CALIFORNIA ELECTRICAL
CONTRACTOR LICENSE EXAM
C-10 • Comprehensive Practice Paper
200 Multiple-Choice Practice Questions
Includes four answer options per question, a correct answer, and a concise rationale for review.
Important notice
This is original educational practice material, not an official CSLB examination, not a reproduction of official
questions, and not legal advice. Electrical work must comply with the currently adopted codes, applicable permits,
manufacturer instructions, and local authority requirements.
Suggested use: answer the questions first, then review the answer and rationale section. Verify code-specific
details against current authoritative requirements.
California Electrical Contractor License Exam (C-10) | Original Practice Material Page 1
, SECTION I — PRACTICE QUESTIONS
Select the single best answer for each question.
1. [Electrical Safety] Before servicing equipment, what is the safest first control for preventing unexpected
energization?
A. Apply lockout/tagout and verify the equipment is de-energized
B. Rely on the wall switch being off
C. Ask a coworker to watch the equipment
D. Wear insulated gloves while leaving it energized
2. [Electrical Safety] Before servicing equipment, what is the safest first control for preventing unexpected
energization? This issue is identified on a commercial tenant-improvement project.
A. Rely on the wall switch being off
B. Ask a coworker to watch the equipment
C. Wear insulated gloves while leaving it energized
D. Apply lockout/tagout and verify the equipment is de-energized
3. [Electrical Safety] An electrician while inspecting a newly installed circuit needs to decide: before servicing
equipment, what is the safest first control for preventing unexpected energization?
A. Ask a coworker to watch the equipment
B. Wear insulated gloves while leaving it energized
C. Apply lockout/tagout and verify the equipment is de-energized
D. Rely on the wall switch being off
4. [Electrical Safety] Which practice is appropriate during maintenance at an occupied building? Before
servicing equipment, what is the safest first control for preventing unexpected energization?
A. Wear insulated gloves while leaving it energized
B. Apply lockout/tagout and verify the equipment is de-energized
C. Rely on the wall switch being off
D. Ask a coworker to watch the equipment
5. [Electrical Safety] A worker discovers a damaged extension cord with exposed conductors. What should
happen?
A. Wrap it with ordinary tape and continue using it
B. Use it only for low-current tools
C. Place it under a mat to protect it
D. Remove it from service and arrange proper repair or replacement
6. [Electrical Safety] A worker discovers a damaged extension cord with exposed conductors. What should
happen? This issue is identified on a commercial tenant-improvement project.
A. Use it only for low-current tools
B. Place it under a mat to protect it
C. Remove it from service and arrange proper repair or replacement
D. Wrap it with ordinary tape and continue using it
California Electrical Contractor License Exam (C-10) | Original Practice Material Page 2
, 7. [Electrical Safety] An electrician while inspecting a newly installed circuit needs to decide: a worker discovers
a damaged extension cord with exposed conductors. What should happen?
A. Place it under a mat to protect it
B. Remove it from service and arrange proper repair or replacement
C. Wrap it with ordinary tape and continue using it
D. Use it only for low-current tools
8. [Electrical Safety] Which practice is appropriate during maintenance at an occupied building? A worker
discovers a damaged extension cord with exposed conductors. What should happen?
A. Remove it from service and arrange proper repair or replacement
B. Wrap it with ordinary tape and continue using it
C. Use it only for low-current tools
D. Place it under a mat to protect it
9. [Electrical Safety] What is the primary purpose of a GFCI?
A. To increase the circuit's voltage
B. To replace equipment grounding conductors
C. To interrupt a circuit when it detects an imbalance indicating current leakage
D. To protect motors from every overload
10. [Electrical Safety] What is the primary purpose of a GFCI? This issue is identified on a commercial
tenant-improvement project.
A. To replace equipment grounding conductors
B. To interrupt a circuit when it detects an imbalance indicating current leakage
C. To protect motors from every overload
D. To increase the circuit's voltage
11. [Electrical Safety] An electrician while inspecting a newly installed circuit needs to decide: what is the
primary purpose of a GFCI?
A. To interrupt a circuit when it detects an imbalance indicating current leakage
B. To protect motors from every overload
C. To increase the circuit's voltage
D. To replace equipment grounding conductors
12. [Electrical Safety] Which practice is appropriate during maintenance at an occupied building? What is the
primary purpose of a GFCI?
A. To protect motors from every overload
B. To increase the circuit's voltage
C. To replace equipment grounding conductors
D. To interrupt a circuit when it detects an imbalance indicating current leakage
13. [Electrical Safety] When using a ladder near electrical conductors, which choice is generally safest?
