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Rationales 2026 Q&A | Instant Download Pdf
1. According to the National Electrical Code (NEC), what is the
primary purpose of grounding electrical systems?
A. To increase voltage output
B. To limit voltage imposed by lightning, line surges, and unintentional
contact with higher-voltage lines while stabilizing system voltage
C. To reduce conductor resistance
D. To eliminate the need for overcurrent protection
Rationale: Grounding serves several critical safety functions. It
stabilizes voltage during normal operation and limits excessive
voltages caused by lightning, surges, or accidental contact with
,higher-voltage conductors. Grounding also helps facilitate the
operation of overcurrent protective devices during faults but does not
replace them.
2. What is the minimum cover required for Schedule 80 PVC conduit
installed under a residential driveway?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
Rationale: NEC Table 300.5 specifies minimum cover requirements for
underground installations. For residential driveways with PVC conduit,
the required cover is generally 18 inches unless a specific exception
applies.
, 3. Which conductor is intentionally connected to earth at the service
equipment?
A. Equipment grounding conductor
B. Grounding electrode conductor
C. Grounded (neutral) conductor
D. Bonding jumper
Rationale: The grounded conductor, commonly referred to as the
neutral, is connected to the grounding electrode system at the service
disconnect. This establishes a reference to earth and allows effective
operation of protective devices.
4. What color insulation is typically used to identify an equipment
grounding conductor?
A. White
B. Gray
, C. Red
D. Green or bare
Rationale: NEC requires equipment grounding conductors to be
identified by green insulation, green with yellow stripes, or left bare.
White and gray are reserved for grounded conductors.
5. A branch circuit supplying continuous loads must have overcurrent
protection rated at least:
A. 100% of the load
B. 110% of the load
C. 120% of the load
D. 125% of the continuous load
Rationale: Continuous loads are expected to operate for three hours or
more. NEC requires branch-circuit overcurrent devices to be sized at
not less than 125% of the continuous load to prevent nuisance tripping
and overheating.