CSLB C10 Test 1 | 120 Exam Questions And Correct Answers (Verified
Answers) Plus Rationales 2026/2027 Q&A | Instant Download Pdf
QUESTION 1: According to the National Electrical Code (NEC), what is
the maximum number of quarter bends (90-degree turns) allowed in a
single conduit run between pull points or outlet boxes?
• A) Two quarter bends (180 degrees total)
• B) Three quarter bends (270 degrees total)
• C) Four quarter bends (360 degrees total)
• D) Five quarter bends (450 degrees total)
Correct Answer: C
Rationale: The NEC limits conduit bends between pull points to a
maximum of 360 degrees total (four 90-degree equivalent quarter
bends) to allow safe wire pulling without jacket damage.
QUESTION 2: 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 in a
residential service fed with 2/300 kcmil copper service-entrance
conductors?
• A) 8 AWG copper
• B) 6 AWG copper
• C) 4 AWG copper
• D) 2 AWG copper
,Correct Answer: B
Rationale: Per NEC Table 250.66, a concrete-encased electrode (Ufer
ground) is never required to be larger than 6 AWG copper, regardless of
the size of the service-entrance conductors.
QUESTION 3: In accordance with California Business and Professions
Code Section 7028, what is the penalty for a first-offense conviction of
contracting without a license in California?
• A) A written warning and mandatory compliance seminar
• B) A misdemeanor charge with a fine up to $5,000, potential
county jail time, or both
• C) A mandatory 5-year ban from ever applying for any state
business license
• D) A civil penalty of exactly $500 payable to the CSLB
Correct Answer: B
Rationale: Contracting without a license in California is a misdemeanor
under B&P Code 7028, carrying fines up to $5,000 and/or county jail
time for a first offense.
QUESTION 4: When installing Electrical Metallic Tubing (EMT), what is
the maximum distance allowed by NEC Article 358 between secure
fastenings/supports from an enclosure, cabinet, or box?
• A) Within 1 foot
• B) Within 3 feet
• C) Within 5 feet
• D) Within 10 feet
,Correct Answer: B
Rationale: NEC 358.30(A) requires EMT to be securely fastened within 3
feet of each outlet box, junction box, cabinet, or other conduit
termination, and every 10 feet thereafter.
QUESTION 5: 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 6: What is the minimum depth required by NEC Table 300.5
for direct burial UF cable installed under a residential driveway with no
concrete slab protection?
• A) 6 inches
• B) 12 inches
• C) 18 inches
• D) 24 inches
Correct Answer: D
, Rationale: NEC Table 300.5 specifies a minimum burial depth of 24
inches for direct-burial cables passing under buildings or driveways
subjected to vehicular traffic.
QUESTION 7: 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 8: In a commercial dwelling unit, GFCI protection is required
by NEC Article 210.8 for all 15- and 20-ampere, 125-volt receptacles
installed in which of the following locations?
• 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
Answers) Plus Rationales 2026/2027 Q&A | Instant Download Pdf
QUESTION 1: According to the National Electrical Code (NEC), what is
the maximum number of quarter bends (90-degree turns) allowed in a
single conduit run between pull points or outlet boxes?
• A) Two quarter bends (180 degrees total)
• B) Three quarter bends (270 degrees total)
• C) Four quarter bends (360 degrees total)
• D) Five quarter bends (450 degrees total)
Correct Answer: C
Rationale: The NEC limits conduit bends between pull points to a
maximum of 360 degrees total (four 90-degree equivalent quarter
bends) to allow safe wire pulling without jacket damage.
QUESTION 2: 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 in a
residential service fed with 2/300 kcmil copper service-entrance
conductors?
• A) 8 AWG copper
• B) 6 AWG copper
• C) 4 AWG copper
• D) 2 AWG copper
,Correct Answer: B
Rationale: Per NEC Table 250.66, a concrete-encased electrode (Ufer
ground) is never required to be larger than 6 AWG copper, regardless of
the size of the service-entrance conductors.
QUESTION 3: In accordance with California Business and Professions
Code Section 7028, what is the penalty for a first-offense conviction of
contracting without a license in California?
• A) A written warning and mandatory compliance seminar
• B) A misdemeanor charge with a fine up to $5,000, potential
county jail time, or both
• C) A mandatory 5-year ban from ever applying for any state
business license
• D) A civil penalty of exactly $500 payable to the CSLB
Correct Answer: B
Rationale: Contracting without a license in California is a misdemeanor
under B&P Code 7028, carrying fines up to $5,000 and/or county jail
time for a first offense.
QUESTION 4: When installing Electrical Metallic Tubing (EMT), what is
the maximum distance allowed by NEC Article 358 between secure
fastenings/supports from an enclosure, cabinet, or box?
• A) Within 1 foot
• B) Within 3 feet
• C) Within 5 feet
• D) Within 10 feet
,Correct Answer: B
Rationale: NEC 358.30(A) requires EMT to be securely fastened within 3
feet of each outlet box, junction box, cabinet, or other conduit
termination, and every 10 feet thereafter.
QUESTION 5: 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 6: What is the minimum depth required by NEC Table 300.5
for direct burial UF cable installed under a residential driveway with no
concrete slab protection?
• A) 6 inches
• B) 12 inches
• C) 18 inches
• D) 24 inches
Correct Answer: D
, Rationale: NEC Table 300.5 specifies a minimum burial depth of 24
inches for direct-burial cables passing under buildings or driveways
subjected to vehicular traffic.
QUESTION 7: 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 8: In a commercial dwelling unit, GFCI protection is required
by NEC Article 210.8 for all 15- and 20-ampere, 125-volt receptacles
installed in which of the following locations?
• 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
