CSLB C-10 Electrical Contractor License Exam Test 1 | 2026/2027
Actual Exam – 120 Verified Questions and Correct Answers | California
State Licensing Board (CSLB)
Question 1: According to NEC Chapter 9, Table 1, what is the maximum
percentage fill allowed for a conduit or tubing containing three or more
distinct electrical conductors or cables?
• A) 31%
• B) 40%
• C) 53%
• D) 60%
Correct Answer: B
Rationale: For conduits containing 3 or more conductors, the maximum
allowable cross-sectional fill percentage is 40% per NEC Chapter 9 Table
1.
Question 2: Under California Contractors State License Board (CSLB)
rules, what is the current bond amount required for a C-10 Electrical
Contractor's bond?
• A) $7,500
• B) $12,500
• C) $15,000
• D) $25,000
Correct Answer: C
,Rationale: The CSLB requires all active licensee classifications, including
C-10 electrical contractors, to maintain a contractor's bond in the
amount of $15,000.
Question 3: Under Cal/OSHA construction safety orders, at what height
is fall protection mandatory for general construction work?
• A) 4 feet
• B) 6 feet
• C) 10 feet
• D) 15 feet
Correct Answer: B
Rationale: Cal/OSHA Title 8 mandates fall protection for employees
working on surfaces with an unprotected side or edge 6 feet or more
above a lower level.
Question 4: What is the standard working space depth required in front
of electrical equipment operating at 600 volts or less (nominal) with
exposed live parts on one side and grounded parts on the other
(Condition 2), per NEC 110.26?
• A) 2.5 feet
• B) 3.0 feet
• C) 3.5 feet
• D) 4.0 feet
Correct Answer: C
,Rationale: Condition 2 of NEC 110.26(A)(1) requires a clear working
space depth of 3.5 feet for systems operating up to 150 volts to ground,
increasing for higher voltages.
Question 5: According to California Business and Professions Code 7159,
what is the maximum down payment allowed by law for a home
improvement contract?
• A) 20% of the total contract price or $2,500, whichever is less
• B) 10% of the total contract price or $1,000, whichever is less
• C) 50% of the total contract price upfront before materials are
ordered
• D) There is no statutory limit on down payments in California.
Correct Answer: B
Rationale: California law restricts home improvement contract down
payments to a maximum of 10% of the total contract price or $1,000,
whichever is less.
Question 6: What is the maximum distance allowed between supports
for Type NM (Romex) cable according to NEC Article 334?
• A) Every 3 feet, and within 8 inches of boxes
• B) Every 4.5 feet, and within 12 inches of boxes
• C) Every 6 feet, and within 12 inches of boxes
• D) Every 10 feet, and within 36 inches of boxes
Correct Answer: B
, Rationale: NEC 334.30 requires Type NM cable to be supported and
secured at intervals not exceeding 4.5 feet and within 12 inches of
every outlet box, cabinet, or fitting.
Question 7: In a commercial dwelling unit or residential kitchen, GFCI
protection is required by NEC Article 210.8 for all 15- and 20-ampere,
125-volt receptacles installed in which location?
• A) Bathrooms only
• B) Bathrooms, kitchens, and rooftops
• C) Bathrooms, kitchens, rooftops, outdoors, and within 6 feet of
the outside edge of a sink
• D) All indoor areas regardless of sink proximity
Correct Answer: C
Rationale: NEC 210.8 expands GFCI requirements to include bathrooms,
kitchens, rooftops, outdoors, and indoor areas within 6 feet of sinks.
Question 8: Under NEC Article 250, what is the minimum size grounding
electrode conductor (GEC) required when connecting to a concrete-
encased electrode (Ufer ground) made of reinforcing steel, regardless of
the size of the service-entrance conductors?
• A) 8 AWG copper
• B) 6 AWG copper
• C) 4 AWG copper
• D) 2 AWG copper
Correct Answer: B
Actual Exam – 120 Verified Questions and Correct Answers | California
State Licensing Board (CSLB)
Question 1: According to NEC Chapter 9, Table 1, what is the maximum
percentage fill allowed for a conduit or tubing containing three or more
distinct electrical conductors or cables?
• A) 31%
• B) 40%
• C) 53%
• D) 60%
Correct Answer: B
Rationale: For conduits containing 3 or more conductors, the maximum
allowable cross-sectional fill percentage is 40% per NEC Chapter 9 Table
1.
Question 2: Under California Contractors State License Board (CSLB)
rules, what is the current bond amount required for a C-10 Electrical
Contractor's bond?
• A) $7,500
• B) $12,500
• C) $15,000
• D) $25,000
Correct Answer: C
,Rationale: The CSLB requires all active licensee classifications, including
C-10 electrical contractors, to maintain a contractor's bond in the
amount of $15,000.
Question 3: Under Cal/OSHA construction safety orders, at what height
is fall protection mandatory for general construction work?
• A) 4 feet
• B) 6 feet
• C) 10 feet
• D) 15 feet
Correct Answer: B
Rationale: Cal/OSHA Title 8 mandates fall protection for employees
working on surfaces with an unprotected side or edge 6 feet or more
above a lower level.
Question 4: What is the standard working space depth required in front
of electrical equipment operating at 600 volts or less (nominal) with
exposed live parts on one side and grounded parts on the other
(Condition 2), per NEC 110.26?
• A) 2.5 feet
• B) 3.0 feet
• C) 3.5 feet
• D) 4.0 feet
Correct Answer: C
,Rationale: Condition 2 of NEC 110.26(A)(1) requires a clear working
space depth of 3.5 feet for systems operating up to 150 volts to ground,
increasing for higher voltages.
Question 5: According to California Business and Professions Code 7159,
what is the maximum down payment allowed by law for a home
improvement contract?
• A) 20% of the total contract price or $2,500, whichever is less
• B) 10% of the total contract price or $1,000, whichever is less
• C) 50% of the total contract price upfront before materials are
ordered
• D) There is no statutory limit on down payments in California.
Correct Answer: B
Rationale: California law restricts home improvement contract down
payments to a maximum of 10% of the total contract price or $1,000,
whichever is less.
Question 6: What is the maximum distance allowed between supports
for Type NM (Romex) cable according to NEC Article 334?
• A) Every 3 feet, and within 8 inches of boxes
• B) Every 4.5 feet, and within 12 inches of boxes
• C) Every 6 feet, and within 12 inches of boxes
• D) Every 10 feet, and within 36 inches of boxes
Correct Answer: B
, Rationale: NEC 334.30 requires Type NM cable to be supported and
secured at intervals not exceeding 4.5 feet and within 12 inches of
every outlet box, cabinet, or fitting.
Question 7: In a commercial dwelling unit or residential kitchen, GFCI
protection is required by NEC Article 210.8 for all 15- and 20-ampere,
125-volt receptacles installed in which location?
• A) Bathrooms only
• B) Bathrooms, kitchens, and rooftops
• C) Bathrooms, kitchens, rooftops, outdoors, and within 6 feet of
the outside edge of a sink
• D) All indoor areas regardless of sink proximity
Correct Answer: C
Rationale: NEC 210.8 expands GFCI requirements to include bathrooms,
kitchens, rooftops, outdoors, and indoor areas within 6 feet of sinks.
Question 8: Under NEC Article 250, what is the minimum size grounding
electrode conductor (GEC) required when connecting to a concrete-
encased electrode (Ufer ground) made of reinforcing steel, regardless of
the size of the service-entrance conductors?
• A) 8 AWG copper
• B) 6 AWG copper
• C) 4 AWG copper
• D) 2 AWG copper
Correct Answer: B
