Electrician Services and Distribution 2

Question 1

What is a 'panelboard' as defined by the NEC?

Accepted Answer

A single- or poly-phase unit for controlling circuits by means of overcurrent devices

Answer

A large switchboard used only in commercial buildings

Answer

A meter base assembly provided by the utility

Answer

A transformer vault enclosure

Question 2

What happens when a circuit breaker trips?

Accepted Answer

It automatically opens the circuit to interrupt overcurrent

Answer

It permanently disconnects the circuit

Answer

It increases the resistance in the circuit

Answer

It reduces voltage to the circuit

Question 3

What is the purpose of a transfer switch in an electrical system?

Accepted Answer

To transfer load between two power sources such as utility and generator

Answer

To convert DC power to AC power

Answer

To step up voltage for distribution

Answer

To measure and monitor power quality

Question 4

What size copper conductor is typically required for a 100-amp service entrance?

Accepted Answer

2 AWG

Answer

4 AWG

Answer

1/0 AWG

Answer

2/0 AWG

Question 5

What is the purpose of a neutral bar in a main electrical panel?

Accepted Answer

To provide a common connection point for grounded (neutral) conductors

Answer

To connect all hot conductors

Answer

To bond the panel to the building structure

Answer

To distribute 240V circuits

Question 6

Per the NEC, where must the grounding electrode conductor connect to a ground rod?

Accepted Answer

Within the first 12 inches of the top

Answer

At the top of the rod only

Answer

Anywhere along the rod

Answer

Only at the midpoint