CSLB-ELECTRICAL CONTRACTOR EXAM (C-10) LAW & BUSINESS
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QUESTIONS AND ANSWERS 2026/2027 | VERIFIED ANSWERS
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1. Under California license law, what is the maximum initial down payment a licensed
electrical contractor can legally request from a residential homeowner on a $12,000 panel
upgrade contract?
A. $1,000 or 10% of the contract price, whichever is less
B. $1,200 representing 10% of the total project cost
C. $3,600 representing 30% of the contract value
D. $500 or 10% of the contract price, whichever is greater
Under California Business and Professions Code Section 7159 (Home Improvement Contracts),
down payments are strictly limited to $1,000 or 10% of the contract amount, whichever
amount is smaller, regardless of the overall cost of the residential scope.
2. A C-10 contractor hires a journey-level electrician as an employee. According to
California Labor Code requirements, when must the worker be provided with a formal
wage notice specifying their regular pay rate?
A. Upon completion of the first payroll cycle
B. At the time of hire before commencing work
C. Within 30 days after performing field labor
D. On the date the first paycheck is distributed
California Labor Code Section 2810.5 requires employers to furnish a written wage notice
detailing pay rates, allowances, and payday schedules at the time of hire prior to initiating
duties.
3. An electrician is sizing a noncontinuous branch circuit for a single-phase resistive heater
rated at 4,800 watts at 240 volts. What is the minimum overcurrent protective device rating
required?
A. 20 amperes
B. 25 amperes
C. 30 amperes
D. 40 amperes
,Current equals power divided by voltage: 4,800W / 240V = 20A. Because the load is
noncontinuous, the overcurrent device is sized at 100% of the load rating, which yields 20
amperes.
4. According to the CSLB rules, within how many days must a licensed contractor notify
the Registrar of Contractors after a change in business address occurs?
A. 15 days
B. 30 days
C. 45 days
D. 90 days
California Business and Professions Code Section 7083 dictates that any change in business
address, name, or personnel must be reported to the CSLB Registrar within 30 days.
5. What minimum size copper equipment grounding conductor is required for a branch
circuit protected by a 60-ampere circuit breaker supplying an industrial motor?
A. 12 AWG
B. 10 AWG
C. 8 AWG
D. 6 AWG
Per NEC Table 250.122, a 60-ampere overcurrent protective device requires a minimum 10
AWG copper equipment grounding conductor.
6. Under Cal/OSHA regulations, workers operating on scaffolding elevated above what
height must be protected by standard guardrails or personal fall arrest systems?
A. 4 feet
B. 6 feet
C. 7.5 feet
D. 10 feet
Cal/OSHA Construction Safety Orders (Title 8, Section 1621/1637) establish that scaffolding
platforms 7.5 feet or higher above the ground require fall protection measures such as
guardrails.
7. A project owner refuses to pay the final progress billing of $15,000 to a C-10 contractor
without justification. What is the deadline for filing a Mechanics Lien on a non-recorded
project after actual completion?
A. 30 days
B. 60 days
C. 90 days
,D. 120 days
Under California Civil Code, if no Notice of Completion or Notice of Cessation is recorded, all
prime contractors and subcontractors have 90 days from project completion to file a
Mechanics Lien.
8. Which continuous current rating multiplier must be applied to branch circuit
conductors feeding a continuous commercial lighting load expected to run for 3 hours or
more?
A. 100%
B. 115%
C. 125%
D. 135%
NEC Article 210.19(A)(1) specifies that branch circuit conductors supplying continuous loads
must be sized at 125% of the continuous load plus 100% of noncontinuous loads.
9. If a prime contractor sends a Preliminary 20-Day Notice late on a commercial retrofit
job, from what point does the lien right coverage start?
A. It invalidates all lien rights for the entire job
B. 20 days prior to the date the notice was actually served
C. On the day the contractor signed the original agreement
D. 20 days following project completion
Under California Civil Code Section 8200, serving a late preliminary notice preserves lien rights
exclusively for labor, materials, and services provided during the 20 days prior to notice
service and thereafter.
10. What is the maximum distance allowable between supports for 1-inch Rigid Metal
Conduit (RMC) installed along a straight electrical run?
A. 6 feet
B. 8 feet
C. 10 feet
D. 12 feet
NEC Table 344.30(B)(2) establishes that 1-inch Rigid Metal Conduit must be supported at
intervals not exceeding 10 feet along straight structural runs.
11. Under California mechanics lien law, a Preliminary 20-Day Notice must be served to
which parties on a private construction project?
A. Owner, direct contractor, and construction lender
, B. Owner, CSLB Registrar, and local building department
C. City inspector, architect, and prime contractor
D. Material supplier, owner, and general liability insurer
California Civil Code Section 8200 specifies that subcontractors and suppliers must serve the
Preliminary 20-Day Notice to the property owner, direct contractor, and construction lender
to protect lien rights.
12. When calculating feeder demand loads for residential electric ranges rated over 1.75
kW, which NEC section table governs the demand factors?
A. Table 220.42
B. Table 220.55
C. Table 310.16
D. Table 250.66
NEC Table 220.55 provides the precise demand factors and loads for household electric
ranges, wall-mounted ovens, and counter-mounted cooking units.
13. A C-10 contractor defaults on an electrical installation project. What bond covers
direct financial damages suffered by the property owner due to non-performance?
A. Contractor’s License Bond
B. Payment Bond
C. Performance Bond
D. Bid Bond
A Performance Bond guarantees that the surety will compensate the project owner or finish
the scope of work if the contractor defaults on contract obligations.
14. What minimum clearance must be maintained in front of an 480V electrical
switchboard (Condition 2: exposed live parts on one side and grounded parts on the
other)?
A. 3.0 feet
B. 3.5 feet
C. 4.0 feet
D. 4.5 feet
NEC Table 110.26(A)(1) specifies Condition 2 clear working space requirements for 151V–600V
nominal installations as 3.5 feet.
15. Under the California Workers' Compensation laws, when must a licensed contractor
carry workers' compensation insurance?
A. Only when employing more than 5 workers
+ TRADE QUESTIONS AND ANSWERS| EXAM PREP |ALL
QUESTIONS AND ANSWERS 2026/2027 | VERIFIED ANSWERS
PLUS RATIONALES | GRADED Q&A COMPREHENSIVE STUDY
GUIDE | VERIFIED LATEST 2027
1. Under California license law, what is the maximum initial down payment a licensed
electrical contractor can legally request from a residential homeowner on a $12,000 panel
upgrade contract?
A. $1,000 or 10% of the contract price, whichever is less
B. $1,200 representing 10% of the total project cost
C. $3,600 representing 30% of the contract value
D. $500 or 10% of the contract price, whichever is greater
Under California Business and Professions Code Section 7159 (Home Improvement Contracts),
down payments are strictly limited to $1,000 or 10% of the contract amount, whichever
amount is smaller, regardless of the overall cost of the residential scope.
2. A C-10 contractor hires a journey-level electrician as an employee. According to
California Labor Code requirements, when must the worker be provided with a formal
wage notice specifying their regular pay rate?
A. Upon completion of the first payroll cycle
B. At the time of hire before commencing work
C. Within 30 days after performing field labor
D. On the date the first paycheck is distributed
California Labor Code Section 2810.5 requires employers to furnish a written wage notice
detailing pay rates, allowances, and payday schedules at the time of hire prior to initiating
duties.
3. An electrician is sizing a noncontinuous branch circuit for a single-phase resistive heater
rated at 4,800 watts at 240 volts. What is the minimum overcurrent protective device rating
required?
A. 20 amperes
B. 25 amperes
C. 30 amperes
D. 40 amperes
,Current equals power divided by voltage: 4,800W / 240V = 20A. Because the load is
noncontinuous, the overcurrent device is sized at 100% of the load rating, which yields 20
amperes.
4. According to the CSLB rules, within how many days must a licensed contractor notify
the Registrar of Contractors after a change in business address occurs?
A. 15 days
B. 30 days
C. 45 days
D. 90 days
California Business and Professions Code Section 7083 dictates that any change in business
address, name, or personnel must be reported to the CSLB Registrar within 30 days.
5. What minimum size copper equipment grounding conductor is required for a branch
circuit protected by a 60-ampere circuit breaker supplying an industrial motor?
A. 12 AWG
B. 10 AWG
C. 8 AWG
D. 6 AWG
Per NEC Table 250.122, a 60-ampere overcurrent protective device requires a minimum 10
AWG copper equipment grounding conductor.
6. Under Cal/OSHA regulations, workers operating on scaffolding elevated above what
height must be protected by standard guardrails or personal fall arrest systems?
A. 4 feet
B. 6 feet
C. 7.5 feet
D. 10 feet
Cal/OSHA Construction Safety Orders (Title 8, Section 1621/1637) establish that scaffolding
platforms 7.5 feet or higher above the ground require fall protection measures such as
guardrails.
7. A project owner refuses to pay the final progress billing of $15,000 to a C-10 contractor
without justification. What is the deadline for filing a Mechanics Lien on a non-recorded
project after actual completion?
A. 30 days
B. 60 days
C. 90 days
,D. 120 days
Under California Civil Code, if no Notice of Completion or Notice of Cessation is recorded, all
prime contractors and subcontractors have 90 days from project completion to file a
Mechanics Lien.
8. Which continuous current rating multiplier must be applied to branch circuit
conductors feeding a continuous commercial lighting load expected to run for 3 hours or
more?
A. 100%
B. 115%
C. 125%
D. 135%
NEC Article 210.19(A)(1) specifies that branch circuit conductors supplying continuous loads
must be sized at 125% of the continuous load plus 100% of noncontinuous loads.
9. If a prime contractor sends a Preliminary 20-Day Notice late on a commercial retrofit
job, from what point does the lien right coverage start?
A. It invalidates all lien rights for the entire job
B. 20 days prior to the date the notice was actually served
C. On the day the contractor signed the original agreement
D. 20 days following project completion
Under California Civil Code Section 8200, serving a late preliminary notice preserves lien rights
exclusively for labor, materials, and services provided during the 20 days prior to notice
service and thereafter.
10. What is the maximum distance allowable between supports for 1-inch Rigid Metal
Conduit (RMC) installed along a straight electrical run?
A. 6 feet
B. 8 feet
C. 10 feet
D. 12 feet
NEC Table 344.30(B)(2) establishes that 1-inch Rigid Metal Conduit must be supported at
intervals not exceeding 10 feet along straight structural runs.
11. Under California mechanics lien law, a Preliminary 20-Day Notice must be served to
which parties on a private construction project?
A. Owner, direct contractor, and construction lender
, B. Owner, CSLB Registrar, and local building department
C. City inspector, architect, and prime contractor
D. Material supplier, owner, and general liability insurer
California Civil Code Section 8200 specifies that subcontractors and suppliers must serve the
Preliminary 20-Day Notice to the property owner, direct contractor, and construction lender
to protect lien rights.
12. When calculating feeder demand loads for residential electric ranges rated over 1.75
kW, which NEC section table governs the demand factors?
A. Table 220.42
B. Table 220.55
C. Table 310.16
D. Table 250.66
NEC Table 220.55 provides the precise demand factors and loads for household electric
ranges, wall-mounted ovens, and counter-mounted cooking units.
13. A C-10 contractor defaults on an electrical installation project. What bond covers
direct financial damages suffered by the property owner due to non-performance?
A. Contractor’s License Bond
B. Payment Bond
C. Performance Bond
D. Bid Bond
A Performance Bond guarantees that the surety will compensate the project owner or finish
the scope of work if the contractor defaults on contract obligations.
14. What minimum clearance must be maintained in front of an 480V electrical
switchboard (Condition 2: exposed live parts on one side and grounded parts on the
other)?
A. 3.0 feet
B. 3.5 feet
C. 4.0 feet
D. 4.5 feet
NEC Table 110.26(A)(1) specifies Condition 2 clear working space requirements for 151V–600V
nominal installations as 3.5 feet.
15. Under the California Workers' Compensation laws, when must a licensed contractor
carry workers' compensation insurance?
A. Only when employing more than 5 workers