A. Carry long metal stock upright beneath the wires
B. Use a nonconductive ladder and maintain required clearance
C. Use an aluminum ladder for stability
D. Rest the ladder against the conductor enclosure
California Electrical Contractor License Exam (C-10) | Original Practice Material Page 3
, 14. [Electrical Safety] When using a ladder near electrical conductors, which choice is generally safest? This
issue is identified on a commercial tenant-improvement project.
A. Use a nonconductive ladder and maintain required clearance
B. Use an aluminum ladder for stability
C. Rest the ladder against the conductor enclosure
D. Carry long metal stock upright beneath the wires
15. [Electrical Safety] An electrician while inspecting a newly installed circuit needs to decide: when using a
ladder near electrical conductors, which choice is generally safest?
A. Use an aluminum ladder for stability
B. Rest the ladder against the conductor enclosure
C. Carry long metal stock upright beneath the wires
D. Use a nonconductive ladder and maintain required clearance
16. [Electrical Safety] Which practice is appropriate during maintenance at an occupied building? When using a
ladder near electrical conductors, which choice is generally safest?
A. Rest the ladder against the conductor enclosure
B. Carry long metal stock upright beneath the wires
C. Use a nonconductive ladder and maintain required clearance
D. Use an aluminum ladder for stability
17. [Electrical Safety] Why must a circuit be tested after being switched off but before work begins?
A. To confirm the circuit is actually de-energized
B. To identify the building owner
C. To measure paint thickness
D. To eliminate the need for lockout/tagout
18. [Electrical Safety] Why must a circuit be tested after being switched off but before work begins? This issue is
identified on a commercial tenant-improvement project.
A. To identify the building owner
B. To measure paint thickness
C. To eliminate the need for lockout/tagout
D. To confirm the circuit is actually de-energized
19. [Electrical Safety] An electrician while inspecting a newly installed circuit needs to decide: why must a circuit
be tested after being switched off but before work begins?
A. To measure paint thickness
B. To eliminate the need for lockout/tagout
C. To confirm the circuit is actually de-energized
D. To identify the building owner
20. [Electrical Safety] Which practice is appropriate during maintenance at an occupied building? Why must a
circuit be tested after being switched off but before work begins?
A. To eliminate the need for lockout/tagout
B. To confirm the circuit is actually de-energized
C. To identify the building owner
D. To measure paint thickness
California Electrical Contractor License Exam (C-10) | Original Practice Material Page 4
CONTRACTOR LICENSE EXAM
C-10 • Comprehensive Practice Paper
200 Multiple-Choice Practice Questions
Includes four answer options per question, a correct answer, and a concise rationale for review.
Important notice
This is original educational practice material, not an official CSLB examination, not a reproduction of official
questions, and not legal advice. Electrical work must comply with the currently adopted codes, applicable permits,
manufacturer instructions, and local authority requirements.
Suggested use: answer the questions first, then review the answer and rationale section. Verify code-specific
details against current authoritative requirements.
California Electrical Contractor License Exam (C-10) | Original Practice Material Page 1
, SECTION I — PRACTICE QUESTIONS
Select the single best answer for each question.
1. [Electrical Safety] Before servicing equipment, what is the safest first control for preventing unexpected
energization?
A. Apply lockout/tagout and verify the equipment is de-energized
B. Rely on the wall switch being off
C. Ask a coworker to watch the equipment
D. Wear insulated gloves while leaving it energized
2. [Electrical Safety] Before servicing equipment, what is the safest first control for preventing unexpected
energization? This issue is identified on a commercial tenant-improvement project.
A. Rely on the wall switch being off
B. Ask a coworker to watch the equipment
C. Wear insulated gloves while leaving it energized
D. Apply lockout/tagout and verify the equipment is de-energized
3. [Electrical Safety] An electrician while inspecting a newly installed circuit needs to decide: before servicing
equipment, what is the safest first control for preventing unexpected energization?
A. Ask a coworker to watch the equipment
B. Wear insulated gloves while leaving it energized
C. Apply lockout/tagout and verify the equipment is de-energized
D. Rely on the wall switch being off
4. [Electrical Safety] Which practice is appropriate during maintenance at an occupied building? Before
servicing equipment, what is the safest first control for preventing unexpected energization?
A. Wear insulated gloves while leaving it energized
B. Apply lockout/tagout and verify the equipment is de-energized
C. Rely on the wall switch being off
D. Ask a coworker to watch the equipment
5. [Electrical Safety] A worker discovers a damaged extension cord with exposed conductors. What should
happen?
A. Wrap it with ordinary tape and continue using it
B. Use it only for low-current tools
C. Place it under a mat to protect it
D. Remove it from service and arrange proper repair or replacement
6. [Electrical Safety] A worker discovers a damaged extension cord with exposed conductors. What should
happen? This issue is identified on a commercial tenant-improvement project.
