Building Engineering Electrical Systems in Buildings 3

Question 1

What NEC article primarily governs the installation of emergency lighting systems in commercial buildings?

Accepted Answer

Article 700

Answer

Article 550

Answer

Article 230

Answer

Article 480

Question 2

Which type of transformer is typically used to step down 480V three-phase to 208/120V in a commercial building?

Accepted Answer

Dry-type step-down transformer

Answer

Autotransformer

Answer

Current transformer

Answer

Isolation transformer

Question 3

What is meant by 'demand factor' in building electrical load calculations?

Accepted Answer

The ratio of maximum demand to total connected load

Answer

The ratio of actual power to apparent power

Answer

The percentage of load operating at full capacity

Answer

The peak power draw over a billing period

Question 4

Which grounding electrode is required by NEC for all new building construction?

Accepted Answer

Concrete-encased electrode (Ufer ground)

Answer

Driven ground rod only

Answer

Water pipe only

Answer

Plate electrode only

Question 5

What is the purpose of a power quality meter installed on a building's electrical system?

Accepted Answer

To monitor voltage, current, harmonics, and power factor continuously

Answer

To measure only peak demand for billing

Answer

To control automatic transfer switches

Answer

To balance loads across phases manually

Question 6

At what maximum height above grade must exterior building lighting circuits with branch circuit wiring be protected by RMC or IMC per NEC?

Accepted Answer

8 feet

Answer

6 feet

Answer

10 feet

Answer

12 feet