EXAM Newest (2026 Update) Actual Practice
Questions – Set 100 Most Common Exam
Questions And Answers In Details 100%
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1. A 120/240V single-phase panelboard is supplied by a feeder. What is the
minimum size copper grounding electrode conductor required when
connected to a concrete-encased electrode for a 200A service?
A. 8 AWG
B. 6 AWG
C. 4 AWG
D. 2 AWG
Answer: ✔ B. 6 AWG
Rationale: According to standard grounding electrode conductor sizing rules, a
200A service typically requires a minimum 6 AWG copper conductor when
connected to a concrete-encased electrode.
2. What is the maximum number of 12 AWG THHN conductors allowed in a
3/4-inch EMT conduit?
A. 16
B. 22
C. 26
D. 30
Answer: ✔ B. 22
Rationale: Based on conduit fill calculations, 3/4-inch EMT allows up to 22
conductors of 12 AWG THHN at 40% fill.
, 3. A motor draws 28 amps at full load. What is the minimum size inverse-time
circuit breaker permitted?
A. 30A
B. 35A
C. 40A
D. 50A
Answer: ✔ C. 40A
Rationale: Motor circuit protection typically allows up to 250% of full-load
current; the next standard breaker size is 40A.
4. In a dwelling unit, what is the required minimum number of 20A small
appliance branch circuits in the kitchen?
A. 1
B. 2
C. 3
D. 4
Answer: ✔ B. 2
Rationale: NEC requires at least two 20A small appliance branch circuits for
kitchen countertop receptacles.
5. What is the voltage drop recommendation for branch circuits to ensure
efficiency?
A. 2%
B. 3%
C. 5%
D. 7%
,Answer: ✔ B. 3%
Rationale: NEC informational notes recommend a maximum of 3% voltage drop
for branch circuits.
6. A transformer is rated 10 kVA, 240V primary. What is the full-load primary
current?
A. 30.2A
B. 41.7A
C. 50.0A
D. 60.4A
Answer: ✔ B. 41.7A
Rationale: I = VA/V = 10,000/240 = 41.7A.
7. What is the minimum burial depth for a PVC conduit carrying residential
branch circuits under a driveway?
A. 12 inches
B. 18 inches
C. 24 inches
D. 36 inches
Answer: ✔ C. 24 inches
Rationale: NEC requires 24 inches minimum cover for PVC under residential
driveways.
8. What type of grounding system uses a separate conductor to bond all metal
enclosures?
A. TT system
B. TN-C system
C. Equipment grounding system
D. Floating system
, Answer: ✔ C. Equipment grounding system
Rationale: Equipment grounding systems use a dedicated grounding conductor
for all metal parts.
9. The maximum number of disconnects permitted for a service is:
A. 3
B. 4
C. 6
D. 8
Answer: ✔ C. 6
Rationale: NEC allows up to six service disconnects in one enclosure or group.
10.What is the ampacity of 4 AWG copper THHN at 75°C?
A. 85A
B. 95A
C. 105A
D. 125A
Answer: ✔ C. 105A
Rationale: 4 AWG copper THHN is rated 105A at 75°C termination rating.
11.A receptacle installed within 6 feet of a sink must be protected by:
A. AFCI only
B. GFCI only
C. Surge protection
D. Overcurrent protection only
Answer: ✔ B. GFCI only
Rationale: NEC requires GFCI protection for receptacles near sinks.