Examination — Local Jurisdiction
Practice Exam 2026 | 100 Questions &
Answers with Detailed Rationales |
Complete Exam Prep & Study Guide
1. A 120/240-volt single-phase dwelling service has a calculated load of 145
amperes. What is the minimum standard service rating that can be selected
when all other service requirements are satisfied?
A. 125 A
B. 140 A
C. 150 A
D. 175 A
Answer: 150 A
Rationale: A service rating must not be less than the calculated load. Where
standard ratings are applicable, the next standard size above 145 A is 150 A.
, 2. A continuous load is calculated at 32 amperes. What is the minimum
conductor ampacity required before applying any other adjustment or
correction factors?
A. 32 A
B. 40 A
C. 35 A
D. 45 A
Answer: 40 A
Rationale: Continuous loads are generally calculated at 125 percent. 32 × 1.25 =
40 amperes.
3. A branch circuit supplies a 4,800-watt, 240-volt resistance heater that
operates continuously. What is the minimum circuit ampacity?
A. 20 A
B. 25 A
C. 25 A
D. 30 A
Answer: 25 A
Rationale: The heater draws 4,800 ÷ 240 = 20 A. Applying 125 percent for
continuous operation gives 25 A.
4. Which conductor is normally permitted as an equipment grounding
conductor when installed in accordance with the NEC?
A. Aluminum only
B. Copper only
C. Copper or aluminum, where permitted by the applicable installation
requirements
D. Steel building framing only
Answer: Copper or aluminum, where permitted by the applicable installation
requirements
,Rationale: Equipment grounding conductors may be copper, aluminum, or
copper-clad aluminum when properly sized and installed for the conditions of
use.
5. A 120-volt branch circuit has a line-to-neutral voltage drop of 3.6 volts.
What is the approximate percentage voltage drop?
A. 2 percent
B. 3 percent
C. 4 percent
D. 5 percent
Answer: 3 percent
Rationale: Voltage-drop percentage equals voltage drop divided by circuit
voltage. 3.6 ÷ 120 × 100 = 3 percent.
6. What is the primary purpose of bonding metal parts that are not intended
to carry current?
A. Increase operating voltage
B. Reduce conductor resistance
C. Provide an effective fault-current path
D. Increase normal load current
Answer: Provide an effective fault-current path
Rationale: Bonding connects normally non-current-carrying metal parts so a
fault can return sufficient current to operate the overcurrent protective device.
7. A 20-ampere, 120-volt general-purpose branch circuit supplies receptacles
in a dwelling. Which conductor size is normally permitted for the circuit?
A. 16 AWG copper
B. 18 AWG copper
C. 12 AWG copper
D. 14 AWG copper
, Answer: 12 AWG copper
Rationale: A 20-ampere branch circuit generally requires conductors with an
ampacity of at least 20 amperes; 12 AWG copper is the standard general-
purpose choice.
8. What is the primary function of a circuit breaker?
A. Regulate power factor
B. Increase circuit voltage
C. Interrupt current when an overcurrent condition occurs
D. Maintain constant load resistance
Answer: Interrupt current when an overcurrent condition occurs
Rationale: Circuit breakers protect conductors and equipment by opening the
circuit when current exceeds their permitted operating limits.
9. A 240-volt single-phase load draws 18 amperes. Approximately how much
power does it consume at unity power factor?
A. 2,160 W
B. 4,320 W
C. 7,680 W
D. 240 W
Answer: 4,320 W
Rationale: For a single-phase resistive load, P = E × I. Therefore, 240 × 18 = 4,320
watts.
10.Which NEC article primarily addresses grounding and bonding?
A. Article 250
B. Article 300
C. Article 250
D. Article 430