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

Standard US residential service is 120/240V single-phase, providing 120V for outlets and 240V for large appliances.

Question 2

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

Accepted Answer

Green or bare copper

Answer

Green insulated wire or bare copper conductor is the NEC-standard color code for equipment grounding conductors.

Question 3

What does GFCI stand for in electrical construction?

Accepted Answer

Ground Fault Circuit Interrupter

Answer

GFCI stands for Ground Fault Circuit Interrupter, a device that detects current leakage to ground and trips within milliseconds to prevent electrocution.

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

NEC requires derating of conductor ampacity when more than 3 current-carrying conductors are bundled together in a raceway or cable.

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

PVC rigid nonmetallic conduit resists moisture and corrosion, making it the preferred choice for outdoor and wet-location installations.

Construction Practice Test

Construction Practice Test

Construction Electrical Systems in Construction