Electrician Grounding and Bonding

Question 1

What is the primary purpose of equipment grounding in an electrical system?

Accepted Answer

To provide a low-impedance fault current path back to the source

Answer

To increase circuit efficiency

Answer

To reduce electrical consumption

Answer

To improve power factor

Question 2

What is the minimum size copper grounding electrode conductor required for a service with 2/0 AWG copper service entrance conductors per NEC Table 250.66?

Accepted Answer

4 AWG

Answer

6 AWG

Answer

2 AWG

Answer

1/0 AWG

Question 3

According to NEC 250.119, which of the following correctly identifies an equipment grounding conductor?

Accepted Answer

Green, green with yellow stripe, or bare

Answer

White or gray insulation

Answer

Black or red insulation

Answer

Orange or blue insulation

Question 4

The main bonding jumper in a service panel connects which two components?

Accepted Answer

The neutral (grounded) bus to the equipment grounding bus and enclosure

Answer

The ungrounded (hot) bus to the neutral bus

Answer

The grounding electrode directly to the service panel enclosure

Answer

The service entrance conductors to the branch circuit breakers

Question 5

Per NEC 250.53(G), what is the minimum depth a ground rod electrode must be driven into the earth?

Accepted Answer

8 feet

Answer

4 feet

Answer

6 feet

Answer

10 feet

Question 6

Which of the following is specifically prohibited from use as a grounding electrode per NEC 250.52(B)?

Accepted Answer

Metal underground gas piping

Answer

Metal underground water pipe

Answer

Concrete-encased electrode (Ufer ground)

Answer

Plate electrode buried 30 inches deep

Question 7

What is the primary purpose of bonding metallic components together in an electrical system?

Accepted Answer

To establish electrical continuity so all metal parts remain at the same potential

Answer

To increase the voltage level throughout the circuit

Answer

To reduce the ampacity requirements of conductors

Answer

To increase resistance in the fault current path