CSLB C10 Test 1 | 150 Questions with
100% Correct Answers QUESTIONS AND
CORRECT ANSWERS LATEST UPDATE
2
1. What is the minimum number of receptacles required in a residential garage?
b ................................................................................ Error! Bookmark not defined.
c .............................................................................................................................. 6
d ............................................................................................................................. 6
a. 0
Answer: b. 1
Rationale: The National Electrical Code (NEC) requires at least one receptacle
outlet in a residential garage for general use. This ensures access to power for
tools, equipment, and other household needs in this frequently used area.
2. Mobile home service equipment shall be line of sight and no more than
_____ from the exterior wall of the home. a. 15 feet
b. 30 feet
c. 50 feet
d. 100 feet Answer: b. 30 feet
Rationale: This distance limitation ensures quick access to the service disconnect in
case of emergency and compliance with mobile home installation requirements.
The line-of-sight requirement allows the occupant to see the disconnect from the
home exterior.
,3. If a service conductor is over 300V but less than 600V, what is the minimum
clearance when running in residential and commercial areas not subject to
traffic?
a. 10 feet
b. 12 feet
c. 15 feet
d. 18 feet
Answer: c. 15 feet
Rationale: Higher voltage conductors require greater clearance to protect
pedestrians and vehicles from accidental contact. The NEC specifies increased
clearances as voltage increases to account for greater shock and arc-flash
hazards.
4. A power meter must be a minimum of _____ feet away from any door, gas
meter, or window opening.
a. 1 foot
b. 3 feet
c. 5 feet
d. 10 feet
Answer: b. 3 feet
Rationale: This clearance prevents interference with access, reduces fire risk near
gas meters, and maintains safe working space. It also ensures that meter readers
and maintenance personnel have adequate room to perform their duties safely.
5. A rod-type grounding electrode should have a minimum diameter of _____.
a. 1/2 inch
b. 5/8 inch
c. 3/4 inch
d. 1 inch
Answer: b. 5/8 inch
, Rationale: The NEC specifies this minimum diameter to ensure sufficient durability
and conductivity for effective grounding. Smaller rods may not withstand driving
forces or provide adequate surface area for ground contact.
6. A grounding electrode must be in contact with soil a minimum of _____.
a. 4 feet
b. 6 feet
c. 8 feet
d. 10 feet Answer: c. 8 feet
Rationale: This depth ensures the electrode reaches sufficient soil moisture for
adequate grounding, regardless of surface conditions. Deeper soil layers maintain
more consistent moisture levels year-round, providing more stable grounding
resistance.
7. If a raceway has various conductors from different systems, how often
should you group each system separately? a. Every 3 feet
b. Every 6 feet
c. Every 10 feet
d. Every 12 feet Answer: b. Every 6 feet
Rationale: Regular grouping prevents inductive interference, maintains
organization, and ensures safe identification during maintenance. This
requirement helps workers quickly identify which conductors belong to which
system when opening raceways or junction boxes.
8. What is the maximum distance a service conductor can run over a roof? a.
3 feet
b. 6 feet
c. 10 feet
100% Correct Answers QUESTIONS AND
CORRECT ANSWERS LATEST UPDATE
2
1. What is the minimum number of receptacles required in a residential garage?
b ................................................................................ Error! Bookmark not defined.
c .............................................................................................................................. 6
d ............................................................................................................................. 6
a. 0
Answer: b. 1
Rationale: The National Electrical Code (NEC) requires at least one receptacle
outlet in a residential garage for general use. This ensures access to power for
tools, equipment, and other household needs in this frequently used area.
2. Mobile home service equipment shall be line of sight and no more than
_____ from the exterior wall of the home. a. 15 feet
b. 30 feet
c. 50 feet
d. 100 feet Answer: b. 30 feet
Rationale: This distance limitation ensures quick access to the service disconnect in
case of emergency and compliance with mobile home installation requirements.
The line-of-sight requirement allows the occupant to see the disconnect from the
home exterior.
,3. If a service conductor is over 300V but less than 600V, what is the minimum
clearance when running in residential and commercial areas not subject to
traffic?
a. 10 feet
b. 12 feet
c. 15 feet
d. 18 feet
Answer: c. 15 feet
Rationale: Higher voltage conductors require greater clearance to protect
pedestrians and vehicles from accidental contact. The NEC specifies increased
clearances as voltage increases to account for greater shock and arc-flash
hazards.
4. A power meter must be a minimum of _____ feet away from any door, gas
meter, or window opening.
a. 1 foot
b. 3 feet
c. 5 feet
d. 10 feet
Answer: b. 3 feet
Rationale: This clearance prevents interference with access, reduces fire risk near
gas meters, and maintains safe working space. It also ensures that meter readers
and maintenance personnel have adequate room to perform their duties safely.
5. A rod-type grounding electrode should have a minimum diameter of _____.
a. 1/2 inch
b. 5/8 inch
c. 3/4 inch
d. 1 inch
Answer: b. 5/8 inch
, Rationale: The NEC specifies this minimum diameter to ensure sufficient durability
and conductivity for effective grounding. Smaller rods may not withstand driving
forces or provide adequate surface area for ground contact.
6. A grounding electrode must be in contact with soil a minimum of _____.
a. 4 feet
b. 6 feet
c. 8 feet
d. 10 feet Answer: c. 8 feet
Rationale: This depth ensures the electrode reaches sufficient soil moisture for
adequate grounding, regardless of surface conditions. Deeper soil layers maintain
more consistent moisture levels year-round, providing more stable grounding
resistance.
7. If a raceway has various conductors from different systems, how often
should you group each system separately? a. Every 3 feet
b. Every 6 feet
c. Every 10 feet
d. Every 12 feet Answer: b. Every 6 feet
Rationale: Regular grouping prevents inductive interference, maintains
organization, and ensures safe identification during maintenance. This
requirement helps workers quickly identify which conductors belong to which
system when opening raceways or junction boxes.
8. What is the maximum distance a service conductor can run over a roof? a.
3 feet
b. 6 feet
c. 10 feet