A. Use it only for low-current tools
B. Place it under a mat to protect it
C. Remove it from service and arrange proper repair or replacement
D. Wrap it with ordinary tape and continue using it
California Electrical Contractor License Exam (C-10) | Original Practice Material Page 2
, 7. [Electrical Safety] An electrician while inspecting a newly installed circuit needs to decide: a worker discovers
a damaged extension cord with exposed conductors. What should happen?
A. Place it under a mat to protect it
B. Remove it from service and arrange proper repair or replacement
C. Wrap it with ordinary tape and continue using it
D. Use it only for low-current tools
8. [Electrical Safety] Which practice is appropriate during maintenance at an occupied building? A worker
discovers a damaged extension cord with exposed conductors. What should happen?
A. Remove it from service and arrange proper repair or replacement
B. Wrap it with ordinary tape and continue using it
C. Use it only for low-current tools
D. Place it under a mat to protect it
9. [Electrical Safety] What is the primary purpose of a GFCI?
A. To increase the circuit's voltage
B. To replace equipment grounding conductors
C. To interrupt a circuit when it detects an imbalance indicating current leakage
D. To protect motors from every overload
10. [Electrical Safety] What is the primary purpose of a GFCI? This issue is identified on a commercial
tenant-improvement project.
A. To replace equipment grounding conductors
B. To interrupt a circuit when it detects an imbalance indicating current leakage
C. To protect motors from every overload
D. To increase the circuit's voltage
11. [Electrical Safety] An electrician while inspecting a newly installed circuit needs to decide: what is the
primary purpose of a GFCI?
A. To interrupt a circuit when it detects an imbalance indicating current leakage
B. To protect motors from every overload
C. To increase the circuit's voltage
D. To replace equipment grounding conductors
12. [Electrical Safety] Which practice is appropriate during maintenance at an occupied building? What is the
primary purpose of a GFCI?
A. To protect motors from every overload
B. To increase the circuit's voltage
C. To replace equipment grounding conductors
D. To interrupt a circuit when it detects an imbalance indicating current leakage
13. [Electrical Safety] When using a ladder near electrical conductors, which choice is generally safest?
A. Carry long metal stock upright beneath the wires
B. Use a nonconductive ladder and maintain required clearance
C. Use an aluminum ladder for stability
D. Rest the ladder against the conductor enclosure
California Electrical Contractor License Exam (C-10) | Original Practice Material Page 3
, 14. [Electrical Safety] When using a ladder near electrical conductors, which choice is generally safest? This
issue is identified on a commercial tenant-improvement project.
A. Use a nonconductive ladder and maintain required clearance
B. Use an aluminum ladder for stability
C. Rest the ladder against the conductor enclosure
D. Carry long metal stock upright beneath the wires
15. [Electrical Safety] An electrician while inspecting a newly installed circuit needs to decide: when using a
ladder near electrical conductors, which choice is generally safest?
A. Use an aluminum ladder for stability
B. Rest the ladder against the conductor enclosure
C. Carry long metal stock upright beneath the wires
D. Use a nonconductive ladder and maintain required clearance
16. [Electrical Safety] Which practice is appropriate during maintenance at an occupied building? When using a
ladder near electrical conductors, which choice is generally safest?
A. Rest the ladder against the conductor enclosure
B. Carry long metal stock upright beneath the wires
C. Use a nonconductive ladder and maintain required clearance
D. Use an aluminum ladder for stability
17. [Electrical Safety] Why must a circuit be tested after being switched off but before work begins?
A. To confirm the circuit is actually de-energized
B. To identify the building owner
C. To measure paint thickness
D. To eliminate the need for lockout/tagout
18. [Electrical Safety] Why must a circuit be tested after being switched off but before work begins? This issue is
identified on a commercial tenant-improvement project.
A. To identify the building owner
B. To measure paint thickness
C. To eliminate the need for lockout/tagout
D. To confirm the circuit is actually de-energized
19. [Electrical Safety] An electrician while inspecting a newly installed circuit needs to decide: why must a circuit
be tested after being switched off but before work begins?
A. To measure paint thickness
B. To eliminate the need for lockout/tagout
C. To confirm the circuit is actually de-energized
D. To identify the building owner
20. [Electrical Safety] Which practice is appropriate during maintenance at an occupied building? Why must a
circuit be tested after being switched off but before work begins?
A. To eliminate the need for lockout/tagout
B. To confirm the circuit is actually de-energized
C. To identify the building owner
D. To measure paint thickness
California Electrical Contractor License Exam (C-10) | Original Practice Material Page 4
