 8 AWG copper or 6 AWG aluminum or copper-clad aluminum. Exception:
Conductors supplying only limited loads of a single branch circuit — such as small
polyphase power, controlled water heaters, and similar loads — shall not be smaller
than 12 AWG hard-drawn copper or equivalent.
A 50 kVA transformer supplies 480 V and 40 A. What is its kW rating?
A. 19 kW
B. 40 kW
C. 68 kW
D. 77 kW - correct answerA. 19kW
kW [single phase] = (E x I)/1000 = (480 V x 40 A)/1000 = 19.2 kW. Note: Do not use the
square root of 3. This is only for 3 phase not single phase.
What is the minimum clear working space in front of a 480 V panel opposite a grounded
wall?
A. 24″
B. 36″
C. 42″
D. 48″ - correct answerC. 42'
The minimum clear working space for 0-150V is 3 feet. The minimum clear working
space for 151-600V is 3 feet 6 inches.
The cable that has an internal bonding strip of copper or aluminum in contact with armor
for its entire length is:
A. MI
B. AC
C. NMC
D. RMC - correct answerB. Type AC.
, 2022 CEC 320.1 Scope. This article covers the use, installation, and construction
specifications for armored cable, Type AC.
The lead wire on a heating cable is red. This indicates:
A. 120 V
B. 208 V
C. 240 V
D. either B or C - correct answerD. 208 volts refers to three phase power where two of
the three legs are used to power equipment. 240 volts refers to single phase power that
is comprised of two legs (both hot). The color red denotes a hot wire that carries
electricity. Thus, red is to be used for both three phase (208 volts) and single phase
(240 volts). For 120 volts, a black OR RED conductor can be used; however, black is
the default color. Be aware that the NEC does NOT allow current carrying conductors to
be white, gray or green. This is the only color restriction.
he following should not be used on a live circuit:
A. voltmeter
B. ohmmeter
C. ammeter
D. wattmeter - correct answerB:
You cannot measure resistance with an ohmmeter on a "live" circuit! The reason for this
is simple: the ohmmeter's accurate indication depends on the only source of voltage
being its internal battery.
The minimum permitted size fixture wire is:
A. No. 14
B. No. 16
C. No. 18
D. No. 20 - correct answerC.
#14 is the smallest wire used in circuits. #18 is flexible wire.
The instrument that tests the resistance of wire insulation is a(n):
A. ohmmeter
B. voltmeter
C. galvanometer
D. Megger - correct answerD.
An ordinary ohmmeter cannot do an adequate job of checking the condition of insulation
subjected to high voltages. A Megger is also called an "insulation tester".
The maximum voltage for a plug fuse is:
