Construction Electrical Systems in Construction

Question 1

What is the standard voltage for most residential electrical service in the United States?

Accepted Answer

120/240V single-phase

Answer

120/208V three-phase

Answer

277/480V three-phase

Answer

240/480V single-phase

Question 2

Which wire color is used for the grounding conductor in standard US residential wiring?

Accepted Answer

Green or bare copper

Answer

White

Answer

Black

Answer

Red

Question 3

What does GFCI stand for in electrical construction?

Accepted Answer

Ground Fault Circuit Interrupter

Answer

General Fault Current Indicator

Answer

Ground Fault Current Insulator

Answer

General Fault Circuit Isolator

Question 4

According to the NEC, what is the maximum number of current-carrying conductors in a conduit before derating is required?

Accepted Answer

3

Answer

2

Answer

4

Answer

6

Question 5

What type of conduit is most commonly used outdoors and in wet locations for commercial construction?

Accepted Answer

PVC (Rigid Nonmetallic Conduit)

Answer

EMT (Electrical Metallic Tubing)

Answer

FMC (Flexible Metal Conduit)

Answer

ENT (Electrical Nonmetallic Tubing)

Question 6

What is the minimum depth required for direct-burial electrical cable (UF cable) under a residential driveway?

Accepted Answer

24 inches

Answer

6 inches

Answer

12 inches

Answer

18 inches

Question 7

Which document serves as the primary standard for electrical installations in construction in the United States?

Accepted Answer

NFPA 70 (National Electrical Code)

Answer

OSHA 1926 Subpart K

Answer

IEEE Standard 141

Answer

ANSI C2 (NESC)